Celiac Disease Symptoms and Gluten-Free Diet Information
Why Gluten Free
What Is The Gluten Free Diet And What You Need To Know Before You Try It. You may have heard the term gluten free, and you may even have a general idea as to what it means to eat a gluten free diet. Most people believe this type of diet is a curse for those who simply cannot tolerate the protein known as gluten, as they will never be able to eat any food that contains wheat, rye, barley, malts, or triticale.
Whilst most patients with celiac disease respond appropriately to a gluten-free diet, usually with responses to symptoms occurring within days to weeks of institution of the diet, a small proportion of patients (approximately 5 ) do not have the expected complete response to a gluten-free diet or they have a relapse of symptoms while apparently on a gluten-free diet. This scenario termed 'nonre-sponsive celiac disease' is multifactorial in nature. The single most common cause of continued or relapsing symptoms in patients with celiac disease is that of inadvertent gluten ingestion. There are many ways in which gluten can get into the diet, and in one series the most common source was commercial cereal in which minor ingredients were derived from the offending grains. However, other sources such as communion wafers and environmental contamination with flour, particularly of baked goods, are also possible. In patients whose serologic tests have returned to normal and where a careful...
The complications of celiac disease can be divided into malignant and nonmalignant complications. In addition, the malignant complications of celiac disease are most commonly that of non-Hodgkin's lymphoma of a T cell variety. This particular tumor occurs in patients who have not been compliant with the diet or within 3 years of diagnosis. The risk of lymphoma or other malignancies appears to drop once a gluten-free diet has been instituted. While the relative risk of malignancy in celiac disease is greatly increased for specific diseases, the actual absolute risk is relatively small. The presentation of lymphomas in the small intestine can be acute with a surgical emergency such as obstruction, perforation, and bleeding, or gradual with insidious return or progress of severe malabsorptive symptoms, often associated with hypoalbuminemia and severe weight loss and malnutrition. The treatment for lymphoma is often unsuccessful. Those patients presenting acutely and managed surgically...
Gluten-sensitive enteropathy or coeliac disease is a malabsorption syndrome due to lymphocyte-mediated hypersensitivity to storage proteins found in wheat and some other cereals. The most important of these is gliadin. Exclusion of gluten-containing foods (wheat, barley, rye and oats) from the diet leads to improvement in symptoms. Tolerance does not develop and avoidance is lifelong. Gluten-free products should be prescribed for patients suffering from this disease (Table 5.8). Table 5.8 Some wheat- and gluten-free products available on prescription and over the counter Gluten-free bread and rolls Glutafin Gluten-free fibre or white mix Juvela Gluten-free harvest mix Glutano Crackers, gluten-free biscuits Glutafin Wheat and gluten-free pasta Schar Wheat and gluten-free pasta Glutano Wheat and gluten-free pasta
Celiac disease is characterized by an immune response to the storage proteins of wheat, rye, and barley, with wheat as the most immunogenic. Wheat gluten is composed of glutenin and gliadin, and evidence suggests that the gliadin fraction induces disease. Information gathered from T cell clones derived from chronic lesions of the small intestines of celiac patients with established disease demonstrate that gliadin peptides are presented by HLA class II molecules to CD4+ T cells. Several studies have suggested that unaltered native gliadin peptides were antigenic but lacked the negatively charged amino acids needed to bind to the recognition sites of the DQ2 or DQ8 molecules. It has since been recognized that the gliadin peptides are made more antigenic by tissue transglutaminase, and it is these altered (deamidated) peptides that either perpetuate or cause gluten sensitivity in celiac disease. inflamed celiac gut also results in a strong autoimmune response to tissue transglutaminase...
Celiac disease is one of the most common, chronic genetic gastrointestinal conditions affecting just under 1 of Caucasian individuals. Whilst it was initially recognized in Northern Europeans, celiac disease will affect Caucasians wherever they live. It can affect people of mixed ethnic background. It is apparently rare in Southeast Asia and sub-Saharan Africa. While celiac disease was once considered primarily a childhood disease, in many geographic locations, celiac disease is more commonly diagnosed in adulthood. The median age in one study in the US was 50 years of age. Even in childhood, the age at diagnosis is now increased from early infancy to later in childhood or adolescence. The spectrum of disease has also changed with an increasing proportion of patients being diagnosed with mono-symptomatic or less severe celiac disease. Many of these patients would not have been diagnosed in the past, but their symptoms described as functional disorders. It is not uncommon to diagnose...
Nonmalignant complications of celiac disease include ulcers and structuring within the intestine that occasionally may present with small bowel obstruction and or bleeding, and recurrent acute pancreatitis as the result of inflammation, probably of the sphincter of Oddi. Nongastrointestinal complications are usually the consequence of malnutrition or specific deficiencies. However, others such as neurological problems including ataxia, peripheral neuropathy, or dementia are of uncertain mechanism and perhaps autoimmune in nature. Other consequences of celiac disease have been discussed in the section on atypical or nongastrointestinal presentations (Table 1). Many, but not all, of these nonmalignant complications of celiac disease will respond to a gluten-free diet.
The term 'gluten' as it is used in the context of celiac disease refers to the storage proteins of wheat (glia-dins and glutenin) and of barley (prolamines), and rye (hordeins), and oats (avedins). Gluten is defined in the setting of celiac disease as any protein-containing derivative of the offending grains or their derivatives. Grains that should be avoided are as follows To achieve healing and maintain health, a well-balanced, interesting dietary life style that avoids gluten should be adopted. However, it is not enough to simply avoid gluten patients need to be enabled to explore dietary alternatives and strategies that minimize impact on their life style. The role of oat toxicity in celiac disease is still controversial. Several recent, well-constructed studies have demonstrated no ill effects when a moderate amount of oat products have been included in the diet of either newly diagnosed or already treated celiac patients. These recent studies have clearly demonstrated that oats...
Coeliac disease deserves a special mention. When discussing this lifelong condition, it is essential that it is not confused with classic food allergy. Allergic reactions usually occur within seconds or minutes of contact with the offending food, or occasionally within hours, whereas coeliac disease rarely causes such an acute, immediate reaction. This is an important distinction, because there is a danger that food companies may place gluten traces in the same danger category as nut traces, with the result that they fall to the temptation of adopting 'may contain' labels. There have certainly been cases where a trace of gluten makes a coeliac unwell, but such cases are not fatal. The symptoms of coeliac disease are very specific. In babies they consist of pale, foul-smelling stools, wind, bloating and poor growth. These symptoms usually develop a few weeks after cereals are introduced into the diet. In those cases where coeliac disease begins as an adult, the symptoms are diarrhoea,...
The recommended test for screening for celiac disease will be tissue transglutaminase antibody along with total IgA level. Tissue transglutaminase will detect 95-100 of cases of celiac disease, and this replaces the IgA anti-endomysial antibody. Note that the diagnosis of celiac disease is made only on the basis of an intestinal biopsy. Dietary changes should not be made until the intestinal biopsy is obtained.
Protein constitutes the most expensive portion of livestock feed. Protein primarily consists of 20 a amino acids linked together by peptide bonds. Both plant and animal tissues contain a diversity of proteins with variable amounts of amino acids. Ten amino acids cannot be synthesized by animal tissues or can be synthesized only to a limited extent. These 10 amino acids are referred to as dietary essential amino acids (Table 1). The primary function of dietary protein in livestock rations is to supply amino acids, the building blocks of proteinaceous body tissues. Ruminant livestock do not have dietary amino acid requirements as such, but depend on ruminal bacterial protein synthesis to supply these nutrients. Because of this, ruminant animals are able to utilize nonprotein nitrogen, such as urea, to replace part of the natural protein in the ration. The use of rumen bypass protein supplements, such as corn gluten meal and blood meal, has been shown to increase growth in beef cattle...
Many natural products, including cereals and other common foodstuffs, induce allergic responses in susceptible individuals. In such cases, after appropriate diagnosis, the individual should avoid the foodstuff responsible. Celiac disease (gluten enteropathy) is a condition characterized by a severe adverse immu-nological gastrointestinal reaction to gliadin, which is a component of gluten, the viscoelastic protein found in wheat and other cereals. Celiac disease is prevalent in all regions where wheat is commonly consumed, and its incidence may reach 0.5 of the population. Celiac patients must exclude gluten from their diets. Thus, products containing wheat, rye, barley, and triticale are not permitted. Although oats were originally proscribed, it is now becoming increasingly clear that they are safe for celiac patients.
The primary product from the milling of wheat is flour for human consumption. Wheat is ground and sieved to produce flour. The resulting by-products are primarily wheat bran and wheat middlings. The bran is the hull of the wheat kernel and the middlings are a mixture of hull (bran) starch and protein (gluten). Wheat midds contain
Often enzymes with similar activities (ie, proteases) are obtained from different sources and assays are used to characterize them in terms of units per gram. If the different enzymes have varying specificity requirements, the results may be misleading. For example, if two proteases have specificities corresponding to elastase and trypsin, an assay based on azocollagen substrate will give a much higher value for the former enzyme, while one based on casein will favor the latter. If the protein to be modified is something quite different, for example, wheat gluten, neither assay will give a reliable comparison. Substrate specificity may be of major importance, as with proteases, or a negligible factor, as with lipoxygenase. It is best to assume that it is important until the contrary is established.
Gluten-sensitive enteropathy (coeliac disease) should be diagnosed with serial small bowel biopsies (duodenum or jejunum), demonstrating typical histo-pathological abnormalities on a normal diet and resolution following a gluten-free diet.6 It has been argued that as this diagnosis has such significant lifelong dietary implications, it should then be followed by a further biopsy demonstrating relapse upon a gluten challenge. Few clinicians carry out this third biopsy.
The dietitian should give an explanation and provide a list of packaged foods that might contain the food to be excluded. Replacements should be suggested, such as an alternative cereal or meat. For example, in patients with wheat or gluten intolerance, the dietician would advise on the availability of wheat- or gluten-free bread and other products. A list of food free from the food allergen is very helpful. Patients should be told how to read labels (such as 'E' numbers) and what to look for when buying packaged foods or eating in a restaurant.
Exogenous gut satiety signals arise from dietary proteins. These have a hormone-like effect and are able to activate, at the level of the gut, satiety signalling pathways. Commonly referred to as bioactive peptides (BAP) (Kitts and Weiler, 2003), these intermediate products of protein hydrolysis can bind to and activate hormone receptors in the lumen of the gut and induce satiety. For example, BAP that have been shown to have a direct effect on food intake suppression via receptors are opioid-like peptides released during the digestion of casein (casomorphins), soy and wheat gluten proteins (Froetschel et al., 2001 Pupovac and Anderson, 2002).
Alfalfa is one of the most popular forage crops grown throughout the world and has good AA balance. It is a good source of most vitamins and many minerals, except P. Coconut is widely distributed in the tropics, and copra, its dry kernel, is used for coconut oil production. The remaining residue or copra meal is low in CP content and is a poor source of AA. Corn gluten feed is the residue remaining after removal of the larger part of the starch, gluten, and germ, and it contains the bran. Corn gluten meal is the residue remaining after removal of the larger part of the starch, germ, and bran. They are satisfactory protein sources for ruminants, but not for nonruminant species because of their AA balance.
Been implicated as contributing to lactose maldigestion. An additional infection resulting in an interference with lactose digestion is Ascaris lumbricoides. Severe protein malnutrition is frequently associated with lactose maldigestion. Other disease conditions that give rise to secondary lactose maldigestion are celiac disease, gluten-induced enteropathy, and tropical and nontropical sprue. The mucosal brush border of the small intestine is severely damaged in each case.
These feeds are largely by-products of the food-processing industry most are the result of vegetable oil production. Soybean meal is the major protein feed (18.1 million t) followed by cottonseed meal (1.5 million t), canola meal (0.25 million t), sunflower meal (0.22 million t), peanut meal (0.15 million t), and linseed meal (0.10 million t). Corn gluten feed and meal (1.32 million t) are byproducts of the corn starch and sweetener industries. Protein feeds derived from the processing of animals for food include tankage and meat meal (3.1 million t), fish meal and solubles (0.74 million t), milk products such as whey (0.36 million t), hydrolyzed feather meal (0.24 t), and smaller quantities of blood meal (11,12).
Overall, healthy individuals can tolerate naturally occurring toxicants. However, there are several conditions under which natural toxicants can create problems. Inborn errors of metabolism or certain drug interactions can make individuals prone to problems caused by natural toxicants. Whereas nutrients can be beneficial to most, they can be deleterious to some, e.g., consumption of lactose by lactose-intolerant people. Other examples include individuals with celiac sprue, sucrase deficiency, fructose intolerance, galactosemia, and phenylketonuria. Individuals taking drugs that inhibit monoamine oxidase enzymes can be affected when eating cheeses or drinking wines, which are high in tyramine. Individuals with sensitivities due to allergies can be affected by foods. Hypersensitivity to a particular substance produces anaphylactic shock. Examples of foods that cause allergies include milk, wheat, nuts, citrus, strawberries, fish (shellfish), and egg. Some individuals have bizarre food...
Mucosal disorders, including inflammatory bowel disease, allergic diseases, and celiac disease, are additional examples of disorders causing protein malabsorption. Once intestinal inflammation is reduced with appropriate medical or nutritional therapy, absorption of protein is usually improved. In Shigella infections, some studies have demonstrated improved nutritional outcomes with a high-protein diet during recovery from the acute symptoms of diarrhea.
Intraepithelial lymphocytes (IF.Ls) reside between intestinal epithelial cells and are the first cells to contact luminal antigen that crosses the mucosa in an M cell-independent manner. This heterogeneous population of mainly T cells comprises a very large number of cells (more than half the number of T cells in peripheral organs) but their function remains poorly understood. The majority of murine IELs (80 ) arc CD3+, and over 75 of these also express CDS. In mice and chickens, significant numbers of yS TCR' IELs are found (40-60 ) in addition to a(3 TCR+ cells however, this number varies with mouse strain, age and housing conditions. The y8 TCR4 IELs represent a minor component of human IELs (-15 ) under normal conditions, but significantly increase under certain conditions, such as celiac disease.
Peptides contribute to the physical properties of food. For example, the smooth texture of cheese is dependent on the extent of proteolysis of casein during the maturation. Proteins and peptides have surface activities and show functional properties such as emulsifying and foaming. Am-phiphatic properties, charge distribution, solubility, and the molecular weights of peptides are related to these functional properties. Usually the functional properties of food proteins are modified by proteolysis. In some proteins, like gluten, whose solubility is very low, the functional properties are improved by limited proteolysis. When a protein has good solubility, functional properties of the peptides derived from it tend to be lower than those of the parental proteins. Enzymatic digests of soybean proteins suppress thermal gelation and freezing-induced insolubilization of proteins. Soybean peptides protect starch from r trogradation.
Intestinal lymphomas are another interesting example of disease originating from the interplay between the intestinal mucosa and the intestinal flora. In the stomach, MALT lymphoma is closely related to Helicobacter pylori colonization and may be cured by H. pylori's eradication. IPSID may be responsive to antibiotics, also suggesting a relationship with small intestinal flora. EATL results from chronic malabsorption, most commonly celiac disease, and occurs mainly in the jejunum. It usually involves multiple segments of the small bowel and may therefore be difficult to resect surgically.
In patients with mucosal layer disease (i.e., no involvement of muscle or serosal layer), food intolerance should be looked for. A trial of sequential elimination of milk, pork, beef, eggs, or gluten may be tried. Enteral elemental diets have been tried in some patients with success. Patients with mucosal layer disease who do not respond to dietary measures or patients with deeper layer involvement should try a course of steroids. Any patient who has traveled to the tropics should be considered for antihelminth therapy. See also Celiac Disease. Colon Disorders Nutritional Management of Disorders. Lactose Intolerance. Small Intestine Structure and Function. Stomach Disorders.
Substitution of one or more dairy macroconstituents in processed cheese manufacture usually does not cause any major technical problems. Processed cheese blends can easily be further enriched with desirable microcomponents (eg, vitamins and minerals). Blends can be tailored to yield less-expensive products. Essential components are casein and casemates (Na, Ca, salts, etc), other proteins (soya, coconut, gluten, etc), suitable vegetable fats, flavorings, vitamins and minerals, food-grade acids (eg, lactic, citric) to correct the pH to 5.8 to 5.9, and emulsifying agents. A suitable blend, suggested for an imitation processed cheese product, is listed as follows (1)
In baking, salt enhances other flavors in the product it also controls the rate of fermentation of yeast-leavened products and prevents the development of undesirable 'wild' types of yeast, which would lead to uncontrolled fermentation rates and variable products. Salt also strengthens the gluten in bread doughs, thus helping to ensure good dough handling and reducing the rate of water absorption. Sodium acid pyrophosphates are used in many industrial baking powders for specialty products. Salting of canned vegetables is primarily for flavor, but it can be used to separate mature, starchy green beans or peas, which will sink, from the younger, fresher beans, which float.
As a small white spot, approximately 2 mm in diameter, on the surface of the yolk. 4 It is larger, 3 4 mm, in the fertilized egg 2 because the embryo usually has progressed to the gastrulation stage by the time of oviposition. The latebra is a small sphere of white yolk in the center of the yolk extending with a narrow neck of this unpigmented yolk to the blastodisc. The concentric rings that are shown in Fig. 1 are not visible to the naked eye. They have been observed in specially stained eggs and are believed to represent alternating layers of yellow yolk that is deposited during the day when the hen is consuming feed and white yolk that is formed at night when the hen is not eating. Carote-noid pigments are responsible for the yolk's yellow color. 4 These pigments are present in ingredients such as yellow corn, corn gluten meal, and alfalfa meal in poultry feeds. 5
Must have some elasticity and be cohesive enough to bear its weight, if it is to form a sheet that will retain its continuity and not tear. Excessive elasticity creates problems with shrinkage of the pieces and difficulties in maintaining uniform piece weight. To obtain the desired characteristics, the dough must contain a substantial amount of wheat flour, to provide the gluten that will give the dough strength and elasticity. In processing, the dough must be developed by a mixing operation that orients the gluten molecules, or it must be repeatedly sheeted and layered. The content of ingredients that weaken or shorten the dough, such as sweeteners and shortenings, must be kept relatively low. Moisture content, for all practical purposes, is the amount of ingredient water added and should be sufficient enough to allow full hydration of the gluten, without weakening the dough excessively. Nearly all cookies and crackers are baked after forming. A few recipes for fried cookies and...
Raw materials used for salmon feed production in Norway in 1999 and 2000 indicate that the average feed was made up of 40 fish meal and fish silage, 7 corn and wheat gluten, 6 various soybean products, 28 fish oil and 3 soybean oil, 12 wheat flour, and 4 vitamins, minerals, and pigment. 4 The optimal dietary protein level for salmon is higher than for terrestrial species because fish use a higher proportion of the protein for energy. Despite this, the proportion of consumed protein retained in the
As a journalist, I have been taught to be suspicious of good intentions voiced by politicians, but Soames and his officials proved true to their word. Improvements in food labelling and in public awareness are there for all to see. That initial, fruitful meeting led to further talks with MAFF officials and industry representatives, a liaison that has continued through to the present day. More recently, support groups such as the Anaphylaxis Campaign and the Coeliac Society have provided high-quality input, through MAFF's consultative process, into the Codex Committee on Food Labelling, the international organisation that sets worldwide standards. During a long, laborious process, Codex agreed a list of foods known to cause hypersensitivity which should always be labelled, including peanuts, tree nuts, egg, milk, fish, shellfish, soya and gluten. In its very own sphere, far different from that of anaphylaxis, the Coeliac Society has been quietly active in keeping the needs of people...
Autoantibodies to endomysial membranes, the outside lining of smooth muscle bundles, are found in patients with dermatitis herpetiformis and with celiac disease, and are primarily IgA. The major test is IIF using the lower part of monkey esophagus as tissue substrate. It appears to be a more specific and sensitive marker of celiac disease than testing for reticulin autoantibodies. In a few patients with celiac disease that have an IgA immunodeficiency, the antibody to endomysial antigens were found to be IgG. Isotype-specific anti-immunoglobulins conjugated to FITC are used as specific reagents to determine the relevant autoantibodies.
The Division of Plant Industry maintains the CSIRO Wheat Research Unit at North Ryde, New South Wales, which has projects on the proteins of wheat and the utilization of gluten. The research program of the Division of Human Nutrition includes investigations on the role of dietary fiber. The Division of Horticulture works on the postharvest handling and storage of fruits and vegetables, and the Division of Entomology has a project on the control of insect pests in stored grains. The Commonwealth Department of Community Services and Health is responsible for the collection of data on the composition of Australian foods and has recently published revised composition tables and a related computer data base (17). The Department of Defence Materials Research Laboratory at Scotts-dale, Tasmania, undertakes food research and development to meet specific needs of the armed forces.
Of the milk proteins, whey protein has been studied the most, probably because it is readily available as a by-product of cheese making. It suppressed food intake more than sucrose and egg albumen at a pizza meal one hour later in young men (Anderson et al., 2004). Similarly, intake of a buffet meal at 3 hours (Bowen et al., 2006a Bowen et al., 2006b) after a 50 g preload of whey was lower than after a glucose preload. However, no differences were found between whey and casein (Bowen et al., 2006a) or among whey, gluten and soy protein preloads (Bowen et al., 2006b). In other reports, however, casein and whey had different effects on food intake. In a study by Hall et al. (2003), a preload containing 48 g of whey resulted in lower ad libitum intake of a buffet meal 90 min later than a preload containing the same amount of casein. In contrast, no differences were found in the intake of a pizza meal 90 min after 50 g pure preloads of casein and whey, but casein suppressed energy intake...
Non-IgE-mediated primary food sensitivities are usually manifested by 6- to 24-h delayed hypersensitivity reactions following ingestion of food material. The allergic reactions develop slowly and peak at 48 h, subsiding 72 to 96 h later. Mounting evidence suggests that the allergic response involves the interaction between specific allergens from the food and sensitized, tissue-bound T cells, releasing inflammatory mediators. Celiac disease or celiac sprue is an example of a non-IgE-mediated immunological primary food sensitivity. Celiac disease sufferers are sensitive to glutens, particularly the gliadin fraction of wheat and related crops. Gliadin is a simple protein found in the gluten, consisting of 43 glutamine. Following ingestion of glutens, the absorptive epithelial cells in the small intestine become damaged by an inflammatory process. The intestinal damage results in a severe malabsorption syndrome, i.e., diarrhea, bloating, weight loss, anemia, fatigue, and muscle and bone...
Milk powder can also be measured comprehensively with on-line NIR gauging, moisture fat and protein and perhaps lactose being four measurements that virtually characterise a formulation. Protein content in flour can be an important on-line measurement in cases where a mill adjusts protein level through gluten addition. Low levels of constituents can be measured such as the caffeine content in coffee. While de-caffeinated product would be difficult to quantify to an adequate accuracy, the 1-2 levels in beans is practical with an on-line gauge.
The disease may result in intestinal inflammation and is associated with celiac disease, refractory sprue, and Crohns' disease. Stool cultures for bacteria, ova, and parasites together with duodenal aspirates may be needed. Duodenal biopsies show loss of plasma cells in the lamina propria. Patients may be treated with metro-nidazole for giardiasis or bacterial overgrowth and with gluten-free diet for celiac disease.
Enteropathy-associated T cell lymphomas are generally seen as jejunal tumors associated with celiac disease. The latter is a malabsorptive state of puzzling pathogenesis, with features of both hypersensitivity (resolution upon elimination of gluten proteins from the diet) and autoimmunity (a strong association with certain major histocompatibility complex (MHC) class II alleles, the presence of reticulin specific antibodies, and heavy lymphocytic infiltration of the jejunal epithelium). It seems likely that the tumor is preceded by the celiac disease and arises from the infiltrating lymphocytes. The tumor cells are of various sizes, sometimes pleomorphic. Jejunal ulceration and perforation often supervene.
The management issues are simplified. For instance, if a person is dehydrated because of hyperglycemic diuresis in uncontrolled diabetes mellitus, the short-term management involves administration of exogenous intravenous fluids to restore normal hydration however, restoring adequate diabetic control to the patient would be the long-term and definitive solution. The undernutrition and growth failure due to undetected celiac disease is easily eliminated by institution of a gluten-free diet. With deficient nutrition in cystic fibrosis, adequate management of pulmonary problems and digestive-enzyme should allow patients to recover and maintain normal nutrition on a balanced oral diet. Thus, medical or surgical address of the underlying disorder, where possible, is the primary tool for management of secondary undernutrition.
Many of the studies on gut responses to gluten have been performed in the established chronic lesion. Little is known of innate responses that can elicit effects within minutes to hours of exposure to gluten. In vitro studies demonstrated an increase in the expression of HLA antigen on the cells in the surface layers of the intestinal mucosa occurring within 2-4 h after exposure to gluten. Gluten also causes the production of the proinflammatory cytokine IL-15 at the surface epithelium. IL-15 expressed by the surface enterocytes activates NK-like T cells to recognize gluten presented by MHC class 1a molecules in the context of the NKG-2D receptor. The NK-like T cell may be a key player in both the damage to the surface epithelium and be a proin-flammatory influence on adaptive response that occurs in the underlying lamina propria. This induction of innate immune responses by gluten may have important consequences. Since the gluten peptides enter into the epithelial compartment and...
The corn wet-milling process is more complex than either of the dry-milling processes. Large plants are necessary for efficiency of production. Dry-milling ethanol plants may use 30,000 to 50,000 bushels of corn per day, whereas wet-milling plants grind 150,000 to over 500,000 bushels per day. The wet-milling process produces alcohol and several human food products including sweeteners and corn oil. In the first step, corn is steeped in weak acid and then milled (ground). After grinding, the kernel is separated into four parts the germ, the starch, the bran (hull), and the gluten meal (protein). The oil is extracted from the germ. The starch is used for human consumption or ethanol production. The primary by-product is corn gluten feed, which contains the bran, steep liquor, and germ meal. This product is 16 24 protein and 40 50 fiber. The corn fiber is highly digestible by ruminants, probably even more rapidly digested than soyhull fiber. 8 The majority (70 75 ) of dry corn-gluten...
Opioid peptides have an affinity for opiate receptors. There are more than 20 endogenous opioid peptides in the human body. Besides analgesic activity, these peptides have various physiological effects such as control of gastrointestinal functions and hormone secretion. Many opioid peptides are released from food proteins by limited proteolysis, f-casomorphin 7 is released from -casein (23) and a-casein exorphin, from bovine asl-casein (24). Gluten exorphins A, B, and C are released from wheat gluten (25,26). -casomorphin exhibits analgesic activity when administered intracerebroventricularly. -casomorphin increases postprandial insulin and somatostatin levels. It also elevates the heart rate.
Added blood in comminuted meat products can be detected by detecting haemoglobin using isoelectric focusing (Horn, 1991). This method can identify a blood content of less than 0.1 . The addition of 4-5 blood in frankfurter-type products has also been detected by rocket immunoelectrophoresis (Bremer et al., 1989). Soy proteins in meat products can also be detected by SDS-PAGE and numerous kits are also available for the ELISA detection of soya, casein and gluten (Tantillo and Tiecco, 1988 Hugo, 1995 Hall et al., 1987). Nuclear Magnetic Resonence (NMR) imaging has also been used to identify pure beef muscle adulterated by liver or kidney to a level of 10 . NMR is discussed in chapter 6.
Classically, in type 2 diabetes, unexplained weight loss is a presenting complaint when polyuria is mild or absent. Moreover, with common forms of childhood gastrointestinal disorders, such as celiac sprue or Crohn's disease, arrested linear growth is often the first clue that something is clinically awry. It provokes the diagnostic inquiry that leads to the recognition of the bowel lesions. In milder presentations of cystic fibrosis, a similar growth failure occurring in infancy, can indicate an underlying pathological disorder.
To produce a more severe clinical course. Dermatitis herpetiformis is a disease characterized by deposition of IgA at the dermal-epidermal junction. Here again, components of the alternative pathway of complement are deposited along with IgA. Dermatitis herpetiformis is often associated with elevated levels of gliadin-specific antibodies and the clinical course of some patients may be reduced by a gluten-free diet. A bullous disease of childhood has been described in which linear deposits of IgA are detected along the basement of affected subepidermal areas, suggestive of the deposition of specific anti-basement membrane IgA antibodies.
The diabetic syndrome in BB rats and NOD mice. The source of dietary protein seems to be the most important factor and intact protein may be required for expression of genetic susceptibility to diabetes in BB rats. Wheat gluten, soybean meal, alfalfa and skim milk powder have been identified as the most likely sources of dietary diabetogens in rodents.
In addition to cow's milk and wheat, which represent more than 80 of all food-sensitive enteropathies in infants, many other foods have been shown on occasion to be the offending agents among older age groups. The major symptoms are diarrhea, abdominal pain, pallor, lethargy, vomiting and loss of weight. Allergic reaction to food is not necessarily evident, and other types of gastroenteropathies need to be excluded. When not recognized early enough, the disease may develop several accompanying symptoms, such as occult intestinal hemorrhage, protein-losing enteropathy, transient gluten intolerance, IgA deficiency and fat malabsorption, among others.
Celiac disease may present in a wide variety of ways (Table 1). In children, the onset of celiac disease is classically described as occurring within the first to seventh year of life with the introduction of cereals to the diet. Symptoms may vary with the age of the child at onset of disease. Young children may develop chronic diarrhea, failure to thrive, muscle wasting, abdominal distension, vomiting, and abdominal pain. Older children may present with anemia, rickets, behavioral disturbances, or poor performance in school. In some children constipation, pseudo-obstruction, and intussusception may be seen. It has been estimated that 2-8 of children with unexplained short stature may have celiac disease. Dental enamel defects involving secondary dentition as well as Table 1 Presentations of celiac disease Gastrointestinal presentations neurological syndrome and epilepsy with intracra-nial calcification have also been reported in children with celiac disease. In adults, celiac disease...
The European Commission has already recognised the need for transparent labelling by requiring that any starches or modified starches which contain wheat gluten are declared as such. Thus a potato starch can be described as starch or modified starch, but wheat starch must be described as wheat starch or modified wheat starch. Many retailers in the UK, together with some manufacturers, are anticipating the needs of their customers by voluntarily providing information about potential allergens in their product. This may be by providing a full breakdown of compound ingredients, by highlighting the presence of potential allergens or by making specific claims such as 'gluten free' on the product. Inevitably the law is slow to respond to the needs of consumers, and this kind of initiative can provide a useful means of communicating helpful information.
The most common cause of protein malabsorption is so-called protein-losing enteropathy. Etiologies include diffuse mucosal disease such as celiac disease or Crohn's disease, elevated right heart pressure with resultant dilatation of lymphatics and leakage of lymph into the lumen, and colitides such as Shigella or Salmonella infections. Since protein is a relatively minor component of dietary energy compared with carbohydrate and fat, symptoms of protein malabsorption can sometimes be minimal. However, infectious colitis or exacerbations of inflammatory bowel disease often present with frequent loose stools, which may be bloody. Rare, congenital etiologies of protein malabsorption include enterokinase and trypsinogen deficiencies (Table 1).
The diagnosis of gluten-sensitive enteropathy (coeliac disease) is an exception. The detection of specific non-IgE antibodies aids the diagnosis of coeliac disease. Gastrointestinal auto-antibodies of the IgA class (anti-reticulin and anti-endomyseal antibodies) are raised in this condition. They are classed weakly, moderately and strongly positive. Moderately and strongly positive levels of the antibodies are both sensitive and specific when assessed against challenges of gluten coupled with intestinal biopsy (see later).6
Cereals do not have any intrinsic non-specific toxins. However, acrylamide, a carcinogen and potential neuro-toxin, has recently been found at levels up to 120 mg 100 g_1 in baked and fried foods, including breads and processed cereals. Research is ongoing, but the early indications are that acrylamide from these sources is unlikely to increase cancer risk. Detrimental effects may be caused by antinutrients in cereals and, in susceptible individuals, by adverse immune responses (celiac disease, food allergies). Cereals may also be a source of toxins of fungal origin (mycotoxins) or of toxic environmental, agricultural, or industrial contaminants.
Celiac disease, also known as gluten-sensitive enteropathy, is the one illness that seems likely to involve a cellmediated mechanism. Celiac disease occurs in certain individuals following the ingestion of wheat, rye, barley, triticale, and perhaps oats. Although the mechanism of celiac disease is not completely understood, an immunocy-totoxic reaction mediated by intestinal lymphocytes is probable. On ingestion of proteins from the offending grains, the absorptive cells of the small intestinal epithelium are damaged and the absorptive function of the small intestine is severely compromised, resulting in a malabsorption syndrome. The symptoms of celiac disease include diarrhea, bloating, weight loss, anemia from inadequate iron absorption, bone pain from impaired calcium absorption, chronic fatigue, weakness, muscle cramps, and, in children, failure to gain weight and growth retardation. The prevalence of celiac disease in the U.S. is not precisely known but is thought to be about 1...
Celiac disease only develops in a minority of DQ2+ individuals. How the consumption of gluten generates an inflammatory state in these individuals can be theorized as follows. First, there may be a trigger of the innate immune response, such as a viral infection or physical injury (surgery) that initiates inflammation and later permeability. Enough triggers repeated over time will alter the immune milieu of the mucosal compartment and perturb gut homeos-tasis, potentially altering the levels of the regulatory cytokines IL-10 and TGF-,3 and increasing the levels of inflammatory cytokines like IFN-7 and ILNA. Determining which factors lead to the loss of tolerance to gluten in DQ2+ individuals who later develop celiac disease will be crucial in understanding the pathogenesis of celiac disease. Possible factors that may lead to the loss of tolerance are recurring gastrointestinal infections, surgery, or pregnancy. The way in which children are first exposed to gluten may also affect...
Coeliac disease also has geographical variations. Although formerly thought to be a disease associated with north-west Europeans, including the countries of their migration, chiefly the USA, an equivalent prevalence is being reported in other European countries (Greco et al. 1989). It appears to be uncommon
(a) Chinese Minchin This is made from wheat gluten and used as a solid condiment. The fungal species involved in fermentation include Aspergillus sp., Chadosporium sp., Fusarium syncephalastum, and Paecilomyces sp. (Padmaja and George 1999) (b) Chinese red rice (Anka) This is produced by fermenting rice with various strains of M. purpureus Went. It is used to color foods such as fish, rice wine, red soybean cheese, pickled vegetables, and salted meats. To make Anka, polished rice is washed, steamed, cooled, inoculated with M. purpureas, and allowed to ferment for a few weeks. Anka has been reported to be effective in treating indigestion and dysentery (Su and Wang 1977) (c) Jalabies These are syrup-filled confectionery available in India, Nepal, and Pakistan made from wheat flour. Saccharomyces bayanus and bacteria are involved in fermentation (Padmaja and George 1999) (d) Indian Kanji This is made from rice and carrots. It is a sour liquid added to vegetables. H. anomala is involved...
In gluten-induced enteropathy a specific protein (gluten) is responsible for stimulating the immune reaction. Foods have been prepared without gluten, that are suitable for these individuals. When a protein is denatured by heat, most of the original tertiary structure is lost, so that many of the sites recognised by antibodies on the native molecule are destroyed. There are many examples of allergenicity being reduced, but not eliminated, by heating. Thermal processing can be part of a procedure for making hypoallergenic food, but will rarely be sufficient on its own.
Diarrhoeal reactions to foods are common. Isolated gastrointestinal symptoms are a rare manifestation of allergy20,21 but are a common feature of intolerance reactions. Wheat is a common cause of diarrhoeal reactions and benign wheat intolerance must be distinguished from coeliac disease. In coeliac disease a different class of antibodies (IgA, not IgE) is generated.
In addition to dietary inadequacy, there are several routes that lead to zinc deficiency. Acrodermatitis enteropathica, the genetic disorder of zinc malabsorption, has already been mentioned. Other, more generalized, malabsorption syndromes (e.g., coeliac disease) can also lead to zinc deficiency. Deficiency has also resulted from inappropriate intravenous feeding and the use of chelation therapy. Children are likely to be particularly at risk of zinc deficiency, because of its involvement in growth.
Coeliac Society gluten-free lists The UK Coeliac Society has been providing information and advice to its members for many years. The Society compiles its own 'List of Gluten-Free Manufactured Products' annually and this is available from its head office in High Wycombe.
Greece was the first partner of the project to set up its food intolerance databank, in August 1996. The databank is run by the Technological Educational Institution (TEI) of Thessaloniki and covers eight food additives and ingredients milk, egg, gluten, wheat, soya, sulphur dioxide, benzoates and azo colours. The databank is updated annually and currently they have approximately 400 products listed from 25 companies. The Technical University of Graz (Erzherzog Johann Universitat) established the Austrian Food Intolerance Databank in October 1996 with the financial assistance of the Austrian Ministry of Science. This databank covers 11 ingredients and additives milk protein, lactose, peanut, soya, wheat, gluten, egg, fish, benzoate, sulphur dioxide, and azo colours. The databank now has 19 contributors, with a total of 1600 products entered.
The South African Food Intolerance Databank (FIDB) was initiated in 1990 by the Grocery Manufacturers Association in South Africa, which modelled the databank on the UK system. In 1995, the Association for Dietitians in South Africa (ADSA) took over responsibility for the project and subsequently produced The South African Free From Handbook of Food Products, a single book listing free-from information in tabular form. The project was supported by a large number of institutions in South Africa, including the Department of Health, Food Legislation Advisory Group, Consumer Services Board and two coeliac groups. Originally, access to the book had been restricted to medical professionals only, and, although the book was largely distributed by dietitians, it was later made available to the general public through bookshops. The databank covered ten ingredients and additives milk, lactose, egg, soya, wheat, rye and gluten, benzoates, sulphur dioxide, BHA and BHT, glutamates and tartrazine....
After the measurement the sample is returned to the line by the piston and a fresh sample taken. It is suggested that this has several advantages, notably the compactness of the spectrometer and the minimal changes required to the production line (drilling a hole in the bottom). No side streaming is required. The procedure is particularly suitable for dry products. It is possible to build standard reference samples into the piston which can be measured as the piston rises falls so that temperature drifts and other extraneous problems are greatly alleviated. The one sided system they describe suffers from the disadvantage that only a small volume of the product is sampled and that it is always taken from the same area of the production line. The authors estimate that the cost of a sensor is of order 30-50,000 (1991) and that the payback period in a large gluten drying plant could be of order 1 year.
An indication of a submucosal tumor (Fig. 10.1.2). Although rare in Japan, extensive villous atrophy is observed in patients with celiac disease and other malabsorption syndromes. Because of the presence of villi in the small intestine, it is often difficult to clearly identify small areas of angiodysplasia compared with that in the large intestine, and careful observation is needed not to overlook the lesion.
Challacombe, eds., Food Allergy and Intolerance, Bailliere Tindall, London, United Kingdom, 1987. P. J. Lemke and S. L. Taylor, Allergic Reactions and Food Intolerance in F. N. Kotsonis, M. Mackey, and J. Hjelle, eds., Nutritional Toxicology, Raven Press, New York, pp. 117-137. D. D. Metcalfe, H. A. Sampson, and R. A. Simon, eds., Food Allergy-Adverse Reactions to Foods and Food Additives, Blackwell Scientific Publications, Boston, Mass., 1991. J. E. Perkin, ed. Food Allergies and Adverse Reactions, Aspen Publishers, Gaithersburg, Md., 1990. W. Strober, Gluten-Sensitive Enteropathy A Nonallergic Immune Hypersensitivity of the Gastrointestinal Tract, J. Allergy Clin. Immunol. 78, 202-211 (1986). R. S. Zeiger and S. Heller, The Development and Prediction of Atopy in High-Risk Children Follow-up at Age Seven Years in a Prospective Randomized Study of Combined Maternal and Infant Food Allergen Avoidance, J. Allergy Clin. Immunol. 95, 1179-1190 (1995).
As a general rule heat decreases the allergenicity of proteins, and heat in the presence of moisture even more so, but this biological activity is rarely removed. Allergenicity of whole wheat flour or purified gluten is only reduced and not eliminated by heating up to 120oC for up to one hour (Varjonen et al. 1996, Sutton et al. 1982). Heating rice glutelin and globulin fractions also reduces IgE binding ability by 40-70 (Shibasaki et al. 1979), but the food remains allergenic. Peanut and nut allergens are resistant to heating and even roasting.
Native to the Middle East and domesticated in the sixth millennium b.c., barley is quite possibly the oldest cultivated cereal in the world. A staple in the eastern Mediterranean, it spread to France and Germany via Spain, and reached Britain around 5000 b.c. In antiquity it was used to make porridge, unleavened bread, and beer. Containing less gluten than wheat, barley produces leavened bread that is coarser, darker, and denser than wheat bread. In medieval Europe, which preferred wheat and rye to barley, barley bread was eaten by the poor and used by the rich as trencher bread instead of plates. Barley water was popular as a potion for the sick. In those parts of Europe where much ale and beer were consumed, barley production sometimes exceeded wheat production. Physicians considered barley an inferior foodstuff that caused wind and that cooled and moistened the body. It was the latter two qualities that made barley water an ideal antidote to fevers.
Yeast alters the physical properties of dough and its handling characteristics during mixing and fermentation. Yeast acts on certain sugars to form alcohol and carbon dioxide. Gluten from the flour absorbs water and forms extensible membranes that trap carbon dioxide and expand to decrease the density of the dough mass. The diffusion and accumulation of carbon dioxide throughout the dough mass generates powerful stretching action. These changes in gluten are described as the mellowing, maturing, or conditioning of the dough (3).
Dietary fat does not affect calcium absorption except in individuals with diseases that impair fat malabsorption (e.g., short bowel syndrome, celiac disease, and pancreatitis). In these conditions, the calcium forms an insoluble and unabsorbable 'soap' with the unabsorbed fat in the alkaline lumen of the small intestine, potentially resulting in impaired bone mineralization. In addition, the luminal calcium is not available to precipitate the oxalates, meaning that the free oxalates will be hyperabsorbed leading to increased risk for renal oxalate stones. Neither dietary phosphorus nor a wide range of phosphorus-to-calcium ratios affect intestinal calcium absorption in very low-birth-weight infants and adults.
Ullrey 5 reviewed the bioavailability aspects of vitamin A precursor materials for swine and reported that pigs were far less efficient than rats or chicks in converting carotenoid precursors to active vitamin A. Thus, bioefficacies (wt wt) ranging from 7 to 14 were observed for corn carotenes in pigs relative to all-trans retinyl palmitate. Hence, carotenoid precursors in corn (also corn gluten meal) have no more than 261 IU mg vitamin A activity when consumed by swine. This is decidedly less than the theoretical potency of 1667 IU mg (assuming all the carotenoids are all-trans-b carotene), which is assumed for the rat. 3 Corn carotenoids consist of about 50 cryptoxanthin, 25 b-zeacarotene, and 25 b-carotene.
Cancer Epidemiology and Associations Between Diet and Cancer. Celiac Disease. Coronary Heart Disease Prevention. Dietary Fiber Physiological Effects and Effects on Absorption. Folic Acid. Food Fortification Developed Countries Developing Countries. Food Intolerance. Food Safety Other Contaminants. Legumes. Niacin. Nuts and Seeds. Pellagra. Phytochemicals Classification and Occurrence. Protein Deficiency. Vitamin A Biochemistry and Physiological Role. Whole Grains.
Established celiac disease is characterized by an inflammatory response in the proximal small intestine. This inflammation consists of increased numbers of lymphocytes, plasma cells, and macrophages in the lamina propria and increased lymphocytes in the surface layer of the epithelium, called intra-epithelial lymphocytes. The surface enterocytes are shorter and wider than normal and have poorly ordered nuclei. The normally tall thin villi are shortened and flattened. The cryptal layer is increased in depth. These changes may be patchy and affect variable lengths of the proximal small intestine ( Figure 1). the actual pathology of the lesion, and clones derived from such cells have been used to characterize the response to gliadin. Lymphocytes in the intraepithelial layer are also increased in number in untreated celiac disease, many of which bear the 7S TCR. These cells slowly decrease when gluten is removed. An early event in the pathology is an increased expression of class II HLA...
Small bowel biopsy remains the gold standard for diagnosis of celiac disease. Over the past decade the diagnostic criteria for celiac sprue have changed. Based on the 1990 revised criteria of the European Society of Paediatric Gastroenterology and Nutrition, the diagnosis of celiac sprue can be made with a diagnostic small bowel biopsy in a patient with highly suggestive clinical symptoms, followed by an objective clinical response to a gluten-free diet. Endoscopic biopsies from the distal duodenum are preferable because the presence of Brunner glands in the duodenal bulb and proximal second portion of the duodenum may affect histologic interpretation. The original criteria requiring a series of three biopsies, i.e., first to confirm the diagnosis, second for demonstration of response to a gluten-free diet and the third for deterioration after gluten challenge, are only required in those few patients in which there is still some diagnostic uncertainty. Endoscopic features observed in...
Osteomalacia is a well-recognized, although uncommon, complication of celiac disease, with bone pain and pseudofractures as features. It is associated with elevated alkaline phosphotase and often normal levels of calcium and phosphate. It usually responds well to a gluten-free diet and calcium and vitamin D supplementation. Osteoporosis, which is common in adults with celiac disease, affects both men and women, and the exact mechanisms are not clear. The prevalence of osteoporosis is even higher in refractory sprue compared to gluten-free-diet-responsive patients. Diagnosis depends on bone mineral density testing with a T-score less than 2.5 SD below mean peak value in young adults. The primary treatment for the osteoporosis in a celiac is the strict gluten-free diet with adequate calcium (1500mgday_1 and vitamin D). Other measures directed at preserving or building bone density may be necessary if the boss mineral loss has been substantial or does not recover with a gluten-free diet.
The ability to make leavened bread from wheat flour depends largely on the unusual properties of the gliadin and glutenin proteins, which together constitute gluten these properties are not shared by the prolamins of barley and wheat, although they are related structurally to the gluten proteins (Shewry, 1995, 1998 Miflin et al., 1999). Gluten storage proteins form a continuous network in dough, conferring the viscoelastic properties necessary to entrap carbon dioxide released during the proofing of leavened bread. The protein network also provides the cohesiveness required for other foods for example, high elasticity is required for making noodles and pasta, while more extensible doughs are needed for making cakes and biscuits (cookies). The quality of wheat is determined by genetic and environmental factors, with poor quality generally resulting from low gluten elasticity (Shewry, 1998 Shewry et al., 2000). Wheat gluten is a complex mixture of proteins with over 50 individual...
Most of the products on the market have been designed for both oral and tube feeding. They have a caloric density of 1.0 Kcal mL. The caloric distribution for pediatric products are typically 10 to 12 of calories from protein, 25 to 44 from fat, and 44 to 63 from carbohydrate. Like adult formulas, these formulas are generally lactose-free and gluten-free. They consist of intact milk protein sources, blends of vegetable oils, hydrolyzed starches, and sucrose, and some have added fiber. All have been formulated to meet the nutrient standards set forth by the National Academy of Sciences-National Research Council Recommended Dietary Allowances (RDAs) (7). These RDAs differ from the RDIs used for adult nutritionals in that they are more age-specific. In most cases, certain nutrients have
Usually established through the staining (chemically or physically attaching specific dyes) of particular components. Some commonly used stains in food research are presented in Table 1. Vaughan (4) described in detail the use of various stains to locate specific components in a variety of commodities. An example of the relationship of microstructural changes occurring during processing looked at the effect of mixing on the structure of dough made from different quality flours by observing uranyl-acetate stained gluten fractions (8). Proper dough development required a matrix network of protein strands. For living cells, which may be harmed by stains, a phase ring and plate may be added to achieve phase contrast (7) as shown in Figure lb.
Echocardiogram by a pediatric cardiologist if not done previously Thyroid function test (TSH and T4) yearly behavioral auditory testing every 6 months until 3 years of age, then yearly. Continue regular eye exams every year if normal, or more frequently as indicated. Between 3 years and 5 years of age, lateral cervical spine X rays (neutral view, flexion and extension) to rule out atlantoaxial instability have the radiologist measure the atlanto-dens distance and the neural canal width. X rays should be performed at an institution accustomed to taking and reading these X rays. Initial dental evaluation at 2 years of age with follow-ups every 6 months. At 2-3 years of age, screen for celiac disease with IgA anti-endomysium antibodies as well as total IgA.
Conditioners (ie, surfactants added to bread dough), which increase the strength and elasticity of gluten in the dough. Bread and other yeast-leavened baked foods made with the addition of dough conditioners typically have larger volume and finer internal texture than products made without such conditioners.
Long-term, systematic research is required to establish quantitative, empirical rules to understand the role of hydrophobicity in functionality of food protein systems. This basic research is required to explain at the molecular basis, various well-known but not clearly understood phenomena such as the thermostability of egg white foams, elasticity of egg white gels, coagulation of casein to form cheese, binding and texture formation of muscle proteins, elasticity and extensibility of wheat gluten dough, and so on.
A typical English muffin dough contains 83 to 87 water (flour basis equals 100 ), 2 sugar, 1.5 salt, 5 to 8 yeast, and 0.5 to 0.7 calcium propionate. Vital wheat gluten at 1 to 2 is sometimes added to increase the chewi-ness of the finished muffin. At this absorption level the dough is very soft, and it must be cold (20 C, 68 F) when taken from the mixer so that it does not stick when it is divided, rounded, and deposited from the intermediate proofer into the griddle cups. Dusting material, usually a blend of corn flour and cornmeal, is used rather liberally (3 4 of the dough weight) to facilitate the various transfers.
EM can be carried out in two modes scanning electron microscopy (SEM) and TEM. SEM is used to examine surfaces. Nonconductive materials such as food specimens need to be made electrically conductive. This oan be achieved by depositing a metal layer such as gold palladium onto the sample using a spatter coater. The sample is scanned by a focused electron beam. In conventional SEM the sample needs to be completely dry because the vacuum within the microscope would cause the water to evaporate. In addition, lipids in the sample would melt under the electron beam (27). Careful specimen preparation is critical to avoid artifacts and essentially determines the value of information obtained (28). The preparation methods are dictated mainly by the type of sample. Moisture and fat content as well as structural differences should be considered. For example, fixation, dehydration, and coating may require longer time for compact structures such as low-fat cheeses compared with full-fat cheeses...
Within the European Union various Member States are beginning to address the issue of labelling of allergens with various degrees of official recommendations. In France, the authorities have published a detailed review of the situation and recommended a number of ways in which industry, collectively, can significantly improve the information given to consumers. A restricted list of allergens is covered but the principal focus is on peanuts and similar derivatives, coupled with clearly defined changes to the legal framework for labelling. In Sweden, labelling legislation requires ingredients known to cause intolerance to be stated in the list of ingredients. Examples quoted include eggs, milk, gluten-containing grains, and legumes such as soyabeans, peas and peanuts. The
Although absorbing oxygen and moisture or emitting carbon dioxide in a package can affect the growth of microorganisms, there are packaging schemes that are specifically designed to inhibit foodborne microorganisms. These fall mainly into two categories, packaging materials and edible films coatings that contain antimicrobial agents that interfere with microbial growth on the surface of the food (Cha and Chinnan, 2004). A variety of antimicrobials can be incorporated into packaging material or applied to the interior surface of the material, ranging from weak organic acids such as acetic, benzoic, lactic, propionic, and sorbic acids enzymes such as lysozyme bacteriocins such as nisin or pediocin triclosan chitosan and fungicides. The selection depends on the target organism and the food. Many of these same agents can be incorporated into edible coatings made from polysaccharides such as starch, cellulose, or gums. Proteins films are based on corn, soy, milk, collagen, and gluten while...
The Coeliac Society was founded in 1968 as a national support group for people with coeliac disease and dermatitis herpetiformis. Coeliac disease is a lifelong inflammatory condition of the intestinal tract which affects the small intestine in genetically susceptible individuals. This is caused by gluten, a protein in wheat, and similar proteins in rye, barley and oats. As well as information leaflets, the society publishes an annual booklet listing 10 000 gluten-free manufactured foods with updates provided throughout the year.
Tropical sprue is a disease of unknown etiology that exclusively affects people living in or visiting specific tropical or semitropical areas, particularly Southeast Asia and the Caribbean, that resembles celiac disease in its intestinal changes. It presents with stea-torrhea, abdominal cramps, bloating, and increased bowel sounds. Most patients improve or are cured with long-term broad-spectrum antibiotic treatment. Fluid and electrolyte replacement should be administered to the acutely dehydrated patient, and megaloblastic anemia is often secondary to folate or B12 deficiency, which should be corrected. Vitamin A deficiency may be an important feature. Sometimes, iron, calcium, or magnesium may be deficient, and these minerals should be replaced. Antibiotic treatment may be helpful.
Table 1 summarizes the limiting amino acids used as feed supplements (1). For grains such as maize, which is fed to both pigs and chickens, the first limiting amino acid is lysine, whereas in protein sources such as rapeseed meal, it is methionine, lysine, or tryptophan. There are three general methods of supplying lysine adding soybean meal, which contains it in high quantity adding a larger quantity of poor-quality protein such as corn gluten meal or adding lysine directly. The first two approaches are more expensive and less economical in view of wasting nitrogen resources, so the direct addition of lysine has been adopted.
When evaluating children and adults with Down syndrome for behavioral concerns, it is important to determine whether there are acute or chronic health problems impacting on development and or behavior. Vision and hearing problems can have a significant effect on a person's ability to function both at home and in the school workplace setting and should be monitored closely as recommended in the Healthcare Guidelines for Persons with Down Syndrome (Cohen, 1999). Other medical problems that can be associated with behavioral changes include hypo- and hyperthyroidism, celiac disease (sensitivity to oats, wheat, barley, and rye), sleep apnea, anemia, gas-troesophageal reflux, and constipation. Evaluation by the primary care physician to assess for medical neurological problems is an important component of the workup for behavioral concerns in persons with Down syndrome of any age.
In the study of an atopic population, eczema and a history of food allergy were reduced at the age of one year in the group fed solids after six months of age compared with those with solids introduced at three months. No food challenges or skinprick IgE testing were performed in the first year, but at five years there was no difference between skin testing to fish, milk and wheat, history of food allergy and eczema between the two groups (Kajosaari 1991). A randomised, population-based study in Finland showed no difference in the cumulative incidence of fish and citrus allergy at three years old between children with fish introduced early or late (after one year old) into the diet, although the children with earlier introduction reacted earlier in life (Saarinen and Kajosaari 1980). Similar observations have been reported with coeliac disease. The later introduction of gluten into the infant diet has altered the age of onset and type of clinical presentation of coeliac disease...
Vitamin B6 functional tests are the erythrocyte aspartate aminotransferase activation coefficient test and the tryptophan load test. Erythrocyte aspartate aminotransferase activity is measured spectrophotometrically in erythrocyte hemolysate without PLP addition (basal) and with PLP addition (stimulated). The activation coefficient is given by the ratio of stimulated to basal activity. Automation of this test is available. Confounding effects of renal and liver diseases, cancer, celiac disease, high protein diet, thiamin status, alcohol intake, stress, and drugs are reported. The tryptophan load test was used in the past because vitamin B6-dependent enzymes are involved in the conversion of trypto-phan to niacin. After an appropriate loading dose of tryptophan and under controlled conditions, vitamin B6-deficient subjects excrete tryptophan metabolites (kynurenine, kynurenic acid, and xanturenic acid) in urine measured spectrophotome-trically after thin-layer or ion exchange...
In industrial processes, the cheapest substrates are used to keep the production costs low. Some of the cheap substrates available include barley, barley malt, blood meal, cane molasses, corn gluten meal, corn meal, corn steep liquor, cotton seed meal, dried distillers' solubles, fish solubles, fishmeal, linseed meal, meat meal, bone meal, oat flour, peanut meal, rice bran, rice flour, soybean meal, wheat flour, whey powder, and yeast hydrolysate (87). The composition of the medium has to reflect the demands necessary for the growth and synthesis of products other than cells. The carbon to nitrogen ratio has been found to be a good indicator for studying the optimum requirements for growth and product formation (88). Generally, media consist of an aqueous solution containing dissolved nutrient salts and a gaseous component (O2). The different nutrient sources commonly used in fermentation media are shown in Table 3.3.
Feeding grain is common in U.S. feedlots. Corn or maize is the most prevalent, followed by grain sorghum (milo), barley, and wheat. Grain use is based on price, availability, and geographic region. Corn is a relatively abundant and inexpensive energy source containing approximately 70 starch. Feedlot diets generally contain 85 grain such as corn 5 to 12 forage or roughage such as alfalfa hay, corn silage, or grasses and 3 to 8 supplement. Diets may contain numerous types of byproduct feeds such as corn gluten feed, distiller's grains, potato wastes, molasses, beet pulp, etc. that may replace 5 40 of the grain, depending on supply, cost, protein, and energy of the by-product feed. Supplements provide protein, minerals, vitamins, and feed additives at appropriate levels based on nutrient requirements of cattle. In feedlot diets, calcium supplementation is required in all cases, owing to the low concentrations of calcium in basal ingredients such as grain. In most cases, unless...
The principal structure-forming ingredient used in biscuit doughs is wheat flour. Very few cookies or crackers are made without any wheat flour, and those are usually quite atypical in organoleptic characteristics. To provide for flour strength in weaker flours, vital wheat gluten can replace wheat flour to a limited extent. Soft wheat flours suitable for biscuits may vary in protein content (mostly gluten) from 7.0 to 9.5 (for cookies) to 10 or more (for crackers). The flour may be unbleached or heavily bleached to a pH range of 4.4 to 4.8 for certain specialty items, such as soft cookies that contain higher levels of sugar and shortening. Cookies using bleached flour will rise higher with little spread in contrast, unbleached flour will typically spread more than it rises. Flours other than wheat can be used in crackers and cookies for color, texture, and flavor. Prime examples of these ingredients would be rye and corn flour. Sorghum flour, cottonseed meal, soybean meal, triticale...
Once the presumptive diagnosis of celiac disease is made then treatment may be commenced. It is important that the patient does not start to restrict their diet until each of the steps including the biopsy have been completed. Once confirmed, the responsibility for directing the management of the patient lies with the physician. The treatment starts with an explanation of the condition and its cause. It is important that the patient understands that this is a chronic inflammatory condition of the gut and not a simple food allergy, that it is permanent eventhough the intestine will heal, and that the central and indeed only treatment at present is a gluten-free diet for life. The clinician should expect shock and even a fully expressed grief reaction on the part of the patient. Disbelief that something as basic to the Western diet as wheat is responsible is common. Some patients are overwhelmed both by the realization of having a chronic illness and others by relief that an explanation...
A general examination of all the major systems of a patient normally supplements the clinician's history taking. In the case of paediatric examination, in particular, it should include the measurement of parameters of growth -height, weight and head circumference - which should be recorded on an appropriate centile chart. Chronic illnesses such as coeliac disease and poorly controlled asthma may result in a thin, short child, as do the use of long-term high-dose steroids.
Rectal challenges The standard test to confirm a diagnosis of celiac disease is the jejunal biopsy, in which a small portion of jejunal mucosa is obtained with the aid of a special capsule that is swallowed, and which passes into the small intestine. When in the correct location, the capsule is triggered and withdrawn it contains a portion of intestinal mucosa, which can then be examined under the microscope. Alternatively, gluten can be instilled into the rectum, in order to look for a reaction that would signify celiac disease. This procedure requires multiple biopsies from the rectum, and it is uncertain whether the results are reliable.
Dermatitis herpetiformis This is characterized by an extremely pruritic papulovesicular eruption, which usually occurs symmetrically on the elbows, knees, buttocks, and back. About 80 of patients with dermatitis herpetiformis have small intestine histology indistinguishable from celiac sprue. The diagnosis is established by skin biopsy demonstrating granular IgA deposits in areas of normal appearing skin. A majority of patients with the skin lesion who undergo small bowel biopsy have intestinal mucosal changes of celiac disease. The skin lesions, as well as small bowel histology, improve on a gluten-free diet. Dapsone is an effective short-term treatment for dermatitis herpetiformis however, it does not have any impact on management of small bowel enteropathy. Also, those with dermatitis her-petiformis who are not compliant with the gluten-free diet are at higher risk for malignancy, as are those with celiac disease. Celiac disease has also been associated with other autoimmune as...
When reading different texts in this area, it becomes evident that in the medical and scientific community, there is no single global consensus on what is food allergy and what is food intolerance. For example, there are authorities who consider coeliac disease as a type of food allergy and others who regard it as a form of food intolerance. Some may not consider it as either. Indeed, it appears that it all depends on what definition one has used. The terminology which appears to have gained credibility amongst many peers is that adopted by the European Academy of Allergology and Clinical Immunology (EAACI).1 The distinguishing feature of this terminology is that it is based on mechanisms rather than clinical symptoms. The structure of this terminology is outlined in Fig. 1.1. Broadly, adverse reactions are divided into toxic and non-toxic reactions.
The gluten protein fraction in wheat flour. Gluten is the water-insoluble viscoelastic protein mass left after soluble proteins, starch, and other nonprotein materials have been washed out from the flour. Gluten is composed mainly of hydrated forms of the two major wheat protein fractions, namely, gliadins (wheat prolamins) and glutenins (wheat glutelins).63 75 These proteins contribute in different ways to the properties of the flour during processing and in the final product. Thus, gliadins provide viscosity and extensibility to bread dough, whereas glutenins provide the elasticity that is all-important in dough stability and in the structure and texture of bread. Differences in proportions and properties of these two protein fractions determine whether a particular wheat variety has good bread-making properties or is more suitable for the production of other products, such as pasta or biscuits. A molecular basis for these properties has been proposed, based on the characteristics...
Absorption of iron in heme from meat is more efficient than as inorganic ferrous or ferric iron. Thus, vegetarian diets present increased risk of iron deficiency. However, most diets, even in affluent westernized countries, are marginal in the amount of iron in relation to population needs. All children are at risk of developing iron deficiency with minor disturbances in dietary quality, iron absorption and metabolism, or with blood loss. Iron absorption takes place in the jejunum and upper ileum so conditions such as gluten-sensitive enteropathy (celiac syndrome), where the brunt of intestinal damage is in the jejunum and upper ileum, may present as severe iron deficiency. Reduced iron absorption during pyrexial illness contributes to iron deficiency in children who suffer frequent infections.
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