Principles Of Hurdle Technology

The microorganisms present in a food should not be able to overcome ie, leap over the hurdles inherent in this food. This is illustrated by the so-called hurdle effect 1 , which is of fundamental importance for the preservation of intermediate-moisture foods 2 and high-moisture foods 3 , since the hurdles in a stable product control microbial spoilage and food poisoning as well as desired fermentation processes. Leistner and coworkers acknowledged that the hurdle effect illustrates only the...

Sterilization Versus Pasteurization

Thermal processing covers the broad area of food preservation technology in which heat treatments are used to inactivate microorganisms to accomplish either commercial sterilization or pasteurization. Sterilization processes are used with canning to preserve the safety and wholesomeness of ready-to-eat foods over long terms of extended storage at normal room temperature (nonrefrigerated) without additives or preservatives, and pasteurization processes are used to extend the refrigerated storage...

Fresh Poultry Meat Composition and Nutritional Value

Poultry meat is widely accepted as a good source of high-quality protein, the B vitamins, and minerals such as iron. The fact that poultry meat is considered to be a source of lean meat and has a higher level of unsaturated fat as compared with red meat has resulted in a significant increase in poultry meat consumption in North America (Table 1) and around the world. Overall, the composition of poultry meat is dependent on species, strain, sex, age, and diet. Table 4 illustrates that species...

Utilization Of Fruit And Vegetable Processing Wastes Via Solidstate Fermentation

Although direct disposal of fruit processing wastes in landfills has become environmentally unacceptable, some fruit processing wastes can be composted under anaerobic condition, and then used as fertilizer in landfills, because such wastes were readily degraded under anaerobic digestion conditions 57,58 . Solid-state fermentation can also be used for composting of fruit and vegetable processing wastes such as apple waste 59 and tomato pomace 60 . Composted apple pomace and other fruit and...

Ice Cream Composition And Physical Properties

Ice cream mix contains a minimum of 10 milkfat and 20 total milk solids, except when fruit, nuts, chocolate, or other bulky flavors are added. If bulky flavors are added, the minimum milkfat is 8.8 and 16.6 milk solids. According to U.S. Federal Standards, ice cream must weigh at least 4.5 lb gal. The minimum gallon weight permits the incorporation of air sufficient to roughly double the volume (or 100 overrun). Percent overrun is defined as weight of 1 gal mix - weight of 1 gal ice cream...

Applications Of Hurdle Technology

The intelligent application of hurdle technology for a mild but efficient food preservation is advancing worldwide in industrialized as well as in developing countries. Some examples and trends are presented next. Deliberate and intelligent hurdle technology for food preservation started about 20 years ago in Germany with meat products. First it was used for the gentle preservation of mildly heated, freshlike meats storable without refrigeration 4 . In the meantime, several categories of these...

Economic Importance Of Coffee

Coffee, a significant factor in international trade for about 185 years, is among the leading agricultural products in international trade along with wheat, corn, and soybeans. The total world exportable production of green coffee in the 1997-1998 growing season is approximately 81.7 million bags Table 1 . This compares with a total production of about 107.5 million bags, the difference being internal consumption. Table 2 shows imports and consumption data. The International Coffee Organization...

Microorganisms In Shellfish

Shellfish is composed of crustaceans shrimp, crabs, lobster, crawfish, etc and mollusks bivalves, squids, snails, etc . Shellfish normally contains more moisture, greater amount of free amino acids, and more extractable nitrogenous compounds than finfish. These biochemical characteristics facilitate bacterial growth and deteriorative reactions resulting in the rapid spoilage of shellfish 27 . Many shellfish grow in estuarine, coastal waters, and aquacultural ponds near residential areas and are...

Restructured Meat Products

The term restructured has the general meaning of binding smaller pieces of meat together to generally give the impression that a larger meat cut has been created that can produce slices of desired size for sandwiches or steak for plating at dinner. Processors have used various technologies to restructure ham since the 1950s. Mixing pieces of meat with ingredients, but especially appropriate levels of salt and alkaline phosphates, results in the osmotic movement of the ingredients throughout the...

The Nutrition Labeling And Education Act Of 1990

Several forces led Congress to pass the Nutrition Labeling and Education Act of 1990 (NLEA). As public interest in foods and nutrition, especially the relationship between diet and health, continued to grow, a number of food manufacturers had begun in the mid 1980s to make health and nutrition claims on certain product labels. Probably the best known of these was the claim that fiber in the diet was believed to reduce the risk of cancer. Because government regulations did not provide for this...

Food Preservation Through Control Of Water

Bound Water Food

As mentioned in the general discussion of food preservation, the most serious limitation of shelf life and nutritional quality is from microbiological activity. This section covers briefly the concept of reducing the amount of water in food systems as a means of food preservation. By lowering the amount of water available for microorganisms to remain active and reducing mobility of potentially reactive chemical species in a food system, it is possible to extend quality of a product from both a...

Freezing Point Depression

Eutectic Freeze Crystallization

Solutes depress the freezing point of water. Therefore, as ice forms and solute concentrations increase, the freezing point decreases. Figure 1 shows how the freezing points of wine and some juices depend on concentration 1 . The freezing point depression is roughly inversely proportional to the solute's molecular weight. Thus, at equal concentrations, freezing point depressions for juices eg, apple juice in which the main solutes are fructose and glucose are greater than those for juices eg,...

Toxicology Principles Definitions And Scope

Toxicology is the study of the adverse effects of substances on living organisms. It is a multidisciplinary field of study dealing with the detection, occurrence, properties, effects, and regulations of toxic compounds. It therefore involves an understanding of chemical reactions as well as biological mechanisms of toxic actions. A toxicological study usually consists of four elements (2) a chemical agent capable of causing a deleterious response (2) a biological system with which the chemical...

Flavor and Aroma of Shiitake Mushrooms

Ribonucleotides have been shown to enhance the flavor of foods. As with L-glutamate (MSG), 5'-guanylate and 5'-inosinate are flavor potentiators, which are the compounds that amplify the effects of other flavor agents. While vegetables are generally low in 5'-nucleotides, ranging 1 to 10 mol per 100 g fresh weight, mushrooms contain large amounts of these nucleotides. Common mushroom (Agaricus) contains about 50 mol and fresh Shiitake mushroom from 182 to 235 mol of 5'-nucleotides per 100 g...

Roles Of Gases Used In Modified Atmosphere Packaging

Gases commonly used in gas packaging are nitrogen, oxygen, and carbon dioxide. Because the gases are those we breathe, the gases used in MAP are neither toxic nor dangerous, nor are they regarded as food additives. Each gas plays a distinct and specific role in MAP foods. Nitrogen is an inert gas that has no effect on the food and has no antimicrobial properties. It is used mainly as a sweep gas to remove oxygen and as a filler gas to prevent package collapse in products that can absorb C02. It...

Functionality Of Food Additives

Adopted from the National Academy of Sciences national survey of food industries the Food and Drug Administration FDA uses the following terms to describe the physical or technical effects for which direct human food ingredients may be added to foods Anticaking agent or free flow agent. Substance added to finely powdered or crystalline food product to prevent caking, lumping, or agglomeration Antimicrobial agent. Substance used to preserve food by preventing growth of microorganisms and...