Cheese varieties exist because manufacturing and curing are carried out to preserve characteristic flavor, body, and texture of a given cheese. Attributes of one cheese may prove to be defects in another.
Even though certain molds are used for manufacturing and curing of cheese, their growth on most cheeses is undesirable (27). Gas production with putrid, unclean odors due to nonstarter bacteria constitute a defect in cheese.
Moisture accumulation on the surface of hard cheeses permits rind rot due to yeasts, molds, and proteolytic bacteria growth, sometimes accompanied by discoloration. Milk itself can at times contribute weedy, feedy, cowy, barny, and related flavors coming from the cow. Psychrotrophic organism growth in milk can generate rancidity due to lipolysis and bitterness due to proteases from these organisms. Specific defects are discussed below.
Swiss is graded by the size, number, and distribution of eyes; there are many defects of the eyes (18). Blind or cheese with no eyes may be due to inhibition of carbon dioxide production of proprionibacteria by pH of less than 5.0, prolonged brining (high salt), and antibiotics or other inhibitors in milk or cheese.
Overset (pinny or too many eyes) is generally caused by improper acidity, high moisture, entrapment of air in curd, and other factors that prevent knitting of curd before gas production. Early gas is caused by Enterobacter aerogenes. Flavor defects, such as stink spots, white spots (28), and excessive amine production, are caused by Clostridium ty-robutyricum, S. faecalis ssp. liquefaciens, and strains of Lactobacillus buchenerii, respectively.
Excessive acidity, below pH 5.0 at three or more days, causes short, crumbly body and a sour, often bitter flavor. Normal body and flavor development may not occur in this cheese. On the other hand, too little acid or pH above 5.3 at three or four days may lead to corky, pasty body with off-flavor development. Open-texture defect may be caused by lactobacillus fermentum, L. brevis, and leuconostocs. Raw milk and rennet preparations have been linked to these defects.
Edam and Gouda are subject to spoilage similar to Cheddar. In these cheeses, brine has been known to contaminate the cheese surface with gas-forming lactobacilli. These may cause the occurrence of phenols, putrid odor, and sulfidelike flavors and excessive production of carbon dioxide. Butyric acid fermentation and carbon dioxide production are due to C. tyrobutyricum. Growth of propioni-bacteria may cause a sweet taste and an open texture due to carbon dioxide.
Excessive acidity is a major defect. Coliform bacteria can grow during draining and salting, causing early gas, which if excessive can yield a spongy condition. Sometimes, due to lack of surface smear growth, typical flavor does not develop.
Blue cheese may not have sufficient mold growth, leading to lack of flavor and general development of cheese attributes. Excessive growth of mold may cause mustiness and loss of flavor. Mold-ripened cheeses are sensitive to bitterness development due to excessive acidity in the curd followed by abundant mycelium growth and proteases. Surface discoloration by other molds is not uncommon. Excessive slime and undesirable flavors occur due to excessive humidity in curing rooms.
Mozzarella cheese is generally shredded before use. Softening of this cheese, due to Lactobacillus casei strain, is a problem during curing. It is also prone to softening and gas production by thermoresistant strains of Leuconostoc.
Cottage cheese has a short shelf life generally due to Pseudomonas, yeasts, and molds. Sometimes bitterness and excessive acid development due to surviving starter culture is noticed during refrigerated storage (Tables 2, 3).
For total dollar annual sales and a breakout by cheese type see Tables 4 and 5.
Was this article helpful?