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The effects of diet ingredients on red meat flavor are dependent on the type of diet, and, to a large extent, on the species: pork, mutton or lamb and beef. Sensory analysis of meat flavor has been used in most of the studies on the effects of feeds on meat flavor. In general, high-energy grain diets produced a more acceptable or a more intense flavor in red meats than low-energy forage or grass diets. Feeding pigs unsaturated fats increases the unsaturation in pork fat but results in only minor changes in pork flavor. Sheep must be fed protected, unsaturated fats in order to increase the unsaturation in their fat to be similar to pork fat. This increased unsaturation results in a greater flavor change in lamb or beef than in pork. Several dietary ingredients such as fish products, raw soybeans, canola oil and meal, and pasture grasses cause undesirable flavors in red meat. Analyses of lamb and beef produced on different diets have shown that type of feed affects the concentration of many flavor volatile compounds. However, only a few studies have quantified the volatiles of beef and lamb produced on different diets, and no reports of studies were found in which the volatiles of pork produced on different diets had been investigated. Hence, the importance of these changes in volatile concentration to meat flavor has not been determined.

Measurements of degradation in frying oils based on oil physical properties and volatile and nonvolatile decomposition products were reviewed. Rapid methods by means of test kits were also considered. Factors that affect the analysis of total polar components (TPC) in frying oils were examined. Relationships between TPC, free fatty acid {FFA} content, Food Oil Sensor readings (FOS), color change (hE), oil fry life and fried-food flavor were evaluated. Flavor scores for codfish, fried in fresh and discarded commercial frying oil blends, were dependent upon individuals in the consumer panel (n = 77). Part (n = 29) of the panel preferred the flavor of fresh fat; others (n = 24) didn't; the rest (n = 24) had no preference. FFA, FOS and TPC were analyzed in two soybean oils and in palm olein during a four-day period in which french fries were fried. Flavor score and volatiles of potatoes fried on days 1 and 4 in each oil were also determined. TPC, FFA and FOS significantly increased (P < 0.05} in all oils during the frying period. TPC and FFA were highest in the used palm olein, and flavor of potatoes fried in palm olein on day 1 was less desirable than those fried in the soybean oils. Potatoes fried in day-1 oils had significantly higher concentrations {P < 0.10) of several pyrazines and aldehydes than those fried in day-4 oils.

Flavor and selected chemical components of ground beef from 60 steers were studied as a function of days (up to 140) that corn was fed to steers after grazing on pasture. During the 140 days on corn, significant changes occurred in the fatty acid composition of ground beef and in its carbohydrate content, titratable acidity, volatile fatty acid content, aroma and flavor. Flavor changes were related to certain chemical components. Results indicate that finishing cattle on corn for periods longer than 80-90 days causes little change in beef flavor.

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