Fats, rancidity

One disadvantage of fats contained within foodstuffs is the deterioration of the fat through oxidative rancidity. Many consumers find the aroma and flavor of deteriorated fats in foods repulsive, while others are fond of country ham and butter which owe thek aroma and flavor to fat rancidity and other breakdown products. The use of antioxidants (qv) makes such products commercially viable. 

Anti-foaming agent Antioxidant Substance which prevents or reduces foaming Substance which prolongs the shelf life of foodstuffs by protecting them against deterioration caused by oxidation, such as fat rancidity and colour changes... 

From the legal point of view, antioxidants are substances which prolong the shelf-life of foodstuffs by protecting them against deterioration caused by oxidation, such as fat rancidity, colour changes and loss of nutrient value. Hundreds of compounds, both natural and synthesised, have been reported to possess antioxidant properties. Their use in food, however, is limited by certain obvious requirements, not the least of which is adequate proof of safety. 

Fats, rancidity, 328 Favorskii rearrangement, 294 Fenton s reagent, 306 Ferrocene, 275 Field effects, 22, 152, 364 Flash photolysis, 304 Fluorination, 121,140,170, 315, 326 Free energy, Gibbs, 34 change and K, 35, 359 of activation, 38, 359 standard, 35... 

The thresholds given by Tallamy and Randolph (1969) (for non-UHT milk) appear to be reasonable and generally acceptable, (i.e., 1.2-1.5 meq/ 100 g fat for trained experts and 2.0-2.2 meq/100 g fat for the average consumer). A report by the IDL (1987) concluded that rancidity is normally detected between 1.5 and 2.0 meq/100 g fat. Rancidity is detected at approximately the same levels in cream (Dunkley, 1951 IDF, 1991). Similar numerical levels apply to milk where FFA content is measured by an extraction-titration method and expressed as meq/1 milk (Brathen, 1980). 

Hydrogenation not only changes the physical properties of a fat, but also— and this is even more important—changes the chemical properties a hydrogenated fat becomes rancid much less readily than does a non-hydrogenated fat. Rancidity is due to the presence of volatile, bad-smelling acids and aldehydes. These compounds result (in part, at least) from attack by oxygen at reactive allylic positions in... 

Kofakowska, A., 1979, Effect of initial processing on fat rancidity dynamics during storage of frozen fish, in Proc. XVth Int.Congress Ref. Bull. Inst. Int. Froid., 59(4), 1184 Chlodnictwo, 1980, 5, 16. 

Chemical refining (reduction of free fatty acids and oxidation products of free fatty adds, which would make the oil or fat rancid removal of the residual... 

Dairy flavors may be used to compensate for the use of nondairy fats or simply to enhance the dairy notes. Product differentiation may be achieved through the use of additional flavorings such as rum, butterscotch, and cream flavorings. The primary flavor issues are adequate dispersion in the product during manufacture and fat rancidity during storage. 

Fatty acids released during hydrolysis of fats do not bring about fat rancidity, because they are sensoriaUy imperceptible in small amounts. The exceptions are fats containing bound fatty acids with shorter carbon chain (4-10 carbons). Butyric acid is released from butter and imparts a nasty, very pungent odour. Acids with 6-10 carbon atoms are also present to a larege extent in coconut or palm kernel oils, as well as in milk fats. Native enzymes or enzymes released by molds give the product a typical soapy off-taste. 

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