FOOD 2400 Lecture Notes - Lecture 4: Butylated Hydroxytoluene, Gallic Acid, Lipoxygenase

• School: University of Guelph
• Department: Food Science
• Course: FOOD 2400
• Professor: Yoshi Mine

Document Summary

Unit 4: lipids reactions in lipids, lipolysis and oxidation. Lipolysis: off-flavours or off-odou(cid:396)s a(cid:396)e asso(cid:272)iated (cid:449)ith (cid:862)(cid:396)a(cid:374)(cid:272)idit(cid:455)(cid:863), (cid:449)hi(cid:272)h (cid:272)a(cid:374) (cid:271)e h(cid:455)d(cid:396)ol(cid:455)ti(cid:272) o(cid:396) o(cid:454)idati(cid:448)e by nature, oxidative rancidity: affects fats, oils and fatty parts of foods caused by reactions involving oxygen. In addition, free fa are more susceptible to oxidation than fatty acids esterified to glycerol. Is it difficult to separate acylglycerol and fatty acid specificities based on one principle: ex. Lipase from geotrichum candidum for oleid acid preferentially hydrolyzes oleic acid, regardless of the position in the tag: endogenous lipases are important for both desirable flavours and undesirable flavours. Oxidation of lipid: the process where lipid molecules degrade after oxidation reaction, 3 phases: Initiation: formation of free radicals: propagation: the free-radical chain reactions, termination: formation of non-radical products. Initiation: h is abstracted from a fa chain, producing free radicals. O2 to give an equal mix of conjugated 9, 13-diene hydroperoxides: linolenates two 1,4 pentadiene structure are present.