Food Chemistry

3.7 Changes in Acyl Lipids of Food 197 accounts for two unpaired electrons in the oxygen molecule. These are the two antibonding ...

198 3 Lipids agreement with the above reaction mechanism. The reaction is illustrated in Fig. 3.24 for the oxidation of linoleic ...

3.7 Changes in Acyl Lipids of Food 199 Fig. 3.25.Side reaction of a branched furan fatty acid with singlet oxygen (R^1 :(CH 2 ) ...

200 3 Lipids Table 3.29.Linoleic acid hydroperoxidesa: decomposition by heavy metal or heme compounds at 23◦C. Relative reaction ...

3.7 Changes in Acyl Lipids of Food 201 (3.66) Suppression of peroxidase and catalase activity is of importance for the shelf lif ...

202 3 Lipids Table 3.30.Rate constants of reactions of reactive oxygen species with food constituents Constituent^1 O 2 HO• O 2 ...

3.7 Changes in Acyl Lipids of Food 203 3.7.2.1.9 Secondary Products The primary products of autoxidation, the mono- hydroperoxid ...

204 3 Lipids Table 3.32.Sensory properties of aroma components resulting from lipid peroxidation Compound Flavor quality Odor th ...

3.7 Changes in Acyl Lipids of Food 205 (Z)-4-heptenal), which occurs in beef and mutton and often in butter (odor threshold in T ...

206 3 Lipids Fig. 3.27.Proton-catalyzed cleavage of linoleic acid 13-hydroperoxide (according toOhloff, 1973) Fig. 3.28.Reaction ...

3.7 Changes in Acyl Lipids of Food 207 (3.74) Alkanes, Alkenes. The main constituents of the volatile hydrocarbon fraction are e ...

208 3 Lipids Fig. 3.29.Lipoxygenase catalysis aProposed mechanism of reaction (according toVeldink, 1977); RH: linoleic acid; LO ...

3.7 Changes in Acyl Lipids of Food 209 Non-specific LOX occur in legumes, e. g., LOX 1 in peas (Table 3.33) and LOX III in soy- ...

210 3 Lipids Fig. 3.31.Mechanism of the cleavage of hydroper- oxides by lyases (according to Wurzenberger and Grosch, 1986) ain ...

3.7 Changes in Acyl Lipids of Food 211 Table 3.34.Occurrence and properties of various hydroperoxide-lyases Occurrence Substrate ...

212 3 Lipids Table 3.35.Products obtained by non-enzymic degradation of linoleic acid hydroperoxides Producta Hydroperoxide inte ...

3.7 Changes in Acyl Lipids of Food 213 Fig. 3.32.Degradation of linoleic acid hydroperoxides to hydroxy-, epoxy- and oxo-fatty a ...

214 3 Lipids texture, decreases in protein solubility (formation of cross-linked proteins), color (browning) and changes in nutr ...

3.7 Changes in Acyl Lipids of Food 215 Table 3.37.Amino acid losses occurring in protein re- action with peroxidized lipids Reac ...

216 3 Lipids pherols secure the stability of the oil end-product. Soya oil, due to its relatively high level of furan fatty acid ...