PAGE 469 470 471 471 471 471 472 472 472 473 473 473 473 474 475 Carotene Oxidation of lipids Copper-induced oxidation Influence of proteins and amino acids Light-induced oxidation Light-induced deterioration Role of riboflavin Deterioration due to microorganisms Deterioration due to hydrolytic changes Lipolysis Factors affecting lipolysis Proteolysis Conclusions References

In a study related to domestic practice, milk was laboratory pasteurized to give the time‐temperature conditions of HTST pasteurization and stored in full glass bottles at 7°C in the dark for up to 14 days. The consumption of O2 during storage was monitored, and the factors responsible for its consumption were quantitatively assessed. The principal factors were: loss through septum, 7.I per cent; ascorbic acid oxidation, 34 per cent; bacterial growth, 36.1 per cent: sulphydryl oxidation. 3.4 per cent. Thus, some 80.6 per cent of the O2 consumed was accounted for. Lipid peroxidation used only 0.07 per cent. Lipolysis was also determined. Nevertheless, preliminary organoleptic findings indicated that oxidized flavour was the predominant element in ‘stale’ milk.