OXYSTEROL FORMATION IN SPRAY-DRIED EGG PROCESSED AND STORED UNDER VARIOUS CONDITIONS - PREVENTION AND RELATIONSHIP WITH OTHER QUALITY PARAMETERS

A factorial arrangement was planned to study the influence of various factors (spray-drying temperature, antioxidant type, antioxidant conce ntration, packing conditions, and storage time) on various responses ( oxysterol formation, fat UV absorptions, polyunsaturated fatty acid lo ss, color loss due to oxidation of carotenoids, and Maillard browning intensity) in egg powder. Positive correlations were found between oxy sterol formation and the other responses. Use of low spray drying temp eratures prevented oxidation during processing and storage of egg powd er. Vacuum packing and dark conditions were highly effective in preven ting oxidation during storage. Propyl gallate seemed to be slightly ef fective in preventing polyunsaturated fatty acid loss, oxysterol forma tion, and color loss during processing and storage, whereas synergisti c combination of ascorbyl palmitate plus dl-a-tocopherol seemed to sho w a slight prooxidant effect in terms of fatty acid and cholesterol ox idation. Propyl gallate concentrations of 100 and 200 ppm seemed to be optimal to prevent, respectively, polyunsaturated fatty acid loss and oxysterol formation and color loss. Propyl gallate seemed to be more effective under highly oxidative conditions.