ABSTRACT
Choline and docosahexaenoate (DHA) are essential nutrients for maintaining normal brain function. However, their existence in fish lecithin is ignored and excluded during the degumming step of conventional fish oil manufacturing process. The study aims to introduce fish lecithin as alternative precursor of choline and omega-3 fatty acids especially DHA for nutritional supplements. Four grades of Thai fish meals with protein contents ranging from 60-70% were used. Their lipid characteristics were examined. Fish meal's fats and lecithin were 9-15 and 2-3 g/100 g, respectively. Total fatty acids constitute 23-27% monoenes without erucic acid and 24-28% polyenes including 15-19% DHA. Lecithin with 50% purity was prepared from grade-1 fish meal by means of consecutive methanol/n-hexane/acetone extraction. The obtained lecithin contains choline upto 66-70 mole% with DHA reaches to 20-23%. Its peroxide value of 57 and acid value of 9 are accepted for food grade lecithin preparation, however, the further refinery process is still suggested. Since the world consumption of nutritional supplement foods is increasing steadily, the results of our study implies that fish lecithin is probably a promising source of choline and omega-3 fatty acids especially DHA for such an objective.
