Nutritional Studies on Dried Functional Food Ingredients Containing omega-3 Polyunsaturated Fatty-Acids.

摘要

The nutritional benefits of fish oils are generally attributed to their content of longchain omega-3 polyunsaturated fatty acids (PUFAs). Diets rich in these fatty acidsare known to reduce the risk of coronary thrombosis, and are recommended tothose who are susceptible to atherosclerosis. In addition, some of these long chainPUFAs play an important role in early infant nutrition, in the development of vitalhuman organs such as the neural tube.However, practical difficulties arise in achieving an adequate daily intake of fishoils to obtain these physiological benefits. Per capita fish consumption is low inmany countries, especially of oily fish with high levels of omega-3 PUFAs. Fish oil,while available as a dietary supplement, is not universally appealing in that form.Attempts to incorporate fish oil into food formulations have had limited successmainly because of fishy flavours coming through in the consumer products. Fishoil is particularly susceptible to oxidation, which results in fishy, painty and metallicflavours.Hence the main aim of this study was the development of a dried ingredient inwhich the formulation and related processing conditions were optimised to protectthe fish oil from oxidation. Protection of any sensitive oil may be achieved bymeans of microencapsulation, whereby oil is dispersed as very fine droplets inemulsions. During subsequent spray drying the droplets are effectively sealedinside a protective coating of protein surrounded by carbohydrate.The objective was, therefore, to evaluate microencapsulation as a means ofextending the shelf-life of fish oil in powder form thus increasing its versatility as anutritional ingredient in food formulations.