Utilizing Immature Macadamia Nuts in Prevention of Thermal Decomposition of Polyunsaturated Fatty Acids (PUFA): Case Study with Docosahexaenoic Acid (DHA)

摘要

Macadamia nuts in Kenya take about 270 days after flowering to attain full maturity. One of the major problems still facing the nut industry is the consistent presence of immature kernels during processing. This problem is due to the fact that most ofnut are supplied by many small-scale producers through middlemen and this makes it difficult to eliminate nuts which have not reached full maturity.The occurrence of phenolic compounds in mature macadamia nuts were first reported by Quinn and Tang (1996), who identified a few of them isolated from the nut oil and shells. The crude oil was found to be very stable as measured by rancimat induction time. Poly-phenol-rich foods are gaining popularity even to the food processor. For the last few decades, many people have become exceedingly afraid of chemical additives synthesized in the industries preferring natural plant additives (Porkorny, 2000). Inthis background, the present study focused on possible utilization of the oil's antioxidant potential in stabilizing docosahexaenoic acid (DHA) against thermal decomposition. DHA is a polyunsaturated fatty acid (PUFA) widely found in fish oil and important in the human health (Mischoulon and Fava, 2000, Edwards et al, 1998). It is, however, one of the most unstable fatty acids and thus highly susceptible to autoxidation. Sanchez-Moreno et al., (2000) found that wine phenolicshave potential as natural plant antioxidants against lipid oxidation. Therefore, the aims of our study were firstly, to investigate how the age of the kernel affects the poly-phenolic content of the nut and secondly, to utilize this natural plant phenolics on lipid-rich food stabilization using DHA as a model for the study.babanaom-10@t.okadai.jp