各種水分活性下における乾のり脂質の変化〔乾のりの品質保持に関する研究-3-〕

概要

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Dried laver “Nori” obtained from a Hyogo Prefectural product, Porphyra yezoensis, contains 2.5% of lipids; these consisted of polar lipods (PL), free fatty acids (FFA), and triglycerides (TG) as the main components. The fatty acid composition is characterized by the content of eicosapentaenoic acid (EPA), which amounts to as much as half, and of palmitic acid (PA), which may reach a quarter. Changes of lipid oxidation in dried laver were investigated as a function of water activity (in the range of 0 to 0.6) during six months storage at 19±1°C. As the criteria of lipid oxidation, the ralative values of FFA/PL, TG/PL, and EPA/PA of each month to the irinitial values were tested. In every case, aw 0.1 to 0.3 around the monolayer or safe storage moisture of dried laver protected the lipids from oxidation. On the contary, either an absolutely dry condition or intermediate water activities accelerated oxidation. Moreover, use of free-oxygen absorber inhibited the lipid oxidation of dried laver in the gas-barrier bag.
日本水産學會の論文