Abstract
Changes in lipid components, fatty acid composition and total tocopherol content during miso making were studied. Lipid components were determined by thin-layer chromatography and their fatty acid compositions by gas chromatography. Total tocopherol contents were determined by bathophenanthroline-FeCl3-orthophosphoric acid procedure after saponification. The results obtained were as follows:
(1) Chemical characteristics of extractable lipids remarkably changed during miso aging process as long as for 70 days after mashing, but remained with little change thereafter except with peroxide value.
(2) Total tocopherol contents were decreased in cooking process of soybean seeds, but not decreased during miso aging.
(3) Triglycerides continued to get hydrolyzed for 50 days, while free fatty acids constantly increased during miso aging.
(4) During miso aging, the C18: 2 decreased in the triglyceride fractions but relatively increased in the diglyceride and monoglyceride fractions, notably after 50 days.
(5) The extractable lipids of 70 and 150 days samples, which apparently showed, browning, were fractionated into three components (F-1, F-2 and F-3) by means of silicic acid column chromatography. F-2 and F-3 components showed antioxidative action with A.O.M test at 63°C.
