NUTRIENT COMPOSITION AND ANTI-NUTRITIONAL FACTORS IN VEGETABLE SOYBEAN .2. OIL, FATTY-ACIDS, STEROLS, AND LIPOXYGENASE ACTIVITY

Seventeen vegetable soybean genotypes were analyzed for oil, fatty acids, sterols and lipoxygenase activity. The mean oil content was 18.44% and ranging from 15.65% for Wilson-5 to 23.36% for Sango. The lipoxygenase activity ranged from 829.8 units/min/mg meal for PI 417310 to 4750.4 units/min/mg meal for PI 423759, with a mean of 2176.3 units/min/mg meal. Beta-sitosterol (45.95%) was the major plant sterol present, followed by stigmasterol (16.48%), campesterol (16.06%) and dihydroxybrassicasterol (5.62%). Palmitic, oleic and linoleic acids comprised over 90% of the total fatty acids. The means of linoleic (53.34%) and linolenic acids (9.19%) were higher than that reported for the grain-type soybean. The concentrations of oleic were inversely related to the concentrations of linoleic (r = -0.820) and linolenic (r = -0.663) acids. The oils of cultivars sango and sooty, and PIs 423759, 417310, 222397 and 171437 possess superior nutritional quality. In general. the high oil, linoleic, linolenic and sterol content of vegetable-type soybeans make them a food with high nutritional quality.