Alpha-linolenic acid content of commonly available nuts in Hangzhou.

The total lipid content of eight species of nuts available in Hangzhou ranged from 49.5 g/100 g weight in Cannabis sativa to 75.4 g/100 g in walnut. The predominant content of lipid is triacylglycerol, ranging from 91.1% in Cannabis sativa to 98.4% in macadamia. There were two polyunsaturated fatty acids (PUFA) in all nuts analyzed; 18:2n-6 and 18:3n-3. The content of 18:3n-3 ranging from 0.2% in almond to 15.2% in Cannabis sativa, 18:2n-6 ranged from 2.5% in macadamia to 61.6% in pine nut. The proportion of total PUFA in analyzed eight nut species ranging from 2.8% in macadamia to 71.7% in walnut (p < 0.001). Monounsaturated fatty acid composition ranged from 18.0% in Cannabis sativa to 82.6% in macadamia (p < 0.001). The proportion of saturated fatty acid ranged from 7.4% in filbert to 14.7% of total fatty acids in macadamia (p < 0.001). No C20 fatty acids were detected in any of the samples in the present study. The lipids content and fatty acid compositions in analyzed samples were varied between nut species. Cannabis sativa and walnut contained relatively high 18:3n-3, consumption of several these nuts each day can contribute to n-3 PUFA intake, especially for the vegetarian population.