67C-22 |
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M. VENKATACHALAM, E. K. Monaghan, H. H. Kshirsagar, and S. K. Sathe. Dept. of Nutrition, Food & Exercise Sciences, Florida State Univ., 402 Sandels Bldg., Mail Code 1493, Tallahassee, FL 32306-1493 Tree nuts are globally popular and are valued for their sensory, nutritional and health attributes. Most tree nut composition data available have been compiled from analysis done by various laboratories over a period of time. As a part of our ongoing investigations on commercially important tree nuts (almond, Brazil nut, cashew nut, hazel nut, macadamia nut, pecan, pine nut, pistachio and walnut), the current study was specifically designed to analyze moisture, total fat and fatty acids, protein, ash, total and reducing sugars, proteolytic activity, total tannins, phytates, hemagglutinin and trypsin inhibitory activity. Full fat tree nut flours were analyzed for moisture, protein, total fat, saturated and unsaturated fat, and ash by AOAC (1995) methods 925.40, 950.48, 948.22, 996.06 and 923.03 respectively. Proteolytic activity was determined by caseinolytic activity at 37°C. Total tannins were extracted in absolute methanol and acidified methanol (1% v/v HCl) and analyzed by vanillin assay (catechin equivalent). Sugars were analyzed by phenol-sulfuric acid method. Hemagglutinating activity was tested as per Sigma protocol for lectin from Glycine max (Soybean, Product No. L1395). Trypsin inhibitor activity was determined according to the AACC method (1983) approved for soy products. Phytates in defatted flours was analyzed by method of Wheeler and Ferrel (1971). On an as is basis, edible nuts had moisture, fat, protein, ash, reducing sugars, total sugars, total tannins and phytates 2-7%, 43-67%, 9-24%, 1-4%, 0.06-0.8%, 0.5-3.6%, 0.01-0.88%, and 0.1-0.5%, respectively. Saturated, monounsaturated and polyunsaturated fatty acids respectively accounted for 7-25%, 27-83% and 4-72% of the total fat. Neither proteolytic activity nor significant hemagglutinating and trypsin inhibitory activities were detected in the tree nuts tested. The chemical composition data may be valuable to tree nut growers, food processors and consumers.
Session 67C, Food Chemistry: Food analysis, irradiation and toxicology
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