Cereal Chem 57:178 - 184. | VIEW
Evaluation of the Nutrient Composition of Wheat. I. Lipid Constituents.
K. R. Davis, N. Litteneker, D. Le Tourneau, R. F. Cain, L. J. Peters, and J. McGinnis. Copyright 1980 by the American Association of Cereal Chemists, Inc.
Nutrient composition was evaluated in wheats from five market classes: hard red winter (HRW), soft red winter (SRW), hard red spring (HRS), durum, and white in subclasses hard white winter (HWW), soft white winter (SWW), hard white spring (HWS), and soft white spring (SWS). Wheats comprised 290 samples, 124 varieties, three crop years, and 40 growing locations. This article presents a summary of the analyses for total fat, tocopherols, and fatty acid profiles. Total fat varied significantly by class and by crop year; some data indicated that they also varied by growing location. The range of total fat was from 0.88% for Wanser (HRW/Pendleton, OR/1973) to 3.33% for 6922A1-160 (SRW/Lafayette, IN/1975) with an overall mean of 2.34+/-0.02% (all on a dry weight basis). Alpha-tocopherol content, in contrast, showed only small but significant differences by growing year. Total (alpha + beta + gamma + delta)-tocopherol content ranged from lows of 0.49 mg/100g for Avon (SWW/Ithaca, NY/1975) to 4.01 mg/100g for Coulee (HWW/Walla Walla, WA/1974). (Beta + gamma)-tocopherol content varied significantly by growing year and by class or subclass. Gamma-tocopherol content varied significantly by crop year and class or subclass, and some data indicated that it also varied by growing locations. Fatty acid methyl esters (FAME) were analyzed by gas liquid chromatography and the results were expressed as the percent of the total FAME represented by each. Of the fatty acids evaluated, only oleate varied significantly by market class, and only oleate did not vary significantly by crop year. Linoleate, palmitate, and oleate comprised approximately 96% of the fatty acids. Palmitate comprised 11% of the fatty acids for Centurk (HRW/Altus, OK/1974) and ranged to 32% for Luke (SWW/Walla Walla, WA/1974) and Hyslop (SWW/Pendleton, OR/1974). Stearate ranged from none for many wheats to 4.6% of total FAME for Brookings (HRS/Brookings, SD/1975). Oleate ranged from 11% for Nugaines (SWW/Walla Walla, WA/1974) to 29% for Botno (durum/Brookings, SD/1975). Linolenate ranged from 0.71% for Winalta (HRW/Pondera, MT/1974) to 4.84% for Coulee (HWW/Pendleton, OR/1973). The most striking variability was in linoleate, which had a range from 45% for Botno (durum/Brookings, SD/1975) to 74% for Scout-66 (HRW/Altus, OK/1974). Data from Centurk grown in 11 locations demonstrated the problems in establishing standards to enforce Title 21 of the Code of Federal Regulations 121.3, which prohibits "Generally Recognized as Safe" status for new varieties that do not provide 80% or more of any nutrient for which that plant is considered to be a significant source.