Fatty Acid Composition in Oil of Recent Rapeseed Hybrids and 00 Cultivars
Milan POSPIŠIL, Dubravka ŠKEVIN, Zvonko MUSTAPIĆ, Sandra NEĐERAL NAKIĆ, Jasminka BUTORAC, Dunja MATIJEVIĆ
Pages: 187-193
Summary
Fatty acid composition in oil of seven new hybrids (‘Artus’, ‘Baldur’, ‘Exact’, ‘Executive’, ‘Extra’, ‘RG 9908’, ‘RG 9909’) and eight 00-cultivars (‘Aviso’, ‘Bristol’, ‘Canary’, ‘Dexter’, ‘Ella’, ‘Kosto’, ‘Navajo’, ‘Royal’) of rapeseed was investigated in the period 2003-2005. The experiments were placed in the experimental field of the Faculty of Agriculture in Zagreb. Fatty acid composition was determined by gas chromatography of their methyl esters, and the oil iodine number was calculated as well. The studied new rapeseed hybrids and 00 cultivars contained no erucic acid or it was present far below 2%. The average content of oleic acid was 61.88±2.64% in hybrids and 62.54±3.90% in 00-cultivars, the content of linoleic acid was 20.52±1.49% and 19.57±2.51%, the content of linolenic acid was 8.39±1.50% and 7.92±2.12%, the content of palmitic acid was 5.13±0.48% and 5.50±0.51%, and the content of stearic acid was 1.48±0.16% and 1.58±0.19%, respectively. Th is ratio of fatty acids confirms the high nutritive quality of rapeseed oil. The iodine value was 112±2 in oil from hybrids and 110±4 in oil from 00-cultivars. In both investigated groups there were no differences in fatty acid composition which could influence the quality and stability of rapeseed oil. The average values in oils obtained from hybrids as well as from 00-cultivars are inside the data prescribed in law regulations. Although, there were several samples in which oleic and palmitic acid contents were above and linoleic and linolenic acid contents (as well as the iodine values) below the limit values, what ought to be incorporated into the revision of present regulations on vegetable oils. Fatty acid composition in hybrids and in 00-cultivars was greatly influenced by weather conditions. In the year with higher mean monthly air temperatures and less precipitation during May and June compared to average long-term weather conditions for these months, oil contained more oleic and less linoleic and linolenic acid.
Keywords
rapeseed; hybrids; 00-cultivars; fatty acid composition
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