Abstract

Canola (Brassica napus L.) seeds were germinated at different temperatures (10 ± 3, 20 ± 3, and 30 ± 3C) for 8 days in controlled conditions. Oil degradation was higher at the moderate temperature (20 ± 3C), while the low temperature (10 ± 3C) resulted in a significant increase in total fatty acid contents (TFA). Wide variations were determined among the major fatty acid proportions during germination of canola seeds at different temperatures. There was a significant decrease in monounsaturated fatty acid (oleic, C18: 1) at the significant expense of polyunsaturated fatty acids (linoleic, C18: 2 and linolenic, C18: 3) with the progressive germination days, especially at low temperature relative to ungerminated seeds. Low temperature induced a significant increase in double bond index (DBI) in comparison to the moderate and higher temperature. The proportion of the essential fatty acids (linoleic, C18: 2 and linolenic, C18: 3) was increased by 2.2 fold at the lower temperature relative to ungerminated seeds. It is concluded that low temperature enhances synthesis of polyunsaturated fatty acids in canola during germination.

Key words: Brassica napus L., temperature, monounsaturated, polyunsaturated, total fatty acids, double bond index (DBI).