Quality changes occurring in stored solin, high linolenic acid and standard flaxseed (Linum usitatissimum L.)

Abstract

Changes occurring in stored solin/flax cultivars over 6 mo at temperatures ranging from 10 to 35°C and moisture contents of 8.0, 9.5, 11.0 and 12.5% were observed. The cultivars were NorLin, McGregor, FP1001 (high linolenic acid), Linola(TM) 947 (solin) and Linola(TM) 989 (solin). Oil composition in all cultivars changed only slightly over 6 mo with a significant increase in palmitic acid. Doubling of free fatty acid levels was considered an indicator of quality deterioration. The deterioration occurred in 6 mo at 8% MC and 20°C in FP1001 and in NorLin, McGregor, and Linola(TM) 947 at 25°C; Linola(TM) 989 could be stored at 30°C. Linola(TM) 989 could be safely stored at moderately higher temperatures at a given moisture level than Linola(TM) 947. Visible mold with corresponding germination loss was usually associated with Aspergillus glaucus group infection. Stored-product insects that could survive and develop on the solin/flax were the red flour beetle, Tribolium castaneum (Herbst), the confused flour beetle, T. confusum J. du Val, the sawtoothed grain beetle, Oryzaephilus surinamensis (L.) and the merchant grain beetle, O. mercator (Fauvel). In general, Linola(TM) 947 and FP1001 were slightly more difficult to store than the other cultivars but there was no consistent difference between solin and flaxseed.