Comparisons of proximate compositions, fatty acids profile and micronutrients between fiber and oil flaxseeds (Linum usitatissimum L.)

Hydrophobic orbitides or cyclolinopeptides (CLs) are specialty micronutrients and of great abundance in flax (Linum usitatissimum L.) seed oils, and show many potential health benefits. The aim of this study was to evaluate the differences in proximate compositions, fatty acids profile and micronutrients including orbitides as well as tocopherol in flaxseeds or their oils from 13 Chinese cultivated oil and fiber flax samples. A total of 14 types of orbitides in 13 oils were identified and quantified by HPLC-ESI-QTOF-MS/MS, concentrations of which varied from 273 ± 3 to 434 ± 7 μg/g of oil. The contents of proximate compositions, orbitides, γ-tocopherol and fatty acid profiles among 13 cultivars were significantly discriminatory. Only oil flax Dingya23 showed significantly higher oil content, with ALA level 55% greater than fiber flax, and the mean proportions of ALA and γ-tocopherol in oils from oil flax were similar to those in oils from fiber flax. In addition, the fiber flax showed higher mean levels of crude protein and total orbitides than oil flax. These results indicated that except for Dingya23, oil flax did not present clear germplasm superiority of components over fiber flax.