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Concentrations of Functional Lipids in Abraded Fractions of Hulless Barley and Effect of Storage
Author(s) -
Liu K.S.,
Moreau R.A.
Publication year - 2008
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2008.00890.x
Subject(s) - endosperm , fractionation , chemistry , germ , food science , chromatography , composition (language) , fraction (chemistry) , sterol , botany , biochemistry , biology , cholesterol , linguistics , philosophy , microbiology and biotechnology
Hulless barley kernels were sequentially abraded to achieve 4%, 8%, 16%, 24%, 32%, and 40% removal. Abraded fines, kernels, and ground kernels were stored at 35 °C and 75% relative humidity for 3 wk. Stored samples were extracted and the levels of oil, free phytosterols, tocopherols (Ts), and tocotrienols (T3s) were analyzed and compared with freshly abraded fractions. The results revealed that oil, sterols, and Ts were concentrated in the outer layers, particularly in the germ layer. In whole kernels, homologues of both Ts and T3s showed the same ranking order in concentrations as α > γ > β > δ. The homologue composition of Ts remained the same but that of T3s changed across the kernel. The %T3 in total tocols increased in fractions with increasing endosperm tissue. Storage caused no change in oil and Ts but significant changes in sterols and T3s. The changes were differential among T3 isomers, with α‐T3 decreasing and δ‐T3 increasing. The degradation of α‐T3 was accelerated in fractions with more endosperm tissue. Grinding kernel samples before storage accelerated sterol degradation but had a limited effect on changes of T3s. A 2nd experiment using a different hulless barley line and ambient storage for 6 mo confirmed all the findings except that the changing trend for sterols was inconsistent. These results provide practical information to those who wish to produce a barley fraction enriched with a particular functional lipid and maintain stability of their products.