Enhancement of α‐tocopherol by ensiling in barley (Hordeum vulgare) and wheat (Triticum aestivum)

Abstract

Experiments were conducted to document the enhancement of tocopherol (Toc), the main source of vitamin E in barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) plants, by ensiling. The Toc content of four genotypes of barley and wheat was significantly enhanced by ensiling in plastic bags, and enhancement rates were 109–337% in barley and 331–503% in wheat. The overall enhancement was driven by the α‐form isomer. A significant interaction of ensiling treatment by genotype was not found in the Toc content in either species, indicating that the enhancement of Toc by ensiling was consistent irrespective of genotypes in both crops. Significant Toc enhancement by ensiling was exclusively found in leaves. The enhancement of Toc was also confirmed in round bale silages in both crops, which is prevalent as preservation methods of forages in many countries worldwide. Tocopherol enhancement was speculated to be likely because of the free phytol derived from chlorophyll breakdown, which was released from chlorophyll in leaves during ensiling to be used in the biosynthesis of Toc.