Determination of Volatile Compounds in Grass and Maize Silages using SPME and GC-MS

Abstract

Volatile compounds from grass and maize silages were detected using solid-phase microextraction (SPME), headspace SPME, and GC-MS. Two grass silages were tested untreated, preserved with formic acid and inoculated with Lactobacillus plantarum, or with wilted grass up to 400 g kg^-1. Two maize silages were tested untreated, inoculated with L. plantarum or L. buchneri or with a mixture of lactic acid bacteria Microsil. The silages were fermented and stored for 4 months. Volatiles were isolated by headspace SPME. Using this method, 21 volatile compounds, fatty acid esters, terpenes and phenolics were detected. The contents of 4-ethylphenol and 2-methoxy-4-vinylphenol were determined.