Seed Odour as Oracle: Advanced Analysis of Soybean Seed Volatile Organic Compounds and Statistical Insights

Soybeans are an important component of agriculture used both for food and industrial purposes. During aging, soybean seeds undergo various biochemical changes, including lipid peroxidation, Maillard reactions, and glycolysis, leading to the production of secondary metabolites as volatile organic compounds (VOCs). Variations in seed quality are sometimes too subtle to detect using traditional evaluation techniques. Hence, this study aims to explore how the analysis of VOCs could be used to better understand the deterioration of soybean seeds. Genetically pure soybean seeds were collected and kept in an ambient environment for eight months. Gas chromatography and mass spectroscopy (GC–MS/MS) were employed to analyze the volatiles emitted from stored soybean seeds. Correlation, Principle Component analysis (PCA) and Factor analysis were performed to identify the key compound contributing to the deterioration of soybean seed quality. Analysis of VOCs emitted from soybean seeds revealed the presence of 68 compounds, including 10 alcohols, 19 aldehydes, 15 acids, 6 esters, 4 alkanes, 4 alkenes, 8 ketones, and 2 amides. PCA and factor loading revealed a close association between the release of ethanol, hexanal, acetaldehyde, and hexanoic acid and the deterioration of soybean seeds. Ethanol (47.5 ng/100 g) and hexanoic acid (73.4 ng/100 g), released after four months of storage, coincide with the onset of seed quality decline below minimum standards, indicating their potential as biomarkers for soybean seed deterioration.