Selenium-Chitosan Treatment Affects Amino Acid Content and Volatile Components of Red Globe Grape during Storage

Abstract

Flavor is an essential attribute of grapes, but it quickly deteriorates and loses its quality. This study examined the effects of the selenium-chitosan treatment on the amino acid content and volatile components of freshly harvested grapes stored at 0°C. The amount and composition of precursors such as fatty acids and amino acids have an important influence on the formation of aroma compounds. In this article, the amino acids, volatile components, and some enzyme activities of different treated grapes were analyzed. The results of the analysis of free amino acid composition indicated that the selenium-chitosan treatment significantly reduced the loss of amino acid content by inhibiting the activities of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), and pyruvate dehydrogenase (PDH). The analysis also revealed that the significant differences in alcohol and aldehyde compounds primarily accounted for the variation in volatile components between treatments. The selenium-chitosan treatment slowed the decline in the content of aldehyde compounds and inhibited the increase in the range of alcohol compounds. These findings demonstrated that treatment with 25 mg L-1 selenium mixed with 1.0% chitosan solution has a positive effect on maintaining the flavor of Red Globe grapes. This treatment is worthy of future promotion.