Effects of Ethephon and Gibberellic Acid Treatments on Post-Harvest Flavor Quality of Green Lemon

This study investigated the effects of Ethephon (CEPA) and Gibberellic acid (GA3) treatments on the post-harvest flavor quality of ‘Yunning No. 1’ green lemon. A comprehensive analysis was conducted on the changes in primary metabolites (sugars, organic acids, amino acids, alcohols) in the pulp and peel, as well as those in major volatile compounds in the peel during fruit storage. The results showed that CEPA treatment initially increased volatile compounds like monoterpenes and sesquiterpenes in the fruit peel during early storage, but later decreased these compounds along with total sugar and amino acid content in the pulp. Conversely, GA3 treatment markedly delayed the decline in sugars and organic acids in the fruit peel, preserved the amino acid content in the pulp and the alcohol content in the peel, and delayed the decrease in volatile compound content in the peel. In conclusion, GA3 treatment effectively delayed the decline in primary metabolites and volatile compounds to maintain the storage quality of green lemon; therefore, GA3 represents a suitable strategy for the preservation of green lemons. CEPA temporarily improved aroma but accelerated quality deterioration, making it better suited for short-term degreening. This study offers a theoretical foundation for optimizing post-harvest degreening and preservation techniques of green lemons.