Comparison of methods to produce high-quality dried triploid Fujian oyster: Hot air drying emerges as a superior technique

Abstract

Dried oysters are widely valued in Asian cuisine for their unique flavor profiles and nutritional benefits. However, as a newly developed variety characterized by rapid growth, the effects of different drying methods on triploid Fujian oysters remain unexplored. In this study, we investigated the effects of different drying methods on the flavor profile of triploid Fujian oyster. Oysters processed by hot air drying (HAD), natural drying (ND), vacuum drying (VD), and vacuum freeze-drying (VFD) were compared with blanched controls (BC). Drying significantly increased the types and concentrations of non-volatile metabolites and flavor substances, with HAD yielding optimal results. The HAD-treated oysters contained the highest contents of key nutritional compounds (N-acetyl-L-aspartic acid: 2.2-fold the mean value across all drying treatments), antioxidants (2-pyrrolidone: 1.5-fold), and flavor substances (pyrazines: 2.0-fold; 2-furanmethanol: 2.8-fold, ethyl acetate: 1.3-fold). Thus, HAD-treated oysters had a rich and balanced aroma profile with excellent umami, sweet, and fruity flavors. The compounds contributing to flavor enhancement (odor activity value > 1) were (E)-2-nonenal, (E)-2-octenal, heptanal, 2-methylbutyraldehyde, and 2-undecanone. Correlation analysis revealed complex relationships between non-volatile compounds and flavor substances. This study provides guidance for optimizing drying techniques and standardizing dried oyster production.