Multi‐Level Quality Differentiation of Fried Grass Carp Fillets: Integrating Exploratory PCA , Supervised PLS ‐ DA Classification, and Correlation Heatmap Analysis to Elucidate Frying Method Effects

This study systematically evaluated the effects of traditional frying (TF, 0–9 min), air frying (AF, 0–17 min), and microwave frying (MF, 0–12 min) on the quality attributes of salt‐sugar marinated grass carp fillets. The results revealed distinct quality profiles driven by the different heating mechanisms. TF produced samples with desirable color (high a * and b * values) and texture (increased hardness and chewiness) but was associated with the highest oil content and significant microstructural disruption. In contrast, AF achieved a comparable color and superior chewiness while maintaining the lowest oil content and a well‐preserved microstructure, underscoring its potential as a healthier alternative technology. MF samples were characterized by a lighter color, myofibrillar densification, heterogeneous water distribution, and localized oil accumulation. Multivariate statistical analysis clearly differentiated the three frying methods and identified seven key discriminating indicators. It is concluded that AF offers a balanced approach to producing fried seafood with desirable texture qualities and reduced oil content, providing a theoretical basis for the development of healthier fried aquatic products.