Textural dynamic crisping mechanism of crisp grass carp: Oxidative stress, apoptosis, collagen filling, and cross‐linking

Abstract

Feeding faba beans to freshwater fish could crisp its muscle texture to avoid softening. However, the dynamic crisping mechanism was unclear. Herein, a 120‐day feeding trial was conducted to systemically investigate the textural crisping mechanism of crisp grass carp (CGC) via molecular‐level, gene/protein expression analysis. In the early crisping stage (0–30 days), the total antioxidant capacity significantly decreased (by 16.79%), TUNEL staining and qRT‐PCR results revealed that apoptosis occurred, which was induced by oxidative stress validating by proteomics. Meanwhile, the content of dityrosine and hydroxylysyl pyridinoline rose, thereby substantially increasing the hardness and chewiness of CGC by 37.51% and 40.84%, respectively. With further crisping (30–90 days), Masson staining exhibited collagen gradually filling the gap between myofibrils, the content and cross‐linking degree of collagen further increased, finally elevating the hardness and chewiness of CGC. This study laid a theoretical foundation for producing and supplying aquatic raw materials with different texture characteristics.