Study on the Quality Characteristics of Preprocessed, Cooked and Frozen-Reheated Tofu Balls

To elucidate the characteristics and evolution of eating quality in tofu balls during preprocessing, cooking, and frozen reheating, volatile compounds and textural properties were systematically analyzed at each stage. Molecular sensory science, texture analysis, and low-field nuclear magnetic resonance were applied. In total, 43 volatile compounds were identified, comprising 14 alcohols, 9 aldehydes, 5 ketones, and 9 esters, as well as 1 acid, 1 furan, and 1 pyrazine. Preprocessed tofu balls were mainly characterized by a beany flavor, primarily attributed to 1-octen-3-ol, 3-heptanol, hexanol, heptanal, hexanal, and 2-pentylfuran. After cooking and frozen reheating, the aroma profile shifted toward beany, sweet-fruity, and cereal-like notes, largely influenced by (E)-2-octenal, ethyl butyrate, and 3-methylbutanol. Following frozen reheating, hardness, gumminess, and chewiness increased significantly. The proportion of bound water increased markedly, and water-holding capacity reached a maximum. In addition, cooked and reheated samples exhibited a desirable brownish-yellow color. This study provides a theoretical basis for developing preprocessed plant-based products that retain traditional tofu flavor while meeting contemporary nutritional requirements. It also offers practical guidance for improving processing technology and the market competitiveness of plant-based meat alternatives.