Tofu processing: selected parameters from the seeds to the final products and by-products

The efficiency of soy food production, particularly tofu, depends on a complex of physicochemical properties of soybean seeds (Glycine max). This study analyzes 187 soybean samples to evaluate the primary determinants of tofu yield/production. The main objective was to analyze the relationships among selected physicochemical properties of soybeans and tofu production. The methods applied were Near-Infrared Spectroscopy (NIR), physical parameters (hydration coefficient, thousand seed weight [TSW]), and correlation and regression analyses to identify relationships among hydration potential, seed properties, dry matter content, and the amino acid profile. Our results show that the hydration potential is strongly positively associated with seed dry matter content, indicating that dry matter is a critical predictor of water absorption efficiency. Raw tofu yield demonstrated a clear positive correlation with the physical properties of the seeds, including TSW and the hydration coefficient. An original contribution of this work is the identification of a negative amino-acid signature associated with reduced tofu yield. Aspartic acid, histidine, alanine, and glycine showed significant negative correlations with tofu raw yield, whereas proline content showed a slight positive association.