ABSTRACT Whole soybean tofu, free of okara byproduct, has gained popularity for higher utilization rate of raw material and lower production cost compared to traditional tofu. In this study, whole soybean pressed tofu samples induced by four co‐coagulants were prepared by ultrafine grind treatment combined with high‐pressure homogenization to the soymilk. The synergetic usage of CaSO 4 and MgCl 2 significantly enhanced the gel strength with 2.01 and 0.66 N, respectively, compared to individual coagulant. This could be attributed to the different mechanisms of CaSO 4 and MgCl 2 in the gelation process. Furthermore, tofu samples with continuous amounts increase/decrease of CaSO 4 /MgCl 2 formed different physicochemical and textural characteristics. Relaxation times measured by nuclear magnetic resonance indicated water moisture gradually decreased with the reduce of T22 component to the minimum of 81.81%. Moreover, chemical interactions analysis showed the proportion of disulfide bonds increased with the amounts of both coagulants, to a maximum of 40.60% with 4.5‰ CaSO 4 /0.5‰ MgCl 2 added, and then decreased. Correlation analysis confirmed proportion of disulfide bonds showed a positive correlation with gel strength, textural characteristics and β‐sheet proportion in the protein secondary structure, furtherly testifying the transformation from α‐helix to β‐sheet led to the changes of chemical interactions and thus affecting tofu properties.
Zhang et al. (2026) studied this question.