Physicochemical Properties of Sufu Produced by Single and Mixed Fermentation with Mucor racemosus and Rhizopus oryzae

Abstract

Sufu is usually prepared by single-fungus fermentation with Mucor racemosus or Rhizopus oryzae. The quality of sufu fermented by different strains tends to differ. In this study, mixed fermentation (using M. racemosus and R. oryzae) and single-fungus fermentation (using only M. racemosus) were carried out, and the changes in physicochemical properties were assessed and compared. We found that the main enzyme activity of sufu in mixed fermentation was higher than that of M. racemosus fermentation, and the biochemical and texture properties of the sufu produced differed significantly between both fermentation processes. Thus, we demonstrated that mixed fermentation has several advantages over M. racemosus fermentation in terms of biochemical profile and texture of sufu. Our results provide insights for improving the efficiency of the industrial production of sufu, as well as sufu quality.

Microbial-derived salt-tolerant proteases and their applications in high-salt traditional soybean fermented foods: a review

“…Mucor can secrete abundant STPs and other beneficial enzymes, while Rhizopus can produce small amounts of ethanol and organic acids, and its growth temperature is lower than that of Mucor . Therefore, Rhizopus is used in the fermentation process of sufu, which breaks the seasonal limitation of sufu production and reduces the amount of ethanol in sufu fermentation (Wang et al 2020 ). The introduction of a mixed starter consisting of yeast and lactic acid bacteria has been shown to be beneficial in enhancing sufu fermentation (Xie et al 2018 ).…”

Evaluation of Sufu Fermented Using Mucor racemosus M2: Biochemical, Textural, Structural and Microbiological Properties

“…Among these, the fermentation strain has an important role in the quality of sufu. Mucor are widely used in the production of sufu, accounting for >90% of all Chinese sufu, due to its well-developed mycelium [ 3 , 8 ]. The Mucor can form a uniform layer of mycelium film on the surface of the tofu, wrapping the tofu pieces, thus giving the sufu a unique texture while keeping the intact shape of the tofu.…”

“…In addition, Mucor secretes multiple enzymes with high activity. The secreted proteases and peptidases can degrade the protein to produce peptones, polypeptides and amino acids which enhance the nutrition of sufu and contribute to its flavor [ 8 ]. Mucor proteases have strong peptidase activity and can hydrolyze bitter peptides into free amino acids, thereby removing or reducing the bitterness of fermented bean curd [ 9 ].…”