Transformation of Isoflavones During Sufu (A Traditional Chinese Fermented Soybean Curd) Production by Fermentation WithMucor flavusat Low Temperature

Abstract

This study evaluated the changes in contents and composition of soybean isoflavone as well as the β-glucosidase production during sufu preparation by Mucor flavus (M. flavus) at low temperature. The results showed that sufu processing not only led to the losses of isoflavones but also caused the redistribution of isoflavone isomers. The levels of aglycones increased during sufu fermentation, while the corresponding levels of glucosides decreased. β-Glucosidase accumulation by M. flavus mainly contributed to the transformation of isoflavone glucosides into aglycones, which was affected by the NaCl supplementation. The highest content of aglycone isoflavones occurring was recorded as 99.4% at 15%NaCl content under investigated conditions. This work suggested that M. flavus had possible application as an alternative starter to produce sufu with the enhancement of the physiological function at lower temperature.

Evaluation of bacterial and fungal communities during the fermentation of Baixi sufu, a traditional spicy fermented bean curd

“…Mold‐fermented sufu is the most common type in various regions in China, and it is generally believed that mucor plays a decisive role in the fermentation of sufu . Baixi sufu seems to belong to this type because few instances of Mucor flavus were identified, and the mucor has been reported in sufu previously . However, Geotrichum candidum was isolated and identified, and far exceeded mucor in the early stage of fermentation.…”

Comprehensive explorations of nutritional, functional and potential tasty components of various types of Sufu, a Chinese fermented soybean appetizer

“…As one of the functional components in Sufu, isoflavones are referred to as phytoestrogens due to their estrogenic activities in soybean and soybean foods, and the corresponding glucosides are converted into the corresponding aglycones through hydrolysis by β-glucosidase during fermentation. The distribution of isoflavone aglycones increased from 13.17% to 39.88% after 16 days of ripening, while the corresponding levels of glucosides decreased (Cheng et al, 2011). On addition, some other functional components, such as GABA, phytosterol and soyasaponin, are also enhanced during fermentation.…”

Ants (Hymenoptera: Formicidae) as Carriers of Fungi in Hospital Environments: An Emphasis on the Genera <I>Tapinoma</I> and <I>Pheidole</I>

“…This difference is because of heat neutralization of infection (Houle et al 1987). In the case of the Mucor genus, several assessments indicate operational growth from 5-38 °C depending on biogeography and tolerances, but trends within the genus display enhanced metabolic function at the lower temperature range of its growth tolerance, i.e., from 5-24 °C (Carvalho et al 1999;Cheng et al 2011;Laoteng et al 1999;Stewart et al 1999;Yazdi et al 2006). This lends support to the observation that in the winter season with the mean winter temperature recorded at 9.7 °C, infection accelerated, and the laboratory containment conditions at 24 °C were not hot enough to deter continued infection.…”

“…However, there is disagreement as to the true tendencies of Mucor spp. They are generally classified as saprophytic (Samisinakova et al 1974;Verma & Krishnan 1985;Pai et al 2004;Pantoja et al 2009;Yoder et al 2009;Cheng et al 2011) but seem to have facultative potential comparable to recognized pathogens (Heitor 1962;Nentwig 1985;Sugar 1992;Sychev 1993;Camalt 2004).…”