Enhancing the functional properties of soymilk residues (okara) by solid-state fermentation with Actinomucor elegans

• Main Authors: Ying Guan, Jinpeng Wang, Junjun Wu, Lixia Wang, Xin Rui, Guangliang Xing, Mingsheng Dong
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2017-01-01
• Series: CyTA - Journal of Food
• Subjects: Soymilk residues (okara); solid-state fermentation; antioxidant activities; ACE-inhibitory activity; Actinomucor elegans
• Online Access: http://dx.doi.org/10.1080/19476337.2016.1226955

In this study, the food-grade fungal strain DCY-1 was isolated from Chinese traditional fermented soymilk residues (okara) and identified as Actinomucor elegans. The novel strain was used in the solid-state fermentation (SSF) of okara to improve their functional properties. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) and reverse-phase high-performance liquid chromatography (RP-HPLC) analyses showed that okara proteins were degraded into peptides during fermentation. SSF okara showed high antioxidant activities, which included reducing power, ferrous ion-chelating activity, and scavenging effect of DPPH, ABTS, and hydroxyl radicals. Compared with the control, the antioxidant activities mentioned above increased by 4.29, 2.32, 3.45, 1.55, and 1.63-fold, respectively. SSF okara also showed a significantly higher ACE-inhibitory activity (61.17% ± 0.94%) at the end of fermentation. Therefore, SSF can be employed as a valuable process to obtain bioactive ingredients from okara, which would encourage their utilization in the formulation of value-added functional foods.