Effect of red beet (Beta vulgaris L.) powder addition on physicochemical and microbial characteristics of tofu

Abstract

This study aimed to investigate the enhancing effects of a specified amount of red beet (Beta vulgaris L.) powder on the quality of tofu over existing ones. Thereafter, physicochemical characteristics and microbial safety were compared between tofu prepared addition of red beet powder (RBP) at different concentrations (0.5-2%) and tofu without RBP. No significant differences in sample yield were observed (p>0.05) and, the brix degree and lightness of tofu significantly decreased with an increase in the RBP concentration (p<0.05). Texture analysis revealed that incorporation of RBP significantly increased the hardness of tofu (p<0.05), while the cohesiveness, springiness, and chewiness were not significantly altered. Furthermore, total phenolic content and antioxidant activity of RBP-incorporated tofu were significantly greater than those of untreated tofu on the DPPH radical scavenging assay, ABTS radical scavenging assay, and ferric reducing antioxidant power assay (p<0.05). In the case of microbial safety, RBP-incorporated tofu contained significantly fewer aerobic bacteria and yeast during storage than tofu without RBP (p<0.05). These results suggest that RBP incorporation in tofu increasees its functional quality and shelf-life. ? The Korean Society of Food Preservation. All rights reserved.