Changes in Phytochemical and Antioxidant Potential of Tempeh Common Bean Flour from Two Selected Cultivars Influenced by Temperature and Fermentation Time

Abstract

Processing option such as fungal fermentation (tempeh) improves legume nutraceutical properties. The aim of this work was to evaluate the physicochemical and antioxidant potential of common bean tempeh flour from two varieties: Bayo victoria (BV) and Pinto durango (PD) processed at two different temperature and fermentation times. Results showed differences between cultivars followed by changes in temperature and fermentation times, being more significant at 35C for 40 h. The phenolic content in both cultivars varied considerably after cooking, being higher in raw flour (0.4–3.0-fold for BV and 0.35–0.5-fold for PD). The highest phenolic content was for BV fermented at 35C and 40 h, whereas for PD was at 30C and 40 h. Antioxidant capacity was evaluated by 2,2-diphenyl-1-picrylhydrazyl, low-density lipoprotein oxidation and hydroxyl radical-scavenging assays. Results showed different antioxidant capacity for each test. The major differences in results were shown between cultivars than the processing variations of temperature and fermentation time. Practical Applications Phaseolus vulgaris is one of the most important grain legumes for human consumption attributable to its nutritional properties, low cost and health promoter effects. However, the nutraceutical properties of this legume have changed due to process variables such as temperature and time of cooking. It has been demonstrated experimentally that fungal fermentation or tempeh production can be an efficient strategy to improve the phenolic content and antioxidant activity of common beans, becoming a favored alternative as an ingredient/supplement development for the prevention and control of degenerative diseases. However, little information is available on the effect of temperature, fermentation time and common bean cultivars in relation with their nutraceutical properties. The present investigation demonstrated that the major effects were between cultivars rather than processing variations of temperature and fermentation time. Therefore, considering cultivars and processing variables, common bean tempeh flour may be an efficient strategy to enhance the antioxidant activity of this seed.