Improving the antioxidant capacity of bread rolls by controlled fermentation of rice bran and addition of pumpkin (Cucurbita pepo) puree

Abstract

A multi-strategic approach was used to manufacture functional bread with health and safety promoting effects. Firstly, predominant LAB strains isolated from mature spontaneous rice bran sourdough (RBS) were screened based on their radical-scavenging activities. Then the selected isolate was identified by a PCR based method. After that, the inhibitory effects of the LAB isolate on Aspergillus niger and Penicillium verrucosum were investigated. Subsequently, the optimized formulation of the controlled RBS (fermented with this isolate as starter culture) along with pumpkin puree was determined based on antioxidant capacity of the product using response surface methodology (RSM). The sequencing results led to the identification of the LAB isolate as Lactobacillus plantarum. In vitro antifungal activities of the LAB isolate were also approved. Furthermore, the results revealed that controlled RBS and pumpkin puree synergistically improved the techno-functional properties of the product in terms of hardness, overall acceptability as well as antioxidant capacity. Mould growth on bread containing controlled RBS was significantly (P < 0.05) lower than the control. According to these results, simultaneous application of the controlled RBS along with pumpkin puree in bread roll is important from technological, sensorial and functional viewpoints in processing of this product. Furthermore, controlled RBS along with pumpkin puree can be used as fiber rich supplements in bread making to produce a clean label food, and to develop not only a safer but also an innovative bakery product.