Development and study on physical and sensory properties of dark chocolates fortified with anthocyanin from broken riceberry rice

Abstract

Broken rice of Thai cross breed black rice, Riceberry, was an under-utilized agricultural by-product that contains high content of anthocyanins, the multiple health benefits flavonoid. In this study, these anthocyanins were used to develop healthy dark hocolates. The anthocyanin extract from the broken Riceberry rice was prepared into anthocyanin powder using freeze-drying technique in which maltodextrin was used as a carrier material. Healthy dark chocolates were prepared by replacing cocoa powder with anthocyanin powder by 5, 10 and 15 g/g cocoa powder, which respectively delivers DC5, DC10, and DC15 anthocyanin-fortified dark chocolate bars. The color analysis showed no blooming (undesired white color at the chocolate surface) in all chocolates. The increase the anthocyanin powder content significantly decreased the hardness of the dark chocolates (33.9-27.2 N). Total anthocyanin content (TAC) in the dark chocolates increased respectively as anthocyanin powder content increased. The health benefit of the anthocyanin-fortified dark chocolates was improved as the DPPH antioxidant activity of all treatments was 4-9% higher than that of the control DC0. Sensory evaluation revealed that DC10 received higher liking scores (6.4-7.5) than the DC0 indicating more consumer preference. The anthocyanin-fortified dark chocolate delivers an alternative strategy to improve the health property of chocolates. This application of anthocyanin from the broken Riceberry rice could help increase the value and the utilization of Thai agricultural by-product.