Development and Quality Assessment of Herb-Flavored Sweetpotato (Ipomoea batatas L.) Chocolate Spread

Abstract

Among the chocolate-related products available in the market is chocolate spread, containing imported hazel nuts and almonds. This makes the product relatively expensive. This study formulates and optimizes the process of herb-flavored sweet potato-chocolate spread. Plackett-Burman (PB) variable screening design and Response Surface Methodology (RSM) were used as experimental designs. A 33 factorial experiment arranged in Central Composite Design (CCD) with sweet potato (Ipomoea batatas L.) (125, 150 and 175 g), cocoa tablet (20, 25 and 30 g) and basil (Ocimum basilicum L.) (5, 10 and 15 g) served as independent variables.

Plackett-Burman variable screening shows that cocoa tablet and basil significantly influenced the acceptability of aroma, flavor, aftertaste and general acceptability while Buffalo’s milk, sweet potato color and cocoa tablet significantly affected the color of the product. The third variable considered was sweet potato. Response surface analysis reveals that basil significantly affect the consistency, flavor, taste, aftertaste and general acceptability of herb flavored sweet potato-chocolate spread. Sweet potato, cocoa tablet and basil did not significantly affect the color and aroma of the product.

Superimposed plots of the different variables indicated that the combination of 150 g sweet potato, 29 g cocoa tablet and basil was the optimum formulation. It was found negative of Salmonella and E.coli and had low microbial count after six weeks of monitoring. The optimized product had low fat, carbohydrates and sugar content but high in dietary fiber. It also contains calcium and potassium.