Development of Plant-Based Spread Using Purple Sweet Potato and Cocoa Powder

Yong, Kar Ting (2026) Development of Plant-Based Spread Using Purple Sweet Potato and Cocoa Powder. Final Year Project (Bachelor), Tunku Abdul Rahman University of Management and Technology.

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Abstract

This study aimed to develop a plant-based spread using purple sweet potato (PSP) and cocoa powder, and to evaluate how different levels of cocoa powder affect its physicochemical properties, antioxidant capacity, nutritional composition, and sensory acceptability. The main objective was to determine whether the addition of cocoa powder could enhance the nutritional value and consumer acceptance of a PSP-based spread. Four formulations were prepared: a control (100% PSP) and three experimental samples (F1, F2, and F3) with 5%, 10%, and 15% cocoa powder, respectively. The spreads were analyzed for pH, °Brix, viscosity, colour, total phenolic content (TPC), DPPH radical scavenging activity, proximate composition, and sensory attributes. Results showed that increasing cocoa powder significantly raised the colour, pH, °Brix, viscosity, protein, fat, and ash content, while reducing moisture and total carbohydrates. For example, F3 had the most improved nutritional and functional profile, recording the highest pH (6.41), °Brix (21.67°), viscosity (282.93 cP), crude protein (7.43%), crude fat (11.33%), ash (2.41%), total phenolic content (15.97 mg GAE/100 g), and DPPH radical scavenging activity (47.12%). However, it received slightly lower scores in sensory evaluation compared to F2. F2 was the most preferred sample by panelists (42% of 50), showing a better balance of taste and aroma despite slightly lower antioxidant and nutrient levels. In conclusion, the incorporation of cocoa powder improved the nutritional and antioxidant properties of the PSP spread, although high cocoa content may affect sensory acceptance. F2 was identified as the most balanced formulation in terms of nutrition and consumer preference. Further product improvement and shelf-life testing are recommended for commercial development