Development and quality evaluation of a peanut based pumpkin seed spread with natural flavors

Abstract

Pumpkin (Cucurbita maxima) seeds are an underutilized, nutrient-rich agricultural by-product that is often discarded as waste despite their exceptional nutritional profile. This study aimed to develop a high-quality spread utilizing pumpkin seed powder and to evaluate its physicochemical, sensory, and microbial characteristics. The experimental spreads were formulated with peanuts (Arachis hypogea) (68.9 g) and pumpkin seed powder (31 g) as base ingredients, with three treatments incorporating distinct natural flavouring agents: scotch bonnet pepper (2.5 g), black pepper (3 g) and garlic (2.5 g). An unflavoured formulation served as the control. Sensory evaluation was conducted with 30 untrained panellists using a 9-point hedonic scale to assess appearance, odor, texture, flavor, mouthfeel and overall acceptability. The scotch bonnet-flavoured spread was identified as the most preferred flavoured spread. Proximate analysis of the optimized spread revealed:3.31 ± 0.01% moisture, 3.9 ± 0.1% crude ash, 31.8 ± 0.1% crude protein, 36.2 ± 0.1% crude fat, 11.4 ± 0.1% crude fiber and 16.7 ± 0.1% carbohydrates, yielding 519.8 kcal per 100 g. Compared to conventional peanut butter the product had lower fat but higher protein, ash, fiber, and carbohydrate contents. During one-month storage at ambient temperature, moisture content and water activity significantly increased (p<0.05), while pH significantly decreased (p<0.05). Total plate count and yeast and mold count indicated that refrigeration maintained microbial counts below Sri Lanka Standards Institution (SLSI) specifications, although preservatives would be required for extended shelf-life at room temperature. This research demonstrates a viable method for valorizing agricultural waste into a nutritionally superior food product, contributing to food security and sustainable resource utilization while offering a healthier alternative to conventional spreads.