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.
