Nutritional, biochemical and phytochemical characterization of seeds and seed oil of pumpkins (Cucurbita maxima) grown in Malawi

Abstract

Pumpkin is a significant part of dish when in season in Malawi. In this study, the proximate composition, physicochemical and phytochemical properties were determined from pumpkin seed and oil. The Cucurbita maxima seed proximate compositions (%) were dry matter (97.58±0.26), crude protein (32.47±0.15), ash (7.38±0.05), crude fat (46.39±0.06), crude fiber (12.29±0.17) and carbohydrate (4.18±0.21), respectively. The physicochemical composition showed that saponification and ester values, in mg KOH/g oil, were the highest, registering 161.705±12.281 and 161.022±12.018 values followed by peroxide value (32.213±0.677 meq O 2 /kg), iodine value (17.769±0.147 g I 2 /g), free fatty acid as oleic acid (1.964±0.025 mg/100 g), refractive index (1.446±0.000), acid value (0.987±0.0125 mg KOH/g) and specific gravity (0.8985±0.00370). Results in seed flour on phytochemical properties, in mg/100 g, were phytate (119.07±6.65), oxalate (1462.77±97.518), alkaloids (90.997±1.574) and flavonoids (61.7605±7.6035). The oil phytochemical content, in mg/100 g, were highest in alkaloids (826.08±0.71), followed by phytate (309.7±16.4), flavonoids (235.36±8.97) and oxalate (87.272±0.612). In seed flour, the pH value was 6.9±0.00, titratable acidity (0.03±0.00 mg/g), vitamin C and phosphorus, in mg/100 g were 4.9876±0.0075 and 329.92±52.04, respectively. Findings from this study showed that pumpkin seed is a good source of essential nutrients for human nutrition and vegetable oil for industrial uses.