Optimization of oil extraction from giant bushel gourd seeds using response surface methodology

Gourd seeds have been identified as a source of edible oil, but there is sparse literature on the effect of processing factors on the characteristics of oil extracted from any Lagenaria spp. Optimization of oil extraction with the aid of expeller was achieved by applying response surface methodology. The variables were roasting temperature (87.70-172.0°C) and roasting duration (7.93-22.07 min), while the responses were oil yield and oil quality (free fatty acid, color, specific gravity, saponification value, moisture, and refractive index). Data obtained were analyzed at P < 0.05. Roasting conditions significantly influenced all the responses at P < 0.05. The optimum roasting condition was 100°C for 20 min, which gave 27.62% oil yield with good quality attributes (free fatty acid: 0.61%, color: 3.47 abs, specific gravity: 0.90 g/mL, saponification value: 289.66 mL, and refractive index: 1.47).