Effect of germination and fermentation on the proximate composition and functional properties of full-fat and defatted cucumeropsis mannii seed flours.

Abstract

Germinated, fermented and raw Cucumeropsis mannii (melon) seeds were processed into flours. A portion of the flours were defatted using n-hexane; both the full fat and defatted flours were evaluated for proximate composition and functional properties. The proximate compositions of the full fat and defatted C. mannii seed flours were: moisture, 4.97-5.67% and 6.17-8.13%; total ash, 1.95-3.24% and 4.38-7.19%; crude protein, 36.62-39.91% and 71.91-77.05%; crude fat, 45.06-49.57% and 1.56-2.57%; crude fibre, 2.71-3.63% and 4.34-4.59%; carbohydrate, 3.78-4.07% and 4.45-6.54%, respectively. The functional properties of the flour from full-fat and defatted seed were: water absorption capacity, 116.67-183.33% and 216.67-267.67%; oil absorption capacity, 252.33-274.00% and 292.00-345.00%; foaming capacity 17.36-30.34% and 34.78-44.69%; foaming stability, 5.17-11.54% and 11.41-14.55%; least gelation concentration, 24.67-28.00 and 13.33-18.67%; emulsion capacity, 49.73-79.28mL/g and 40.34-65.61mL/g; bulk density 0.65-0.81g/mL and 0.36-0.39g/mL; protein solubility 4.00-5.89% and 5.21-7.11%, respectively. Germination enhanced the water absorption capacity, foaming capacity and protein solubility while fermentation increased the emulsion capacity. Defatting improved the water and oil absorption capacities, foaming capacity and protein solubility. The flour from germinated seeds may find use as ingredients in food emulsion and salad dressing, while those from fermented seeds may be used as food thickeners.