Evaluating belinjau (Gnetum gnemon L.) seed flour quality as a base for development of novel food products and food formulations

Belinjau (Gnetum gnemon L.) seed flour was evaluated for nutritional composition, antioxidant activity and functional properties. Seed flour was found to be rich in protein (19.0 g/100 g), crude fibre (8.66 g/100 g), carbohydrates (64.1%), total dietary fibre (14.5%) and encompassed adequate amounts of essential amino acids, fatty acids and minerals. Antioxidant compounds such as total phenols (15.1 and 12.6 mg GAE/100 g), tannins (35.6 and 16.1 mg CE/100 g) and flavonoids (709 and 81.6 mg CEQ/100 g) were higher in ethanolic extracts over aqueous extracts, respectively. Inhibition of DPPH was high in ethanol extracts (48.9%) compared to aqueous extracts (19.7%), whereas aqueous extracts showed a higher FRAP value compared to ethanol extracts (0.98 and 0.61 mmol Fe(II)/100 g, respectively). Results on functional properties revealed acceptable water and oil absorption capacities (5.51 and 1.98 g/g, respectively), emulsion capacity and stability (15.3% and 6.90%, respectively), and foaming capacity (5.78%). FTIR spectral analysis showed seed flour to encompass major functional groups such as: amines, amides, amino acids, polysaccharides, carboxylic acids, esters and lipids. As belinjau seed flour possesses a rich nutraceutical value, it has high potential to be used as a basic raw material to develop new low cost nutritious functional foods.