Physicochemical and functional properties of oleaster (Elaeagnus angustifolia L.) polysaccharides extracted under optimal conditions.

This research aimed to optimize the polysaccharides extraction of oleaster fruit and then to investigate the physicochemical and functional properties of extracted polysaccharides. Temperature, water to dry matter ratio, time, and alcohol ratio were considered as variables. Purity of extracted polysaccharides was considered as the response. Optimization of polysaccharides extraction from full grain oleaster showed that all variables had effects on the purity of extracted polysaccharides alone or by interacting with other variables. The results showed that the temperature, 60 °C; water to dry matter ratio, 53:1 (V/W); time, 5 h; and alcohol ratio of 2.9 (V/V) were the best conditions for achieving the highest purity in extracted polysaccharides. The extracted polysaccharides had the potential of emulsion formation with high stability; however, foamability was not observed in this polysaccharide. In addition, the solubility of polysaccharide powder was high, and it increased with an increase in temperature, which resulted in a decrease in water absorption indicating the effect of heat on the structure and the amount of water absorption of extracted polysaccharides. The results obtained from FTIR confirmed the polysaccharide nature of extracted powder, and the X-ray diffraction pattern of extracted polysaccharides showed its semi-crystalline structure.