Evaluation of the effect of Salt, temperature and pH on the functional properties of defatted pumpkin seed flour and its protein isolate

In the last few years there has been a growing trend to use pumpkin seed flour as a good protein and oil source. Owing the thick peel and large seeds, pumpkin produce large amount of waste during both the processing and consumption. In general these wastes consist of a lot of protein. The objective of this study is to investigate the functional properties of defatted pumpkin seed flour and its protein isolate. Pumpkin protein isolate were prepared from defatted pumpkin flour through the alkaline extraction and isoelectric precipitation. Chemical composition (protein, fat, ash, carbohydrate and water contents), functional properties (water and fat absorptions, foaming and emulsion capacity) of pumpkin protein isolates were determined and compared with defatted pumpkin seed flour.The protein contents of the isolate obtained from defatted pumpkin flour were 85.55%. There were statistically significant differences in case of water and fat absorption, foaming capacity, and emulsion capacity between isolate and defatted pumpkin seed flour (P≤0.05). Also the effect of salt, temperature and pH on the functional properties of defatted pumpkin seed flour and its protein isolate were significantly different (P≤0.05).The results revealed that the pumpkin protein isolate consisted of a lot of protein. Good functional properties of pumpkin, makes it ideal substitutes for other dietary proteins.