Effect of salt concentration and drying temperature on functional properties of sesame (Sesamum indicum L.) meal protein isolate

Sesame meal with high protein content is the by-product of sesame oil extraction. Using sesame meal protein in food formulations enhances the functional and nutritional attributes of food. In the present study, the effect of salt concentration (18% and 22% w/v) and drying temperature of sesame seeds (45 oC and 180 oC) on functional attributes (solubility, water, and oil hold capacity, stability and capacity of foam, stability and activity index of emulsion, and the least gelation concentration (LGC) at different pH) were investigated. Sesame protein isolate (SPI) samples revealed the lowest changes in functional attributes at isoelectric pH, and the highest effect was obtained at pH 11. Salt concentration and drying temperature of sesame also significantly affected the functional and structural attributes of SPI (p < 0.05). The highest salt concentration and drying temperature of sesame are 22% and 180 degrees C, respectively, increasing the solubility, foam capacity and stability, oil and water hold capacity, emulsion activity, and stability. In addition, at pH 7, 9, and 11, the control sample and sample treated with 22% of salt concentration at 180 oC had the lowest and highest ability to form a gel as compared to other treatments. The structural attributes showed the presence of protein and denaturation in the structure of all samples. Given the good functional attributes of protein treated at higher salt concentration and drying temperature, this SPI can improve functional attributes in different food formulations.