Nutritional and functional characterization of defatted oilseed protein isolates

In present study efforts were made to elucidate the importance of oilseeds as non-conventional protein sources. Purposely, three different oilseeds i.e. sesame, flaxseed and canola were initially subjected to proximate and mineral composition. Afterwards, defatted oilseed meals were used to prepare protein isolates through isoelectric precipitation method. The resultant protein isolates were examined for protein content, recovery and yield. Moreover, functional properties i.e. water and oil absorption capacities, foaming and emulsifying properties along with nitrogen solubility index and least gelation concentration of protein isolates were also determined. The results indicated highest crude protein content in whole as well as defatted sesame. Likewise, sesame protein isolates (SPI) exhibited maximum values for crude protein content (90.14±2.37%) followed by canola protein isolates CPI (89.75±3.58) and flaxseed protein isolates FPI (86.37±3.69). Likewise, protein isolates recovery was maximum in SPI (36.86±1.22) trailed by FPI (31.59±0.98) and CPI (30.52±1.20). Similar trend was noticed for yield i.e. SPI (79.03±2.18), CPI (78.53±4.02) and FPI (74.61±2.93). Moreover, higher water absorption capacity was revealed in SPI followed by CPI and FPI. Similarly, maximum foaming capacity was observed in SPI tracked by FPI and CPI. Conclusively, defatted oilseed meals contain appreciable quantities of quality proteins. In the nutshell, sesame protein isolates exhibit better recovery, yield as well as functional properties in comparison with flaxseed and canola protein isolates. Therefore, these can be a potential candidate for utilization in various food formulations. (author)