Recovery of proteins from coconut milk whey employing ultrafiltration and spray drying.

The coconut whey (CW) (underutilized by-product of virgin coconut oil production, with 2-3% protein) was subjected to ultrafiltration for concentration of protein and sugar removal prior to spray drying. The process parameters of ultrafiltration were standardised with respect to transmembrane flux, protein retention efficiency and removal of sugar by using 300 kDa membrane cut off, feed pH 4 and 2 bar transmembrane pressure at temperature 25 ± 2 °C. The protein content was found to increase in the retentate after ultrafiltration (termed as concentrated coconut whey, CCW) (from 21 to 46%, w/w) and sugar content to reduce (from 59 to 34%, w/w). The color lightness (L*) values of the CW and CCW powders obtained by spray drying were found to be 83.81 ± 0.33 and 80.70 ± 0.47, respectively. Both the samples of coconut protein powders were found to be microbiologically safe having water activity index for CCWP of 0.27 and CWP of 0.26. Carr index values for CCW (32.95) and CW (33.14) powders indicate both of them to have fair flowability. The powders have high potential as new source of protein or as a functional ingredient in the food processing industries.