Studies on the functional properties of protein concentrate of Kappaphycus alvarezii (Doty) Doty – An edible seaweed

Protein concentrate (PC) of Kappaphycus alvarezii (cultivated on the West coast of India), was extracted and its functional properties were evaluated. The K. alvarezii PC contained 62.3 ± 1.62% proteins. At pH 12, the nitrogen solubility of this PC was 58.72 ± 1.68% in the presence of 0.5 M NaCl. The emulsifying and foaming properties of this PC varied with time and pH. However, it formed remarkably stable emulsions with Jatropha oil after 720 min (i.e. E720 = 53.67 ± 1.59). On the other hand, maximum foaming ability (53.33 ± 2.31%) of the PC was recorded at pH 4.0. This PC had high oil (1.29 ± 0.20 ml oil/g PC) and water absorption capacity (2.22 0.04 ml H2O/g PC). DSC analysis revealed thermal transitions at about 109.25 °C at neutral pH. The results obtained in this investigation suggest the suitability of K. alvarezii PC as an inexpensive source of protein; thus this PC could be incorporated into several value-added food products.