Development and Characterization of Gelatin-Free Set-Yoghurt Incorporated with Seaweed Phycocolloids

The potential use of seaweed phycocolloids as stabilizing agents in gelatin-free set-yoghurt was evaluated. Three seaweed phycocolloids, namely carrageenan, alginate, and agar-agar, were extracted from Kappaphycus alvarazii, Sar-gassum wightii, and Gracilaria salicornia, respectively. Pre-liminary trials were conducted to determine the optimal in-corporation levels of phycocolloids in gelatin-free set-yoghurts. Based on syneresis percentage, 0.12% (w/v) car-rageenan, 0.2% (w/v) alginate, and 0.3% (w/v) agar-agar levels were selected as the best incorporation levels for set-yoghurt production. The hardness, syneresis, color, proxi-mate composition, and sensory properties of the set-yoghurt containing selected levels of phycocolloids were assessed in comparison with the control, a set-yoghurt con-taining gelatin (0.8% w/v). All the phycocolloids-incorporated set-yoghurt showed lower (p<0.05) hardness and yellowness and higher syneresis compared to gelatin incorporated set-yoghurt (0.8% w/v), and higher lactic acid bacteria count on day 7 of storage at 4 ℃. Protein content was high (p<0.05) in gelatin added set-yoghurt and lowest in agar-agar set-yoghurt. Alginate-added set-yoghurt had a similar protein content as the gelatin-incorporated yoghurt. Consumer preferences for all sensory attributes of alginate yoghurt were comparable to or higher than those of gelatin-added yoghurt, whereas carrageenan and agar-agar-incorporated set-yoghurt received lower preference for certain sensory attributes such as flavor, texture, and mouth feeling. In conclusion, carrageenan, alginate, and agar-agar derived from seaweed can be effectively utilized as stabilizers in set-yoghurt. Out of the tested phycocolloids, alginate stands out as it maintains the sensory attributes and protein content, making it a particularly suitable choice to use as a stabilizing agent in set-yoghurt.