Investigation of the effects of homogenisation and gelling agents on the physicochemical, textural, and sensory properties of Yoghurt

Yoghurt, a fermented dairy product, is valued globally for its nutritional benefits and unique sensory properties. Optimizing its texture, stability, and shelf life remains essential for commercial success. This study investigated the combined effects of milk homogenization and the incorporation of gelling agents—pectin and gelatin—on the physicochemical and sensory quality of yoghurt. A 10% skimmed milk powder solution was prepared, pasteurized, and split into two batches: homogenized (140 bar at 60°C) and non-homogenized. Each batch was further subdivided for the addition of pectin or gelatin, followed by inoculation with a 2% lactic acid bacteria starter culture. Samples were incubated at 43°C until pH 4.4 was reached. Physicochemical parameters such as pH, viscosity, syneresis, and texture were analyzed, alongside sensory evaluation by a semi-trained panel. Homogenization improved texture, gloss, and viscosity while reducing syneresis. Pectin significantly reduced whey separation, while gelatin enhanced creaminess and set firmness. The combination of homogenization and appropriate gelling agents resulted in yoghurt with improved consumer acceptability and shelf stability. These findings demonstrate the critical role of processing techniques and additives in tailoring yoghurt characteristics to market preferences.