Can ultrasonication improve coagulation properties of indigenous and exotic cow milk for dairy product processing?

This study investigates the effects of ultrasonication on milk coagulation properties, focusing on milk from indigenous Thamankaduwa White (TW) and exotic Holstein Friesian (HF) cattle. Milk samples were subjected to ultrasound treatment (20 kHz with a 2 cm probe depth and 60 % amplitude) at three energy densities (504, 612, and 720 J mL^-1). Acid-induced gels were formed using a lactic acid starter culture, while rennet-induced gels were produced through enzymatic coagulation. The results demonstrate that ultrasonication significantly enhances the water-holding capacity (WHC) in both gel types, particularly in HF milk treated at 720 J mL^-1. Ultrasonication also altered gel hardness, cohesiveness, and microstructure, with TW milk showing more pronounced changes. These include larger and more abundant void spaces in rennet gels and a coarser protein network in acid-induced gels. Ultrasonication offers a practical and efficient method to improve dairy product quality by enhancing WHC, hardness, and cohesiveness while reducing syneresis in milk gels. This technology also promotes the utilization of milk from underutilized indigenous cattle breeds, such as TW, in the dairy industry, contributing to sustainability and addressing industry challenges.