Physico-chemical and Engineering Properties of Cow and Buffalo Milk Based Khoa Powder: A Comparative Study

Aim: The study was focused on the evaluation of different Physico-chemical and engineering properties of cow and buffalo milk-based solar-assisted tray drying khoa powders. Background: Drying of milk and milk products was considered the best way to preserve the milk solids. Drying is the process wherein moisture is removed from the food material as a result of concurrent heat and mass transfer. Khoa powder is a desiccated product that potentially offers an economically attractive long-life product that can supplement the traditional, perishable khoa. Under the sub-tropical conditions prevailing in India the shelf life of khoa can be extended only to a limited period. Methodology: The present work was conducted at the Department of Dairy Engineering, College of Dairy Science, Kamdhenu University, Amreli, Gujarat, India from February 2022 to January 2024. The fresh buffalo milk (BM) and cow milk (CM) were collected from local dairy farms. The cow and buffalo milk khoa were prepared following the traditional khoa making process. The khoa powder from khoa was made with the help of hot air circulation in a solar-assisted tray dryer. The temperature inside the tray was 65°C to ensure that the khoa was dried at the appropriate rate. Obtained buffalo and cow milk khoa powders were analyzed for chemical composition (moisture, fat, protein, ash and carbohydrate), physical and engineering properties (bulk density, tapped density, porosity, Carr’s index, Hausner ratio, angle of repose, water activity) and colour parameters (L*, a*, b*, chroma, yellowness index, whiteness index and browning index). Results: The average bulk density, tapped density, porosity, carr’s index, Hausner ratio, angle of repose, water activity, L*, a*, b* and browning index of buffalo and cow milk-based khoa powder were 589 kg/m3, 709 kg/m3, 0.47, 16.91 %, 1.204, 42.7°, 0.28, 68.72, 1.37, 22.47, 40.11 and 551 kg/m3, 643 kg/m3, 0.56, 14.32 %, 1.167, 43.2°, 0.32, 80.92, -0.68, 24.19, 33.96, respectively. Conclusion: Khoa powder is used in various Indian sweets and desserts, to provide a rich, creamy texture and enhance the flavor of these. Therefore, there is further scope for improvement in the flavour and texture of the khoa-based product by incorporating khoa powder in the commercial mix.