Heat Induced Changes in Milk and Traditional Milk Products
Dharani Muthusamy *
Department of Dairy Chemistry, Verghese Kurien College of Dairy and Food Technology, Kerala Veterinary and Animal Sciences University, Mannuthy, Thrissur, Kerala -680 651, India.
Indu Balakrishnan
Department of Dairy Chemistry, Verghese Kurien College of Dairy and Food Technology, Kerala Veterinary and Animal Sciences University, Mannuthy, Thrissur, Kerala -680 651, India.
*Author to whom correspondence should be addressed.
Abstract
Milk is subjected to various heat treatments from mild to severe conditions, with primary objective to enhance the product shelf life and to ensure the food safety. Study on heat induced changes to milk will have significant knowledge on nutritional aspects of the milk and some dairy processing techniques can be altered to reduces the negative impact of heating on milk and milk products. Several unidentifiable milk residues were found while processing and their effect on milk digestibility was not yet studied in detail. As infant milk formula is constituted with concentrated of milk protein and milk bioactive substance, insights on changes to these components would be inevitable. Thermally induced changes also greatly affect the rheological and sensory properties of dairy products. Functional properties of protein such as solubility, emulsion formation and foaming capacity are influenced by heating. Heating conditions leaves behind certain reversible and irreversible physio-chemical changes to milk constituents. This chapter emphasis the heat induced changes in milk constituents milk protein, fat, lactose and salts in an elaborate manner; since studies on product chemistry was focused, changes in bioactive compounds were not given importance. Concern was extended to allergenicity, cross-linking and digestibility of milk constituent wherever possible.
Keywords: Milk, heat, casein, whey protein, allergenicity, traditional milk products, UHT