COMPOSITION AND PHYSICO-CHEMICAL CHARACTERISTICS OF BUFFALO MILK WITH PARTICULAR EMPHASIS ON LIPIDS, PROTEINS, MINERALS, ENZYMES AND VITAMINS

The businesses community will be provided information on milk composition comprising various nutrients and enzymes. The nutrients determine the dietary value of milk for human consumption and helps in selecting milk for various types of human population like growing children, nursing mothers, young persons involved in hard jobs or elderly people. The enzymic profiles as well as the nutrient molecules determine the suitability of milk for various processes and end products. These two sets of parameters determine the market value of milk and milk products and its suitability for export to various regions. During my stay at INRA France, I got an opportunity to interact with scientists of international stature and learned various techniques how to add value to our milk and how to tailor this natural resource with the needs of local and international market. I will review results of my several research studies and would try to link them for addressing our local issues. By modifying the forces (hyhobic and electrostatic interactions, hydrogen bonding and presence of micellar calcium phosphate) responsible for the structure and the stability of casein micelles, alkalinisation induces a disruption of casein micelles in milk. A study was conducted to compare the alkalinisation-induced physico-chemical changes of casein micelles of buffalo and cow milks with a special attention to the mineral fraction. Between pH 6.7 and 10.8, the whiteness decreased from 73.5 to 50.9 and from 71.3 to 50.9 units and the viscosity increased from 1.8 to 10.2 and from 1.5 to 4.8 mPa s for buffalo and cow milks, respectively. Simultaneously, > 90% of nitrogen contents were in the supernatants of ultracentrifugation at pH 9.7 and 8.6 for buffalo and cow milks, respectively. Chromatographic analyses showed that caseins were totally solubilised at these pH values. Calcium and inorganic phosphate concentrations progressively increased in the supernatants of ultracentrifugation and decreased in the ultrafiltrates. At alkaline pH, the negative charge of caseins increased and the inorganic phosphate ion changed its ionisation state from HPO4 2- to PO4 3- form. This form has a greater affinity for calcium and can demineralise casein micelles. The consequences were modifications of proteinprotein and protein-minerals interactions resulting in micellar disruption. The dissociations took place at pH 9.7 and 8.6 for buffalo and cow milks, respectively. These differences were due to higher concentrations of casein and minerals in buffalo than in cow milk, which were also our criteria of selection of the former as a model. Keywords: Milk, products, physiochemical, nutrients, vitamin, enzymes