Evaluation of the lipolytic activity in mare's milk during storage at low temperature

The chemical composition of mare's milk is more similar to human milk than to mammary secretion from other species and it is characterised by interesting nutritional properties. As there's a lack of mare's milk for a human diet and it is difficult to guarantee a continual supply, freezing technologies could be used to preserve the nutritional properties of this product. Samples of mare's milk, obtained from Haflinger breed, were frozen and stored for 60, 120 and 180 days at -20°C and -80°C, to evaluate the effect of the temperature on the activity of lipoprotein lipase (LPL) naturally present in this product. The amount of free fatty acids, monoglycerides and diglycerides was measured. The composition of fatty acids and triglycerides was also determined. The milk stored at -20°C, in the first period of storage, showed a greater amount of monoglycerides, diglycerides and free fatty acids than the milk samples stored at -80°C. During the rest of the storage period lipolysis didn't increase at either the temperatures. It would seem that the reduction of lipolytic phenomena could occur not only by applying low temperatures but also by increasing the speed of the freezing process.