Frozen Storage Of Pasteurized Buffalo Milk And Its Effect On Blood Lipids And Liver Function In Mice On The High Fat Diet

Buffalo milk is the second largest source of milk supply and it take an important part of the world dairy industry. Buffalo milk is known as "milk noble". Pasteurized milk has more rich nutriments as compared to cow milk, pasteurization has less nutrient damage, but the shelf-life is short and the sales radius is short. Hence, it is very imperative to find an method of less nutrient loss to extend the shelf-life. Freezing is the most commonly used method to save the bioactive substances but there is no literature available whether the freezing process could make a difference in buffalo milk In the present study buffalo milk were pasteurized at (80℃,15s) and stored at -18℃ and -30℃,in this study. Hygiene index, freshness index, nutritive index and sensory index were used to evaluate shelf-life in the day 0,15,30,45,60 and 75, respectively. The main objective research is to lay foundation for freezing storage of pasteurized buffalo milk.polyunsaturated fatty acid (HUFA) can regulate the fat metabolism and protect the liver function Buffalo milk has rich high unsaturated fatty acids but there is no literature available whether the buffalo milk could make a difference in the fat metabolism and protect the liver function high fat diet mice were divided into four groups,and each group add 0、0.5mL、1.OmL buffalo milk, deep sea fish oil(20mg HUFA, positive group)),respectively. and basic diet mice were divided as control group.. Experimental feed were offered for 90 consecutive days. At the end of experimental period live weight of the mice were measured and mice were dissected, and liver function index, serum biochemical index were measured. The results were shown below.Experiment l:The preserved effect of freezing temperature on the pasteurized buffalo milk1 The effect on hygiene index of pasteurized buffalo milkThe total aerobic and psychrophilic bacteria count of pasteurized buffalo milk under national standard showed a decreasing trend. On the day 45th, the mortality of aerobic bacteria of pasteurized buffalo milk stored at -18℃ and -30℃ is 11.43% and 12.42%, respectively; the mortality of psychrophilic bacteria count of pasteurized buffalo milk stored at -18℃ and -30℃ is 7.95% and 8.80%, respectively. At the end of test, the mortality of aerobic bacteria of pasteurized buffalo milk stored at -18 ℃ and -30℃ is 12.67% and 13.49%, respectively. The mortality of psychrophilic bacterial count of pasteurized buffalo milk stored at -18℃ and -30 ℃ is 10.00% and 11.10%, respectively. During the test, The CFU of coliforms was always less than 3.0, Staphylococcus aureus was not detected.2. The effect on nutritive index of pasteurized buffalo milkDuring the test, milk protein and fat showed slight degradation. On the day 45th, the degradation of milk protein that stored at -18℃and -30℃ was 1.35, and the degradation of milk fat was 1.58%. At the end of test, the degradation of milk protein that was stored at -18℃and -30℃ was 2.70% and 2.50%, respectively, and the degradation of milk fat that was stored at -18℃ and -30℃ was 3.08% and 2.76%, respectively, so pasteurized buffalo milk nutrient level was not affected.3. The effect on freshness index of pasteurized buffalo milkDuring the test, the pH of pasteurized buffalo milk stored at -18℃ and -30℃ all showed declining trend, but the value belong to normal range; the acidity titration around 13°T below national standard (18°T). The alcohol and thermal stability of all pasteurized buffalo milk stored at -18℃ and -30℃ showed negative response within 45 days, but on day 60th, the stability test emerged floc particles that indicated buffalo milk stability was destructed. Until 45 days of the experimental period.4. The effect on sensory index of pasteurized buffalo milkthe sensory score of pasteurized buffalo milk stored at -18℃and -30℃ was not changed, as no difference was observed between fresh and frozen buffalo milk within 45 days, whereas after 45 days, pasteurized buffalo milk occurred strange in color, taste and organization. hygiene, nutritive, freshness, and sensory index of pasteurized buffalo milkSummary:The hygiene, nutritive value, freshness, and sensory index of pasteurized buffalo milk which stored at -18℃ and -30℃ meet national standards during 45 days. From this finding, it can be suggested that preservation of Pasteurized buffalo milk at -18 ℃ for 45 days can save energy and cost.Experiment 2:The effect of pasteurized buffalo milk on weight、fat metabolism and liver function with high-fat dietMice fed on high-fat diet induced body gain, liver index increase, liver disorders and metabolic syndrome. Mice group fed on fish oil had reduced liver index (P>0.05) Compared with control group, the weight gain of mice in 0.5mL buffalo group was not obvious (P>0.05).but the other groups was obvious (P<0.05)Pasteurized buffalo milk and fish,increased HDL-C; Pasteurized buffalo milk and fish oil could reduce ALT and AST in high-diet mice serum and repair liver function,fish oil could significantly reduce ALT(P<0.05). High dose buffalo milk group mice had low ALT as compared to low dose buffalo milk group which possibly indicated that the action of ALT dependent on the dose of buffalo milk. From the present experiment it can be concluded that low dose buffalo milk is required to reduce the action of ALT.