The Applied Research Of Tibetan Kefir In Whey

Whey is the main by-product of cheese processing which not only has kept more than 20% of proteins in milk but also contains fat, vitamin and many other nutrients. Whey is a good source of functional proteins, peptide, fat, minirals and lactose. But more than 90% of whey is moisture which gives a big budget for the treatment of it. If the whey is not disposed very well, it will give a certain damagement to the environment. And now the whey protein and whey powder have been raw materials with high value and widely applied in the processing of certain food.Tibetan Kefir is one kind of kefirs in Tibet, and it is a micro-ecological community composed by a varity of microorganisms which includes bacterials and yeasts. Tibetan Kefir has been used on a lot of fermentation products which have good taste. At the same time, Tibetan Kefir can give a certain effect on the nutrients value of products because of the rich species composition. But the Tibetan Kefir is rarely used on the products of whey and this article will do some researches in the application of Tibetan Kefir on the products of whey.The main research methods and contents are as followed:First of all, in order to explore whether there were some particularities existence in the physical and chemical properties, the article produced a new kind of whey powder using the vacuum freeze drying technology and named it as Tibetan Kefir Whey Powder. This new kind of whey powder has no particles and is easily dissolved in the water. The whey powder contains 4.92% moisture, 10.09% ash, 60.63% lactose and 8.65% crude proteins. And the research also finds that there are 17 kinds of hydrolysate amino acid in the new kind of whey powder. The ratio of aromatic amino acids is higher than WPC-34 in the contact the ratio of aliphatic ones is lower. And there are also 16 kinds of free amino acid in it which is higher than the market WPC-34 rather in the quantities or the types of it.Secondly, on the foundation of the production of this new kind of whey powder, the article did some research on the shelf life of the new kind of whey powder. During the 120-day storage period, the moisture, HMF, sulfur content of barbituric acid values significantly increased with the extension of storage time(p<0.01), and lactose and protein content with the extension of storage time significantly reduced(p<0.01). The color difference changed a little and had a slight fluctuation, but the general state was growth. In the period of 120-day storage time, there were no pollution of e.coli. or other pathogenic bacteria. The shelf life which was determinated in this experience is 105 days and the one which was calculated by the formula of the storage period is 112.1 days. And the relative error is just 6.76%. Acording to the experiment by using the formula model, the storage time under the condition of room temperature 25℃ and 50% RH is 112.1 days and are relatively longer than the common kinds of whey powders.Finally, based on the characteristics of the high moisture content of whey, the article used the Tebiten Kefir in the processing of whey beverages. Firstly, the article filtrated the fermentation time and temperatures on the basic of pH and lactose content and got the fittest conditions of the growth of probiotics. On this basis, this article used the method of culture medium and PCR-DGGE profiles to analysis the content of colony, the number of stains and the types of them. And at the basic of this, this article got the appropriate fermentation conditions. This sets a good basic for the research of the new kinds of fermentation whey beverages.