When the yogurt prepared by the above method is cooled to 15℃, food-grade citric acid is added to adjust the pH value to 4. 1, then the mixture is stirred, and 29kg of orange pectin solution and 3.5kg of orange essence are added. The preparation method of citrus pectin solution is as follows: 2.2 kg of citrus pectin is added to 27 kg of water and stirred evenly. It is best to homogenize the above mixture with colloid mill at 20MPa and then heat it to 565,438 0℃. In the whole process, pay attention to the temperature difference between the heating medium and the material should not be higher than 5℃. When the temperature reaches 5 1℃, check the temperature quickly and accurately. And let it cool to 32℃, pay attention to the temperature difference between the cooling medium and the material should not be higher than 5℃.
When the material is cooled to 32℃, it is homogenized again under the pressure of 20MPa, and then heated to 90℃ for 30s. Pay attention to continuous stirring during heating and heat preservation. In addition, during heating sterilization, the temperature difference between the heating medium and the material should not exceed 5℃. Finally, the sterilized materials are cooled to 22℃ and packaged under aseptic conditions at this temperature to obtain the final product. At this time, the number of bacteria was detected, and the result was 90 /mL. If this product is stored at room temperature, there will be no whey precipitation and flavor deterioration after 6 months.
(2) In the second method, all the operations in 1 are repeated, but the control parameters need to be slightly changed, that is, when the material is heated to 90℃ and sterilized for 30s, the cooling temperature is changed from 22℃ to 30℃, and packaging is carried out at this temperature. The product was stored at 65438 05℃ for 6 months, and there were still no quality accidents such as whey precipitation and flavor deterioration.
(3) The third method repeats the operation of the first method, but sugar and fruit essence are not added in the formula. After aseptic packaging, the bacterial count of the product prepared according to the above formula is 92 /mL. After storage for 6 months, there is no separation and precipitation of whey, and its flavor is like fresh products.
(4) Method 4 repeats the production operation of method 1, but changes the following process parameters. One is to change orange essence into raspberry essence (also called raspberry). Secondly, when the temperature rises to 565,438+0℃, the temperature difference between the heating medium and the cooling medium and the material is 8℃, which decreases from 565,438+0℃ to 32℃. The products made according to this process and formula have no whey precipitation and precipitation, and the flavor has not changed after being stored at room temperature for 6 months.
(5) The production process of the fifth method remains unchanged, but after the last homogenization, the materials are put into glass bottles and then sterilized at 90℃ for 30s. Finally, cooling to room temperature to obtain the product. The product prepared by this method is stored at room temperature for 6 months, and the flavor of the product remains unchanged, and there are no quality accidents such as whey precipitation and precipitation.
Extended data:
nutritive value
During the fermentation of yogurt, about 20% of sugar and protein in milk are hydrolyzed into small molecules (such as galactose and lactic acid, small peptide chains and amino acids), and the fat content in milk is generally 3% ~ 5%. After fermentation, the fatty acids in milk can be increased by 2 times compared with raw milk. These changes make yogurt easier to digest and absorb, and the utilization rate of various nutrients can also be improved. Yogurt is fermented from pure milk. Lactic acid bacteria can not only retain all the nutrients of fresh milk, but also produce various vitamins necessary for human nutrition during fermentation, such as VB 1, VB2, VB6, VB 12, etc.
efficacy
This "milk factor" has the natural function of lowering blood lipid and cholesterol, which hinders the body's absorption of fat. Moreover, yogurt also contains lactic acid, which can effectively inhibit the proliferation of spoilage bacteria in the intestine, inhibit the production of harmful substances, and promote the peristalsis of the intestine, so it has great weight loss and slimming value.
We say yogurt is a good diet food because it is rich in lactic acid bacteria. After entering the intestine, lactic acid bacteria will proliferate Bifidobacterium, inhibit the activity of harmful bacteria, improve the intestinal environment and effectively treat chronic constipation.
Meanwhile, yogurt is also a dairy product. Calcium in dairy products will reduce the amount of parathyroid hormone, thus hindering the activity of enzymes and slowing down the process of fat burning in the body.
Maintain the ecological balance of intestinal flora, form a biological barrier, and inhibit harmful bacteria from invading the intestine. It can prevent constipation by producing a large number of short-chain fatty acids to promote intestinal peristalsis and a large number of bacteria to grow and change osmotic pressure. Yogurt contains a variety of enzymes, which can effectively promote the digestion and absorption of nutrients.
Yogurt can prevent aging by inhibiting the growth of saprophytic bacteria in the intestine, inhibiting food spoilage in the intestine to produce toxins, and preventing the liver and brain from being damaged by these toxins. Yogurt can inhibit the growth of saprophytic bacteria and some harmful bacteria in the intestine. So as to inhibit carcinogens produced by these bacteria and achieve the purpose of preventing cancer.
To improve human immune function, lactic acid bacteria can produce some substances to enhance immune function, which can improve human immunity and prevent diseases. Yogurt containing a large number of active bacteria is helpful to improve lactose intolerance, constipation, diarrhea, enteritis, helicobacter pylori infection and other diseases.
The Human Nutrition Research Center of the US Department of Agriculture is conducting research on the elderly at Tufts University. Researcher Gene Mayer said that yogurt can not only improve the intestinal environment, but also improve human immunity.
Coincidentally, a study in Taiwan Province Province also found that yogurt can improve the therapeutic effect of some anti-inflammatory drugs. Yogurt can lower blood pressure. Dr. Alvaro A Liang, an epidemiologist at Harvard School of Public Health, said that the study found that people who drink 2-3 servings or more of yogurt every day have a 50% lower risk of hypertension than those who don't drink yogurt.
References:
Baidu Encyclopedia-Storage of Yogurt