Yogurt is a food for all everyone. Sometimes people regard it as a drink. Yogurt is rich in nutrient facts, and more nutritional value, so people often drink yogurt. Sometimes you will find that the yogurt at room temperature is degraded, is it broken? Today I will tell you the reason, and tell you how to distinguish the quality of yogurt.
Why does yogurt get thinner?
The production of yogurt should be pretreated by homogenization and sterilization, and adding about 7% of sucrose, and then inoculating the specific lactic acid bacteria that have been cultured at a temperature of about 42 degrees Celsius. Lactic acid bacteria multiply by milk nutrition and produce lactic acid and aroma substances. The protein in milk has the property of solidification in acid and gradually becomes a fine and delicate and fragile condensation under the action of lactic acid bacteria.
When the acidity is right, the yogurt is transferred to 4 degrees Celsius, and the activity of the lactic acid bacteria stops. The yogurt that is sold directly at this time is called a solidified yogurt. The solidified yogurt is slowly agitated to obtain a uniform semi-solid flowable dairy product, which is a stirred yogurt. Slow agitation does not destroy the protein colloid, so the product is fine and has a certain consistency. If it is stirred quickly, it will destroy the protein colloid and make the product thin. The agitated yogurt made with pure milk is not very viscous and still has a certain fluidity.
Some products use milk and milk powder as raw materials, and the protein content in the product is higher and more viscous. In order to increase the consistency of the yogurt, a variety of thickeners such as gelatin or dietary fiber may be added to the preparation. Gelatin is a protein colloid, which is the main component of meat jelly, which can be digested and absorbed by the body. Dietary fiber thickeners include seaweed gum, pectin, plant seed gum, cellulose derivatives, and the like. They do not harm the human body, have no heat, and can also play a beneficial role in dietary fiber.
Why is yogurt thinning at room temperature?
When the yogurt is stirred at room temperature, the reticular structure formed inside the original yogurt is destroyed, causing the whey to precipitate, so that the yogurt becomes thin.
What is the yogurt degraded?
Look at the packaging:
Firstly, check the food packaging to see if the shelf life expires or is close to the shelf life. Then, check the shape of the package. The deteriorated yogurt will produce a lot of gas due to internal fermentation. If you see the package is bulging up, it means the yogurt has deteriorated, don't drink it. Finally, check the outer packaging.
Look at the storage environment:
Check the yogurt storage status. Yogurt is very easy to spoil, especially during the summer. Yogurt should be stored in a refrigerator or freezer between 2 and 6 ° C. You should be careful when placing yogurt at room temperature. Check the shelf life in general, the shelf life of yogurt is 3 to 5 days.
Look at traits:
The normal yogurt clot is even, delicate, uniform in color, does not spurt out bubbles, and may have a small amount of whey (clear liquid) on the surface; Some Degraded yogurt does not condense into a block, but in a liquid state, especially a layer of water on the surface. Some have bubbles, and the color becomes darker or greener. (Note: Due to the different ingredients added in the blended yogurt such as the existing fruity yogurt, different colors will appear, so you should pay attention to it).
The normal yogurt has a light scent and a milky scent; while the degraded yogurt has a strong sour taste or a mildew flavor with alcoholic fermentation, so it is well distinguished from the sense of smell. It is the best way to smell from the place where the bottle is packed, it is more obvious.
You can taste it if you can't distinguish it by smell. Deteriorated yogurt will become sour, the taste and texture will not be smooth, if you always drink yogurt, you will feel the difference.