Preservation method of homemade juice D Preservation time and temperature: The higher the preservation temperature, the longer the preservation time and the greater the loss of Vc;
So keep it in the refrigerator as short as possible and drink it as soon as possible.
Air: Vc in fruit juice is easily oxidized by oxygen in the air;
Still have to do a good job of sealing the storage tank.
PH value: acidic environment is beneficial to Vc preservation, and Vc oxidation rate is high in alkaline environment;
Copper ion: the existence of copper ion will lead to the loss of Vc in fruit juice;
These two factors can actually be avoided in the production process.
Water: If water is mixed into the juice, the oxidation speed of Vc will be obviously accelerated.
Don't mix water with oak juice. If you have to add water, squeeze less.
In addition, the stability of Vc is also affected by light, ultraviolet and sucrose. Therefore, when freshly squeezed fruit juice can't be drunk at one time, it can be sealed and stored in the refrigerator (avoid using copper or iron utensils), and don't store it for too long.
Men, women and children like to drink juice, especially in hot summer. Drinking a glass of juice is very refreshing. Is drinking fruit juice harmful? I'll sort out the information about the dangers of drinking juice for you. I hope you like it!
Advantages of drinking freshly squeezed juice Fresh squeezed juice is really nutritious. After it enters the human digestive system, it will make the blood alkaline and expel toxins accumulated in cells, such as heavy metals such as lead, aluminum and mercury and free radicals, so it has the function of detoxification and purification.
Freshly squeezed fruit juice has the functions of promoting digestion, stimulating appetite, whitening skin, bodybuilding and losing weight. For patients, the elderly and infants, gastrointestinal function is weak, gastrointestinal peristalsis is slow, there are fewer lactic acid bacteria in the intestine, and food remains in the gastrointestinal tract, which is difficult to digest. It is very suitable for supplementing the deficiency of nutrients in the diet by drinking fruit juice.
When the juice is first squeezed out, the main nutrients in the fruit are preserved, but the vitamins in it are unstable in chemical properties and will gradually decompose and lose their activity. Some trace physiological active substances will gradually lose or become weaker forms. Like many fresh foods, the longer they are preserved, the more the nutrients will drop, the lighter the taste and the lighter the color will be. This is because its flavor substances and natural pigments are gradually decreasing. Because fruits and vegetables contain highly active antioxidants and other ingredients.
After an apple is squeezed into juice, many antioxidant components of enzymes are still alive, and some components are still changing. The fastest loss component is vitamin C. The loss rate of vitamin C varies from 20% ~ 100% when different kinds of fruit juices are stored under different conditions. Generally speaking, the greater the acidity of fruit juice, the longer the storage time of vitamin C, because vitamin C is the most stable under such conditions, and microorganisms are not easy to reproduce. Only minerals, dietary fiber and starch are resistant to storage and will not change much.
Therefore, freshly squeezed juice should be drunk as soon as possible. Such as hawthorn juice, orange juice and grape juice. The shelf life in the refrigerator is three days, and the peach juice and pear juice with low acidity are best drunk within two days.
Harm of drinking fruit juice 1: Fruit juice will make you anemic.
Fructose will hinder the body's absorption of copper. The lack of copper will affect the production of hemoglobin, which will lead to anemia. Einstein Medical Center conducted a retrospective survey of more than 0/00 anemia children in/kloc, and found that more than 80% of them had a hobby of drinking fruit juice.
Domestic survey data show that the physical development of children addicted to juice drinks is polarized, either too thin or too fat. Because the sugar content of fruit juice drinks is too high, children can get a lot of heat energy from it after drinking, which affects eating dinner. This will inevitably lead to insufficient intake of protein, some vitamins, minerals and trace elements, which will affect physical and intellectual development.
Hazard 2 of fruit juice: it is easier to increase fat accumulation.
Fruit juice contains a lot of fructose. Experts point out that eating a lot of fructose will increase the risk of heart disease and type 2 diabetes, because fructose is more easily converted into fat by the liver than glucose.
Many research reports show that fruit juice is good for health and can lose weight. In 2008, a survey of 3,665,438+08 children aged 2 to 65,438+065,438+0 found that children who drink at least 6 ounces (about 65,438+077 ml) of fruit juice every day are lighter and have more vitamins and minerals than children who don't drink fruit juice at all. However, many experts believe that this data only reflects the correlation between fruit juice and healthy diet, not the causal relationship.
Hazard 3 of fruit juice: Artificial colors affect IQ.
Whether it is a fruit-flavored drink or a low-concentration juice drink, artificial colors will be used. Bright colors will make consumers associate drinks with fruits in perception. When the juice content is too small to make colorful fruit-colored drinks, cheap artificial colors are the best choice.
The harm of artificial pigments to human body, especially children, has long been studied in modern nutrition.