Raisins are a type of food formed by dehydrating grapes with the help of heat from the sun or artificial heating. They are high in sugar and are a source of high-energy nutrients.

Raisins have low water content and are easy to transport and store. Due to the strict requirements of raisin production on grape varieties and the climate of producing area, grape production is only distributed in California, China, and other grape-producing areas.

Raisins get their nutrients from grapes, and they inherit many of the antioxidant benefits of grapes. In the process of grape drying, there is the concentration of substance components and decomposition and transformation of substance due to oxidation and other reasons. Raisins are a nutritious natural carbohydrate food source.

Fatty acids are one of the body's main sources of energy. The fatty acids in grapes come mainly from grape seeds and a little from the skin.

Resveratrol is a very important nutrient component of grapes and their related products. Resveratrol is a non-flavonoid polyphenol compound containing the structure of astragalus, which has antiviral, tumor inhibitory, antioxidant, free radical scavenging, anti-mutagenesis, blood lipid-lowering, cardiovascular protection, anti-aging, beauty, and other effects.

Raisins may reduce the risk of cardiovascular disease. Raisins have been shown to lower blood pressure.

Traditionally, raisins have been blamed for cavities due to their sugar and stickiness. In recent years, several studies have suggested the opposite, suggesting that raisins do not cause cavities. Three main factors contribute to tooth decay: low oral pH, food sticking to the teeth, and bacterial activity. Studies have shown that eating raisins alone does not lower mouth pH below the threshold for enamel dissolution.

And raisins contain a variety of antioxidants, such as oleanolic acid, which inhibits the bacteria Streptococcus mutants, which causes tooth decay.

Sticky fibers can delay the passage of food from the stomach into the small intestine, causing feelings of satiety, while reducing glucose concentration in the blood and indirectly affecting insulin stability. Can improve blood cholesterol levels. Insoluble dietary fiber is difficult for the human body to absorb, so that stool is loose and improves constipation. Raisins contain both types of fiber, so daily consumption can increase your total dietary fiber intake.

The antibacterial mechanism of food is different from that of antibiotics, which is not easy to make bacteria develop drug resistance, which also makes the antibacterial activity of grape and raisin extract a good application prospect. The composition of raisins is relatively complex, and the bacteriostatic effect may be the result of a variety of different active ingredients.

Raisins should be made from grapes with thin skin, soft flesh, a beautiful appearance, and high sugar content. After harvesting, cut off small or damaged seeds and cut them into smaller bunches if the bunches are too large and spread them on a plate.

To speed up drying and shorten the evaporation time of water, lye treatment can be used. Dip for 1 to 5 minutes in a solution of 1.5 to 4 percent sodium hydroxide. After soaking the raw materials in alkali, rinse them in clean water immediately. The drying time of fruits treated with alkali can be shortened by 8 to 10 days.

Leave the grapes in the sun for approximately 10 days. When part of the surface is dry, turn them all over. Under clear weather, the total drying time is usually 20 to 25 days. The fruit used to make raisins must be ripe. Raisins contain only 15-25% water and up to 60% fructose, making them very sweet.

As a result, raisins can be preserved for a long time, and the fructose in them may crystallize over time, but this does not affect their edibility. Raisins can be eaten as a snack or used in pastries, and some local cooks use raisin seasoning.