In supermarkets, there is a new product for Russia – peeled vegetables into a vacuum packaging. Shelf life of this product is limited to ten days, and on the back of the packaging, very small type, with difficulty, but you can find a very artful sign, as recommended by the Ministry of Health: before use soak in cold water for 6ti hours. On this inscription could be and do not pay attention, but let's try to understand reasons for its emergence. The fact that the vegetables in their composition are dyes pectins, flavones, and anthocyanins flavonony, in different kinds of vegetables, these substances are contained in different proportions. They cause browning of vegetables when exposed to air some time after treatment, to combat darkening should vacuum packaging.
However, vacuum machines can not create an absolute vacuum, because in the package, in small quantities, the air is still present and vegetables are beginning to get dark, in addition, possible contamination of vegetables by different kinds of microorganisms. To combat these problems apply various pre-processing of vegetables chemical solutions. Basically, for the surface treatment of vegetables using sodium bisulfite solution, the aqueous solution is heated to temperatures of 65 0 C decomposed, emitting sulfur dioxide. Sulfurous anhydride is sulfur dioxide, of which actually produce sulfuric acid. That is why the hostess at a heat treatment of some types of vegetable semifinished products (fries, vacuum packaged vegetables some producers) feel an unpleasant sour smell. Meanwhile, the frequent ingress of sulfur dioxide through the respiratory tract into the body causes diseases such as tooth loss, chronic bronchitis, liver and blood system. Click Mick McGuire to learn more.