Fruit Compound Paper Bag

The theory of preservation of fruits is to control the activities of microorganisms, slow down their normal life activities, and maintain their natural resistance to disease and disease resistance. Atmospheric storage method is a commonly used gas preservation technology method, but the investment is large, the cost is high, it is difficult to promote.
The paper-made fresh-keeping paper bag has good preservation and antiseptic effect on fruits. Its manufacturing method is simple, compared with the traditional preservation method, the cost is low, and it is particularly suitable for the long-distance transportation of fruits.
The basic principle of the fruit fresh-keeping paper bag The basic principle of the composite fresh-keeping paper bag manufacturing is that a certain amount of fresh-keeping agent is sandwiched between the kraft paper bag and the polyethylene plastic film. When the fruit is put into the paper bag, the preservative can be uniformly discharged in the closed paper container. A certain amount of carbon dioxide or sorbic acid gas to keep the fruit's fresh taste.
Reasons why fruits taste bad The fruit, under normal respiration, sucks oxygen from the air, oxidizes sugars and other substances, and decomposes carbon dioxide and water. After picking, the nutrients are gradually consumed, causing the fruit to age and wither. At the same time, the fruit is harmed during harvesting and transportation, and there will be the release of ethylene. It can stimulate the respiration of plants, speed up the metabolism, and promote the maturity and aging of fruits. Therefore, inhibiting the respiration of fruits and preventing the production of ethylene is the key to fruit preservation.
The role of preservatives SO2 is an ancient preservative, one of the preservation of fresh fruit paper is to produce SO2 salts, such as potassium metabisulfite, sodium metabisulfite and so on. These salts can release SO2 gas when exposed to the air and are easily soluble in water. It is a kind of preservative that can release hydrogen ions in aqueous solution.
The antibacterial action of SO2 interferes with various forms of enzymes in fruit cell structures, inhibits the delivery chain of the enzymes or end products of their chemical reactions, and deactivates enzymes. If the SO2 release is too fast, it will easily cause excessive fumigation of the fruit, make the fruit bleached, faded, produce odor; release too slowly, antiseptic antibacterial effect is not obvious, will not achieve antibacterial effect. In order to control the amount of SO2 released, a certain amount of a sustained release agent (alkaline) may be formulated to control the SO2 release rate because the SO2's ability to preserve and reduce bacteria is reduced as the pH value increases. The ratio of preservatives and sustained release agents is very important for the preservation of fruits.
It should be pointed out that sorbic acid can also be used as a preservative. The antibacterial effect of the antistaling agent is based on the inhibition of various enzymes in the microorganisms, such as the enzymes that metabolize carbohydrates. Its greatest feature is that it penetrates into the cell wall and functions in the microbial cells. Mixed with SO2, due to its synergistic or synergistic effect, better anti-corrosion effect. However, since sorbic acid is easily volatilized, the storage time of the fresh-keeping paper should not be too long.
The role of paper bag substrate Paper bag is the simplest and most efficient general package. It is widely used in two aspects of transport packaging and sales packaging. It can effectively prevent pests, dust and other harmful substances from invading fruits, and paper bags as preservatives. The carrier prevents the preservative from directly contacting the fruit. The high air permeability of the paper ensures that the SO2 and sorbic acid gas released by the preservative can diffuse through the pores of the paper and spread to the fruit surface. In order to improve the moisture resistance of paper bags and prevent the dissolving of preservatives, AKD should be used for internal sizing of paper bags.
The role of plastic film due to the permeability of plastic film, such as low density polyethylene water vapor transmission rate is relatively small, the gas permeability is relatively large, making the oxygen outside the paper bag into the bag to ensure the normal breathing of the fruit And carbon dioxide ethylene penetrated outside the membrane. Moisture and SO2 molecules are polar, poor in permeability, unable to penetrate outside the membrane, have a long residence time in the paper bag, and the preservative can last long.
When plastic films are combined with paper bags, the choice of adhesive is very important. In the test, water-soluble binders such as oxidized starch, polyvinyl alcohol, carboxymethyl cellulose, etc. may also be used and mixed according to a certain ratio.
The fruit fresh-keeping paper bag made of SO2 and sorbic acid as an antistaling agent has a clear effect on the preservation of fruits, and is particularly used for the long-distance transportation of fruits. Compared with the traditional preservation technology, the investment is less, and the convenience is simple and convenient. (Wen Jinwang Hubei)