Oxygen Absorbers for Long Term Food Storage
People pay more and more attention to food preservation while developing food production and food processing. In order to achieve the purpose of food preservation and prolong the shelf life of food, various preservation technologies are adopted, such as low temperature preservation, high temperature preservation, dehydration preservation, osmotic pressure of food, hydrogen ion concentration of food, irradiation preservation, air isolation, addition of preservative, using of deoxidizer and so on.
There are three reasons for food spoilage:
1. Biological changes -- insect's reproduction ,the reproduction of microorganisms such as bacteria, mold, yeast
2. Chemical changes - Chemical changes of acid decomposition, Browning and composition of oil by oxygen and ultraviolet light;
3. Physical changes -- moisture transfer, evaporation, drying, influence of moisture, starch aging, etc.
Common methods of preserving food
1. Refrigeration, freezing, drying, salt preservation, sugar preservation, smoking preservation, heating preservation;
2. Ultraviolet sterilization, far infrared sterilization, radiation sterilization, ultra-high pressure sterilization, spray or add alcohol sterilization;
3. Adjust water activity value and PH value;
4. Vacuum preservation and full of inert gas;
5. Added food additives such as antibacterial agents and antioxidants;
6. Seal the deoxidizer.
Deoxidizer has been invented for a long time, but it has been used in food preservation for only about 20 years, but it has occupied a very important position in various preservation technologies. Compared with other preservation technologies, the application of deoxidizer preservation is undoubtedly the most convenient and economical method.
Mechanism of action of deoxidizer : oxygen is one of the important factors causing food spoilage. Many ingredients in food are related to the presence of oxygen closely. From the view point of biochemical , fats oxidize when exposed to oxygen, vitamins and a variety of amino acids lose their nutrients, and oxygen also discolors or discolors unstable pigments.From the perspective of microorganism, most microorganisms will grow well in the aerobic environment. Even if the oxygen content is as low as 2%~3% in the packaging environment, most aerobic bacteria and facultative anaerobic bacteria can still grow, the biochemical reaction will still take place.
Through the chemical reaction, the oxygen in an airtight container , can be removed in a short period of time . Then making food kept in anaerobic condition (O2 concentration below 0.01%), to effectively control the growth of bacteria, mold and other microbes, to prevent oil oxidation, thus can effectively keep food's fresh color, aroma, taste, prevent vitamins and other nutrients were oxidative damage, prolong shelf life.
According to its composition, deoxidizer can be divided into two type: one is a deoxidizer that using inorganic matrix as the main body, such as reducing iron powder series deoxidizer, sulfite series deoxidizer; The other is the deoxidizer which using organic substrate as the main deoxidizer, such as enzymes, ascorbic acid, oleic acid.
The characteristics of using deoxidizer to preserve food:
1. Complete removal of oxygen, and the oxygen concentration in the package can be rapidly reduced to below 0.01% in a short time;
2. Maintain long-term anaerobic state;
3. It has a wide use effect and it's effective for oxidation and discoloration;
4. Suitable for powder and liquid food;
5. The taste of food will not change;
6. Separated from food, not with food intake into the body, can be used safely
7. Features such as appropriate price, small size and convenient use make it easier to popularize;
8. Convenient for production, no matter large or small;
9. The oxygen indicator which has been developed at the same time, can be used for checking whether the oxygen is none or not , and bring convenience to users.
Deoxidizer can be used in baking food to prevent mildew. It can be used to prevent myoglobin from being oxidized during the storage of fresh meat, so as to remove oxygen and protect color. For cooked meat products, it has the function of inhibiting fat oxidation and preventing mould growth. Inside the package of tea leaves, it can prevent the tea leaves from fading, discoloration and vitamin oxidation. Therefore, if it can be moisture-proof and light-proof, plus deoxygenation package, it can keep the green tea leaves fresh and tender after being stored at a low temperature for one year. Deoxygenated packaging is used in solid beverage to remove oxygen from emulsified structure and prevent oil oxidation through gas balance. Deoxygenated packaging in cereal after remove oxygen can prevent moth and mildew. It can be used in peanut, walnut and sesame to prevent oil failure. If using in fruit and vegetable dry products or powders, can prevent vitamin degeneration and discoloration.