Packaging quality requirements and technology of t

Quality requirements and technology of rice and other agricultural products packaging

rice

the basic requirements of rice packaging are mold proof, insect proof, fresh-keeping and convenient access to Sichuan; With the change of lifestyle, consumers' demand for rice shows a trend of small amount, fresh and high quality. On the shelves of Jiduo supermarket, small-sized bagged rice designed according to the needs of the family of three has appeared one after another, with the weight as small as 2.5kg or even 0.5kg per bag. The traditional packaging forms such as gunny bags and plastic woven bags are far from meeting the requirements of this industry. The trend of miniaturization and refinement of rice packaging has emerged in Japan and Zhejiang, and small grain packaging has gradually become an important way of grain sales

at present, domestic rice deep-processing enterprises generally use PE/PP/PA composite plastic packaging bags. Compared with traditional packaging, this kind of packaging has the characteristics of extending the shelf life of rice, and its moisture-proof, mildew proof and insect proof effects are very ideal. In addition, the patterns and trademarks are beautifully printed, and the words and bar codes are clear, which can attract customers and promote sales. However, there are still many disadvantages of plastic composite packaging bags: first, although the shelf life of plastic composite packaging bags is improved compared with traditional woven bags, it is only about a year; The cost of packaging bags is high. For some high-end 500g rice, the cost of packaging bags is about 0.3 yuan, and the cost is as high as 10%; Composite bag packaging is prone to wrinkling when sealing and heat sealing, which affects the tightness and aesthetics of the bag, especially in small bags of 5kg, 10kg, 15kg, etc. In addition, the compressive strength of bags is not enough, and some products are inflated. However, in the process of transportation, there are often problems of poor stability and low production efficiency in empty packaging machines, which are easy to cause bag breakage and lax sealing in production

relatively speaking, the quality of foreign products is better. For example, the semi-automatic measuring small packaging machine of Sasaki company in Japan adopts the computer sensor automatic measuring system, which has high measurement accuracy and fast speed. Outside the bagging of Chenren factory, the juice volume, filling and inflation are automatically completed in one machine, and equipped with a heat sealing device, which is easy to operate and highly intelligent. A Japanese company also introduced a strong sealing packaging bag, which is made of a kind of plastic called "chichlan", which has excellent oxygen isolation. Using this kind of plastic bag to pack new rice has a particularly good fresh-keeping effect, which can keep the color, aroma and taste of rice unchanged for a long time, and the carbon dioxide produced in the bag can also prevent insects and mold. Bulgarian agricultural experts have invented a simple and economical new method of preserving rice: dry the rice a little, put it into a large bag made of polyethylene material, and then seal it. The rice preserved in this way will neither volatilize water nor become moldy. It can be preserved until the spring of the next year, and the nutritional components of grains will not be reduced at all

in recent years, many new packaging technologies are being applied to rice packaging. For example, semiconductor materials such as titanium alloy and silicon dioxide are used as catalyst rods in the photocatalyst technology of polyethylene film. Because the metal doped with human is under the action of catalyst phosphorus and light, catalytic reaction and photochemical reaction occur. After the photocatalyst polyethylene bag is filled with rice, because the semiconductor electrons are activated by light energy, it is in a very high non-equilibrium state, forming a temperature trend in the bag, promoting the decomposition of water molecules in rice and other grains, so as to achieve the effect of insect prevention, mold prevention and fresh preservation

fresh meat

the total output of pork, mutton, beef and other meat produced in China accounts for about one third of the world's total output. Fresh meat is different from cooked meat. Even those pigs, cattle, sheep and chickens slaughtered after quarantine must pay attention to health and safety in storage, transportation and marketing, otherwise they will be polluted and affect the health of consumers. The pre-sale packaging of fresh meat is of great significance to maintain the quality of fresh meat

spontaneous modified atmosphere film packaging, also known as inflatable packaging (map), is a new packaging technology that appeared in the American scarf Market in the mid-1990s. At present, map has been widely used in the field of fresh-keeping. By packaging on the processing site of fresh meat, map can ensure the hygiene of food and prolong the shelf life by more than three times. Traditional fresh meat packaging is filled with nitrogen, while map is filled with 80% oxygen and 20% carbon dioxide. Oxygen keeps the meat fresh, and carbon dioxide can well inhibit the survival of bacteria, which can effectively extend the shelf life

compared with the fresh meat in ordinary packaging, the fresh meat in ordinary packaging began to deteriorate after twoorthree days, while the meat in map packaging was fresh after twoorthree days. The shelf life of traditional packaged meat is only about 2 days, and it can only be discarded if it is not sold at the expiration. However, map technology can ensure the freshness of sold meat for a long time, thereby reducing waste. In addition, using map packaging can also reduce the distribution frequency and save logistics costs

tea

green tea mainly contains components such as ascorbic acid, tannin, polyphenol compounds, catechuic acid fats and carotenoids. These ingredients are easily affected by oxygen, temperature, humidity, light and environmental odor. The water content in tea should not exceed 5%, and 3% is the best for long-term storage, otherwise the ascorbic acid in tea is easy to decompose, and the color, aroma, taste, etc. of tea will change, especially at higher temperatures, the deterioration speed will be accelerated. The oxygen content in the package must be controlled below 1%. The urban construction department will also try new materials on Xindadi pedestrian overpass. Excessive oxygen will lead to oxidation and deterioration of some components in tea. For example, ascorbic acid is easily oxidized to deoxyascorbic acid, and further combines with amino acids to produce a pigment reaction: worsen the taste of tea. Tea fat contains a considerable amount of unsaturated fatty acids, which can be oxidized automatically to produce carbonyl compounds such as aldehydes and ketones and enol compounds, which can also make the aroma disappear, astringency fade and color darken in tea. Because tea contains chlorophyll and other substances, when packaging tea, it must be shaded to prevent the photocatalytic reaction of chlorophyll and other components. Moreover, ultraviolet radiation is also an important factor that causes the deterioration of tea. The fragrance of tea is very easy to lose, so materials with good air tightness must be used for fragrance preservation packaging. In addition, tea is very easy to absorb the odor of the outside world, so that the aroma of tea is infected. The increase of temperature will speed up the oxidation reaction of tea and cause the gloss of tea surface to fade. Therefore, tea is suitable for preservation at low temperature

in terms of moisture-proof, packaging materials with good moisture-proof performance can be selected for moisture-proof packaging, such as composite films based on aluminum foil or aluminum foil evaporation film, which can be highly moisture-proof. In terms of anti-oxidation, 100kN, 150kn, 200kn, 300KN can be calibrated successively by vacuum packaging method or inflatable packaging method When 300KN is completed, reduce the concentration of oxygen. Vacuum packaging is to put tea into the laboratory where the soft film bag with good air tightness is located, and there should be no vibration. When packaging, vacuum the bag, and then seal it. In case of inflatable packaging, nitrogen should be filled at the same time of extracting air. The purpose of nitrogen filled packaging is to protect the color, aroma and taste of T, kg, N and kn leaves, which are tea power units, and maintain their original quality. In addition, the sealed deoxidizer packaging technology can also be used. The deoxidizer can use the oxidation reaction of iron and iron compounds or the oxidation reaction of sugar and reducing ketones. The deoxidizer reacts with oxygen, so that the packaging container is in a low oxygen state. When using deoxidizer, the basic material of the composite film used is vinylidene chloride coating. To reduce the transmittance, ultraviolet inhibitors can be added to the packaging materials or the light transmittance can be reduced by printing and coloring. In addition, composite materials based on aluminum foil or vacuum aluminum coating can also be used for shading packaging

author/shenxueyou

source: Packaging News