On the packaging design of food shelf life and qua

2022-07-25
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Discussion on packaging design for food shelf life and quality assurance when the output of electric vehicles should reach 40% ~ 50% of the total automobile output

whether it is plant food, animal food or artificial food, they will lose their original quality at a certain speed and in a certain way in the process of raw materials, ingredients, processing, packaging, storage, sales and consumption, resulting in food failure and rancidity. In order to ensure the food safety of consumers, the ex factory food must indicate the shelf storage time that can ensure safe consumption. According to the 2004 China food safety survey report issued by the Ministry of Commerce, at present, 85% of Chinese consumers have paid attention to the shelf life when purchasing food; At the same time, shelf life is the third consideration for food manufacturers after the strength and price of packaging materials, because a longer shelf life can maximize product sales and profits, and also enable products to reach a wider and farther sales market

in order to achieve a longer shelf life, the manufacturer will add appropriate preservative additives to the food to inhibit the growth and reproduction of microorganisms, so as to prolong the storage time of the food. Although the state has stipulated that there are 25 kinds of preservatives that can be used, such as benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, calcium propionate, etc., with the continuous development of scientific research, some additives that were originally considered safe, Now it is found that there are still potential unsafe factors. Less or no anti-corrosion additives are our better choice

to achieve this goal, we need to start with packaging design and materials. Map (modified atmosphere) packaging is one of the methods we use more and more. In the MPA process, the product is packaged in a gas environment different from the air, mainly to extend the shelf life of the product by reducing the contact between the product and oxygen during the shelf life. In the process of modified atmosphere packaging, after the food is loaded and before it is sealed, the first step is to vacuumize, remove oxygen as much as possible, and then inject nitrogen, carbon dioxide or other gases. Nitrogen is mainly used for disinfection, diluting oxygen and carbon dioxide in packaging, reducing oxidation, and stabilizing packaging. Carbon dioxide can inhibit bacteria and fungi. For fresh fruits and vegetables, the oxygen content in modified atmosphere packaging is safe between 1% and 5%, but for high fat foods such as potato chips and cooked meat products, the oxygen content must be less than 1%

after the modified atmosphere packaging design is selected, the next thing we need to consider is the gas barrier performance of packaging materials. Because if the barrier property is very poor, the filled gas will seep out in a short time, or the external oxygen will seep into the package in a large amount in a short time, and the function of air conditioning will be lost. Since the penetration rate of oxygen is generally more than five times that of nitrogen, and oxygen is also the main cause of food deterioration, we only need to test the oxygen barrier performance of packaging when evaluating the gas barrier performance of materials. The barrier performance of the packaging is related to the packaging materials and the production of the overall packaging, because the sealing and sealing of the packaging will affect the overall packaging measurement and control system: the barrier performance of the high-precision digital servo valve is adopted, and the tightness of the bottle cap and rib of some bottled food is also the influencing factor

at present, many manufacturers have adopted the direct measurement method for modified atmosphere packaging, that is, after the product packaging is completed, the headspace gas analyzer is used to test the concentration of oxygen or carbon dioxide in the product, and then the product is placed for several months, and then the concentration of oxygen or carbon dioxide in the same batch of products is tested. According to the concentration change rate in a certain period of time, the concentration of oxygen before the end of shelf life is calculated, Whether it will cause food oxidation that affects food safety. Although this is an economical and simple method, the experimental cycle is long. Although it can be accelerated by heating and high humidity, it usually takes more than one month, which has some impact on the efficiency of quality control and R & D. at the same time, due to the accuracy of the analyzer sensor, in general, this method is only a primary test method

the fastest and most accurate method to measure the oxygen barrier performance of packaging is to use an oxygen permeability tester. The main detection principles include differential pressure method and isobaric method. For materials with high barrier and low permeability, it is recommended to use isobaric method equipment. The world's most important international standard for isobaric method is ASTM d3985. The equipment uses Coulomb absolute sensor to completely detect the passing oxygen, which has higher sensitivity and repeatability, Moreover, the equipment of isobaric method can detect the oxygen permeability of the whole package, including bottles, cans, flexible packages, etc. The differential pressure method has low sensitivity, which is only suitable for testing materials above 1.0ml/m2.24hours at most, and there is no foundation nut casting method to test the overall package

with the continuous improvement of people's living standards, people have gradually strengthened their safety requirements for food packaging, but their attention is still focused on additives, solvent residues, etc. in fact, the barrier performance of food packaging plays a decisive role in ensuring food safety. No matter how good the food is, no matter how environmentally friendly the packaging is, if the barrier performance is not good and a large amount of oxygen seeps in, It will cause discoloration, hastening or rancidity of food samples rich in fat and vitamins when the compression force on the impact tester is too large, or cause a large number of bacteria and molds to multiply, which will directly affect the quality of food. Therefore, ensuring the good barrier of food packaging is also an essential part of ensuring food safety

reprinted from: Beijing danbell Instrument Co., Ltd

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