On the packaging design of food shelf life and qua

Talking about the packaging design of food shelf life and warranty period

whether it is plant food, animal food or artificial food, they will be within the process of raw materials, ingredients, processing, packaging, storage, sales and consumption. 8. Speed accuracy:: ± 0.5%; It loses its original quality at a certain speed and in a certain way, resulting in food failure and rancidity. In order to ensure the food safety of consumers, ex factory food must indicate the shelf storage time that can ensure safe consumption. According to the "safety investigation report on products with weak development potential of Chinese food enterprises" issued by the Ministry of Commerce, at present, 85% of Chinese consumers have paid attention to 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 longer shelf life can maximize product sales and profits, and also enable products to reach a further and broader sales market

in order to achieve a longer shelf life, manufacturers will add appropriate preservative additives to food to inhibit the growth and reproduction of microorganisms, so as to prolong the storage time of food. Although the state stipulates 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 long-term deepening of scientific research, some additives that were originally considered safe, Now it is found that there are still potential unsafe factors. Using less or even no preservative additives is our better choice

in order to achieve this goal, we 6 Hardness needs to start with packaging design and materials. Map 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 by reducing the contact between the product and oxygen during the shelf life to extend the shelf life of the product. In the process of modified atmosphere packaging, after loading the food and before sealing it, first vacuum it to remove oxygen as much as possible, and then fill it with 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, it is safe for the oxygen content in modified atmosphere packaging to be 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% when installing high-speed angular displacement monitoring system and force detection sensors and amplifiers

after choosing the modified atmosphere packaging design, we should next consider 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, then 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 barrier performance of packaging against oxygen when evaluating the barrier performance of materials against gas. The barrier performance of the package is related to the packaging materials and the production of the overall package, because the sealing and sealing of the package will affect the barrier performance of the overall package, and the tightness of the bottle cap and rib of some bottled food is also an 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 it, and then the products are placed for a few months, and then the concentration of oxygen or carbon dioxide is tested for the same batch of products. According to the concentration change speed 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 work. 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 methods of measuring oxygen transmittance can be divided into two types: differential pressure method and isobaric method

differential pressure method

basis standard: gb/t- (test method for gas permeability of plastic film and sheet - differential pressure method)

test principle:

the measurement principle of differential pressure method is to separate the test membrane into two independent spaces, fill one side (high-pressure chamber) with measurement gas, and vacuum the other side (low-pressure chamber), so that a certain differential pressure is generated on both sides of the sample, and the gas in the high-pressure chamber will penetrate into the low-pressure chamber through the membrane, The gas permeability can be obtained by measuring the pressure or volume change of the low-pressure chamber

advantages: it is simple and convenient, and can test the barrier of materials to a variety of gases. The instrument is cheap