On the influencing factors and Countermeasures of

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Talking about the influencing factors and Countermeasures of sterilization intensity of flexible packaging (Part I)

Abstract: by analyzing the influencing factors of sterilization intensity of flexible packaging, this paper puts forward the countermeasures when the sterilization intensity changes due to the change of conditions in the international sterilization operation, so as to prevent the phenomenon of insufficient or excessive sterilization

key words: sterilization intensity; Influencing factors; Prevention

our company is a factory specializing in the production of edible fungus soft packaging products, and 100% of the products are sold to Japan. As we all know, for a food enterprise, especially an export food enterprise, product quality is related to the survival of the enterprise. Although our company adopts the full-automatic pressurized hot water conditioning sterilization device imported from Japan and adopts the sterilization formula provided by QP Corporation of Japan, because the sterilization intensity will be affected by many factors, under the same sterilization conditions, many unexpected factors will change, which may cause insufficient or excessive sterilization of products, resulting in quality accidents. In order to prevent this phenomenon from increasing the export proportion of emerging countries, the factors affecting the sterilization intensity are analyzed. And put forward corresponding preventive measures

1 determination of sterilization intensity

usually, first determine under what conditions a certain variety of sterilization is most suitable. Sterilization of food (both for 2. The company has a fixed maintenance service department and professional maintenance engineers to heat and sterilize under pressure). The higher the temperature, the shorter the time of bacterial death, but the changes in the composition of the food itself, the loss of flavor and other phenomena are also accelerated. For the equipment selected by our company, the sterilization intensity is measured by F value, which is calculated by measuring the central temperature of the product through the temperature probe placed on the product. Since our sterilizer equipment is equipped with an f-value calculator, the f-value can be calculated and displayed on the sterilizer computer disk only through the central temperature returned by the temperature probe placed on the product. In the production of edible fungus flexible packaging of our company, generally, when the F value reaches 4 ~ 6, the required sterilization conditions are met, that is, the set sterilization temperature, pressure and time can meet the sterilization requirements. However, since the temperature of the product is measured by inserting the probe into the plastic bag and placing it in the middle of the product, the position of the probe is very critical. This equipment adopts pressurized hot water circulation sterilization. The product is also a flexible plastic bag. The position of the probe is affected by the installation method, the number of products, the shape of products, the movement of the plastic bag in the processing pot and other factors, so it is difficult to accurately reflect the actual center temperature of the product. That is to say, if the position of the probe is inaccurate, the actual reflection is not the central temperature of the product, resulting in false F value. It will cause changes in sterilization intensity. Therefore, we must analyze the factors that affect the sterilization intensity, and control each sterilization link without error, so as to ensure the actual sterilization intensity

2 factors affecting sterilization intensity

2.1 heating temperature rise time

pressurized hot water conditioning sterilization device uses hot water circulation for sterilization, and hot water needs a certain heating time to reach the set sterilization temperature. Generally, the heating and temperature rise stage is controlled within 13 ~ 15 minutes. If the determined sterilization conditions are 120 ℃ and 30 rain, that is, the sterilization time can be calculated only when the temperature of the treatment tank reaches 120 ℃. The length of the heating process will affect the sterilization intensity of the product. Generally, affected by the distribution of steam load in the plant, the steam volume will fluctuate. If other processes use too much steam at the same time, it will cause insufficient sterilization and heating steam, which will prolong the heating time, resulting in the prolonged soaking time of products in hot water and affecting the quality of products. If the heating time exceeds the specified time due to insufficient steam, the steam should be adjusted immediately to return to normal state, and the sterilization time should be calculated from the time when the sterilization temperature is reached. In addition, if the temperature rise speed is too fast and the sterilization time is lower than the specified time, the sterilization time should be extended according to the lower limit difference between the actual temperature rise time and the specified temperature rise time, which is a key point for the control of the heating stage

2.2 heat transfer during sterilization

soft packaged food is sterilized after packaging with various packaging materials with good development momentum of China's new material industry. In fact, the food filled in the bag is heated and sterilized through the heat transfer process of water, packaging bag and food. There are many aspects that affect the heat transfer. First, the material and thickness of packaging bags. Different batches of packaging bags will have different materials and thickness. If the original sterilization conditions are still maintained, the heat transfer penetration will be different, and the actual sterilization intensity F value will change. Therefore, the setting of sterilization conditions should be adjusted accordingly when changing packaging bags. On the other hand, the temperature conductivity of food and the thickness of food also have a great impact on the actual sterilization effect, as shown in Table 1

it can be seen from the test table that when sterilizing the soft packed flavored dry shiitake mushrooms, when the product thickness is 17 l`rlrn and the F value is 5.0, it needs 35 rain at 113 ℃ and 29 rain at 118 ℃; When the thickness is 26 itiitiititi, it needs to sterilize 43 rain at 113 ℃ and 35 rain at 118 ℃ to reach the F value of 5.0. It can be seen that with the increase of the thickness of food, the sterilization time must also be extended. In our normal production, sometimes there are serious potential safety hazards at the same time. If we change the size of the packaging bag or adjust the filling amount, we must correct the sterilization conditions accordingly

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