文档介绍：Canning food means sterilizing it and keeping it sterile by sealing it in containers made from either glass or tin.
Chapter 10 Canning of fruits and vegetables
The first section Principle of canning
Principle of Canning
1、Sealing the container immediately after heat processing and making it impossible for anisms to invade the food and re-infect it.
2、Sealing creates a vacuum inside the container. This vacuum protects the color and flavor of the product, helps to retain the vitamin content, prevents rancidity due to oxidation.
一、Canning and anisms
Under the normal canning conditions, heat may be applied for destruction of mildew and microzyme. Bacteria is the most important anism that leads to corrosion of can.
The first section Principle of canning
二、Determination of sterilizing F value of canning
1、Significance of canning products sterilizing
(1)kill the anisms caused corrosion and produced toxin.
(2)have cooking effect, improve the texture, taste and appearance, reach the edible requirement.
Intention of sterilizing is different from that of bacteriology, the later refers to kill all anisms, but the former only reach the condition mercial asepsis.
The first section Principle of canning
2、Selecting of sterilizing object杀菌对象菌的选择
芽孢的耐热性比营养体强,若有芽孢菌存在时,则应以芽孢菌作为主要的杀菌对象。
By determining that bacterial heat resistance changed with medium pH, there followed the classification of foods into groups, such as acid and nonacid foods.
The first section Principle of canning
,将mildow霉菌和microzyme酵母菌这类耐热性低的微生物作为主要杀菌对象,所以比较容易控制和杀灭。,对象菌为anaerobic clostridium。
在罐头工业上一般采用产生toxin(毒素)的clostridium botulinum肉毒梭状芽孢杆菌和aliphatic bacillus脂肪芽孢杆菌()为杀菌对象菌。
The first section Principle of canning
3、Determination of sterilizing F value
It is necessary to know the time and temperature required to adequately sterilize canned foods.
This procedure involves not only the destruction of spores by moist heat, but also the rate of heat ration and heat