Method for sterilizing low-acid fruit and vegetable juice by cooperation of freezing pretreatment and ultrahigh pressure

Abstract

The invention relates to a food sterilization treatment process, and aims to provide a method for sterilizing low-acid fruit and vegetable juice by the cooperation of freezing pretreatment and ultrahigh pressure. The method comprises the following steps of: placing fresh fruit and vegetable juice just processed in a container; freezing and storing at -20 DEG C for more than 24 hours; thawing thefrozen fruit and vegetable juice at room temperature; carrying out ultra-high pressure treatment of 400-600Mpa on the thawed fruit and vegetable juice; packaging and filling the ultra-high pressure treated fruit and vegetable juice to form commercial products. According to the invention, after freezing, thawing and ultrahigh pressure, the fruit and vegetable juice product can achieve commercial sterilization (the total number of colonies is less than 102CFU / ml, and the pathogenic bacteria-Escherichia coli are not detected) effect. And when the freezing time is more than 24 hours, the sterilization effect is basically unchanged, namely the freezing pretreatment is carried out for 24 hours. In addition, along with the improvement of pressure and pressure maintaining time in ultrahigh pressure processing, the sterilization effect is also gradually improved.

Description

technical field [0001] The invention relates to a food sterilization treatment process, in particular to a method for sterilizing low-acid fruit and vegetable juices through freezing pretreatment and ultrahigh pressure. Background technique [0002] Ultra-high pressure sterilization technology is a hot spot in the research field of food product sterilization technology at home and abroad in recent years. It is one of the most suitable sterilization technologies for industrialization, and it is also one of the best technical choices that can replace thermal sterilization in industrial sterilization treatment processes. Compared with heat sterilization technology, the biggest advantage of ultra-high pressure sterilization technology is that it can achieve room temperature sterilization, which has significantly less impact on the nutritional quality of food products than heat sterilization, and retains sensory qualities such as color and smell of the product itself to the greate...

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Problems solved by technology

[0003] However, in the research on the sterilization effect of ultra-high pressure, scholars at home and abroad have found that ultra-high pressure has a good bactericidal ability in a highly acidic environment (pH4.5) The bactericidal ability is limited, it is difficult to achieve the effect of commercial sterilization, and the bactericidal ability to spore-forming bacteria is even more limited

This limits the industrial application of this technology. Products that can be sterilized by ultra-high pressure are limited to high-acid products, while a large number of low-acid products still mainly use thermal sterilization technology.

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