阅读说明：本技术 一种减少热加工副产物的低温结合超高压灭菌牛奶的制备方法 (Preparation method of low-temperature and ultrahigh-pressure combined sterilized milk for reducing thermal processing byproducts ) 是由 张燕 吴士莹 张金会 于 2019-11-12 设计创作，主要内容包括：本发明涉及液态乳制品加工领域,提供了一种减少热加工副产物的低温结合超高压灭菌牛奶的制备方法。使用原奶检验合格的新鲜生牛乳作为原乳,方法包括：1)低温预处理：原料乳净乳后50℃保温10-20min,15-20MPa下均质；2)罐装：将步骤(1)中预处理好的原乳灌装于无菌食品级PET瓶中；3)超高压灭菌：将步骤(2)中罐装好的牛乳置于超高压装置中,在500-600MPa下处理10-15min,即可得到减少了热加工副产物的灭菌牛奶。使用本发明方法中的低温结合静态超高压处理,能有效减控传统热加工液态奶中产生的热加工副产物包括糠氨酸、5-羟甲基糠醛、羧甲基赖氨酸和羧乙基赖氨酸降低营养损失,提高液态奶的质量安全性。(The invention relates to the field of liquid dairy product processing, and provides a preparation method of low-temperature and ultrahigh-pressure sterilized milk for reducing thermal processing byproducts. The method uses the fresh raw milk qualified by raw milk inspection as raw milk, and comprises the following steps: 1) low-temperature pretreatment: cleaning raw materials, keeping the temperature at 50 deg.C for 10-20min, and homogenizing under 15-20 MPa; 2) canning: filling the raw milk pretreated in the step (1) into a sterile food-grade PET bottle; 3) ultra-high pressure sterilization: and (3) placing the canned milk in the step (2) into an ultrahigh pressure device, and treating for 10-15min under 500-600MPa to obtain the sterilized milk with reduced thermal processing by-products. By combining the low temperature with the static ultrahigh pressure treatment in the method, the thermal processing byproducts generated in the traditional thermal processing liquid milk, including the furfuryl acid, the 5-hydroxymethyl furfural, the carboxymethyl lysine and the carboxyethyl lysine, can be effectively reduced and controlled, the nutrient loss is reduced, and the quality safety of the liquid milk is improved.)

1. A preparation method of low-temperature and ultrahigh-pressure combined sterilized milk for reducing thermal processing byproducts is characterized by comprising the following steps: the method comprises the following steps:

1) low-temperature pretreatment: cleaning raw materials, keeping the temperature at 50 deg.C for 10-20min, and homogenizing under 15-20 MPa;

2) canning: filling the raw milk pretreated in the step (1) into a sterile food-grade PET bottle;

3) ultra-high pressure sterilization: putting the canned cow milk in the step (2) into an ultrahigh pressure device, wherein the working medium is as follows: water, working medium temperature: treating at 3-6 deg.C under 500-600MPa for 10-15min to obtain sterilized milk with reduced thermal processing by-products.

2. The method for preparing low-temperature combined ultra-high-pressure sterilized milk with reduced thermal processing byproducts according to claim 1, wherein the raw milk in step 1) is qualified fresh raw milk.

3. The method for preparing low-temperature combined ultra-high-pressure sterilized milk with reduced thermal processing by-products according to claim 1, wherein the method comprises the following steps: the method comprises the following steps:

1) low-temperature pretreatment: cleaning raw materials, keeping the temperature at 50 ℃ for 15min, and homogenizing under 18 MPa;

2) canning: filling the raw milk pretreated in the step (1) into a sterile food-grade PET bottle;

3) ultra-high pressure sterilization: putting the canned cow milk in the step (2) into an ultrahigh pressure device, wherein the working medium is as follows: water, working medium temperature: treating at 5 deg.C under 550MPa for 12min to obtain sterilized milk with reduced thermal processing by-products.

Technical Field

The invention relates to a preparation method of low-temperature and ultrahigh-pressure combined sterilized milk for reducing thermal processing byproducts, and belongs to the field of liquid dairy product processing.

Background

Cow milk is rich in nutritional values, such as protein, sugar, fat, a large amount of minerals, vitamins and the like, and the nutritional substances are easily absorbed by human bodies and bring beneficial effects to human health. In order to ensure the edible safety and the product quality, the fresh milk needs to be subjected to proper heat treatment before entering the market, so as to kill pathogenic microorganisms and prolong the shelf life as much as possible. Currently, pasteurization, ultra pasteurization (ESL), ultra high temperature flash pasteurization (UHT), and the like are widely used in commercial milk and dairy products, and pasteurized milk, ESL milk, and UHT milk are common commercially available liquid milk.

Because milk is rich in milk protein and lactose, the heat treatment can kill pathogenic bacteria and microorganisms causing milk spoilage and simultaneously generate Maillard reaction, and Maillard reaction products not only influence the nutritional value of the milk product, but also change the sensory value and functional characteristics of the milk, and simultaneously generate substances and even carcinogens which have potential harm to human bodies. Typical thermal processing byproducts in dairy products are mainly furfuryl acid, 5-hydroxymethylfurfural (5-HMF), carboxymethyl lysine (CML), carboxyethyl lysine (CEL) and the like, and traditional thermal processing or over-processing causes the generation of the byproducts. Therefore, the dairy industry urgently needs improvement and innovation of processing technology, and on the premise of ensuring the microbial safety, the nutrition loss and safety risk of the dairy product are reduced, and the nutrition quality of the dairy product is improved.

The ultrahigh pressure technology is a novel cold sterilization technology, can effectively kill microorganisms, and keeps the nutritional ingredients in milk while ensuring the biological safety. At present, the sterilization agent has been successfully used for sterilizing products such as aquatic products, meat products, fruit juice and the like, and only a small amount of products are adopted in Australia in the processing of dairy products. At present, the combination of low-temperature pretreatment and static ultra-high pressure sterilization technology is not applied to dairy product processing.

Disclosure of Invention

In order to solve the problems that the heat processing by-products of the dairy products are generated and the nutritive value of the dairy products is reduced due to the Maillard reaction caused by the heat sterilization of the existing fresh milk, the invention provides the preparation method of the milk by combining low temperature and ultrahigh pressure sterilization, and provides a new processing technology for reducing the heat processing by-products in the dairy products, ensuring the quality safety of the dairy products and improving the nutritive value of the dairy products.

The technical problem to be solved by the invention is realized by adopting the following technical scheme:

1) low-temperature pretreatment: cleaning raw materials, keeping the temperature at 50 deg.C for 10-20min, and homogenizing under 15-20 MPa;

2) canning: filling the raw milk pretreated in the step (1) into a sterile food-grade PET bottle;

3) ultra-high pressure sterilization: and (3) placing the canned milk in the step (2) in an ultrahigh pressure device (the temperature of a working medium is 3-6 ℃) and treating for 10-15min under the pressure of 500-.

In the invention, the raw milk in the step 1) is fresh raw milk qualified by raw milk inspection.

Preferably, the preparation method of the low-temperature and ultra-high pressure sterilized milk with reduced thermal processing by-products comprises the following steps:

1) low-temperature pretreatment: cleaning raw materials, keeping the temperature at 50 ℃ for 15min, and homogenizing under 18 MPa;

2) canning: filling the raw milk pretreated in the step (1) into a sterile food-grade PET bottle;

3) ultra-high pressure sterilization: putting the canned cow milk in the step (2) into an ultrahigh pressure device, wherein the working medium is as follows: water, working medium temperature: treating at 5 deg.C under 550MPa for 12min to obtain sterilized milk with reduced thermal processing by-products.

The invention has the effect that the low-temperature combined static ultra-high pressure sterilization technology is used for replacing the existing heat sterilization technology to process the fresh milk, so that the heat processing byproducts including the furfuryl acid, the 5-HMF, the CML and the CEL generated by the traditional processing technology in the liquid dairy product are obviously reduced. The invention improves the safety of the liquid dairy product to a certain extent and keeps the original nutritive value of the fresh milk to the maximum extent, thereby improving the quality of the dairy product and reducing the potential safety risk of the traditional dairy product.

Drawings

FIG. 1 shows the comparison of the content of furfuryl acid in liquid milk produced by different processes

FIG. 2 is a graph comparing the content of 5-hydroxymethylfurfural (5-HMF) in liquid milk produced by different processing techniques

FIG. 3 is a graph comparing the content of carboxymethyl lysine (CML) in a bound state in liquid milk produced by different processing techniques

FIG. 4 is a graph comparing the content of bound carboxyethyl lysine (CEL) in liquid milk produced by different processing techniques

Detailed Description

The present invention will be further described with reference to the following examples.

Example 1

(1) Low-temperature pretreatment: cleaning milk, keeping the temperature of the original milk at 50 deg.C for 20min, and homogenizing under 15 MPa;

(2) canning: filling the raw milk pretreated in the step (1) into a sterile food-grade PET bottle;

(3) ultra-high pressure sterilization: and (3) placing the canned milk in the step (2) in an ultrahigh pressure device (the temperature of a working medium is 3-6 ℃) and treating for 15min under 500MPa to obtain the sterilized milk with reduced thermal processing byproducts.

Example 2

A preparation method of low-temperature and ultrahigh-pressure combined sterilized milk for reducing thermal processing byproducts comprises the following steps:

1) low-temperature pretreatment: cleaning raw materials, keeping the temperature at 50 ℃ for 15min, and homogenizing under 18 MPa;

2) canning: filling the raw milk pretreated in the step (1) into a sterile food-grade PET bottle;

3) ultra-high pressure sterilization: putting the canned cow milk in the step (2) into an ultrahigh pressure device, wherein the working medium is as follows: water, working medium temperature: treating at 5 deg.C under 550MPa for 12min to obtain sterilized milk with reduced thermal processing by-products.

Table 1 and fig. 1-4 show that, in comparison with pasteurized, ESL and UHT milk on the market, examples 1 and 2 significantly reduce the contents of furfuryl acid, 5-hydroxymethylfurfural (5-HMF), bound Carboxymethyllysine (CML) and bound Carboxyethyllysine (CEL) in the liquid milk while reaching standards for microbial detection. Compared with UHT milk, the liquid milk sterilized by low temperature and ultrahigh pressure can reduce the thermal processing by-product generated by thermal processing by more than 50 percent; the production amount of advanced glycation end products (CML, CEL) is also obviously lower than that of pasteurized milk and ESL milk, so that the nutritional value of the fresh milk is maintained to the maximum extent, and the nutritional quality and the edible safety of the liquid milk are improved.

TABLE 1 microbiological indicator of milk sterilized at low temperature in combination with ultra-high pressure

(+) represents the detection, and (-) represents the non-detection