阅读说明：本技术 一种零乳糖稀奶油及其制备方法 (Lactose-free cream and preparation method thereof ) 是由 崔树勇 李亚杰 尹玉庆 于 2020-04-27 设计创作，主要内容包括：本发明提供一种零乳糖稀奶油的制备方法,所述方法包括在混料过程中加入经检验合格的、温度为4～8℃的生牛乳和乳糖酶,搅拌均匀,在4～8℃条件下水解24～35小时；或者在混料过程中将经检验合格的、温度为4～8℃的生牛乳经过巴氏杀菌65～85℃/15秒,并降温至38～42℃后,添加乳糖酶,搅拌均匀,在38～42℃条件下水解2～4小时；再取样检测,要求乳糖水解率在98%以上,乳糖残留量在0.3%以下时,获得零乳糖牛乳；零乳糖牛乳再经过脂肪分离机得到零乳糖稀奶油。本发明在超高温灭菌之前进行乳糖彻底水解,保证产品达到零乳糖水平再进行超高温灭菌和无菌灌装,实现乳糖水解率98%以上,达到零乳糖水平,符合国标要求的乳糖含量在0.5%以下。(The invention provides a preparation method of lactose-free cream, which comprises the steps of adding raw milk and lactase which are qualified by inspection and have the temperature of 4-8 ℃ in the process of mixing materials, uniformly stirring, and hydrolyzing for 24-35 hours at the temperature of 4-8 ℃; or pasteurizing the raw milk qualified by inspection and at the temperature of 4-8 ℃ for 65-85 ℃/15 seconds in the material mixing process, cooling to 38-42 ℃, adding lactase, uniformly stirring, and hydrolyzing at the temperature of 38-42 ℃ for 2-4 hours; sampling and detecting, and obtaining the lactose-free cow milk when the lactose hydrolysis rate is required to be more than 98% and the lactose residual quantity is required to be less than 0.3%; and (4) the lactose-free cow milk is subjected to a fat separator to obtain lactose-free cream. The method carries out the complete hydrolysis of the lactose before the ultrahigh temperature sterilization, ensures that the product reaches the zero lactose level, then carries out the ultrahigh temperature sterilization and the aseptic filling, realizes the lactose hydrolysis rate of more than 98 percent and reaches the zero lactose level, and the lactose content meeting the national standard requirement is below 0.5 percent.)

1. A preparation method of lactose-free cream is characterized in that: adding raw milk and lactase which are qualified through inspection and have the temperature of 4-8 ℃ in the material mixing process, uniformly stirring, and hydrolyzing for 24-35 hours at the temperature of 4-8 ℃; or pasteurizing the raw milk qualified by inspection and at the temperature of 4-8 ℃ for 65-85 ℃/15 seconds in the material mixing process, cooling to 38-42 ℃, adding lactase, uniformly stirring, and hydrolyzing at the temperature of 38-42 ℃ for 2-4 hours; and sampling and detecting, and obtaining the lactose-free cow milk when the lactose hydrolysis rate is required to be more than 98% and the lactose residual quantity is required to be less than 0.3%.

2. The method of preparing a lactose-free cream of claim 1, wherein: the lactase is added in an amount of 0.05-0.1% of the raw milk.

3. The method of preparing a lactose-free creme as claimed in claim 1 or 2, wherein: the lactase adopts beta-galactosidase.

4. The method of preparing a lactose-free cream of claim 1, wherein: separating the obtained lactose-free milk by a fat separator, and cooling to obtain lactose-free cream.

5. The lactose-free cream prepared by the preparation method of any one of claims 1-4.

6. The lactose-free creme of claim 5, wherein: the lactose residual quantity in the lactose-free cream is below 0.5 percent, and the lactose-free cream meets the national standard lactose-free requirement.

Technical Field

The invention belongs to the technical field of dairy products, and particularly relates to lactose-free cream and a preparation method thereof.

Background

Lactose intolerance is non-infectious diarrhea, also known as lactase deficiency, caused by the fact that lactase is poorly secreted and cannot completely digest and decompose lactose in breast milk or cow's milk. Lactase deficiency is a worldwide problem, the incidence rate of people in the far east is high, and most people do not have symptoms.

The raw milk naturally contains 4-6% of lactose, the lactose content of the cream produced by the prior art is more than 2.5%, and a lactose-free cream product is not reported. In order to make people not only supplement nutrition but also not be troubled by lactose intolerance, lactose-free cream is developed.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a preparation method of lactose-free cream, which uses lactase and a new process of low-temperature long-time hydrolysis or high-temperature short-time hydrolysis to completely hydrolyze lactose in raw milk to reach the level of less than 0.5 percent of the national standard, namely the lactose-free level; the invention also aims to provide the lactose-free cream prepared by the preparation method.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a preparation method of lactose-free cream comprises the steps of adding raw milk and lactase which are qualified through inspection and have the temperature of 4-8 ℃ in the mixing process, uniformly stirring, and hydrolyzing for 24-35 hours at the temperature of 4-8 ℃; or pasteurizing the raw milk qualified by inspection and at the temperature of 4-8 ℃ for 65-85 ℃/15 seconds in the material mixing process, cooling to 38-42 ℃, adding lactase, uniformly stirring, and hydrolyzing at the temperature of 38-42 ℃ for 2-4 hours; and sampling and detecting, and obtaining the lactose-free cow milk when the lactose hydrolysis rate is required to be more than 98% and the lactose residual quantity is required to be less than 0.3%.

Furthermore, the lactase is added in an amount of 0.05-0.1% of the milk.

Preferably, the lactase is beta-galactosidase.

Further, the lactose-free milk is centrifugally separated by a fat separator to obtain lactose-free cream and lactose-free skim milk.

The invention also provides the lactose-free dilute cream prepared by the preparation method.

Furthermore, the residual amount of lactose in the lactose-free cream is below 0.5 percent, thereby meeting the requirement of national standard for lactose-free.

Has the advantages that: the method carries out the complete hydrolysis of the lactose before the ultrahigh temperature sterilization, ensures that the product reaches the zero lactose level, then carries out the ultrahigh temperature sterilization and the aseptic filling, realizes the lactose hydrolysis rate of more than 98 percent and reaches the zero lactose level, and the lactose content meeting the national standard requirement is below 0.5 percent.

Drawings

FIG. 1 shows the results of lactose detection of cream in example 1 of the preparation method of the present invention;

FIG. 2 shows the lactose test results of the cream of example 2 of the preparation method of the present invention.

Detailed Description

The invention is illustrated below with reference to specific examples. It will be understood by those skilled in the art that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention in any way.

Example 1: low temperature long time hydrolysis

A preparation method of lactose-free cream comprises the following steps:

1.1) the raw milk is qualified by inspection and is collected into a milk storage tank, and the temperature is maintained at 6 ℃;

1.2) adding beta-galactosidase in raw milk, wherein the addition amount is 0.1 percent, and uniformly stirring; hydrolyzing for 24-35 hours at 6 ℃;

1.3) sampling again and detecting, and obtaining zero-lactose cow milk when the lactose hydrolysis rate is required to be more than 98% and the lactose residual quantity is required to be less than 0.3%;

1.4) separating and cooling the obtained lactose-free milk to prepare lactose-free cream; and sampling and detecting to meet the national standard zero lactose requirement.

As shown in fig. 1, the lactose test results of the cream prepared by the preparation method of example 1: the hydrolysis rate reaches 99.1 percent, and the actual detection average value of the lactose is 0.2 percent.

Example 2: high temperature short time hydrolysis

A preparation method of lactose-free cream comprises the following steps:

2.1) the raw milk is qualified by inspection and is collected into a milk storage tank, and the temperature is maintained at 6 ℃;

2.2) pasteurizing raw milk at 65-85 ℃/15 seconds, and cooling to 40 ℃;

2.3) adding beta-galactosidase into the raw milk, wherein the addition amount of beta-galactosidase is 0.05 percent, uniformly stirring, and hydrolyzing for 2-4 hours at 40 ℃;

2.4) sampling again and detecting, and obtaining zero-lactose cow milk when the lactose hydrolysis rate is required to be more than 98% and the lactose residual quantity is required to be less than 0.3%;

2.5) separating and cooling the obtained lactose-free milk to prepare lactose-free cream; and sampling and detecting to meet the national standard zero lactose requirement.

As shown in fig. 2, the lactose test results of the cream prepared by the preparation method of example 2: the hydrolysis rate reaches 99.1 percent, and the actual detection average value of the lactose is 0.2 percent.