NL2020932B1

NL2020932B1 - Method for adjusting the flavor of yogurt with lactobacillus casei

Info

Publication number: NL2020932B1
Application number: NL2020932A
Authority: NL
Inventors: Xiao Gongnian; Chen Bo; Yuan Haina; Wang Weijun; Yu Lingen; Yu Liang; Zhu Ruina; Gong Jinyan; Zhu Like
Original assignee: Univ Zhejiang Sience & Technology; Zhejiang Inm Food Co Ltd
Priority date: 2018-05-15
Filing date: 2018-05-15
Publication date: 2019-01-28
Also published as: NL2020932A

Abstract

The invention relates to a method. for adjusting' the flavor of yogurt with Lactobacillus casei, which belongs to the field of dairy processing. The method comprises the following steps: fresh milk filtration, milk purification, cooling, pre—sterilization, standardization, dosing, mixing, stirring, heat treatment, homogenization, sterilization, cooling, inoculation, fermentation, demulsification, cooling, filling, cooling and refrigeration. Compared. with the traditional method. for preparing' yogurt, the method uses new technologies and new methods such as adjusting the flavor of yogurt by using the valuing effect of Lactobacillus casei on lactalbumin hydrolysate and controlling the ratio of inoculated strains and operating conditions, thus improving the nutrition and flavor of yogurt, and the yogurt made by the method for improving the flavor of yogurt has better rheology and smoothness.

Description

P414/NLpd

METHOD FOR ADJUSTING THE FLAVOR OF YOGURT WITH LACTOBACILLUS CASEI

Technical Field

The invention belongs to the field of dairy processing technology, and specifically relates to a method for adjusting the flavor of yogurt with Lactobacillus easel .

Background Art

Yogurt is fermented from fresh milk by lactic acid bacteria. In the process of lactic acid bacteria fermentation and milk acidification, the acidity of milk is reduced from about pH6.7 to less than pH4.6.Yogurt becomes a popular food for its comprehensive nutrition and rich lactic acid bacteria. In addition to all the nutrients of fresh milk, yogurt has the following effects of: maintaining the ecological balance of intestinal flora and inhibiting the invasion of harmful bacteria to the intestinal tract; promoting intestinal peristalsis through the production of a large number of short-chain fatty acid; changing the osmotic pressure through mass growth of thallus to prevent constipation; promoting digestion and absorption through yoghurt which contains a variety of enzymes; inhibiting the growth of saprophytic bacteria in the intestinal tract and protect the brain and liver against these harmful substances; preventing aging; lactic acid bacteria can produce some substances that raise the immunologic function, improve the immunity of human bodies and prevent diseases .

Much more frequently seen in cow milk, thallus is in the shape of a slender chain, without motility, without forming spores, being gram-positive and microaerobic. Lactobacillus easel decomposes protein to produce aromatic substances while fermenting lactose to form lactic acid, and lactobacillus casei is a necessary strain in the ripening of cheese. The highest acidity condition for growth is 1.5%~1.8% lactic acid, the moderate temperature is 30°C, but it can also grow below 100°C.

Lactobacillus casei can enter the digestive system of the intestinal tract after passing the test of gastric acid to really play a probiotic function, and small peptide of protein can be used as a probiotic factor to promote the growth of lactobacillus casei in the large intestine.

Summary of the Invention

Aiming at the problems existing in the prior art, the object of the invention is to design and provide a technical scheme for a method for adjusting the flavor of yogurt with lactobacillus casei.

To achieve the object of the invention, the present invention provides the following technical scheme:

The method for adjusting the flavor of yogurt with Lactobacillus casei is characterized by including the following steps : (a) Filter and clarify fresh milk; (b) Cool and pre-sterilize; (c) Standardize, with fat b3.2%, protein b2.9%, and nonfat milk solid b8.1%; (d) Sugar melting: Connect a certain amount of raw milk at sterilization temperature up to above 90°C into a dosing vessel, add 2~4% white sugar, stir to make it mixed evenly for later use; (e) Dosing, mixing and stirring: Add a certain amount of condensed milk enzymolysis-crystallized through trypsase with sucrose content of 40-45%, stir to make it mixed evenly for later use; (f) Homogenize; (g) Sterilization and cooling; Sterilization temperature is 90~95°C, and sterilization time is 5min; (h) Inoculation and fermentation: Use DVS mixed strains, i.e. lactobacillus bulgaricus and streptococcus thermophilus at the ratio of 1.7:1.3, expand culture of Lactobacillus casei with a seeding tank, inoculate in a 5L tank and culture for l-3h with cow milk as the culture medium at the inoculation temperature of 40~45°C, maintain the fermentation temperature at 43°C~46°C, and cool when the acidity reaches 70sT and the state of tissue meets the requirements; (i) Fill.

Compared with the prior art, the method has the advantages that: 1 . A series of complex dissociation and structural reorganization occurs during this process by using milk protein enzymolysis to form special flavored yogurt that is beneficial to the proliferation of Lactobacillus casei. The method controls the reaction substrate composition of Lactobacillus casei, which is conducive to the formation of stable color and luster.

Compared with the prior art, the method overcomes the adverse effect of the metabolic decomposition of traditional strains on the stability of color and luster of fermented yogurt. 2. Compared with the traditional yogurt processing technology, the method can improve the flavor of traditional yogurt by using a new method for the working procedure of adding condensed milk.

Detailed Description of the Preferred Embodiments A further detailed description of the method is made below in combination with test cases and embodiments. All the percentage contents in the following embodiments and comparative examples are percentage mass contents.

Embodiment 1

A method for adjusting the flavor of yogurt with Lactobacillus casei, comprising: first, filter fresh milk. The formula is: 91.4% raw milk after microfiltration, with white sugar content of 8.5%, 170u/T Lactobacillus bulgaricus and 130u/T streptococcus thermophilus. The process of yogurt making comprises the following steps: (a) Preparation and cooling of raw milk: Meet the incoming inspection standard of fresh milk for yogurt technology, with nonfat milk solid of not less than 8.5%, without antibiotics as required for raw milk, lysozyme as an antibacterial factor cannot be detected; filter with about 80 meshes, and cool to 2°C~6°C with a plate heat exchanger. (b) Pre-sterilize at the sterilization temperature of 85~95°C; the time is 5~15min. (c) Standardize by separating dilute cream or adding dilute cream, with fat :3.2 , protein :'2.9 , and nonfat milk solid b8.1%; (d) Sugar melting: Connect a certain amount of raw milk with sterilization temperature up to above 90°C into a dosing vessel, add 2~4% white sugar, stir to make it mixed evenly for later use; (e) Dosing, mixing and stirring: Add a certain amount of condensed milk enzymolysis-crystallized (with 10-20% raw milk) through trypsase with sucrose content of 40-45%, stir to make it mixed evenly for later use; (f) Homogenize; the temperature is about 60°C, and the pressure is 18~20MPa; (g) Sterilize and cool; the sterilization temperature is 90-95°C, and the sterilization time is 5min; fast cool to about 45°C, with material cooling time no more than 45min; (h) Inoculation and fermentation: Connect lactobacillus bulgaricus and streptococcus thermophilus at the ratio of 17:13, after inoculation, intermittently stir for lOmin in positive and negative directions, with the speed controlled at 35r/min; maintain the temperature at 43°C~46°C; cool when acidity reaches 70sT and the state of tissues meets the requirements; cool to the temperature of 2-6°C; (i) Fill.

The yogurt prepared in this embodiment gives a thick and smooth mouth feel, shows good color and luster, have a good flavor, high stability and smoothness, resists damages due to unexpected mechanical collision in the links of logistics and sales, without whey precipitation within the shelf life.

Claims

UITTREKSEL The invention relates to a method for adjusting the flavor of yogurt with Lactobacillus casei, which belongs to the field of dairy processing. The method comprises the following steps: fresh milk filtration, milk purification, cooling, pre-sterilization, standardization, dosing, mixing, stirring, heat treatment, homogenization, sterilization, cooling, inoculation, fermentation, demulsification, cooling, filling, cooling and refrigeration. Compared with the traditional method for preparing yogurt, the method uses new technologies and new methods such as adjusting the flavor of yogurt by using the valuing effect of Lactobacillus casei on lactalbumin hydrolysate and controlling the ratio of inoculated strains and operating conditions, thus improving the nutrition and flavor of yogurt, and the yogurt made by the method for improving the flavor of yogurt has better rheology and smoothness .