Method for preparing direct vat set Lactobacillus casei subsp. rhamnosus freeze-dried powder

Abstract

The invention discloses direct vat set Lactobacillus casei subsp. rhamnosus freeze-dried powder and a preparation method thereof. The method comprises the following steps: propagating Lactobacillus casei subsp. rhamnosus by a two-step method to make cells in a synchronous growth period as possible; and in a production culture medium, controlling pH to between 6.0 and 6.8 with NaOH solution on line, culturing for 16 to 24h at a temperature of between 35 and 37 DEG C, centrifugating, collecting bacterial sludge, adding protective agent solution, pre-freezing for 0.5 to 2.0h at a temperature of between -40 and -65 DEG C, making the thickness of bacteria on the wall of a container between 5 and 15 mm, and drying to prepare the direct vat set freeze-dried powder. The viable count of the freeze-dried powder reaches between 10<11> and 10<12>cfu / g; and the freeze-dried powder has the characteristics of good rehydration, good luster, good fluidity, easy storage and transportation, convenient production and the like, and can be directly used for fermentation production of pickles, sausages, acidophilus milk, L-lactic acid, corn flour, bean meal and peanut meal, and used as a probiotic preparation and the like.

Description

technical field [0001] The invention relates to the preparation of lactic acid bacteria freeze-dried powder, in particular to a direct-throwing type Lactobacillus casei subspecies rhamnose freeze-dried powder and a preparation method thereof. Background technique [0002] Traditional commercial starters contain a small amount of live bacteria, about 10 7 -10 8 per g, it cannot be used directly for production, it needs to be activated and amplified before it can be used for dairy production. Increased and changed, resulting in unstable quality of fermented products and poor repeatability. Direct input lactic acid bacteria starter refers to a new type of starter that is directly applied to production without activation and amplification. The key to this kind of starter is to have a high number of viable bacteria to ensure a small amount of inoculation and rapid growth after inoculation. Rehydration can complete the fermentation process in a relatively short period of time. ...

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Problems solved by technology

[0009] The Chinese invention patent whose patent number is 200410088476.1 (authorized announcement number CN 1285292C) discloses "a kind of direct-throwing compound bacterial powder product and production method thereof for producing kimchi", which is a composite bacterial agent, and the number of viable bacteria in the bacterial powder is 10 8 ~10 9 1 / g, in the process of expanding the culture, there was no online pH control, so high-density culture could not be realized. It took 36-50 hours for the fermentation of kimchi, and it did not involve the nitrite in kimchi after fermentation. Clarify the packaging method of freeze-dried powder

[0010] The aforementioned prior art does not adopt on-line regulation and control of the fermentation pH value, and the selected enrichment medium, harvesting bacterial age, protective agent, pre-freezing conditions and packaging conditions are not suitable. There are disadvantages such as long fermentation time and poor rehydration rate during production, and the freeze-dried powder contains sugars such as lactose and glucose, which will absorb moisture during storage

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