Preparation method of corn steep liquor

Abstract

The invention relates to the field of amino acid fermentation, and specifically discloses a preparation method of corn steep liquor. According to the preparation method of the invention, corn kernels are soaked in sulphurous acid, concentration is carried out to obtain a corn steep liquor, microfiltration is performed on the corn steep liquor by using a filter membrane having a pore size of 0.05-0.1mum until the concentration factor is 10-12 to obtain a filtrated liquid and a retentate, and the filtrated liquid is concentrated until a baume degree of 8-24 is achieved so as to obtain the corn steep liquor. According to the invention, the microfiltration is performed on the corn steep liquor before the preparation of the corn steep liquor, microorganisms which cause contamination with corn steep liquor fermentation are trapped, the prepared corn steep liquor can be used in the amino acid fermentation after undergoing high temperature sterilization, contamination degree of the corn steep liquor used in the amino acid fermentation is greatly reduced, contamination rate is reduced, and acid yield level of amino acid is increased at the same time.

Description

Technical field [0001] The invention relates to the field of amino acid fermentation, and specifically provides a preparation method of corn steep liquor. Background technique [0002] Corn steep liquor is a yellowish-brown liquid that is concentrated from corn kernels soaked in sulfurous acid. It is rich in soluble protein, auxin and some precursor substances, and is an important composite raw material in amino acid fermentation. The quality of corn steep liquor not only affects the level of amino acid fermentation, but also has a great relationship with whether the fermentation is infected with bacteria. [0003] The existing preparation method generally is to obtain corn steep liquor after soaking corn kernels with sulfurous acid, and then obtain corn steep liquor through multi-effect concentration. The corn syrup prepared by the existing method is generally directly used as the raw material for amino acid fermentation in the production of amino acid after steam high temperatur...

AI Technical Summary

Problems solved by technology

However, the corn steep liquor prepared by the existing method often contains some insoluble particles and microbial spores. During the sterilization process, there is a difference in temperature between the inside and outside of some larger insoluble particles, which causes the microorganisms contained inside to not be completely killed. Species of spore microorganisms cannot be completely killed by conventional moist heat sterilization methods. For amino acid fermentation strains that are poorly resistant to miscellaneous bacteria and have a long fermentation period (above 48h), these residual microorganisms often cause varying degrees of miscellaneous bacteria pollution. As a result, the fermentation index is reduced or even the tank is inverted, and the acid production level is also reduced accordingly

Even if the sterilization temperature is increased or the sterilization time is prolonged, the contamination rate of miscellaneous bacteria cannot be effectively reduced. On the contrary, the nutrient content of corn steep liquor will be lost due to the long-term high temperature, which will have a great impact on the production of amino acids.