The invention relates to a method for extracting
bile salt hydrolase (BSH) of two kinds of yeasts and a production technology of functional
kefir, applicable to the production of functional
kefir and sour
kefir in fermented dairy products. The invention adopts high-
throughput screening technique and phthalic
aldehyde method to acquire two kinds of yeasts which can lower
cholesterol efficiently and have higher capacity of fermenting
lactose, and Oxford cup method to acquire strains yielding the BSH highly through secondary screening. The invention optimizes the
fermentation conditions and extraction method for the two kinds of yeasts to produce the BSH, and adopts proper
cracking method by ultrasonic wave, which solves the problem that the
cell walls of the yeasts are difficult to be cracked, and the
cracking effect can be compared with that of the
high pressure cell cracker.
Kluyveromyces Marxianus K1 (CGMCC No 1812) and M3 (CGMCC No 1811) which can lower the
cholesterol efficiently can yield the BSH highly and can ferment
lactose to yield
ethanol highly, are adopted to prepare the kefir of high quality that has the function of lowering the
cholesterol. The
fermentation process of preparing the functional kefir is simple with shorter
fermentation period and lower cost. Thus, the fermentation process is applicable to
mass industrial production.