Control Technology Study On Isolation And Identification Of Thermophilic Acidophilic Bacteria In Apple Juice Concentrate Processing

The capacity and production of Chinese apple juice industry is the largest in the world,is more than 60% of the total apple juice concentrate quantity. But the apple veberage that comes from apple juice concentrate has off flavor because of thermopHilic acidopHilic bacteria and its growth. ThermopHilic acidop Hilic bacteria is a barrier of the export of apple juice concentrate. So it is very important to control thermopHilic acidopHilic bateria for the apple juice concentrate industry. This article studied the effect of sterilization of united sterilization of different sterilizer and washing and sterilizing raw material and tanks and pipes and ultrafiltration, and this method of sterilization was verified in the whole production line, the results of this article is as following:(1)The thermopHilic acidopHilic bacteria was separated from apple juice concentrate and water used on production line and soil. The cell is G+, rod or bent rod, some has spore, the diameter is more than 0.5μm;16SrDNA series analysis proved that the separated strains are Alicyclobacillus genus , Alicyclobacillus acidoterrestris and alicyclobacillus cycloheptanicus 2 speces , Alicyclobacillus acidoterrestris is normal in apple juice concentrate.(2)On the basis of the method of isolation of thermopHilic acidopHilic bacteria from American Krueger lab (the temperature of incutation of thermopHilic acidopHilic bacteria is 41℃) and Japanese officia(ltemperature of incubation of thermopHilic acidopHilic bacteria is 45℃),the number of colonies of incubation of thermopHilic acidopHilic bacteria is increased by increasing sampling volume and improving inoculation method.(3)There was no effect on 41℃and 45℃thermopHilic acidopHilic bacteria when the content of ClO2 was 20mg/L , time was 1min～5min and the content of ClO2 was 40mg/L ,time was 1min～3min. The effect of sterilization on 41℃and 45℃thermopHilic acidopHilic bacteria was obvious when the content of ClO2 was 40mg/L,time was 4min and 5min, further more,the effect of sterilization on 41℃thermopHilic acidopHilic bacteria was better than that on 45℃.For the effect of sterilization on 41℃and 45℃themopHilic acidopHilic bacteria, the content of ClO2 of 80mg/L was better than 20mg/L and 40mg/L. The optimal sterilization content and time of ClO2 was 120mg/L and 1～5min.this condition be able to reduce the number of the colony to less than 1cfu/mL.(4)When the content of sodium hydroxide was 1%～5 %, the range of temperature was 60℃～90℃, the sodium hydroxide solution can kill thermopHilic acidopHilic bacteria. Especially, the effect of sterilization on 45℃thermopHilic acidopHilic bacteria was obvious; when the content of sodium hydroxide was 1%～5 %, the effect of sterilization on 41℃and 45℃thermopHilic acidopHilic bacteria be able to increase with the higher of temperature. Especially, the effect of sterilization was the best when the content of sodium hydroxide was 4% and 5%.(5)At room temperature, 0.5%～4% hydro peroxide solution can sterilize thermopHilic acidopHilic bacteria, when the content of hydro peroxide was 2%～4%, at room temperature, the hydro peroxide solution be able to kill 45℃TAB well.Combination sterilization technique of washing step by step and chlorine dioxide(ClO2) and sodium hydroxide and hydrogen peroxide will sterilize TAB in apple juice production line effectively, meet the requirements of the import country'law.