| China is the biggest apple production country of the world,in 2004,apple yield of China is about 20.2 million tons. China has become the biggest apple juice concentrate production country of the world, In 2004 China exported 478000 tons AJC, it is about 50% of the volume of trade of the world.But,in China there are some quality problems in AJC product, Alicyclobacillus acidoterrestris problem is one of them.It is very difficult to remove Alicyclobacillus acidoterrestris from AJC,because it has very strong heat-resistant and Acid-resistant ability.In the present,there has no a reliable method to control Alicyclobacillus acidoterrestris in AJC,Alicyclobacillus acidoterrestris problem has become one of the most stubborn problems of AJC manufacturer. The detection and control of Alicyclobacillus acidoterrestris is also a dearest task of AJC manufacturer. In this paper,we isolate native Alicyclobacillus acidoterrestris from AJC production line of Shaanxi HengXing fruit juice co.,ltd,which is biggest base of AJC processing in China,using16SrDNA method and API kit to identify the isolated strain,research on using High Hydrostatic Pressure(HHP)and heat treatment to kill Alicyclobacillus acidoterrestris and discuss biology characteristic of Alicyclobacillus acidoterrestris. The main results showed that, ①Isolates successfully a native Alicyclobacillus acidoterrestris strain from AJC production line of Shaanxi HengXing fruit juice co.,ltd with AAM culture medium (pH 3.7) as isolate culture medium. ②It conclusion that both isolated strain and standard strain are Alicyclobacillus acidoterrestris by using morphologic and analysing　16SrDNA. Obtaining respective DNA list of isolated strain and standard strain. ③Obtaining the standard system identification coding of API-20E on Alicyclobacillus acidoterrestris:1-2-2-3-0-4-2. ④Alicyclobacillus acidoterrestris growth conditions The pH range of growth conditions of Alicyclobacillus acidoterrestris (standard) and Alicyclobacillus acidoterrestris (isolated) are 2.7-6.0 and 2.7-6.7; The temperature range of growth conditions of Alicyclobacillus acidoterrestris (standard) and Alicyclobacillus acidoterrestris (isolated) are28℃-60℃and 24℃-60 ℃. ⑤Obtaining the regularities of distribution of Alicyclobacillus acidoterrestris on AJC production line; ensuring cleaning and sterilizing raw material fruit ultrafiltration second pasteurize aseptic packaging as four keypoints of controlling Alicyclobacillus acidoterrestris ⑥Obtaining respectively growth dynamics curve of Alicyclobacillus acidoterrestris (standard) and Alicyclobacillus acidoterrestris (isolated) in apple juice ⑦Achievement to getting dynamic model which can describe the course of HHP kills Alicyclobacillus acidoterrestris Alicyclobacillus acidoterrestris (standard): y=-2.677026+0.012427P+0.059163t-0.000010470P2-0.000100P*t-0.000195t2 Alicyclobacillus acidoterrestris (isolated): y=-4.726613+0.019035P+0.103616t-0.000015898P2-0.000165P*t-0.000502t2 P∈[400, 550] t∈[10,25]　⑧Obtaining The D-value of Alicyclobacillus acidoterrestris under different pressures treating of HHP Alicyclobacillus acidoterrestris (standard): D400Mp=13.07min,D450Mp=7.97min,D500Mp=3.99min,D550Mp=3.84min Alicyclobacillus acidoterrestris (isolated): D400Mp=13.05min,D450Mp=6.37min,D500Mp=6.37min,D550Mp=5.16min ⑨Achievement to getting dynamic model which can describe the course of heat treating kills Alicyclobacillus acidoterrestris Alicyclobacillus acidoterrestris (standard): y=13.779790+0.254721T+0.199456t-0.001075T2-0.001743T*t-0.000807t2　Alicyclobacillus acidoterrestris (isolated): y=-21.476622+0.418240T+0.226495t-0.001948T2-0.001990T*t-0.000897t2　T∈[85, 95] t∈[3,40] ⑩Obtaining The D-value of Alicyclobacillus acidoterrestris under different temperatures treating Alicyclobacillus acidoterrestris (standard): D80℃=48.31min,D85℃=26.85min,D90℃=15.70min,D95℃=5.47min; Alicyclobacillus acidoterrestris (isolated): D80℃=54.53min,D85℃=32.70min,D90℃=11.81min,D95℃= 6.29min... |
PDF Full Text Request