Isolation And Identification For The Main Patulin-producing Stains And The Study Of Patulin Control Technology In Apple Juice Concentration Processing

Apple is one of Chinese few Compete agricultural products in world market after we joined the WTO. It has great influence on motivating agricultural structure adjustment ,augment peasant's income and earn foreign exchange through exports.AJC is the prevailing product of the apple processing industry. It is much attracts the attention of the world. Patulin is a mycotoxin that may carcinogenesis. It may easily transfer into juice , and has been found all over the world. Patulin is more stable in apple juices than in other medium. There is 50% remains even after 10～20 min treated at 80℃. So, it is much easy to transfer into apple juice. This research choose rotten fruits from the AJC raw materials producing region as the research object , and isolate several fungi in them, so as to ascertain main patulin-producing fungi in Shaanxi. After experiment we can get the most important patulin-producing fungi, and then the optimal condition for patulin producing and property were studied. At last, resins were used to decrease the patulin. The result showed in the following: 1. 15 Patulin-Producing Strains isolated from raw material was Identificated in morphology,in which all of them are penicillium and aspergillus。Then ITS-rDNA Sequence Analysis were used to confirm it. The ITS-rDNA Sequence were submitted to European Molecular Biology Laboratory(EMBL),and contrasted by DNA Sequence in Genebank to identify them .They are: Penicillium expansum strain ATCC 7861,Penicillium expansum strain ATCC 7861,Aspergillus versicolor strain SRRC 153,Aspergillus oryzae NRRL 506,Penicillium griseoroseum strain VIC,Penicillium polonicum strain NRRL 995,Penicillium coprophilum strain NRRL 13627,Aspergillus sojae strain ATCC 14895,Aspergillus toxicarius,Penicillium cordubense,Penicillium viridicatum strain FRR 963,Aspergillus toxicarius,Penicillium tricolor strain ATCC 10413,Penicillium expansum strain ATCC 7861,Aspergillus oryzae strain SRRC 2103.In that about 90% of them has been detected is Penicillium expansum. 2. The Penicillium expansum can growth at pH2.8～pH7.6,patulin can be synthesis at pH1～pH8.4. pH4.80 is the most optimal condition for Penicillium expansum to produce patulin. When the temperature is 20.5～29.5℃,sugar 10.2～13.8°Brix and time 57.1～76.2h , 95% yield of patulin will outweigh 69.52μg/L, it is best scope for patulin yield. 3. Find monthly distribution regulation of patulin in AJC after inspected two successive manufacture season. 4. The patulin content the concentrated apple juice manufacturing process was tested in the experiment, and the parameter of its distribution in various workshop section has been obtained by experiment. 5.　Remove patulin through the ion exchange resin after ultra filter. The result shows, ①ultra filters has certain effect on removing the patulin from apple juice, while adsorption can remarkably remove the patulin, ②NO.1and NO.2 anion adsorption resin are the proper carrier of removing the patulin from apple juice .NO.2resin is the better carrier of aid, but both NO.1 and NO.2 do not absorb sugar. ③the proper parameter of the dynamic adsorption and separation of NO.1 resin is, flowing speed:6BV,beginning temperature 20℃.