Control And Detection Technology Of Osmphilic Yeast In Apple Juice Concentrate

China is the largest apple planting and apple juice concentrate production country, theyield and quality of China’s apple and apple juice processing industry have made abreakthrough. The development of apple and its processing industry have improved the addedvalue of products, absorbed a large number of social surplus labor, and promoted the rapiddevelopment of the regional economy and the social stability, which makes a contribution tothe economic development of our country. At the same time, along with the high number offood safety incident and the development of living standard, governments and people of allcountries have stricter requirement for the food safety and quality and the standard of exportproducts. In the world-wide, the export of agricultural products created new games, dumpingand anti-dumping, trade barriers and others have improved the export standard day by day. Inrecent years, international trade disputes, returns and claim caused by the out of limits ofheavy metal, patulin, pesticide residues and microorganism are common occurrences, whichaffect the development of apple juice industry in a serious way. Therefore, to seek a simple,quick, and low cost method to prevent and control the poisonous and harmful substances inthe apple juice is badly needed.In this paper, the Omophilic yeasts in concentrated apple juice were isolated andidentified and medium was optimized. Then hot kill parameters were studied and dynamicswas researched. The production line of apple juice concentrate was sampling inspected andsome effective methods were used to control Osmophilic yeasts, and the whole productionline of apple juice concentrate was checked in order to evaluate the control effect.The main results obtained the following:1. The apple juice concentrate was used as raw materials, and one of Osmophilic yeastwas isolated and identified. The method of response surface was used and the incubationconditions，including sugar concentration，pH，incubation time and incubation temperature were optimized. Taking the growth of colonies as general evaluation measure，it was foundthat the isolated Osmophilic yeast can grow in all kinds of sugar concentrate, but high sugarconcentration could inhibit the growth of Osmophilic yeast evidently. The results indicate thatthe best process parameters are as follows: sugar concentration in medium was40%, pH valuewas5.3, the incubation temperature was25℃, in this condition, the colony count ofOsmophilic yeast was181cfu/mL.2. The hot kill parameters of isolated Osmophilic yeast showed that the yeast was allkilled by processing at80℃or88℃for600s or at96℃for30s. Dynamics model of isolatedOsmophilic yeast killed by heating was：Y=505.62-13.18×T+0.62×t－0.005T×t，killingtemperature T∈[80,96] and time t∈[15，600]. D value of different temperature is as follows:D80℃=430s; D88℃=273s; D96℃=27s. The results show that quality of apple juiceconcentrate treatment by different temperature and time can achieve export requirements.3. The cold storage tanks of production line were tested and the actual production ofapple juice concentrate resisting Osmophilic yeast pollution were evaluated, somecorresponding measures were taken to reduce the pollution. The results show that, thesterilization temperature reached100%for cold storage tank could kill all of Osmophilicyeast. At the same time, the production line of apple juice concentrate was monitored, and allkinds of methods including improving temperature, sterile membrane filtration,high-temperature sterilization of clear apple juice and monitoring of production line wereused and the control of Osmophilic yeast was coming true.4. The whole process of apple juice concentrate production and the air pollution ofmanufacturing plant were analyzed, and the effectiveness of control measures were thecomprehensive evaluated. The results showed that the pollution of Omsophilic yeast can becontrolled by the use of various control method. At the same time, Omsophilic yeast in airmay produce secondary pollution, so measures should be taken to ensure the health ofenvironmental air.