Application Of Bio-deacidification Technology In Prunus Juice

Green plum has the homology of medicine and food and it tastes bad because of its highacid content. The mechanism of reducing sourness carried out by Lactobacillus plantarumand oenococcus oeni was studied when fresh green plum juice was chose as raw material.Moreover, the effects of both glucose and tryptone on reducing sourness by Lactobacillusplantarum LP-l134-1-P and oenococcus oeni6066in malic acid buffer system and citric acidbuffer system were studied. And changes of organic acid were determined by HPLC topreliminarily explore the mechanism of reducing sourness by MLF. Results are as follows:The acidity of the system was reduced by more than17.61%when over109CFU/g ofLactobacillus plantarum LP-l134-1-P was used to ferment green plum juice with a initial pHvalue≥3.50at30.0℃.1.00%tryptone improved the rate of reducing sourness by15.19%while the acidity of the system increased if1.00%glucose was added.More than61.35%of the acidity was reduced by oenococcus oeni at a cell density of108CFU/mL with a initial pH value≥3.40at25.0℃. The fermentation time was shortenedwith tryptone content of1.00%and compared to groups without glucose,1.00%glucoseinhibited the reduce of acidity. As a result the rate of reducing sourness dropped over27.04%.More than70%of total malic acid was degraded in the malic acid buffer system (pH3.60) incubated with Lactobacillus plantarum LP-l134-1-P at a cell density of109CFU/g at30.0℃. The rate of citric acid degradation was9.39%in citric acid buffer system (pH3.60)which could be raised by27.83%and11.78%respectively after2.00%trytone or2.00%glucose was added. If2.00%trytone and2.00%glucose were added, the rise of citric aciddegradation rate was7.41%. Thus came to the conclusion that both tryptone and glucose isbenefical for Lactobacillus plantarum LP-l134-1-P to degrade citric acid.More than70%of total malic acid was degraded in the malic acid buffer system (pH3.60) incubated with oenococcus oeni at a cell density of108CFU/g at25.0℃. The rate ofcitric acid degradation was11.14%in citric acid buffer system (pH3.60) which increased by21.18%and5.32%respectively after2.00%trytone or0.50%glucose was added. If2.00%trytone and0.50%glucose were added, the rise of citric acid degradation rate was57.72%. Itwas indicated that both tryptone and glucose is conducive for Lactobacillus plantarum LP-l134-1-P to degrade citric acid.