Diazinon Reduction In Apple Juice Using Probiotic Bacteria During Fermentation And Refrigerated Storage
Abstract The main objective of this work was to study the effects of probiotic strains, probiotic primary inoculated population, concentrations of spiked diazinon, physiology of probiotic bacteria, fermentation times and cold storage period in six consecutive stages on diazinon reduction in apple juice. Chemical properties (pH, total acidity, and sugar content), probiotic viability and diazinon reduction percent were monitored during fermentation and cold storage. Dispersive Solid Phase Extraction (dSPE) followed by gas chromatography-mass spectrometry was used to extract and measure diazinon concentration. Results showed that Lactobacillus acidophilus revealed the highest ability to reduce diazinon in apple juice after fermentation. Inoculation of L. acidophilus at 9 log CFU/mL, showed significantly higher diazinon reducing ability than 7 log CFU/mL. Ability of L. acidophilus to reduce the concentration of 1000 µg/L of spiked diazinon was significantly greater than 5000 µg/L. Heat-killed (dead) L. acidophilus bacteria reduced less diazinon content at the end of fermentation than viable bacteria. Furthermore, 72 h of fermentation was more effective in diazinon reduction. Level of diazinon in treatments containing L. acidophilus decreased significantly during cold storage period, so that it is completely disappeared at the end of storage (28 days) along with maintaining health-promoting properties of probiotic apple juice.