Pretreatment sterilization of garlic and ginger using antimicrobial agents and blanching

The sterilization rates were investigated to develop effective pretreatment methods of garlic and ginger using antimicrobial agents and blanching. Antibacterial components in chopped garlic and ginger, such as allicin, ginger, and shogaol, exhibited an antibacterial effect that reduced bacteria by a factor of 10¹ (CFU/g). The total number of bacteria in garlic and ginger was decreased by 10¹ (CFU/g) after individually soaking in 1% (w/w) citric acid, calcium oxide and 200 ppm sodium hypochlorite solution for 1 h, respectively. When chopped garlic and ginger were immersed in 1% (w/w) calcium oxide solution for 1 h, the bactericidal effect was increased by 10⁴-fold. Total cells with thermoduric bacteria exhibited a 10³-10⁴-fold reduction after heating for 30-40 s at 90-95°C. The combination of soaking in 200 ppm sodium hypochlorite solution and blanching at 95°C, 40 s showed 10¹-fold decrease in total number of cells compared to blanching in whole ginger.