Microbial reduction effect of steam heating, UV irradiation, and gamma irradiation on red pepper powder

This study evaluated the effect of steam heating, gamma irradiation, and ultraviolet (UV) irradiation on microorganism reduction in order to determine an effective sterilization method for red pepper powder. The effect of each treatment on the reduction of thermoduric bacteria and total aerobic bacteria in red pepper powder were as follows: 10 kGy gamma irradiation, reduction of 4 log and 6 log CFU/g, respectively; 12 mW/cm² UV irradiation (264 nm UV-C), reduction of less than 1 log CFU/g; steam heating at 120^oC for 40 s, reduction of approximately 2 log CFU/g. High-temperature short-time processing at 110^oC for 30 s reduced the total bacterial count in Gochujang solution from 5.70 log CFU/g to 2.26 log CFU/g; at 121^oC, the solution was commercially sterile. Steam heating resulted in 1, 2, and 4 log microbial inactivation in garlic, onion, and pepper powder, respectively. Steam sterilization, which consumers prefer over other methods, may be an effective method for reducing microorganisms in spice powders, including those in red pepper powder.