Peppers contain phenolic compounds (mainly flavonoids), which play important roles in human health as antioxidants, and they possess anti-inflammatory, anti-allergic, anti-viral, and anti-bacterial activities . The ionizing radiation treatments did not cause marked modifications in total phenolic compounds at day 0. The concentration in control non-irradiated group was 43.9 ± 12.5 mg/100 g, and attained 44.2 ± 11.9 mg/100 g after a radiation dose of 6 kGy. As shown in Figure 4, the concentration of total phenolic compounds during storage showed somewhat greater stability in irradiated samples (fell only by 1 to 4%) than in the control group (loss of 6.5%). Therefore, these results indicated that irradiation up to 6 kGy is effective for the preservation of total phenolic contents in hot peppers even though there was oxygen inside the package.