Postirradiation changes of the microbiological quality, aflatoxin, capsinoids, volatile oils, and the color of red pepper powder

Abstract

Red pepper powder from a local market was vacuum-packaged in aluminum foil bags, irradiated by a 60Co gamma irradiator at seven doses (0, 3, 6, 9, 12, 15, and 18 kGy) and stored at ambient temperature for 8 months. Postirradiation changes of the microbiological quality, aflatoxin B1, volatile oils, pungency, and the color of red pepper powder during different storage periods were investigated. The results showed that γ-irradiation could effectively decontaminate the red pepper powder, which reduced the content of the total aerobic bacteria by 6 logs when irradiated at 18 kGy, and the irradiation effectively reduced the fungal load but had no obvious effect on the content of aflatoxin B1. The 18 kGy irradiation did not change the color of sample and reduced the amount of terpenes by 3%. However, during the storage period, the terpene's content in the irradiated samples showed a lower reduction compared with the control. Practical applications The study showed that irradiation had an obvious bactericidal effect, and a dose of 18 KGy could effectively decontaminate the spices, which made the microbiological quality achieve the national hygienic standard of irradiation spices. Gamma irradiation had no significant effect on the terpenes of red pepper powder, which were the main constituent of the volatiles. During storage, the pungency decreased a lot, but could be well preserved by aluminum foil bag. This study could provide some reference for the setting of irradiation dose and the detection of higher-dose irradiated spices, and provide a new way for the storage of red pepper powder.