Induction of gamma irradiation for microorganism decontamination of dried lotus pollen (Nelumbo nucifera)

Abstract

Gamma irradiation has been known for its great effect for inactivating microorganisms in various foods and it has been a safe method for food decontamination. In this present study, the dried lotus pollen was conducted to determine the effect of using gamma irradiation on the microbial load and antioxidant properties. The dried pollen lotus samples were irradiated with gamma irradiation at doses of 5 and 10 kGy and the total plate count (TPC) and total yeast and mold (Y&M) were determined. The study revealed that high microbial level of TPC and Y&M were found in non-irradiated. At dose of 5 kGy showed that gamma radiation was able to reduce the microorganism contamination in dried lotus pollen. The result permitted to accomplish the satisfactory microbial content for Thai community product standard of dried herb number 480/2547. In part of the antioxidant property, there was no any significant difference among the non-irradiated and irradiated samples in 60% ethanol extract. Surprisingly, total phenolic content and DPPH were increased by gamma radiation in hot water extract. Therefore gamma irradiation at 5 kGy could be a potential method for microbial decontamination of dried pollen lotus to improve hygienic quality.