Application of gamma irradiation to reduce microbial contamination in herbal cosmetic products

This study addresses the decontamination of herbal powder cosmetics by gamma irradiation to reduce the total microbial colony count in facial herbal powder, herbal rose brush on and talcum. Pre-irradiated samples showed total colony counts of 3.00×10⁴, 2.70×10⁴ and 1.00×10³ CFU/g. At 3rd day after application, irradiation reduced the total colony counts to 1.90×10², 6.00×10² and 1.20×10² CFU/g. Moreover, the total colony counts of the three samples were found to be less than 100 CFU/g after 3 months storage. The non-uniformity of ΔE^? revealed that time affected the color of brush on and talcum, which differed from their original color; however, irradiation affected the colors of the brush on only (P<0.05), by reducing its brightness and increasing redness and yellowness of the products. Paired preference tests were conducted in facial herbal powder and herbal rose brush on. The results showed no significant preferences between the non irradiated and irradiated of the two products at P max=75%, α=0.05, β=0.10. This concludes that the irradiation does not affect the preference of the products, and it can be an alternative technology to reduce microbial decontaminations in herbal products.