The impact of gamma radiation on microbial sanitization, sensory qualities, nutritional values, and functional groups of Illicium verum Hook. f

Abstract

Star anise is a key ingredient among the African spices commonly used in uncooked foods such as beverages, desserts, and other culinary preparations. This study investigated the microbial reduction, sensory characteristics, nutritional aspects, and transformations of functional groups in star anise samples following gamma irradiation at various doses. The samples were stored at room temperature and analyzed immediately after irradiation, after three and six months of storage. In the non-irradiated star anise samples, aerobic bacteria such as Bacillus spp., Salmonella spp., Clostridium spp., Shigella, Staphylococcus, Escherichia coli , and yeast-like fungi were identified. The results also indicate a reduction in the total microbial population of the irradiated samples compared to the non-irradiated ones, with the optimal radiation dose recorded at 8 kGy. The sensory characteristics of the star anise samples were also investigated, and the results show a slight improvement in some of the sensory attributes of the star anise samples, such as appearance, color, texture, and overall acceptability, particularly for higher radiation doses after irradiation and during storage. Furthermore, insignificant differences were observed in the nutritional parameters before and after irradiation. Similarly, no substantial changes in the functional groups of the star anise compounds were noted in both irradiated and non-irradiated samples. The findings of this study, therefore, support the application of gamma irradiation in the manufacturing of spice powder for commercial purposes and validate the techniques as safe and effective in advancing spice safety standards.