Abstract:
To determine the optimal sterilization method for Tsampa storage, Tsampa samples from the control, moist-heat sterilization, dry-heat sterilization,
60Co irradiation sterilization, microwave sterilization, and ozone sterilization groups were stored for 30 and 60 days. These samples were then analyzed for essential nutritional components, lipid oxidation indicators, microbial indicators, and volatile flavor compounds. The samples from the moist-heat, dry-heat, and microwave sterilization groups exhibited significant alterations in moisture content (
P<0.05), leading to drastic changes in other nutrient contents and high levels of lipid oxidation. All five sterilization methods demonstrated good sterilization efficacy and inhibited lipoxygenase activity (
P<0.05) but significantly increased total acid and malondialdehyde contents (
P<0.05). Among them, the lipid oxidation levels in the Tsampa were higher in the moist heat, dry heat, and irradiation sterilization, while the ozone sterilization exhibited relatively lower in the Tsampa. In total, 59 volatile compounds were detected in Tsampa, including 18 aldehydes, 9 esters, 12 alcohols, 10 ketones, 3 acids, 3 furans, and 4 other substances. Moist-heat sterilization resulted in a decrease in the relative amount of organic acids, whereas dry-heat, irradiation, and microwave sterilization led to conspicuous increase in ester and acid contents. However, ozone sterilization had a relatively weak effect on volatile compound content, showing no significant difference compared with the control group. Therefore, ozone sterilization is the optimal Tsampa sterilization method, as it has minimal effect on the essential nutritional components and lipid oxidation indicators, while maintaining good sterilization efficiency and flavor retention.