Effects of different drying methods on the quality of ginkgo powder

Taking ginkgo fruits as raw material, ginkgo powder was prepared by five different drying methods, which were hot air drying, vacuum freeze drying, microwave drying, spray drying, and drum drying. The effects of five different drying methods on the removal rate of ginkgolic acid, nutrient active components, color difference, water holding capacity, oil retention and gelatinization properties of ginkgo biloba were studied. The results showed that drum drying method had the most significant effect on the ginkgo acid removal and the removal rate reached 78.61%, which greatly improved product safety, while the other drying methods were less than 40%.Spray drying and vacuum freeze drying had better retention of active ingredients, and the retention rates of flavonoids and lactones were 86% and 90% respectively, while drum drying was relatively poor.The total color difference ΔE of spray drying and vacuum freeze drying were smaller ( about 20.43) , while the drum drying was 12.80%, 8.23 g/g and 2.95 g/g respectively. The solubility, water absorption index and oil absorption index of ginkgo powder were all higher.In order to ensure the safety of the ginkgo powder, and take the production costs and the feasibility of industrial production into consideration, the drum drying method in preparation of ginkgo powder was the best.