微波辅助对桑叶提取物浓缩干燥的协同增效研究OA

This study systematically evaluated the effects of different concentration and drying strategies on the quality attributes of mulberry leaf crude extract powder.Conventional rotary evaporation followed by spray drying(SC)was used as the control process.Microwave-assisted processing was introduced to establish four additional combinations,rotary evaporation-hot air drying(XR),rotary evaporation-microwave drying(XW),microwave concentration-hot air drying(WR),and microwave concentration-microwave drying(WW).The samples were comprehensively compared in terms of physicochemical properties,microstructure,retention of major nutritional and bioactive components,and in vitro antioxidant activity.The results demonstrated that the WW treatment exhibited a marked advantage in processing efficiency,with the total concentration and drying time reduced by approximately 90%compared with the XR group.Microwave drying significantly modified the powder microstructure without disrupting the principal chemical backbone.Relative to the SC group,the WW group showed increases of 39%and 49%in soluble protein and polysaccharide contents,respectively.Flavonoid and total phenolic contents reached the highest levels,increasing by 54%and 118%,respectively,while the loss of 1-deoxynojirimycin(1-DNJ)was minimized to approximately 22%.Antioxidant assays indicated that the WW group exhibited the strongest scavenging activities against DPPH∙ and ABTS∙ radicals.Correlation analysis revealed a highly significant positive correlation between ABTS∙ radical scavenging activity and total phenolic content(P<0.01),whereas the correlation between DPPH∙ scavenging activity and phenolic content was comparatively weak though still positive.Principal component analysis further indicated that the concentration method exerted a relatively limited influence on overall sample characteristics,whereas the drying method was the dominant factor driving inter-sample variation and significantly amplified differences among treatments.In conclusion,microwave concentration combined with microwave drying represents an efficient and promising processing strategy for mulberry leaf crude extract powder,providing robust technical support for the industrial production of functional plant-based ingredients.