青贮甜菊叶内甜菊糖苷提取行为研究

Study on Extraction Behavior of Steviol Glycoside from Stevia Silage Leaves

【目的】为促进甜菊叶收储方式革新,打造低成本甜菊糖原料叶生产体系。【方法】本研究对不同青贮时长甜菊叶内甜菊糖苷提取行为进行分析。【结果】当青贮时间为3、7、15、21、30、60 d,甜菊叶所含各甜菊糖苷的常温水浸泡压榨提取效率随青贮时间延长逐渐增高,提取后各甜菊糖苷残余量随青贮时间延长而下降;70℃水浴浸泡提取4次后,日晒干叶中甜菊苷(Stevioside, STV)和瑞鲍迪苷(Rebaudiosides)系列(RA、RF、RC和RB等)甜菊糖苷残余量为2.7%~6.3%,青贮6月后直接浸提的各甜菊糖苷残余量为8.2%~13.3%,青贮6月烘干后再浸提的各甜菊糖苷残余量为12.2%~30.8%。【结论】本文除对影响青贮甜菊叶内各甜菊糖苷提取效率因素进行了探讨外,还基于研究结果对甜菊湿法收贮必要性和可行性进行了分析,为建立甜菊低成本收储方式提供参考。

【Objective】To establish a low-cost stevia production system and to promote innovation of stevia leaf collection and storage,【Methods】this study analyzed extraction behavior of steviol glycosides in leaves at different silage durations.【Results】The results showed that,after silage for 3 d,7 d,15 d,21 d,30 d and 60 d,extraction efficiency of steviol glycosides in stevia leaves was increased gradually with the extension of silage time during room temperature water soaking and pressing extraction,and amount of steviol glycosides kept in the residual decreased with the extension of silage time.After extracted by soaking in water bath at 70℃for 4 times,the residual contents of stevioside(STV)and rebaudiosides series(RA,RF,RC and RB,etc.)kept in sun-dried leaves ranged from 2.7%to 6.3%.The residual content of each steviol glycoside directly extracted after 6 months of ensiling ranged from 8.2%to 13.3%,while residual contents of RA,STV,RF,RC and RB kept in silage for 6 months and drying ranged from 12.2%to 30.8%.【Conclusion】In this paper,factors those affecting extraction efficiency of steviol glycosides from silage stevia leaves were discussed,and feasibility as well as necessity of wet storage of stevia leaves were analyzed too,which can provide a reference for the low-cost storage of stevia.