Physical and chemical characteristics of Aloe ferox leaf gel

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• 作者：C.  ; O'Brien^a ; B.-E.  ; Van Wyk ;   ; ^a ;   ; ^{bevanwyk@uj.ac.za} ; F.R.  ; Van Heerden¹ ;   ; ^a
• 关键词：Free sugars ; Gel composition ; Gel conductivity ; Gel yield ; Hydrolyzed sugars ; Organic acids ; Quality control
• 刊名：South African Journal of Botany
• 出版年：2011
• 出版时间：October 2011
• 年：2011
• 卷：77
• 期：4
• 页码：988-995
• 全文大小：198 K

文摘

Aloe ferox leaf gel differs substantially from that of Aloe vera but almost no commercially relevant data is available this species. Leaf dimensions, gel yields and gel compositions were studied, based on samples from several natural populations. Glucose is the only free sugar in aloe gel (0.1 to 0.4 mg ml^?1 in A. ferox). Monosaccharides released after hydrolysis show potential for gel fingerprinting and allow for a distinction between A. ferox and A. vera. The former yields various combinations of glucose and galactose as main monosaccharides, while the latter yields only mannose. Further variation studies are recommended because A. ferox appears to have three different gel chemotypes. Conductivity shows species-specific ranges ?in A. ferox below 3000 ¦ÌS cm^?1 in fresh gel and above 3100 ¦ÌS cm^?1 in aged gel (corresponding values for A. vera were 1670 and 1990 ¦ÌS cm^?1). The level of phenolic (bitter) compounds in A. ferox gel can be reduced by treatment with activated charcoal, resulting in a small loss of total dissolved solids. Alcohol precipitable solids and insolubility are useful variables for quality control of gel powder. The methods and data presented are the first steps towards developing quality criteria for A. ferox leaf gel.