Quantitative colorimetric analysis of aloe polysaccharides as a measure of Aloe vera quality in commercial products.
Aloe vera inner leaf gel has been used as a medicinal remedy for many years. Yet some aloe products do not demonstrate beneficial effects, indicating that poor quality products are reaching the market. Therefore, an efficient and accurate method is needed to evaluate the quality of aloe products. This paper describes a quick, quantitative colorimetric assay that has been developed for the determination of glucomannan in aloe gel and products. With this method, interference by non-aloe polysaccharides or other extraneous components was absent or negligible. Data indicate that the glucomannan can be determined at parts per million (mg/L) in aqueous solutions with an accuracy of 100 +/- 5% at a 10 mg/L concentration. The correlation coefficient is 0.999, and linearity is from 0.9 to 72.7 mg/L in the test solution. The method is inexpensive, simple, sensitive, and reproducible. This method was applied to determine the polysaccharide content of commercial aloe products. Both qualitative and quantitative information can be obtained in about 5 min.
Mannatech, Inc., 600 South Royal Ln, Suite 200, Coppell, TX 75019, USA. aeberendu@mannatech.com
Alexis R
AR
Eberendu
Gabriela
G
Luta
Joshua A
JA
Edwards
Bill H
BH
McAnalley
Brice
B
Davis
Santiago
S
Rodriguez
C Ray
CR
Henry
D000504:Aloe / Q000737:chemistry* / Q000378:metabolism*; D004396:Coloring Agents / Q000494:pharmacology; D003224:Congo Red / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D008351:Mannans / Q000032:analysis; D010936:Plant Extracts / Q000032:analysis; D011134:Polysaccharides / Q000032:analysis* / Q000737:chemistry; D012680:Sensitivity and Specificity; D013053:Spectrophotometry; D013997:Time Factors
D004396:Coloring Agents; D008351:Mannans; D010936:Plant Extracts; D011134:Polysaccharides; C022901:(1-6)-alpha-glucomannan; D003224:Congo Red; C008315:maltodextrin