Effects of heat treatments on the stabilities of polysaccharides substances and barbaloin in gel juice from Aloe vera Miller

Abstract

Research was conducted on the gel juice from Aloe vera, a traditional medicinal plant, to investigate the effects of heat treatment on bioactive substances including polysaccharide and barbaloin. The effect of methanol solvent on compositional variations of barbaloin was also taken into consideration. Results show that the polysaccharide from Aloe vera exhibited a maximal stability at 70 °C decreasing either at higher or lower temperatures. Heating promoted a remarkable decrease in barbaloin content depending on temperature and time, more affected than polysaccharide of the gel juice from Aloe vera. Barbaloin is unstable when dissolved in methanol resulting in the transformation into a series of unidentified compounds, in addition to aloe emodin with the period of storage at 4 °C in refrigerator.