Transformation and degradation of barbaloin in aqueous solutions and aloe powder under different processing conditions

Abstract

Aloe vera is one of the few edible species in the genus Aloe, and its products are widely used in foods, cosmetics, health care products, medicines and other fields. Barbaloin is the highest content of anthraquinones in aloe, which has potential allergenicity, and it is one of the important indicators for the quality control of aloe-containing products. Aiming at resolving the problems of barbaloin instability, easy sensitization and high residue, the transformation and degradation mechanisms of barbaloin under different processing conditions (temperature, pH, food additives and metal ions) were studied in this research, and the toxicity of the products were evaluated. The results showed that the transformation and degradation of barbaloin can be significantly accelerated by high temperature, alkaline conditions, calcium chloride, carboxymethyl cellulose, Fe3+ and Mg2+ (p < 0.001). However, they can be significantly inhibited by the acidic environment and Pb2+ (p < 0.001). And the transformation and degradation of barbaloin in aloe powder were almost the same as those in the barbaloin aqueous solution. The main transformation and degradation products of barbaloin were isobarbaloin, aloe emodin, 10-Hydroxyalloin A and 10-Hydroxyalloin B, and the other two unknown products were isomers. And aloe emodin may have greater toxicity hazards and potential safety risks. The molecular electrostatic potential properties also indicated that the 10th carbon atom of barbaloin, isobarbaloin, 10-Hydroxyaloin A and 10-Hydroxyaloin B may be more likely to break chemical bonds and generate new transformation and degradation products. These research results can be applied to the control of barbaloin and aloe emodin in the processing of aloe-containing products, so as to provide the basis for the better development and utilization of aloe.