Gel extracted from Khruea-ma-noi (Cyclea barbata Miers) leaves: Chemical composition and gelation properties

Abstract

Gel extracted from Khruea-ma-noi leaves, which are widely consumed by villagers in Northeast Thailand, has a unique characteristic that could be used for food and nutritional applications, such as in therapeutic diets and in the food industry. Since little is known scientifically about this plant, this study identified the plant's scientific name and determined the chemical composition of the Khruea-ma-noi polymer and its gelling mechanism. Results reveal that Khruea-ma-noi is classified as Cyclea barbata Miers. Its main polymer is polygalacturonic acid of average molecular weight 741 kDa with 66.3% methylated. Dried powders of extract and purified gels contained 415 and 724 g kg -1 of soluble dietary fiber and 7.1 and 13.9 g kg-1 of divalent cations, respectively. Factors affecting gelling ability and characteristics include phenolic compounds, oxidizing and reducing agents, pH, divalent cations and temperature. Most gels formed were thermoreversible except at pH 7. © 2005 Society of Chemical Industry.