Chickpea and soybean protein delivery systems for oral ingestion of hydroxycitric acid

Abstract

The plant derived product, hydroxycitric acid (HCA), extracted from the rind of Garcinia cambogia is a promising weight loss agent. Since HCA irritates the stomach and undergoes gastrointestinal degradation, encapsulation was carried out using two protein matrices, chickpea and soybean, towards fabricating vehicles for oral delivery of HCA. Encapsulated particles of both proteins displayed high encapsulation efficiency and loading capacity of HCA and were spherical with micron to submicron range sizes. The particles displayed steric stability or incipient instability in solution. Storage stability studies revealed that HCA shows photosensitivity and thermal sensitivity, and therefore, dark and refrigerated conditions are suggested for the improvement of stability of HCA on storage. Chickpea protein facilitated photo-stability while soybean protein facilitated storage-stability of HCA. At pH 2 and pH 6.8, release profiles of HCA from chickpea protein and soybean protein particles fitted best to the Higuchi model displaying mainly a diffusional release mechanism with a less Fickian behaviour. At the intestinal pH, the bioaccessibility of HCA from chickpea protein matrix was higher (52%) compared to that from soybean protein matrix (35%). Results indicate that chickpea protein is a promising matrix for encapsulation of HCA for safe, efficacious and controlled oral delivery of HCA.