Effect of sodium tripolyphosphate on the characteristics of anthocyanin microcapsules extracted from purple sweet potato (Ipomoea batatas L.)

Abstract

One of the cheapest and widely available sources of anthocyanin in Indonesia is purple sweet potato (Ipomoea Batatas L.). The content of anthocyanin is about 61.85 mg per 100 g of purple sweet potato. An anthocyanin is a group of pigments that causes reddish colour, which mostly located in a water-soluble liquid cell. Anthocyanin has been allowed as a food colouring additive, since it is a non-toxic compound for the human body. However, anthocyanin has low storage stability, therefore it important to improve its stability. This research investigated the microencapsulation process of anthocyanin using chitosan with crosslinking agent sodium tripolyphosphate. The addition of sodium tripolyphosphate may affect the microencapsulation results, such as: the size of anthocyanin microencapsulation, structural properties of the microencapsulation spectra, and effectiveness of the crosslinking agent concentration on the microencapsulation process. The analysis performed in this research were as follow: Yield of Microcapsules (YOM), UV-Vis Spectrophotometry, and Particle Size Analysis. The analysis results showed that Yield of Microcapsules (YOM) and Total Monomer Anthocyanin (TMA) increased when TPP concentrations got increased. The optimum condition was achieved at concentrations of tripolyphosphate 1.5 (w/v) with the value of microcapsules result (YOM) of 1.11 g and the Total Monomer Antosianin (TMA) of 96.5%, respectively. Additionally, the anthocyanin capsule has a uniform size of ± 28 nm.