Iron Encapsulation by Deacetylated Glucomannan as an Excipient Using the Gelation Method: Characteristics and Controlled Release
1Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro, Jl. Prof. Sudarto, SH, Tembalang, Semarang 50239, Indonesia
2Institute of Food and Remedies Biomaterial (INFARMA), Universitas Diponegoro, Jl. Prof. Sudarto, SH, Tembalang, Semarang 50239, Indonesia
Received: 10 January 2021
Accepted: 13 November 2021
glucomannan; deacetylation; gelation; iron encapsulation
Research background. Deacetylation and the use of CaCl2 as a gelation agent improve the performance of glucomannan as iron encapsulant using the gelation method. This study was conducted to investigate the effects of deacetylation using NaOH and pH gelation on the characteristics of encapsulated iron using the CaCl2 gelation method.
Experimental approach. Glucomannan was deacetylated at various NaOH concentrations and was subsequently utilized as an iron excipient using the pipette-dropped gelation method in CaCl2 solution to directly investigate the gelation process of encapsulation. The pH of the gelation solution was also changed. The beads were subsequently vacuum-dried.
Results and conclusions. Deacetylation led to lower endothermic peak temperature of the glucomannan than that of the native one. The deacetylation degree (DD) and gelation pH did not significantly affect the diameter of the beads but influenced their appearance and physical characteristics. The backbone of glucomannan was not changed by either the deacetylation degree or the pH of the gelation treatment. The highest encapsulation efficiency (73.27 %) was observed in the encapsulated iron using the glucomannan matrix of the highest deacetylation degree (82.56 %) and gelated in pH=10 solution. The highest deacetylation degree of glucomannan caused the beads to have the highest swelling, which led to the release of a higher amount of iron. Glucomannan deacetylation improved the pH sensitivity of iron encapsulation, in which more iron was released at a pH=6.8 than of pH=1.2. The Weibull model was the best-fitted model to represent the profile of iron release from the deacetylated glucomannan matrix using the gelation method (R2>0.93) at pH=6.8 and pH=1.2 solutions.
Novelty and scientific contribution. This result supports the application of deacetylated glucomannan using NaOH as a pH-sensitive matrix on iron encapsulation using CaCl2 solution as gelation agent. A higher deacetylation degree leads to the release of a higher amount of iron from the matrix. The encapsulation is not only protecting the iron but also delivering it to the absorption site and controlling the iron release which are useful in supplement formulation. or food fortifications. The results show that the deacetylated glucomannan as the matrix holds more iron in encapsulation process.