Encapsulation of Lactobacillus acidophilus FNCC 0051 in Hydrogel Using a Complex Coacervation of Glucomannan and Chitosan

Background and Objective: Probiotic is functional food gave good effect to human body if it is consumed in adequate amount.Its viability becomes lower during processing, storing and delivering to the body.Therefore, it needs to be protected.Hydrogel formed from interaction between glucomannan and chitosan may protect it.The aims of this study were to evaluate the characteristics of hydrogel made from glucomannan and chitosan and its efficiency in encapsulating Lactobacillus acidophilus FNCC 0051.Materials and Methods: Hydrogel was prepared by extruding 0.5% w/v chitosan in 1% acetic acid to 0.5% w/v carboxymethyl glucomannan.Properties of hydrogel such as particle size, morphology Fourier Transform Infra Red (FTIR) spectra and swelling ratio were measured.Encapsulation efficiencies were evaluated by enumerating encapsulated and unencapsulated cells.Data were analyzed using one way-ANOVA, then continued with Duncanʼs Multiple Range Test (DMRT).Results: The result of the study showed that hydrogel formed using complex coacervation between glucomannan and chitosan had the spherical shape with the particle sizes around 1.09-2.31µm.The new peak spectra at 1589 cmG 1 confirmed that L. acidophilus was encapsulated in hydrogel matrix.The hydrogel respectively showed minimum and maximum swelling ratio at pH values of 5 and 8. Encapsulation efficiency was 66.1±3.0%when the cells were released in pH 8.It was not significantly different to the efficiency in pH 7. Enumerating unencapsulated cells provided lower encapsulation efficiency.Conclusions: L. acidophilus can be encapsulated in hydrogel using complex coacervation of glucomannan and chitosan.The low swelling ratio at lower pH provide better protection for the cell in the stomach, while the high swelling ratio at higher pH may be used to release the cell in small intestine.Further researches may be conducted to increase the encapsulation efficiency.