Determination of the effects of some gums on the encapsulation of different phenolic compounds

Phenolic compounds have an important place in the daily diet because of their positive effects on human and animal health. Despite beneficial effects, they are not resistant to food processing. Being affected by heat, light and oxygen, deformations can occur in their structures. In this study, according to ionic gelation method microencapsulation of phenolic compounds with various hydrophilic/hydrophobic properties with different thickening agents that have diverse viscosity is aimed. In the study, four types of wall materials (alginate, alginate-gum arabic, alginate-carrageenan and alginate-guar gum) and seven kinds of phenolic compounds (tannic acid, chlorogenic acid, gallic acid, p-coumaric acid, caffeic acid, naringin and hesperidin) were used. The thickeners used were selected among the nine types of gums having the lowest, highest and median viscosity values at the conclusion of the rheological analyzes made. In the choice of the phenolic compounds, those having different solubility are preferred. The effect of the thickening agents with different viscosities and especially the use of different phenolic compounds, in terms of water solubility on encapsulation efficiency, have been investigated. In addition, particle sizes and swelling rates of the obtained capsules were determined. It was determined that decreased water solubility of phenolic compounds increased the encapsulation efficiency. Among the phenolic compounds used in this study, the encapsulation efficiency of tannic acid, having the highest water solubility, was 28.4±0.3%, while the encapsulation efficiency of hesperidin, having the lowest water solubility, was 88.7±0.7%. In different experiment in this study, encapsulation efficiency of alginate-gallic acid microencapsules not containing the core material in the jelling bath were found as 33.96±0.42%, the ones that added half concentration of core materials were 63.25±0.20%, and the capsules that added equal concentration of core material were found as 89.05±0.62%. The particle volumes of microencapsules produced without using thickeners were identified as 0.54±0.01 mm3, while the particle volumes of gum arabic, carrageenan and guar gum capsules were identified as 0.71±0.02, 0.75±0.03, 1.14±0.03 mm3. In the swelling rate analysis, increase in volumes of capsules was observed only in guar gum containing capsules, where there was no change in other formulations. According to results of this study, it was understood that the solubility of the core-material in the phase of encapsulation process is important and it affects the encapsuation efficiency. It has been shown that adding specific concentration of the core material to the phase that encapsulation occur to prevent efficiency losses is beneficial.