Ferulic acid, that is one of the hydroxybenzoic acids and a phenolic compound, is encapsulated in nopal mucilage. It is beneficial for human body and prevents from cell aging, carcinogenic effects of free radicals. Torres et al. found that this mucilage is promising for encapsulating active ingredients (2012).
Nopal mucilage is composed of pectic polysaccharides (Amin, Awad, & El-Sayed, 1970). It is yielded from peeled fruits of O. ficus indica plant. Phenolic compounds are very sensitive to heat and light. And also most of them may cause bitter taste. In order to protect against light, pH, heat; and increase its bioavailability, ferulic acid is encapsulated (Munin & Edwards-Lévy, 2011).
Water is used to disperse the polymers. Mucilage should be diluted to 1o Brix since it increases viscosity and viscous liquids cannot be dried by spray drying. 0.3 g ferulic acid is expected to be enough for 1 L mucilage as it is in “Microencapsulation by spray drying of gallic acid with nopal mucilage” experiment. Homogenization provides encapsulation of ferulic acid with pectic polymers. Pectic polymers surround molecules.
Solution is dried by spray dryer with rotary atomizer. One of the important points is; since, ionic strength affects coating formation, solution is prepared by deionized water. It is not necessary to adjust pH. There are two kind of interaction between ferulic acid and mucilage. First one is cross linking by esterification with hydroxyl groups of polysaccharides. Second one is electrostatic interactions. Ferulic acid can make covalent bond with polysaccharides in the cell membrane and nopal mucilage contains these pectic polysaccharides (Grassby, 2008).
In this method; homogenization level, temperature of spray drying, concentration of ferulic acid and mucilage may affect particle size. Particle size can be less than 5 microns or measured between 10-100 microns. Results of “Microencapsulation by spray drying of gallic acid with nopal mucilage” experiment (Torres, Cruz, et al., 2012) show that fine particles may have less than 5 microns diameter while Fang and Bhandari found that particles that is encapsulated by spray drying method have 10 to 100 microns diameter.
Release of ferulic acid can be monitored by spectrophotometer at intensity range of 1.0-0.8 counts. Mucilage-ferulic acid interactions are stronger than mucilage-gallic acid interactions, since ferulic acid takes place in esterification reactions with pectic polysaccharides. In their study Torres et al. (2012) mentioned that gallic acid is released 65% in 2.47 days. So, longer time or less efficiency is expected at small intestine conditions.
REFERENCES
Amin, E. S., Awad, O., & El-Sayed, M. (1970). The mucilage of Opuntia ficus indica. Carbohydrate Research, 15, 159-161
Fang, Z., & Bhandari, B. (2010). Encapsulation of polyphenols-a review. Trends in Food Science & Technology, 21, 510e523.
Grassby, T. (2008). Phenolics and phenolic-polysaccharide linkages in Chinese water chestnut (Eleocharis dulcis) cell walls. Unpublished doctoral dissertation, University of East Anglia, Norwich, England.
Munin, A., & Edwards-Lévy, F. (2011). Encapsulation of natural polyphenolic compounds; a review.Pharmaceutics, 3, 793-829.
Torres, L., Cruz, E., Calderas, F., Laredo, R., Olivares, G., Gallegos-Infante, J., Rocha, N., & Ramírez, J. (2012). Microencapsulation by spray drying of gallic acid with nopal mucilage. Food Science and Technology, 50, 642-650.
No comments:
Post a Comment