Microencapsulation of gallic acid in chitosan, β-cyclodextrin and xanthan
Highlights
► The gallic acid was encapsulated by lyophilization method in matrices of chitosan, β-cyclodextrin and xanthan. ► With the chitosan matrix, a higher encapsulation efficiency, and capsules with characteristic shape were obtained. ► Encapsulated GA retained antioxidant capacity.
Introduction
Gallic acid (3,4,5-trihydroxybenzoic acid, GA) is a hydroxybenzoic acid biosynthesized from precursors of the shikimate pathway by the enzyme dihydroshikimate. It is found in great abundance in the plant kingdom, especially in berries, citrus fruits, cereals, tea, wine and herbs. GA occurs naturally both in the free form and as an ester or salt. The salt form is called gallate and is part of the ellagitannins structure, which is a constituent of the hydrolysable tannins (de la Rosa et al., 2010).
Gallic acid has several biochemical properties, as antioxidant (Jung et al., 2010), an antimicrobial agent (Chanwitheesuk et al., 2007), and an antihyperglycaemic agent (Punithavathi et al., 2011); it also prevents oxidative stress (Pal et al., 2010) and some kinds of cancer (Ho et al., 2010). GA retains these properties even at low amount (between 5 and 20 mg), but it is unstable at extreme temperatures or in the presence of oxygen or light, conditions which are common in food processing and storage (Jacques et al., 2010, Yang et al., 2007). Microencapsulation may maintain the bioactivity of this compound. However, the degree of protection provided by microencapsulation is determined by the choice of encapsulation method (Gouin, 2004). Lyophilization is the most efficient technique to protect GA against chemical decomposition because the low processing temperature and reduced moisture reduce the loss of bioactivity better than other methods, such as coprecipitation, neutralization, atomization and solvent evaporation (Yamada et al., 2000). Microencapsulation by lyophilization protects the compound in a polymer matrix, maintaining its bioactivity and controlling its release (Pothakamury and Barbosa-Gnovas, 1995). The composition of the coating material is a major determinant of both the capsule's functional properties and how it can be used to improve the performance of a particular active compound (Desai and Park, 2005).
Biopolymers such as chitosan have been used in previous studies to encapsulate phenolic extracts obtained from natural sources (Belščak-Cvitanović et al., 2011, Deladino et al., 2008). Chitosan is a biodegradable polymer obtained from the partial deacetylation of chitin. It has a linear structure of N-acetyl-d-glucosamine with polar groups, such as OH and NH2, which can act as electron donors (Shahidi et al., 1999). This polymer has great potential for applications in the pharmaceutical industry as a lipophilic encapsulation for drugs (Ribeiro et al., 1999) and in the food industry as an encapsulation for probiotics and prebiotics (Chávarri et al., 2010), aromatic compounds (Higuera-Ciapara et al., 2003), enzymes (Anjani et al., 2007) and antioxidants (Deladino et al., 2008, Weerakody et al., 2008).
Cyclodextrin (CDS) has been used in previous studies to microencapsulate pure phenolic compounds, such as quercetin (Pralhad and Rajendrakumar, 2004), kaempferol (Mercader-Ros et al., 2010), naringin (Sansone et al., 2011) and ferulic acid (Wang et al., 2011b). However, there are no studies of the microencapsulation of gallic acid with cyclodextrin. CDS consists of cyclic oligomers of α-d-glucose linked by glycosidic bonds. It is produced during starch metabolizing by certain bacteria, such as Bacillus macerans (Szente and Szejtli, 2004). The most common types of CDS are α, β and γ, which consist of six, seven and eight glucose units, respectively. Purification of the α and γ forms greatly increases the cost of production; therefore, the β-CDS is most widely used in commercial settings. Cyclodextrins are commonly used to protect the flavors and aromas of food (Yuliani et al., 2006) as well as vitamins (Gonnet et al., 2010, Nevado et al., 2000), antioxidants (Wang et al., 2011a, Wang et al., 2011b) and fat-soluble pigments (Blanch et al., 2007) because they form inclusion complex. In aqueous solution, the apolar cyclodextrin cavity is occupied by water molecules, which are not energetically favorable and are readily replaced by “guest molecules” that are less polar than water (Astray et al., 2009). The inclusion of polyphenols in β-CDS has the advantage of improving water solubility, especially for less soluble phytochemicals (Wang et al., 2011b).
Xanthan is an extracellular polysaccharide produced by Xanthomonas bacteria. It is chemically composed by glucose, mannose, and glucuronic, pyruvic and acetic acids. Xanthan is used in many products as a thickening (Sopade et al., 2008) or stabilizing agent (García-Ochoa et al., 2000). Xanthan has been used as an encapsulant for aromatic compounds (Secouard et al., 2007), drugs (Talukdar et al., 1998) and microorganisms (Papagiannis and Anastasiadis, 2009). However, there are no reports of encapsulating phenolic compounds with xanthan.
This study aimed to encapsulate gallic acid in chitosan, β-cyclodextrin and xanthan matrices by lyophilization, to investigate the encapsulation efficiencies and to measure antioxidant capacities of the encapsulated gallic acid. The encapsulation was evaluated by Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–vis), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).
Section snippets
Materials
Molecular weight chitosan medium (C) (Sigma–Aldrich), β-cyclodextrin hydrate (β-CDS) (Sigma–Aldrich), xanthan (X) (Sigma–Aldrich), gallic acid (GA) (Fluka) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) (Sigma–Aldrich) were used in this work. All other chemicals and solvents were high performance liquid chromatography (HPLC) grade.
Microencapsulation of GA with C, β-CDS and X
The complexes were prepared in the presence of GA and C, GA and β-CDS, GA and X, according to the lyophilization methods described by Pralhad and Rajendrakumar (2004) and
Efficiency of encapsulation
Encapsulation efficiency results and antioxidant activity of encapsulated GA/C, GA/β-CDS and GA/X are shown in Table 1.The encapsulation of GA in the matrix C presented the highest values of encapsulation efficiency, being statistically different from β-CDS and X matrixes.
Gallic acid has low solubility in water (Hoepfner et al., 2002), however it can form hydrogen bonds because it has polarizable hydroxyl of phenolic and carboxylic groups both intramolecular as well as intermolecular (Carvalho
Conclusion
Gallic acid was encapsulated in matrices of C, β-CDS and X by lyophilization. The encapsulated gallic acid showed no loss of antioxidant capacity and different characteristics to the pure gallic acid that were confirmed by SEM, DSC, TGA and UV. However, with the chitosan matrix a higher encapsulation efficiency, and capsules with characteristic shape were obtained.
Further studies should be performed to measure the release of GA from the capsules, to ascertain its antioxidant activity under
Acknowledgments
To CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior), CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) and LSS-UFRGS (Laboratório de Sólidos e Superfícies - Universidade Federal do Rio Grande do Sul) for their support.
References (55)
- et al.
Formulation and biological evaluation of glimepiride–cyclodextrin–polymer systems
Int. J. Pharm.
(2006) - et al.
Microencapsulation of enzymes for potential application in acceleration of cheese ripening
J. Int. Dairy
(2007) - et al.
A review on the use of cyclodextrins in foods
Food Hydrocolloid.
(2009) - et al.
Stabilization of all-trans-lycopene from tomato by encapsulation using cyclodextrins
Food Chem.
(2007) - et al.
Encapsulation of polyphenolic antioxidants from medicinal plant extracts in alginate–chitosan system enhanced with ascorbic acid by electrostatic extrusion
Food Res. Int.
(2011) - et al.
Use of a free radical method to evaluate antioxidant
LWT – Food Sci. Technol
(1995) - et al.
Antimicrobial gallic acid from Caesalpinia mimosoides Lamk
Food Chem.
(2007) - et al.
Microencapsulation of a probiotic and prebiotic in alginate-chitosan capsules improves survival in simulated gastro-intestinal conditions
Int. J. Food Microbiol.
(2010) - et al.
Encapsulation of natural antioxidants extracted from Ilex paraguariensis
Carbohydr. Polym.
(2008) - et al.
Solid-state characterization and dissolution profiles of the inclusion complexes of omeprazole with native and chemically modified b-cyclodextrin
Eur. J. Pharm. Biopharm.
(2007)
Xanthan gum: production recovery, and properties
Biotechnol. Adv.
Microencapsulation: industrial appraisal of existing technologies and trends
Trends Food Sci. Technol.
New trends in encapsulation of liposoluble vitamins
J. Controlled Release
Anti-metastasis effects of gallic acid on gastric cancer cells involves inhibition of NF-kB activity and downregulation of PI3 K/AKT/small GTPase signals
Food Chem. Toxicol.
Effect of dietary mixture of gallic acid and linoleic acid on antioxidative potential and quality of breast meat from broilers
Meat Sci.
Study of the solubility antioxidant activity and structure of inclusion complex of vanillin with b-cyclodextrin
Food Chem.
Influence of b-cyclodextrin complexation on carbamazepine release from hydroxypropyl methylcellulose matrix tablets
Eur. J. Pharm. Biopharm.
Influence of the preparation method on the physicochemical properties of ketoprofen–cyclodextrin binary systems
Int. J. Pharm.
Physicochemical characterization and dissolution properties of meloxicam–cyclodextrin binary systems
J. Pharm. Biomed. Anal.
Gallic acid prevents nonsteroidal anti-inflammatory drug-induced gastropathy in rat by blocking oxidative stress and apoptosis
Free Radical Biol. Med.
Study of freeze-dried quercetin–cyclodextrin binary systems by DSC, FT-IR, X-ray diffraction and SEM analysis
J. Pharm. Biomed. Anal.
Encapsulation of Pediococcus acidilactici cells in corn and olive oil microcapsules emulsified by peptides and stabilized with xanthan in oil-in-water emulsions: Studies on cell viability under gastro-intestinal simulating conditions
Enzyme Microb. Technol.
Fundamental aspects of controlled release in foods
Trends Food Sci. Technol.
Antihyperglycaemic antilipid peroxidative and antioxidant effects of gallic acid on streptozotocin induced diabetic Wistar rats
Eur. J. Pharmacol.
Increase in stability and change in supramolecular structure of β-carotene through encapsulation into polylactic acid nanoparticles
Int. J. Pharm
Food applications of chitin and chitosans
Trends Food Sci. Technol.
Novel modified starch xanthan gum hydrogels for controlled drug delivery Synthesis and characterization
Carbohydr. Polym.
Cited by (123)
Evaluation of MgAl LDH incorporated Gallic acid anti-corrosion impact on mild steel in tempered 3.5% NaCl solutions: Integrated electrochemical and morphological studies
2023, Journal of Industrial and Engineering ChemistryFlavonoid content and antifungal activity of Celastrus hindsii leaf extract obtained by supercritical carbon dioxide using ethanol as co-solvent
2023, Biocatalysis and Agricultural BiotechnologyPost grafted gallic acid to chitosan-Ag hybrid nanoparticles via free radical-induced grafting reactions
2023, International Journal of Biological MacromoleculesSpray drying encapsulation of phenolic compounds and antioxidants
2023, Spray Drying for the Food Industry: Unit Operations and Processing Equipment in the Food IndustryAntioxidant and anticancer activities of gallic acid loaded sodium alginate microspheres on colon cancer
2022, Current Applied PhysicsCitation Excerpt :FTIR, SEM, DSC, TGA were used to characterize the microspheres. As a result of the encapsulation, GA did not show any loss of antioxidant activity and it was stated that the most efficient microsphere of three different polymers was obtained with chitosan [62]. In 2013, Neo et al.