Incorporation Of Gallic Acid Research Articles

Sustainable materials for novel food packaging based on alginate, methylcellulose and glycerol films functionalized with gallic acid

In the last years, new sustainable materials have been explored as plastic replacement in food industry. With the objective of developing sustainable active materials for food packaging, polysaccharide-based films: alginate, methylcellulose and glycerol-based films (ALG-MC-GLY (65:30:5)) were formulated and functionalized with different concentration of gallic acid (0.1, 0.5 and 0.8 % w/v). The mechanical, physicochemical, optical and functional properties of the films were evaluated. The incorporation of gallic acid resulted in films less resistant to tensile stress and less elastic, exhibiting reduced water vapor permeability. The physico-mechanical characterization was corroborated by FTIR spectra, HRSEM imaging and BET analyses, which demonstrated the interactions between the polymeric chains and gallic acid through localized hydrogen bonding, leading to denser structures with increased brittleness at higher concentrations of gallic acid. Moreover, the films functionalized with gallic acid displayed enhanced antioxidant properties in a concentration-dependent manner. These findings suggest that the ALG-MC-GLY based films loaded with gallic acid hold significant promise as alternative active food packaging materials.

Coassembly of Fiber Hydrogel with Antibacterial Activity for Wound Healing.

Wound healing remains a critical challenge due to its vulnerability to bacterial infection and the complicated inflammatory microenvironment. Herein, we report a novel antibacterial hydrogel constructed only by gallic acid (GA) and phycocyanin (PC), which is expected for the treatment of bacteria-infected wounds. These GA/PC hydrogels (GP) was found to coassemble into fibrous networks with a diameter of around 2 μm mainly through noncovalent interactions of hydrogen bonds, van der Waals force, and π interaction. Notably, these GP hydrogels showed excellent rheological properties (i.e., storage modulus of more than 9.0 × 104 Pa) and outstanding biocompatibility and antibacterial activities. Thanks to the incorporation of GA and PC, the GP hydrogels enabled adherence to the moist wound tissue and achieved a sustained release of GA and PC into the wound skin, therefore effectively attenuating inflammation and accelerating wound healing both in normal mice and bacteria-infected mice through regulating the expression of the tight junction protein and the alleviation of oxidative stress. Considering these results, these GP hydrogels are demonstrated to be a promising candidate for bacteria-infected wound healing.

Active Packaging Film Based on Poly Lactide-Poly (Butylene Adipate-Co-Terephthalate) Blends Incorporated with Tannic Acid and Gallic Acid for the Prolonged Shelf Life of Cherry Tomato

The antimicrobial property is the key feature of active packaging. Biological macromolecules such as tannic and gallic acids are naturally found in plants such as tea, fruits, berries, and grapes. The incorporation of tannic acid (TA) and gallic acid (GA) in the biodegradable polymer blend Poly Lactide-Poly (Butylene Adipate-Co-Terephthalate) (PLA-PBAT) was used in this study to assess the potential of active packaging. TA and GA (10 wt%) composite films showed a 65%–66% increase in the UV barrier property. The tensile strength value increased after the incorporation of TA and GA (10 wt%), respectively. Overall, 1.67 and 2.2 log reductions in E. coli and L. monocytogenes growth were observed, respectively, in the presence of TA (10 wt%) composite film. In addition, TA composite film was able to maintain and enhance the quality of cherry tomatoes for up to 20 days of storage at room temperature. For cherry tomatoes packed in PLA-PBAT-TA10 (wt%), TSS decreased by 6.3%, pH was 4.3, and a microbial reduction of 2.70 log CFU/mL was observed. In conclusion, TA composite film had confirmed significant UV blocking properties, surface hydrophobicity, and antibacterial properties, which show its potential as an active packaging film.

Active caseinate/guar gum films incorporated with gallic acid: Physicochemical properties and release kinetics

Composite active films based on sodium caseinate/guar gum were prepared by the incorporation of gallic acid at different concentrations to investigate its effect on the structure, physicochemical properties, and the release kinetics from the film. The incorporation of gallic acid imparted changes in the FT-IR spectra. Water vapor permeability (WVP) of films decreased up to 21% after the incorporation of gallic acid in the film. The gallic acid released from the films GAI* 60 μg.ml−1 , GAII* 250 μg.ml−1 and GAIII* 650 μg.ml−1 was 67%, 32% and 30% respectively. Similarly, the diffusion coefficient was also affected by an increase in the concentration and was: 8.10 × 10 −12 m 2 s −1 , 6.23 × 10 −12 m 2 s −1 , and 4.5 × 10 −12 m 2 s −1 for GAI, GAII and GAIII films respectively. Molecular docking suggested the potential inactivation of oxidative enzymes due to binding of gallic acid near their active sites. Therefore, gallic acid releasing films maybe considered as an active food packaging for fruits and vegetables (F&V). • Physicochemical properties of caseinate films were modified by the incorporation of gallic acid. • Permeability and light barrier properties of the films were significantly affected by the incorporation of gallic acid. • A maximum of 67% of gallic acid was released from the film with lowest gallic acid concentration. • The DPPH antioxidant activity of food simulant solutions ranged between ∼40 and 80%. • Oxidative enzyme inactivation by using phenolic compounds is a new concept in food packaging domain.

Construction of an antibacterial hydrogel based on diammonium glycyrrhizinate and gallic acid for bacterial- infected wound healing

The current antibacterial wound dressings with antibiotic substances or metal bactericidal agents may lead to severe multidrug resistance and poor biocompatibilities. Herein, we report an inherent antibacterial hydrogel constructed by only two naturally small molecules gallic acid (GA) and diammonium glycyrrhizinate (DG) for promoting Staphylococcus aureus (S. aureus)-infected wound healing. The resultant GAD hydrogel can be fabricated by co-assembly of these two materials through simple steps. Thanks to the incorporation of GA and DG, GAD hydrogel enabled a strong mechanical performance and great self-healing property with a sustained-release of drugs into skin wounds. Moreover, the cell viability assays showed that GAD hydrogel had good cytocompatibility by promoting cell proliferation and migration. In addition, GAD hydrogel had broad antibacterial efficiency against both Gram-positive and Gram-negative bacteria. Taken together, GAD hydrogel is a promising dressing to accelerate bacterial-infected wound healing through reconstructing an intact and thick epidermis without antibiotics or cytokines.

Gamma irradiation synthesis of pectin- based biohydrogels for removal of lead cations from simulated solutions

Bio-based hydrogels (denoted as PC-PAAc/GA) comprised of Pectin (PC) and polyacrylic acid (PAAc) reinforced with different ratios of gallic acid (GA) were prepared by gamma radiation at irradiation dose 20 kGy. The prepared hydrogels were investigated by different analytical tools. The swelling performance was studied versus time, pH of the medium and gallic acid content. The experimental data depicted that the swelling increases with pH of medium until the equilibrium of swelling after 350 min. The maximum swelling was attained at pH10 for both PC-PAAc and PC-PAA/GA1.5. Also, the data reveal that the incorporation of GA in the hydrogel matrix enhanced the swelling performance of the hydrogel up to an optimum value of GA, i.e. PC-PAA/GA1.5. Further increase in GA concentration leads to formation of a highly crosslinked structure with reduced swelling. The results demonstrated that the prepared hydrogels displayed excellent antibacterial activity against gram + ve bacteria (E.coli) and gram-ve bacteria (S.aureus). This potent antimicrobial activity is mainly originated from GA which was proved as a strong antibacterial agent. Moreover, the removal performance of the investigated hydrogels was verified towards Pb+2 cation as one of the most poisonous heavy metals. The data revealed that the maximum removal percentage of Pb (II) was attained by PC-PAAc/GA1.5 hydrogel (90 mg g−1). The correlation coefficients of the Langmuir model are too higher than that of the Freundlich model that assumed the adsorption of lead cations is mainly a chemical process.

Active and Robust Composite Films Based on Gelatin and Gallic Acid Integrated with Microfibrillated Cellulose.

Background: Gelatin is a renewable, biodegradable, and inexpensive food polymer. The insufficient mechanical and functional properties of gelatin-based films (GBF) restrict their commercial application in food packaging. This work proposed a facile strategy to prepare an active and robust GBF that has the potential to be used in food packaging. Methods: A strong and active GBF was prepared based on the principle of supramolecular chemistry via the incorporation of gallic acid (GA) as an active crosslinking agent and of microfibrillated cellulose (MFC) as a reinforcing agent. Results: Under the appropriate concentration (1.0 wt%), MFC was evenly dispersed in a gelatin matrix to endow the film with low surface roughness and compact structure. Compared with the GF, the tensile strength and elongation at break of the resultant film reached 6.09 MPa and 213.4%, respectively, representing the corresponding improvement of 12.8% and 27.6%. Besides, a significantly improved water vapor barrier (from 3.985 × 10−8 to 3.894 × 10−8 g·m−1·Pa−1·s−1) and antioxidant activity (from 54.6% to 86.4% for ABTS radical scavenging activity; from 6.0% to 89.1% for DPPH radical scavenging activity) of GBFs were also observed after introducing the aromatic structure of GA and nano-/microfibrils in MFC. Moreover, the UV blocking performance and thermal stability of GGF and GGCFs were also enhanced. Conclusions: this work paves a promising way toward facile preparation of multifunctional GBFs that have great potential to be used in fabricating active and safe food packaging materials for food preservation.

Gallic acid encapsulated pea flour‐based nanofibers produced by electrospinning as a potential active food packaging material

AbstractThe main aim of the article was to produce gallic acid‐loaded pea flour/polyethylene oxide (PEO)‐based nanofibers through the electrospinning method as an alternative active packaging material. Incorporation of gallic acid caused significant changes in both solution properties and fiber morphology. Increasing gallic acid concentration resulted in increasing conductivity and decreasing consistency index, by the way decreasing average fiber size diameter. In thermogravimetric analysis (TGA), gallic acid addition resulted in a decrease in thermal degradation value of nanofibers. In addition to these changes, new chemical bands formed were an indicator of the successful encapsulation of gallic acid in Fourier‐transform infrared (FTIR) spectra. Nanofibers also showed promising results in terms of encapsulation of bioactive compounds. Therefore, gallic acid‐loaded pea flour/PEO‐based nanofibers might be considered as a promising active packaging material.

Incorporation of salmon bone gelatine with chitosan, gallic acid and clove oil as edible coating for the cold storage of fresh salmon fillet

Edible coating is an effective strategy to improve the product quality and extend the shelf life of meat products. The objective of this research was to extract gelatine from salmon fish bone and develop a salmon bone gelatine-chitosan based edible coating incorporating gallic acid and/or clove oil as bioactive ingredients for the preservation of fresh salmon fillet at cold storage (4 °C for 15 days). The extraction yield of salmon bone gelatine was 2.5 ± 0.5% wet basis. The salmon bone gelatine extract coating (GE) successfully inhibited discolouration, pH change, lipid and protein oxidation and microbial growth of salmon fillet, but was less effective compared to chitosan coating (CH). The combination of gelatine and chitosan (GE-CH) and the incorporation of gallic acid (GE–CH–GA) improved the antioxidant effects of the coating. In contrast, incorporation of clove oil (GE–CH–CO) enhanced the antimicrobial effects. Overall, the combination of gelatine, chitosan, gallic acid and clove oil (GE–CH–GA-CO) had the best performance on salmon fillet preservation and prolonged the shelf life for at least 5 days. These findings suggest the potential to develop this mixture (GE–CH–GA-CO) as a practical commercial method for the preservation of fresh fish meat.

Effects of chitosan grafted phenolic acid coating on microbiological, physicochemical and protein changes of sea bass (Lateolabrax japonicus) during refrigerated storage.

This project aimed to evaluate the effects of gallic acid (GA) and protocatechuic acid (PA) grafted onto chitosan (CS) on the improved quality of sea bass (Lateolabrax japonicus) during refrigerated storage. The incorporation of GA and PA onto CS (CS-g-GA and CS-g-PA) were achieved by the carbodiimide-mediated grafting procedure. Samples were treated with different solutions (deionized water [CK], 1% CS [m/v], 1% CS-g-GA [m/v], and 1% CS-g-PA [m/v]) for 10min, which were then stored at 4 °C. Microbiological quality, including total viable counts (TVC), psychrophilic bacterial counts (PBC), Pseudomonas bacterial counts, and H2 S-producing bacterial counts were measured. Physicochemical parameters, including pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA) value, water holding capacity (WHC), and K value, were measured. The changes in protein characteristics, including sulfhydryl groups (SH), Ca2+ -ATPase activity, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and tertiary structure of protein were analyzed periodically, along with texture profile analysis (TPA). The results demonstrated that the CS copolymers treatment exhibited better preservation effects. The CS-g-GA and CS-g-PA treatments could significantly inhibit the growth of microorganisms and retard the increase of pH, TVB-N, TBA, WHC, and K-value during refrigerated storage compared with the CK and CS groups. Additionally, the CS-g-GA and CS-g-PA treatments could delay the protein oxidation by keeping a higher SH level and Ca2+ -ATPase activity. The CS copolymers treatment could also extend the shelf life for another 6 days compared with that of CK. As a result, CS copolymers can be employed in a promising method for the preservation of sea bass. PRACTICAL APPLICATION: The incorporation of gallic acid and protocatechuic acid onto chitosan (CS-g-GA and CS-g-PA) showed superior antioxidant and antimicrobial activities when applied on sea bass. The CS-g-GA and CS-g-PA coatings could maintain the quality and freshness of refrigerated sea bass. Additionally, this research could provide a theoretical basis for the application of graft copolymers on the preservation of aquatic products.

Evaluation of multifunctional properties of gallic acid crosslinked Poly (vinyl alcohol)/Tragacanth Gum blend films for food packaging applications

The natural polymer Tragacanth Gum is less explored as a supporting matrix, there are very less studies conducted using this polymer in literature. So the present study aims to explore the consequences of different weight percent (wt.%) of gallic acid (GA) on physicochemical properties of Poly (vinyl alcohol)/Tragacanth Gum blend films. The incorporation of GA resulted in more strengthened but less flexible films as confirmed by tensile tests. DSC studies confirmed the miscibility of composite films in the given composition range and TGA studies revealed increased thermal stability. The morphological studies revealed a homogeneous distribution of GA at lower wt.% in the blend system. X-Ray Diffraction study depicted; the added GA lost crystalline structure after incorporating it into the blend. The Water Vapor Transmission Rate (WVTR) was improved after the incorporation of GA into the blend system. Overall migration studies revealed the limited release of GA from the matrix into food simulants. Soil degradation rate increased as the wt.% of GA increased. The composite films presented strong antioxidant activity; therefore, prepared composite films could be used as an alternative to current packaging materials.

Development of a microemulsion for encapsulation and delivery of gallic acid. The role of chitosan

A novel water-in-oil (W/O) microemulsion based on natural oils, namely extra virgin olive oil (EVOO) and sunflower oil (SO), in the presence of non-ionic surfactants was successfully formulated. The novel microemulsion was used as a carrier for gallic acid (GA) to assure its protection and efficacy upon nasal administration. The work presents evidence that this microemulsion can be used as a nasal formulation for the delivery of polar antioxidants, especially, after incorporation of chitosan (CH) in its aqueous phase. The structure of the system was studied by Small Angle X-ray Scattering (SAXS), Dynamic Light Scattering (DLS) and Electron Paramagnetic Resonance (EPR) spectroscopy techniques. By the addition of CH, the diameter of the microemulsion remained unaltered at 47 nm whereas after the incorporation of GA, micelles with 51 nm diameter were detected. The dynamic properties of the surfactant monolayer were affected by both the incorporation of CH and GA. Moreover, the antioxidant activity of the latter remained unaltered (99 %). RPMI 2650 cell line was used as the in vitro model for cell viability and for GA nasal epithelial transport studies after microemulsion administration. The results suggested that the nasal epithelial permeation of GA was enhanced, 3 h post administration, by the presence of 0.2 % v/v microemulsion in the culture medium. However, the concentration of the transported antioxidant in the presence of CH was higher indicating the polymer’s effect on the transport of the GA. The study revealed that nasal administration of hydrophilic antioxidants could be used as an alternative route besides oral administration.

Assessment of active chitosan films incorporated with gallic acid

Chitosan films with antioxidant and antimicrobial properties were prepared by the incorporation of gallic acid as a bioactive. The films obtained were homogeneous, transparent and colorless with high mechanical resistance. Results indicated that films had antimicrobial activity against E. coli, especially those films plasticized with 15 wt % glycerol and containing 20 wt % gallic acid, which showed the biggest inhibition halo. Additionally, gallic acid-incorporated chitosan films exhibited a great antioxidant activity with DPPH scavenging capacity values of 99% and a bioactive release of 33% after 4 days, suggesting the potential suitability of these modified chitosan films as active films for food or pharmaceutical purposes.

Biodegradable protein films from gallic acid and the cataractous eye protein isolate

Films have been prepared from the natural antioxidant gallic acid and a proteinaceous source, the discarded emulsion obtained after cataract surgery referred to as the cataractous eye protein isolate (CEPI). Fourier transform spectroscopy (FTIR) and SDS PAGE studies confirmed the crosslinking of gallic acid with CEPI. The cross-section and surface of films were further characterized by scanning electron microscopy (SEM). The decrease in crystallinity of the films was confirmed by X-ray diffraction studies. The thermal property of the films is enhanced by the addition of gallic acid as evidenced from the Thermogravimetric analysis (TGA) studies. Films having 2% (w/w) gallic acid exhibited the maximum tensile strength of 2.88 ± 0.32 MPa comparable to other cross-linked films such as soy, casein, canola based protein films. The light barrier property of the films improved with incorporation of gallic acid. The cross-linked films were degraded by the application of the enzyme trypsin. The films also showed good antioxidant properties as determined from the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The gallic acid incorporated nontoxic CEPI films are biodegradable and possess appreciable mechanical properties and could find use in diverse applications including pharmaceuticals.

Development of antimicrobial packaging materials by incorporation of gallic acid into Ca2+ crosslinking konjac glucomannan/gellan gum films

Antibacterial films were prepared by incorporating konjac glucomannan (KGM) and gellan gum (GG) as a matrix, glycerin as a plasticizer, CaCl2 as a cross-linking agent, and gallic acid as a natural antibacterial agent. Structure was analyzed by using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Thermal stability of the blends was higher than pure GG, due to Ca2+ crosslinking between GG and KGM. Water contact angle and water vapor permeability were analyzed to determine hydrophobicity of films. Morphological studies revealed that surface compactness and homogeneity of blended films increased with KGM content. The addition of KGM improved the mechanical strength of films significantly. Moreover, KGM improved the release capacity of the blended films, while enhancing antimicrobial activity against Escherichia coli and Staphylococcus aureus. The antioxidant properties of gallic acid embedded in films were measured. Composite films containing 70 wt% KGM (Ca-KG7) displayed the best properties. These findings suggest an alternative method for synthesis of GG-based packaging films with improved properties.

Enhancing oxidative stability of walnuts by using gallic acid loaded lentil flour based electrospun nanofibers as active packaging material

The objective of this study was to enhance oxidative stability of walnuts present in active packages produced by electrospinning technology. Gallic acid was encapsulated into lentil flour/polyethylene oxide (PEO) nanofibers. To promote the solubility of lentil proteins, pH of solutions was adjusted to pH 1 and pH 10 which were far away from isoelectric point of lentil proteins. While acidic solutions had lower viscosity values than alkaline solutions, their electrical conductivity values were significantly higher. When the scanning electron microscopy (SEM) images were examined, it should be noted that alkaline nanofibers showed homogenous structure. Although gallic acid was not so stable at alkaline conditions, gallic acid loaded nanofibers prepared at alkaline pH still showed antioxidant activity after electrospinning. The physical and thermal properties of encapsulated gallic acid and nanofibers were examined by Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA) and differential scanning calorimeter (DSC) analyses. FTIR results indicated the effect of pH on chemical properties of nanofibers and the interaction between gallic acid and lentil flour-based nanofibers. Gallic acid addition reduced onset temperature and thermal stability. Therefore, it could be taken as evidence of incorporation of gallic acid. Disappearance of enthalpic peak related to melting of crystalline structure of gallic acid in DSC thermal curves confirmed successful encapsulation of gallic acid. Fabricated gallic acid loaded nanofibers were used to pack walnuts and the reduction in oxidation of walnuts with lower peroxide, p-anisidine and Totox values was observed. This would make these packaging materials substantially preferable for packing of foods being highly susceptible to oxidation.

Enhancement of Galloylation Efficacy of Stigmasterol and β-Sitosterol Followed by Evaluation of Cholesterol-Reducing Activity.

In this study, incorporation of gallic acid into typical phytosterols (β-sitosterol and stigmasterol) through Steglich esterification was optimized employing the protection and deprotection strategy. A novel mechanism leading to side esterification was discovered. Complication of the phenolic hydroxyl groups and side reactions were successfully reduced under the optimized conditions. The structural identity and purity of galloyl stigmasterol and galloyl β-sitosterol were confirmed by NMR, FT-IR, and HPLC-MS. Evaluation of galloyl β-sitosterol and galloyl stigmasterol revealed their excellent antioxidant and cholesterol-reducing activities. Significant enhancement of cholesterol-reducing activity by galloylation was unveiled especially for β-sitosterol. Galloyl β-sitosterol had slightly better antioxidant activity at ambient temperature and better cholesterol-reducing activity. Molecular modeling suggested that a subtle difference of galloyl β-sitosterol and galloyl stigmasterol in activities could be attributed to variation of molecular rigidity and conformation. The excellent properties of galloyl β-sitosterol and galloyl stigmasterol suggested their great potential application in the food industry.

Bioactive Multilayer Polylactide Films with Controlled Release Capacity of Gallic Acid Accomplished by Incorporating Electrospun Nanostructured Coatings and Interlayers

The present research reports on the development of bi- and multilayer polylactide (PLA) films by the incorporation of electrospun nanostructured PLA coatings and interlayers containing the antioxidant gallic acid (GA) at 40 wt% onto cast-extruded PLA films. To achieve the bilayer structures, submicron GA-loaded PLA fibers were applied on 200-µm cast PLA films in the form of coatings by electrospinning for 1, 2, and 3 h. For the multilayers, the cast PLA films were first coated on one side by electrospinning, then sandwiched with 10-µm PLA film on the other side, and the resultant whole structure was finally thermally post-treated at 150 °C without pressure. Whereas the bilayer PLA films easily delaminated and lacked transparency, the multilayers showed sufficient adhesion between layers and high transparency for deposition times during electrospinning of up to 2 h. The incorporation of GA positively contributed to delaying the thermal degradation of PLA for approximately 10 °C, as all films were thermally stable up to 345 °C. The in vitro release studies performed in saline medium indicated that the GA released from the bilayer PLA films rapidly increased during the first 5 h of immersion while it stabilized after 45–250 h. Interestingly, the PLA multilayers offered a high sustained release of GA, having the capacity to deliver the bioactive for over 1000 h. In addition, in the whole tested period, the GA released from the PLA films retained most of its antioxidant functionality. Thus, during the first days, the bilayer PLA films can perform as potent vehicles to deliver GA while the multilayer PLA films are able to show a sustained release of the natural antioxidant for extended periods.

The antioxidant and anti-hepatic fibrosis activities of acorns (Quercus liaotungensis) and their natural galloyl triterpenes

Acorn is an edible plant and it has also been used as traditional food. In our investigation of the antioxidant and anti-hepatic fibrosis constituents of acorns (Quercus liaotungensis), the novel galloyl triterpenes were discovered, their potential mechanisms were investigated by microscope observation, and western blot. Evaluation of their antioxidant and antiproliferation against t-HSC/Cl-6 cells indicated that acorn can be used as antioxidative and anti-hepatic fibrosis food, and the galloyl triterpenes may represent attractive ingredients. Furthermore, the novel galloyl triterpenes were rationally designed by incorporation of gallic acid into phyto-triterpenes through esterification, and obtained 9 compounds. With radical scavenging and ferrous ion chelating methods revealed their excellent antioxidant activities. Evaluation of anti-hepatic fibrosis activities indicated that galloyl triterpenes exhibited excellent inhibition activities than substrate. The galloyl triterpenes offers an intriguing solution for naturally derived antioxidants and liver protector, and maybe is invaluable for further development of anti-fibrosis drugs.

Effect of gallic acid/chitosan coating on fresh pork quality in modified atmosphere packaging

Fresh meat safety and quality is a major concern of consumers in the current food market. The objective of this research was to investigate a newly developed gallic acid/chitosan edible coating on the preservation of fresh pork quality in modified atmosphere package (MAP) stored at 4 °C. The pork loins were coated with 2% chitosan (CHI), 0.2% gallic acid in 2% chitosan (CHI/0.2G), or 0.4% gallic acid in 2% chitosan (CHI/0.4G). Results showed that the antimicrobial activity of the chitosan coating was increased with the incorporation of gallic acid. The CHI/0.2G and CHI/0.4G pork loins also had lower lipid oxidation and myoglobin oxidation. However, the CHI/0.4G sample exhibited a pro-protein oxidation effect, suggesting an optimal concentration of gallic acid should be incorporated. This research provides a practical method in application of gallic acid/chitosan coatings on preservation of fresh pork to improve the safety and quality in MAP environment.