Grapefruit Seed Extract Research Articles

Edible Coating Using a Chitosan-Based Colloid Incorporating Grapefruit Seed Extract for Cherry Tomato Safety and Preservation.

A novel chitosan coating containing grape fruit seed extract (GSE) improved the microbiological safety against Salmonella and storability of cherry tomatoes without altering their flavor, demonstrating its strong potential as an effective postharvest technology. Chitosan coating containing GSE might be preferable over chitosan coating without GSE for application to tomatoes that are stored at room temperature in that it more effectively inhibits microbial growth and weight loss than the coating without GSE at 25 °C.

Larvicidal effects of grapefruit seed extract (GSE) on brine shrimp Artemia salina

Grapefruit seed extract (GSE) has been widely used as a natural antimicrobial and antifungal agent, as a food preservative, and as a sanitizer in hand wash, soap, and dentifrice. GSE is considered environmentally safe, without toxicity to humans or animals at effective concentrations. However, few reports have examined the toxicity of GSE to invertebrate larvae. Therefore, we investigated the larvicidal effects of two commercially available GSEs from the USA and Brazil against larvae of brine shrimp Artemia salina. Additionally, we investigated the effects of naringin, quercetin, and citric acid on A. salina to identify the active larvicidal compounds of GSE. After a 24-h incubation, we found that 0.1% GSE was extremely larvicidal, whereas <0.01% GSE was non-larvicidal. It is likely that citric acid, naringin, and quercetin act synergistically on A. salina nauplii larvae. Our results suggest that GSE at moderate doses is valuable for developing larvicidal agents in aquatic environments.

Effects of Grapefruit Seed Extract on Oxidative Stability and Quality Properties of Cured Chicken Breast.

This study investigated the antioxidative and functional effects of a curing agent containing grapefruit seed extract (GSE) on the quality and storage characteristics of chicken breast. The total polyphenol and total flavonoid contents of GSE were 45.06 mg/g and 36.06 mg/g, respectively. The IC50 value of 2,2-diphenyl-1-picrylhydrazyl hydroxyl scavenging of GSE was 333.33 μg/mL. The chicken breast comprised six groups: no-treatment (N), 0.2% ascorbic acid + 70 ppm sodium nitrite (C), 0.05% GSE (G0.05), 0.1% GSE (G0.1), 0.3% GSE (G0.3), and 0.5% GSE (G0.5). The pH and cooking loss of cured chicken breast decreased with increasing GSE levels, and the water holding capacity increased with increasing GSE levels. The hardness and chewiness of GSE-treated chicken breast were higher than those of N and C. Hunter's L and a color values increased significantly after GSE addition. Moreover, 0.1% GSE (G0.1) increased the flavor and total acceptability scores. The 2-thiobarbituric acid and volatile basic nitrogen values of the 0.5% GSE group decreased significantly compared with those of C group. Total microbial counts of GSE-treated chicken breast were higher than those of C, but that lower than those of N. Adding GSE to chicken breast delayed lipid peroxidation and had antimicrobial effects during cold storage. GSE improved shelf life and palatability; therefore, it could be used as a natural antioxidant and functional curing agent ingredient in meat products.

Seed-surface disinfection and germination effects of grapefruit seed extract (GSE) on Lactuca sativa seeds

It investigated that the seed sterilization and germination effects on Lactuca sativa seeds of two commercially available grapefruit seed extracts (GSEs) from the USA and Brazil. The total bacterial counts in the 0.05% GSE (USA) treatment groups were 0.0 CFU/g for all tested incubation times (1-6 h). All GSE treatments groups (from both the USA and Brazil) showed no or slightly harmful effects on L. sativa seed germination and seedling growth after 24 and 48 h. Additionally, seeds treated with 0.05% GSE showed slightly stronger anti-germination effects and seedling growth inhibition than those treated in a solution of the same concentration but with the pH adjusted to 7.0. We also evaluated the anti-germination effects of naringin, quercetin, and citric acid on L. sativa seeds to identify the active compounds in GSE. We observed no anti-germination effects in the naringin-treated group. In the quercetin-treated group, there was a slight dose-dependent anti-germination effect (0.01-0.1%). In groups treated with 0.01% and 0.05% citric acid (pH 4.79 and 4.03, respectively), no and slight anti-germination effects, respectively, were observed. However, there were strong anti-germination effects among seeds treated with 0.1% citric acid (pH 4.79). We found that 0.05% GSE (from both the USA and Brazil) had strong seed sterilization effects and no anti-germination effects. Together, these results indicate that GSE may be useful as a treatment for seed sterilization without inhibiting seed germination or seedling growth.

Enhanced Antimicrobial Activity on Non-Conducting and Conducting Air Filters by Using Air Ions and Grapefruit Seed Extract

ABSTRACTThe application of grapefruit seed extract (GSE) and air ions to filters was investigated with the goal of collecting indoor bioaerosols. GSE exhibits antimicrobial activity because it contains flavonoids such as naringin. Air ions are usually generated by electric ionizers and can inactivate bacteria, viruses, and fungi. In this study, GSE particles were coated onto three different filters: polypropylene (PP), activated carbon fiber (ACF), and metal foam (MF). Ions were supplied to the filter surface using an ionizer. The rate of surface inactivation of Staphylococcus aureus was measured. When only GSE was applied to the filters, the inactivation rate was about 60%; when air ions were applied, the rate was about 70–80%. When both GSE and ions were applied simultaneously, the inactivation rate increased to 80–90%. The physical collection efficiencies of the as-purchased filters were in the following order: PP > ACF > MF. However, when ions were supplied to the filters, the collection efficiencies increased to over 98% for each filter. The inactivation rate of the ACF filter was the highest (92.5%). Therefore, we conclude that the ACF filter is the most efficient of these three filters for inactivating S. aureus.

Effects of malic acid or/and grapefruit seed extract for the inactivation of common food pathogens on fresh-cut lettuce.

This study investigated the antimicrobial activity of malic acid (MA), grapefruit seed extract (GSE), and combined (MA+GSE) treatment against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on fresh-cut lettuce. The antimicrobial effects of 1% MA and 0.5% GSE alone and in combination (1% MA+0.5% GSE) were tested on artificially inoculated lettuce during storage at 5°C for 14 days. The maximum reductions of E. coli O157:H7, S. Typhimurium, and L. monocytogenes were 4.96, 4.80, and 3.95 log CFU/g observed with MA+GSE during storage for 14 days, respectively. MA+GSE showed the greatest reduction against in E. coli O157:H7 and L. monocytogenes. These results indicate that the combined treatment was more effective than MA and GSE alone treatment. Therefore, it suggests that MA + GSE could be used as an effective intervention method for improving microbiological safety of fresh-cut lettuce.

Bactericidal Efficacy of a Disinfectant Spray Containing a Grapefruit-seed Extract, Citric acid, Malic acid and Benzalkonium Chloride against Salmonella Typhimurium and Brucella ovis

살모넬라증과 부루셀라증은 가축 및 사람에 심각한 피해를 유발하는 질병으로, 축산업과 식품산업에 많은 경제적 손실을 초래하고 있다. 본 연구에서는, 자몽종자추출물, 구연산, 사과산 그리고 염화벤잘코늄을 주성분으로 하는 스프레이형 소독제의 Salmonella Typhimurium과 Brucella ovis에 대한 효력시험을 수행하였다. 살균효력시험은 배지희석법에 따라 수행하였으며, 스프레이형 소독제와 시험 세균들을 처리조건에 따라 경수와 유기물로 희석하여 반응을 시켰다. 유기물 조건에서, Salmonella Typhimurium과 Brucella ovis에 대한 스프레이형 소독제의 살균력은 경수조건에서의 살균력과 비교하여 낮게 나타났는데, 이는 유기물들에 의한 소독제의 살균 유효성분에 대한 저해작용에 따른 것으로 사료된다. 스프레이형 소독제는 Salmonella Typhimurium과 Brucella ovis와 같은 인수공통전염병 유발 병원균들에 대해 살균효과를 나타내어, 살모넬라증과 브루셀라증과 같은 세균성 질병의 확산을 제어하는데 효과적으로 이용될 수 있을 것으로 사료된다.

Grapefruit Seed Extract and Lemon Essential Oil as Active Agents in Corn Starch–Chitosan Blend Films

The effect of lemon essential oil (LEO) and grapefruit seed extract (GSE) addition to starch–chitosan blend films on their functional properties and the associated structural changes were studied. Likewise, the films’ antioxidant properties and antimicrobial activity against some molds and Gram (+) and Gram (−) bacteria was evaluated. Composite active films exhibited a yellowish color, especially in the case of LEO addition. Film microstructure was analyzed by SEM evidencing a good incorporation of GSE to film matrix, while LEO droplets were dispersed in the polymer blend. Oxygen and water vapor barrier properties were not notably modified by the presence of active agents. FTIR analyses revealed that hydrogen bonding occurs in the blend films as the main interaction mechanism between components. Films containing LEO or GSE were less stiff and resistant but more stretchable than the control ones, being this effect concentration dependent. No notable antimicrobial action was observed in the films, which suggest that the required final concentration of active compounds must be fitted considering the minimum inhibitory concentration (MIC) values for a specific microorganism and its release kinetics to the food matrix.

Grapefruit seed extract incorporated antimicrobial LDPE and PLA films: Effect of type of polymer matrix

Antimicrobial low-density polyethylene (LDPE) and poly(lactide) (PLA) films were prepared by blending with grapefruit seed extract (GSE) incorporated thermoplasticized starch (TPS) using extrusion blowing and extrusion casting methods, respectively. The effect of polymer matrix was studied by comparing the film properties such as optical, mechanical, water vapor barrier, and antimicrobial properties. Scanning electron micrograph (SEM) result indicated that the TPS was homogeneously dispersed through both polymer matrix. Though transparency, mechanical, and gas barrier properties of the blend films decreased compared with their neat films, the blend films showed UV-light screening function and antimicrobial activity against food-borne pathogenic bacteria, E. coli and Listeria monocytogenes, which was mainly attributed to the GSE. While PLA/TPS film exhibited strong antibacterial activity against both bacteria, LDPE/TPS film showed lower antibacterial activity. This was presumably because the GSE was entrapped more tightly by the LDPE than the PLA. Packaging application test using minced fish paste also showed that the PLA/TPS film was more effective to prevent bacterial growth than LDPE/TPS film.

Effect of Grapefruit Seed Extract on Thermal Inactivation of Listeria monocytogenes during Sous-Vide Processing of Two Marinated Mexican Meat Entrées

D- and z-values for Listeria monocytogenes were obtained for two Mexican meat entrées: pork meat marinated in tomatillo (green tomato) sauce (PTS) and beef marinated in a red chili sauce (BRCS), with addition of 0, 200, and 800 ppm of grapefruit seed extract (GSE). Meat samples inoculated with L. monocytogenes were packaged in sterile bags, immersed in a water bath, and held at 55, 57.5, 60, and 62.5°C for different periods of time. Depending upon the temperature, D-values at 0 ppm of GSE ranged from 26.19 to 2.03 min in BRCS and 26.41 to 0.8 min in PTS. Adding 800 ppm of GSE to BRCS thermally treated at 55 and 62.5°C significantly decreased inactivation time by 35%. A reduction in time of 25.9, 10.6, and 40.1% at 55, 57.5, and 60°C, respectively, was observed in PTS with 800 ppm of GSE. The z-values of L. monocytogenes were not significantly affected by GSE addition; average z-values were 7.25 and 5.09°C for BRCS and PTS, respectively. Estimated thermal lethality for a 7-D log reduction of L. monocytogenes under commercial-size sous-vide conditions at a reference temperature of 55°C was reached at 78 and 71 min for BRCS without and with 800 ppm of GSE, respectively. For PTS, 7-D reduction was attained at 69 and 61 min without and with addition of 800 ppm of GSE, respectively. Supplementing both Mexican meat entrées (BRCS and PTS) with 800 ppm of GSE rendered L. monocytogenes cells more sensitive to the lethal effect of heat. The results of this study will assist the retail food industry in designing acceptance limits on critical control points pertaining to cooking regimes to effectively eliminate L. monocytogenes in BRCS and PTS sous-vide processed Mexican meat entrées.

Preparation and application of agar/alginate/collagen ternary blend functional food packaging films

Ternary blend agar/alginate/collagen (A/A/C) hydrogel films with silver nanoparticles (AgNPs) and grapefruit seed extract (GSE) were prepared. Their performance properties, transparency, tensile strength (TS), water vapor permeability (WVP), water contact angle (CA), water swelling ratio (SR), water solubility (WS), and antimicrobial activity were determined. The A/A/C film was highly transparent, and both AgNPs and GSE incorporated blend films (A/A/CAgNPs and A/A/CGSE) exhibited UV-screening effect, especially, the A/A/CGSE film had high UV-screening effect without sacrificing the transmittance. In addition, the A/A/C blend films formed efficient hydrogel film with the water holding capacity of 23.6 times of their weight. Both A/A/CAgNPs and A/A/CGSE composite films exhibited strong antimicrobial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli) food-borne pathogenic bacteria. The test results of fresh potatoes packaging revealed that all the A/A/C ternary blend films prevented forming of condensed water on the packaged film surface, both A/A/CAgNPs and A/A/CGSE composite films prevented greening of potatoes during storage. The results indicate that the ternary blend hydrogel films incorporated with AgNPs or GSE can be used not only as antifogging packaging films for highly respiring fresh agriculture produce, but also as an active food packaging system utilizing their strong antimicrobial activity.

Effects of Plant-Derived Extracts, Other Antimicrobials, and Their Combinations against Escherichia coli O157:H7 in Beef Systems

The antimicrobial effects of thyme oil (TO), grapefruit seed extract (GSE), and basil essential oil, alone or in combination with cetylpyridinium chloride (CPC), sodium diacetate, or lactic acid, were evaluated against Escherichia coli O157:H7 in a moisture-enhanced beef model system. The model system was composed of a nonsterile beef homogenate to which NaCl (0.5%) and sodium tripolyphosphate (0.25%) were added, together with the tested antimicrobial ingredients. Beef homogenate treatments were inoculated (ca. 3 log CFU/ml) with rifampin-resistant E. coli O157:H7 (eight-strain mixture) and incubated at 15°C (48 h). The most effective individual treatments were TO (0.25 or 0.5%) and GSE (0.5 or 1.0%), which immediately reduced (P < 0.05) pathogen levels by ≥3.4 log CFU/ml. Additionally, CPC (0.04%) reduced initial E. coli O157:H7 counts by 2.7 log CFU/ml. Most combinations of the tested plant-derived extracts with CPC (0.02 or 0.04%) and sodium diacetate (0.25%) had an additive effect with respect to antibacterial activity. In a second study, antimicrobial interventions were evaluated for their efficacy in reducing surface contamination of E. coli O157:H7 on beef cuts and to determine the effect of these surface treatments on subsequent internalization of the pathogen during blade tenderization. Beef cuts (10 by 8 by 3.5 cm) were inoculated (ca. 4 log CFU/g) on one side with the rifampin-resistant E. coli O157:H7 strain mixture and were then spray treated (20 lb/in2, 10 s) with water, GSE (5 and 10%), lactic acid (5%), or CPC (5%). Untreated (control) and spray-treated surfaces were then subjected to double-pass blade tenderization. Surface contamination (4.4 log CFU/g) of E. coli O157:H7 was reduced (P < 0.05) to 3.4 (5% CPC) to 4.1 (water or 5% GSE) log CFU/g following spray treatment. The highest and lowest transfer rates of pathogen cells from the surface to deeper tissues of blade-tenderized sections were obtained in the untreated control and CPC-treated samples, respectively.

Treatment of Air Filters Using the Antimicrobial Natural Products Propolis and Grapefruit Seed Extract for Deactivation of Bioaerosols

Two natural products; i.e., grapefruit seed extract (GSE) and propolis, were investigated for use in antimicrobial air filters. Staphylococcus aureus was investigated as a test bioaerosol, and was deposited on the antimicrobial filters, which were treated by spraying with various areal densities of GSE and propolis. The pressure drop and particle penetration were investigated to assess the filtration performance of the bioaerosol, and the bacterial-inactivation performance of the filters was evaluated by quantifying S. aureus. There was little change in the pressure drop as a function of the areal density of GSE up to 185.9 μg/cm2; however, a significant change in the pressure drop was found for the air filter coated with propolis at an areal density of 98.4 μg/cm2. The penetration levels of bioaerosols in both filters were uniform and in the range 1.4–2.0% (based on particle number), regardless of the areal density of the deposited GSE or propolis. The inactivation rates of the filters with identical deposition masses of GSE and propolis were similar in the ranges of 92.1–100%, 75.2–89.1%, and 54.4–75.5% at the control filters with colony numbers of 103, 104, and 105 CFU/mL, respectively. The bacterial inactivation rate could be described by an exponential function of the areal density of GSE/propolis per number of colonies.Copyright 2015 American Association for Aerosol Research

Grapefruit seed extracts as organic post-harvest agents: precious lessons on efficacy and compliance

Organic bananas for export are commonly protected against crown rot using formulations containing grapefruit seed extracts (GSEs). The production process and chemical composition of these GSEs are unclear; however, various formulations have been found to be compatible with organic agriculture standards as ‘plant preparations’ by organic certification bodies. In mid-2012, widespread contamination of bananas involving quaternary ammonium compounds (QACs), notably benzalkonium chloride (BAC) and didecyl dimethyl ammonium chloride (DDAC) was detected and could evidently be attributed to GSE formulations containing these compounds. The author reports the results of chemical analyses of commercial export consignments of organic bananas from Peru and Ecuador and pineapples from Costa Rica. These consignments were treated with approved commercial GSE-based organic post-harvest formulations. Analyses were conducted within the scope of a commercial residue screening programme. Results indicated frequent contamination of fruits with QACs. Chemical analysis of pure GSE-based post-harvest formulations showed widespread contamination with QACs, proving that these formulations cause QAC contamination in fruits. In vitro testing of the antimicrobial action of GSE-based formulations indicates that their efficacy is essentially due to QACs, which is confirmed in the previous literature. Because no credible chemical pathway for natural formation of QACs during extraction from grapefruit seeds has been found, QACs are considered as chemical contaminants. Certification bodies must be careful while evaluating the equivalence of such products to the standards of organic agriculture. Thorough information about the nature, origin, production process and chemical composition is needed in addition to scientific evidence of efficacy in the equivalence declaration process to avoid fraud.

Preparation of a porcine plasma protein composite film and its application.

To use blood released from slaughtering houses, a porcine plasma protein (PPP)/nanoclay composite film was prepared. The tensile strength and elongation at break values of the PPP composite film with 5% nanoclay were 10.01MPa and 6.55%, respectively. The PPP composite film containing 1% grapefruit seed extract (GSE) was applied to pork meat, and the populations of inoculated Escherichia coli O157:H7 and Listeria monocytogenes in the pork meat packaged with the PPP composite film decreased by 0.8 and 1.0 log CFU/g, respectively, after 7days of storage compared to the populations of the control. In addition, thiobarbituric acid values in the pork meat packaged with the PPP composite film were less than those of the control sample during storage. These results suggest that the PPP nanocomposite film containing 1% GSE can be used as a packaging material to maintain the quality of pork meat.

Functional chitosan-based grapefruit seed extract composite films for applications in food packaging technology

Chitosan-based composite films with different amounts of grapefruit seed extract (GFSE) (0.5, 1.0 and 1.5% v/v) were fabricated via solution casting technique. Experimental results showed that GFSE was uniformly dispersed within all chitosan film matrices. The presence of GFSE made the films more amorphous and tensile strength decreased, while elongation at break values increased as GFSE content increased. Results from the measurement of light transmission revealed that increasing amounts of GFSE (from 0.5 to 1.5% v/v) did not affect transparency of the films. Furthermore, packaging of bread samples with chitosan-based GFSE composite films inhibited the proliferation of fungal growth as compared to control samples. Hence, chitosan-based GFSE composite films have the potential to be a useful material in the area of food technology.

Analysis of benzethonium chloride, methyl paraben and triclosan from grapefruit seed/grape seed/pomegranate seed extracts using LC-PDA and LC-MS

Commercial products labeled as grapefruit seed extract (GSE) are promoted as natural antimicrobial agents for both internal and external use. A simple, precise and more sensitive UHPLC analytical method is presented for the simultaneous detection and quantitation of three preservatives namely methyl paraben (1), benzethonium chloride (2), and triclosan (3) in various commercial Grapefruit seed/grape seed/pomegranate seed samples. Compound identity was further confirmed by electrospray ionization mass spectrometry (HRESI-MS). The main constituent identified was benzethonium chloride, a synthetic antimicrobial agent which was found in 5 samples. Positive ion electrospray MS of the commercial GSE sample showed a molecular ion at m/z 412 [M+] that matched with that of a standard of benzethonium chloride. Triclosan detected in three samples and methyl paraben was not detected in all the samples analyzed.

Development and characterization of carrageenan/grapefruit seed extract composite films for active packaging

Carrageenan-based antimicrobial films were developed by incorporation of grape fruit seed extract (GSE) at different concentration into the polymer using a solvent casing method and their physical, mechanical, and antimicrobial properties were examined. The carrageenan/GSE composite films appeared yellowish tint due to the polyphenolic compounds in the GSE. SEM analysis showed rough surface with sponge like structures on the cross section of the films. FT-IR results indicated at GSE had good compatibility with carrageenan. The amorphous structure of polymer films was not changed by the incorporation of GSE. But, the addition of GSE increased moisture content, water vapor permeability, and surface hydrophilicity of the films. The tensile strength and elastic modulus decreased with increasing content of GSE, however, the elongation at break increased significantly up to 6.6μg/mL of GSE then decreased thereafter. Thermal stability of the films was not influenced by GSE incorporation. The carrageenan/GSE composite films exhibited great antibacterial activity against food borne pathogens. These results suggest that the carrageenan-based composite films have a high potential for being used as an antimicrobial or active food packaging applications.

Antibacterial effect of grapefruit seed extract (GSE) on Makgeolli-brewing microorganisms and its application in the preservation of fresh Makgeolli.

To develop a new preservation method, the antimicrobial activity of grapefruit seed extract (GSE) against Makgeolli-brewing microorganisms and food-borne pathogens was assessed, and a general analysis and sensory evaluation of fresh Makgeolli with added GSE was made. The minimum inhibitory concentration (MIC) values of GSE against 10 strains of Makgeolli-brewing microorganism were 0.0122 to 1.5625 μL/mL. The MIC values against 6 strains of food-borne pathogens were 0.0061 to 0.7813 μL/mL. On addition of 0.1% (v/v) and 0.2% GSE in bottled fresh Makgeolli, no significant difference in the pH, or the contents of total acids, ethanol, or methanol in the Makgeolli, were observed compared with control Makgeolli (with no GSE), during the preservation period (8 weeks) at 10 °C. In the Makgeolli with 0.1% and 0.2% GSE, the total bacterial counts decreased significantly by 4.9% (P < 0.01) and 11.2% (P < 0.001), respectively, versus the control. The decreases in yeast count were significantly lessened by 15.33% and 15.24% (both P < 0.001), respectively, after 8 weeks of storage, compared with the control. In the sensory evaluation of Makgeolli with 0.1% and 0.2% GSE, the refreshment and overall acceptability received significantly better scores than the control (P < 0.01), with no change in sweetness, bitterness, sourness, turbidity, color, or odor. These results suggest that GSE controls the growth of Makgeolli-brewing microorganisms and extends the shelf life (ca. 2 wk), without decreasing overall acceptance. A new preservation method for fresh Makgeolli by adding grapefruit seed extract (GSE) was developed. As fresh Makgeolli contains live microorganisms, the preservation period is 1 wk, which is relatively short. GSE controls the growth of Makgeolli-brewing and Makgeolli-spoiling microorganisms. 0.1% to 0.2% GSE is optimum for prolonging the shelf life (2 wk) of bottled fresh Makgeolli, and has no adverse effect on overall acceptability. We demonstrated that GSE is an effective natural additive that prolongs the shelf life of fresh Makgeolli with no significant loss in quality.

Poly(vinyl alcohol)‐Based Film Potentially Suitable for Antimicrobial Packaging Applications

This work aimed at developing a thin and water-resistant food-grade poly(vinyl alcohol) (PVOH)-based matrix able to swell when in contact with high moisture content food products without rupturing to release antimicrobial agents onto the food surface. This film was prepared by blending PVOH and 7.20% (wt/wt of PVOH) of poly(ethylene glycol) (PEG) with citric acid as crosslinking agent. The film-forming solution was then casted onto a flat surface and the obtained film was 60 μm in thickness and showed a good transparency (close to T = 100%) in the visible region (400 to 700 nm). After immersion in water for 72 h at room temperature, the crosslinked matrix loses only 19.2% of its original weight (the percentage includes the amount of unreacted crosslinking agent, antimicrobial in itself). Water content, degree of swelling, and crosslinking density of the film prove that the presence of PEG diminishes the hydrophilic behavior of the material. Also the mechanical properties of the wet and dry film were assessed. Alongside this, 2.5% (wt/wt of dry film) of grapefruit seed extract (GSE), an antimicrobial agent, was added to the film-forming solution just before casting and the ability of the plastic matrix to release the additive was then evaluated in vitro against 2 GSE-susceptible microorganisms, Salmonella enteritidis and Listeria innocua. The results indicate that the developed matrix may be a promising food-grade material for the incorporation of active substances.