Oxygen Permeability Of Films Research Articles

Effect of blending sequence and epoxy functionalized compatibilizer on barrier and mechanical properties of PBS and PBS/PLA nanocomposite blown films

AbstractThis study focuses on developing compostable nanocomposite blown films, aiming to enhance oxygen barrier properties while maintaining good mechanical performance. Polybutylene succinate (PBS) and its blend with polylactic acid (PLA) were selected as matrices for the films. Organo‐montmorillonite Delite®43B (D43B) clay was incorporated to improve oxygen barrier, and random ethylene‐methyl acrylate‐glycidyl methacrylate terpolymer served as a plasticizer and reactive compatibilizer. Different blending sequences were examined to determine the optimal one that led to significant enhancements in both the barrier and mechanical properties of the final nanocomposite blown film. Various techniques, including SEM, TEM, XRD, DSC, oxygen permeability, and tensile testing were employed to characterize the morphology of the compounds and blown films. The results reveal greater oxygen barrier properties depending on the blending sequence. Indeed, a reduction in oxygen permeability exceeding 50% was observed following the addition of 3 wt% of D43B to the PBS/PLA film, selectively localized in the PLA phase. This enhancement further intensified after the addition of 5 wt% of the epoxy functionalized compatibilizer.Highlights Enhancing PLA‐PBS compatibility with the epoxy functionalized compatibilizer led to a reduction in the final film's oxygen permeability. Achieving ideal ductility and barrier balance in films requires a synergistic blend of components: D43B, PLA, PBS, and compatibilizer. Optimizing balanced synergistic effects among compounds depends on the blending sequence method.

Application of Poultry Gelatin to Enhance the Physicochemical, Mechanical, and Rheological Properties of Fish Gelatin as Alternative Mammalian Gelatin Films for Food Packaging.

This study aimed to describe the properties of cold water fish gelatin (FG) blended with poultry gelatin (PG) for a production of a sachet containing olive oil. To find a desirable film, the different ratio of FG-PG-based films were characterized in terms of mechanical properties. As the proportion of PG in PG-FG-based increased, the tensile strength and Young's modulus were increased, and the elongation at break and heat seal strength of the films were decreased. The 50-50 film had favorable characteristics to use as a sachet. The amount of acid index and peroxide of the oil stored in the sachets after 14 days showed that there is a significant difference (p < 0.05) between the films. The barrier properties of the films including the water vapor permeability and oxygen permeability of films were increased from 1.21 to 4.95 × 10-11 g m-1 Pa-1 s-1 and 48 to 97 cm3 mµ/m2 d kPa, respectively. Dark, red, yellow, and opaque films were realized with increasing PG. Fourier transform infrared (FTIR) spectra approved a wide peak of approximately 2500 cm-1. The rheological analysis indicated that, by adding PG, viscosity, elastic modulus (G') and loss modulus (G'') were increased significantly (p < 0.05) about 9.5, 9.32 and 18 times, respectively. Therefore, an easy modification of FG with PG will make it suitable for oil sachet packaging applications for the food industry.

Loading oregano essential oil into microporous starch to develop starch/polyvinyl alcohol slow-release film towards sustainable active packaging for sea bass (Lateolabrax japonicus)

Microporous starch (MS) was used as an adsorption carrier to load with oregano essential oil (OEO). The starch/polyvinyl alcohol (STA/PVA) films containing OEO or MS loaded with OEO (OEO-MS) were prepared. The films’ properties and their application in sea bass packaging were investigated. The FTIR spectra indicated that OEO and OEO-MS were successfully incorporated into STA/PVA film and their interaction occurred through hydrogen bonds. The SEM results demonstrated that loading OEO into MS promoted the dispersion of OEO in the film. The incorporation of OEO-MS improved tensile strength of film and reduced its flexibility. The water vapor and oxygen permeability of film decreased for OEO-MS incorporation, while the addition of OEO showed opposite results. The films containing OEO or OEO-MS both exhibited antioxidant and antibacterial activities. It showed that the release rate of OEO released from films into food simulant (10% ethanol) slowed down for loading OEO into MS. The preservation results of sea bass showed that the films containing OEO or OEO-MS could efficiently inhibit the growth of microorganisms, lipid oxidation and the decomposition of protein of sea bass. The STA/PVA film added with OEO-MS was the best to maintain the freshness of sea bass and prolonged its shelf life. Therefore, this sustained release active films showed a good potential for aquatic products packaging.

Evaluation of High Oxygen Permeability Ionomer (HOPI) Oxygen Permeability for Proton Exchange Membrane Fuel Cells (PEMFCs)

The performance of proton exchange membrane fuel cells (PEMFCs) is sensitive to Pt loading in the cathode catalyst layer, with lower Pt loadings significantly increasing the oxygen transport resistance of the catalyst-ionomer interface when using perfluorosulfonic acid (PFSA) ionomers. The oxygen permeability is suspected to be locally decreased at Pt interfaces due to ionomer densification caused by the Pt-ionomer interactions. However, due to the high cost of Pt, it is important to be able to reduce Pt loadings without increasing oxygen transport resistance. With this goal in mind, new precommercial high oxygen permeability ionomers (HOPIs) with blocky backbone units are being studied. These HOPIs show significantly lower local oxygen transport resistance in fuel cells as well as greater efficiency and durability. However, there was a question of whether HOPI’s higher in-situ oxygen permeability is due solely to reduced densification or if it is also due to increased bulk permeability of the films. Here we evaluated this question using a unique oxygen permeability measurement apparatus that measures the oxygen permeability of thin-films supported on mesoporous substrates. This apparatus allows films to be characterized without the polarized Pt surfaces used in other oxygen permeability diagnostics, providing insights into the bulk permeability of cast thin-films with minimized substrate effects. This presentation will present our findings of the oxygen permeability of pristine thin-film HOPIs characterized against that of the baseline PFSA ionomer. Results show that the HOPI is significantly more oxygen permeable than the baseline. This finding is supported by our molecular dynamics simulations of these ionomer films. This increased bulk film oxygen permeability indicates that a significant portion of the decreased oxygen transport resistance in the cathodes is associated with the greater bulk permeability of these films and not just local Pt interface effects.This material is based upon work supported by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE) under the Fuel Cell Technologies Office, Award Number DE-EE0008822.

Improving the Oxygen Barrier of Polyamide Food Packaging by Using Nanoclay

The effect of nanoclay additive on polyamide film oxygen permeability is investigated from the perspective of possible use as a laminate component for low-cost food packaging material. Montmorillonite nanoclay was melt-mixed in an industrial grade polyamide by twin-screw extrusion and the mixture was hot-pressed to a ~50 µm thick film. The film with 10 wt.% of nanoclay loading showed a 17 % decrease in the oxygen transmission rate (OTR), as compared to the pristine polyamide film (72 and 87 cm3/m2∙24 h, respectively). Despite the relatively high loading of the filler the obtained OTR exceeds that of the food packaging preferred upper limit of 10 cm3/m2∙24 h. XRD measurements confirmed the near-complete exfoliation of the nanoclay platelets. The platelets were found to be at an average angle of 9.5 degrees relative to the film’s surface plane. To comply with the requirements for food packaging, this angle needs to be decreased down to 0.4 degrees. To achieve this, different film-making methods enabling better control over the filler particles’ orientation need to be explored. Nanoclay addition increased the films’ yield strength (23 % for 10 wt.% film) and stiffness, while not affecting the films’ optical appearance.

Characterization and Release Kinetics Study of Active Packaging Films Based on Modified Starch and Red Cabbage Anthocyanin Extract.

Active packaging films were prepared by adding red cabbage anthocyanin extract (RCAE) into acetylated distarch phosphate (ADSP). This paper investigated the influence of the interaction relationship between RCAE and the film matrix on the structure, barrier, antioxidant and release properties of active films. Sixteen principal compounds in RCAE were identified as anthocyanins based on mass spectroscopic analysis. Micromorphological observations indicated that the RCAE distribution uniformity in the films decreased as the RCAE content increased. When the concentration of RCAE was not higher than 20%, the moisture absorption and oxygen permeability of films decreased. The stability of RCAE in the films was enhanced by the electrostatic interaction between RCAE and ADSP with the formation of hydrogen bonds, which facilitated the sustainability of the antioxidant properties of films. The release kinetics of RCAE proved that the release rate of RCAE in active films was the fastest in distilled water, and Fickian’s law was appropriate for portraying the release behavior. Moreover, the cytocompatibilty assay showed that the test films were biocompatible with a viability of >95% on HepG2 cells. Thus, this study has established the suitability of the films for applications in active and food packaging.

Effect of starch aldehyde-catechin conjugates on the structural, physical and antioxidant properties of quaternary ammonium chitosan/polyvinyl alcohol films

The application of catechin in active packaging films is restricted by the low stability of catechin. In this study, the stability of catechin was elevated by conjugating catechin with starch aldehyde. The obtained starch aldehyde-catechin conjugates were added into quaternary ammonium chitosan (QAC)/polyvinyl alcohol (PVA) blend to prepare active packaging films. The structural, physical and antioxidant properties of QAC/PVA films containing starch aldehyde-catechin conjugates were determined. Results showed starch aldehyde-catechin conjugates formed hydrogen bonding with QAC/PVA film matrices and changed the uniformity of films. After starch aldehyde-catechin conjugates were added into films, the water vapor permeability, tensile strength and elongation at break of films were increased by 2.51%–16.03%, 11.73%–20.15% and 0.78%–12.15%, respectively; whereas the oxygen permeability of films was reduced by 6.67%–53.33%. Starch aldehyde-catechin conjugates increased the 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging efficiencies of films by 852.3%–995.5% and 599.5%–669.3%, respectively. The developed films were used to package peanut oil at 37 °C for 28 days. As compared with oil packaged in QAC/PVA film, oil packaged in QAC/PVA films containing starch aldehyde-catechin conjugates showed significantly lower peroxide values and thiobarbituric acid reactive substance levels. Results suggested QAC/PVA films containing starch aldehyde-catechin conjugates had a good potential in peanut oil packaging.

Development of active packaging films based on quaternary ammonium chitosan, polyvinyl alcohol and litchi (Litchi chinensis Sonn.) pericarp extract

Litchi (Litchi chinensis Sonn.) pericarp contains abundant polyphenols that are suitable materials for developing active packaging films. In this study, 1 wt%, 3 wt% and 5 wt% of litchi pericarp extract (LPE) was added into quaternary ammonium chitosan (QAC) and polyvinyl alcohol (PVA) matrix to develop active packaging films. The structural, physical and functional properties of QAC-PVA (QP) films were compared with LPE (QP-LPE films) and without LPE (QP films). Results showed QP film had a heterogenous cross-section whereas QP-LPE films displayed rough and uneven cross-sections. After adding LPE, the N–H, O–H, C – H and C=O stretching bands of QP films shifted due to the formation of intermolecular interactions between LPE and film matrix. LPE made the colorless QP film turned brown. QP-LPE films presented lower ultraviolet–visible light transmittance than QP film. After adding LPE, film thickness increased from 0.091 to 0.103 mm, film water vapor permeability increased from 14.98 × 10−11 to 17.21 × 10−11 g m−1 s−1 Pa−1, film oxygen permeability increased from 0.16 to 0.22 cm3 mm m−2 day−1 atm−1, film tensile strength increased from 14.10 to 17.41 MPa, and film elongation at break decreased from 36.94% to 25.13%. QP-LPE films quickly released polyphenols in distilled water within 4 h and displayed potent antioxidant activity. The antimicrobial ratio of the film against Escherichia coli, Salmonella typhimurium, Staphylococcus aureus and Listeria monocytogenes was elevated from 50.40−68.04% to 58.93−91.38% after adding LPE. Results suggested QP-LPE films could be utilized as antioxidant and antimicrobial packaging materials in food industry.

Semi-transparent regenerated cellulose/ZnONP nanocomposite film as a potential antimicrobial food packaging material

A facile and straightforward route was proposed for preparing semi-transparent antimicrobial nanocomposite films using regenerated cellulose (RC) and zinc oxide nanoparticles (ZnONP) with acceptable transparency for potential food packaging applications. The RC/ZnONP nanocomposite films were characterized by their mechanical strength, UV–vis barrier properties, water vapor permeability (WVP), and antimicrobial activities against six foodborne pathogenic bacteria. The UV and oxygen barrier properties, thermal stability, and crystallinity of the RC/ZnONP nanocomposite films were significantly ( p < 0.05) improved by adding 7 wt% of ZnONP to RC films. However, the mechanical strength and WVP of the RC/ZnONP nanocomposite films were not significantly ( p > 0.05) altered by the addition of ZnONP. As shown in SEM and AFM images, the addition of ZnONP altered the surface morphology of the RC/ZnONP nanocomposite films. The results of antimicrobial tests indicated that adding 3 wt% of ZnONP could effectively inhibit the growth of pathogenic foodborne gram-positive ( B. cereus, S. aureus, and L. monocytogenes ) and gram-negative ( E. coli, S. typhimurium, and V. parahaemolyticus ) bacteria. UV transmittance and oxygen permeability of films reduced by 32 and 37%, respectively, at a ZnONP concentration of 3 wt%. Owing to the significant antibacterial activity of prepared films against the bacteria mentioned before, they could be applied for packaging meat products. • A facile method was applied to make semitransparent RC/ZnONP nanocomposite films. • RC/ZnONP showed antibacterial activity against pathogenic foodborne bacteria. • ZnONP improved the thermal stability and water vapor and UV barrier of RC films. • Surface morphology and crystallinity of RC films were affected by ZnONP.

Characterization of physicochemical and antimicrobial properties of plasma‐treated starch/chitosan composite film

AbstractThe aim of this study was to examine mechanical and physical properties of starch/chitosan composite film exposed to low‐pressure air and argon plasma at 600 mTorr for different duration (4, 8 and 12 min) and evaluate the shelf life of the chicken breast fillet packaged with plasma‐treated films. The mechanical properties of the composite films were improved significantly.It is shown that argon plasma is more efficient in improving the tensile strength of the films and increased it from 10.59 to 22.09 Mpa after 12 min of process due to the formation of a stable cross‐linked network on the surface of the polymer, although film's stretchability, modified in air plasma, was significantly more. Solubility and hydrophilicity of the films were increased; however, no significant change in the water vapor transmission rate was observed. Oxygen permeability of films improved after both plasma treatment. Total viable count and oxidative (TBA) changes of fillets were analyzed during shelf life. The results showed that Cold plasma treatment could not prolong the shelf life of the fillets through plasma‐treated films.

Active polyethylene films incorporated with β-cyclodextrin/ferula asafoetida extract inclusion complexes: Sustained release of bioactive agents

In this work polyethylene (PE) films with antimicrobial ferula asafoetida leaf and gum extract/beta-cyclodextrin (BCD) inclusion complexes were developed to have controlled release of active compounds. The active complexes were extruded with PE polymer granules and converted into a film by blowing. Results revealed that the properties of films were predominantly affected by the extract and the presence of BCD in some cases improved their properties. The results showed that the tensile strength and oxygen permeability in films incorporated with gum extract/BCD inclusion complexes (Gum-BCD) were 1.3 and 1.8 times higher, respectively than the films incorporated with leaf extract/BCD inclusion complexes (Leaf-BCD), while the ΔE, water vapor transfer rate and melting point in them were 17.7, 1.2 and 0.95 times, respectively less than Leaf-BCD films. Inclusion of bioactive compounds in BCD was associated with sustained release of the compounds, and even some compounds such as galbanic acid and kamolonol were not found in the simulant during the study period. After 21 days, the growth of Aspergillus niger and Saccharomyces cerevisiae were reduced by more than 2 logarithmic cycles in Leaf-BCD and Gum-BCD films.

Evaluation of Interactions Between Carboxymethylcellulose and Soy Protein Isolate and their Effects on the Preparation and Characterization of Composite Edible Films

Interactions between carboxymethylcellulose (CMC) and soy protein isolate (SPI) were assessed to determine their effects on the physicochemical and morphological properties of SPI-based films. The protein-polysaccharide interactions were investigated by measuring zeta potentials, showing a dependence on the pH, ionic strength and polysaccharide concentration. SPI-based films were prepared with different CMC concentrations (0–0.5%) at pH 11 and the pH of biopolymer coacervation (pHc). The addition of CMC improved mechanical strengths of all films, but films prepared at pHc showed a reduction in percentage of elongation at break, becoming more brittle than at pH 11. The water vapor permeability did not show a strict dependence on the CMC concentration or pH, while the oxygen permeability of films prepared at pH 11 decreased with the addition of CMC until reaching a minimal value at 0.375% CMC. These results reveal the significant effects of SPI-CMC interactions on the formation and properties of films, indicating the potential of this approach to better tailor edible films and coatings for specific applications.

Properties and Application of Multifunctional Composite Polypropylene-Based Films Incorporating a Combination of BHT, BHA and Sorbic Acid in Extending Donut Shelf-Life.

To extend the shelf-life of packaged donut without the addition of preservative, polypropylene-based active composite films loaded with a combination of sorbic acid, BHA and BHT were prepared by the extrusion moulding method: T1 (Control-pure PP-film), T2 (PP-BHT1%-SA2%), T3 (PP-BHA3%-SA2%) and T4 (PP-BHT1%-BHA1%-SA2%). The incorporation of active additives enhanced water vapour permeability (WVP) and increased oxygen permeability of films. Active films had higher antioxidant activity than pure PP in the order T4 > T2 > T3 (89.11, 83.40 and 79.16%). In vitro examinations demonstrated a significant antibacterial effect on Escherichia coli and S. aureus growth. Overall migration was not significantly different for watery food simulants, while in acidic and fatty foods increased it significantly. The effect of the active films on the fried and packaged donut samples showed significantly higher moisture contents and peroxide values, while acidity was lower. T2 film is proposed due to the preservation of the intrinsic properties of the film, increasing the storage period up to 25 to 50 days.

Nanocomposite films consisting of functional nanoparticles (TiO2 and ZnO) embedded in 4A-Zeolite and mixed polymer matrices (gelatin and polyvinyl alcohol)

In this study, nanocomposite films with enhanced functional properties were prepared by loading titanium dioxide (TiO2) and/or zinc oxide (ZnO) nanoparticles within 4A zeolite (4AZ) particles, and then incorporating these nanocomposites into a poly (vinyl alcohol) (PVA) and gelatin matrix. The composition and morphology of the films were characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). The thermal behavior of the films was established using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). SEM showed the nanoparticles were dispersed throughout the films when used at these levels. FTIR indicated that the inorganic nanoparticles interacted with the PVA/gelatin polymer network through hydrogen bonding. XRD confirmed that the nanoparticles were in a crystalline state within the films. DSC and TGA showed that introduction of the nanoparticles modified the nanocomposite’s thermal behavior. Nanoparticle addition had a number of effects: (i) it decreased film transparency from 78.7% to 69.4% 72.0% and 69.7%; (ii) it decreased film water vapor permeability (WVP) from 8.20 × 10−9 to 5.13 × 10−9, 5.71 × 10−9 and 5.24 × 10−9 g/Pa.h.m; (iii) it reduced film oxygen permeability from 4.57 to 3.29, 3.10 and 3.00 mEq/g; and (i) it increased film tensile strength (TS) from 14.6 to 22.0, 20.3 and 18.0 MPa, for PVA/gelatin films containing 0%, 1.5% ZnO, 1.5% TiO2 and 1% (ZnO + TiO2) nanoparticles, respectively (with the nanoparticles being trapped within 4AZ). Moreover, active nanocomposite films exhibited significant antimicrobial effects especially against gram-negative bacteria. Overall, our results show that nanoparticle-loaded PVA/gelatin nanocomposites may be useful as active biodegradable nanocomposite films for application in the packaging industry and that their properties can be modulated by controlling the nature and level of nanoparticles incorporated.

Low-Density Polyethylene Films Carrying ferula asafoetida Extract for Active Food Packaging: Thermal, Mechanical, Optical, Barrier, and Antifungal Properties

The physical, thermal, mechanical, optical, microstructural, and barrier properties of low-density polyethylene films (LDPE) containing ferula asafoetida leaf and gum extracts were investigated. Results showed a reduction in elasticity and tensile strength with increasing extract concentration in the polymer matrix. The melting temperature and enthalpy increased with increasing concentration of extracts. The films containing extracts had lower L∗ and a∗ and higher b∗ indices. The films containing leaf extract had more barrier potential to UV than the gum extracts. The oxygen permeability in films containing 5% of leaf and gum extracts increased by 2.3 and 2.1 times, respectively. The morphology of the active films was similar to bubble swollen islands, which was more pronounced at higher concentrations of gum and leaf extracts. FTIR results confirmed some chemical interactions of ferula extracts with the polymer matrix. At the end of day 14th, the growth rate of Aspergillus niger and Saccharomyces cerevisea in the presence of the PE-Gum-5 reduced more than PE-Leaf-5 (3.7 and 2.4 logarithmic cycles, respectively) compared to the first day. Our findings showed that active LDPE films have desire thermo-mechanical and barrier properties for food packaging.

Construction of EVA/chitosan based PEG-PCL micelles nanocomposite films with controlled release of iprodione and its application in pre-harvest treatment of grapes.

A novel nanocomposite poly(ethylene-co-vinyl acetate) (EVA) film with controlled in vitro release of iprodione (ID) was prepared. Chitosan (CS) was used as the reinforcement which enhances the water and oxygen permeability of films. ID loaded poly(ethylene glycol)-poly(ε-caprolactone) (PEG-PCL) (IPP) micelles were used as the drug carrier which endows the films with antifungal and controlled release ability. IPP micelles with spherical shape and uniform size were obtained, and the maximum encapsulation efficacy (EE) was 91.17±5.03% by well controlling the feeding amount of ID. Incorporation CS could improve the oxygen and moisture permeability of films, and the maximum oxygen permeability (OP) and water vapor transmission rate (WVTR) were 477.84±13.03cc/(m2·d·0.1MPa) and 8.60±0.25gm-2 d-1, respectively. After loading IPP micelles, the films showed an improved antifungal ability and temperature-sensitive drug release behavior, and were found to enhance the quality of grapes by pre-harvest spraying.

Physical, Chemical, Thermal and Microstructural Characterization of Edible Films from Mechanically Deboned Chicken Meat Proteins

Mechanically deboned chicken meat protein concentrate (CMPC) was mixed with 30, 40 and 50% glycerol to produce films and physical, thermal, chemical, morphological and microstructural properties of films were characterized. The apparent porosity of films increased with increasing glycerol content which was due to the increase of free volume in film matrix (P < 0.05). The higher the apparent porosity, the greater the water vapor and oxygen permeability of films were (P < 0.05), which means gas molecules are permeating through pores. Puncture strength of films decreased as glycerol concentration increased, whereas puncture deformation was increased (P < 0.05). Lower glass transition temperature (Tg) observed as glycerol concentration increased, and Tg values of films were well fitted to Gordon-Taylor model as a function of glycerol mass fraction. Higher glycerol concentrations led to decrease of onset temperatures of weight losses, while weight loss increased. Infrared spectra of films showed similar backbone structure, but increasing glycerol concentration affected to peak intensity around 1000–1100 cm−1. All films had low percentage of degree of crystallinity. CMPC films showed lower contact angle than 65° and all films had hydrophilic surfaces. The surface morphology of films showed that films plasticized with 40% glycerol had the lowest roughness value (P < 0.05). Micrographs of films also showed porous surface structure as glycerol concentration increased, and these images supported the results of porosity, mechanical and barrier properties of films. It can be concluded from these results that glycerol at 40% concentration showed the best results when compared with the other two concentrations.

Effect of edible pectin-fish gelatin films containing the olive antioxidants hydroxytyrosol and 3,4-dihydroxyphenylglycol on beef meat during refrigerated storage

The objective of this research was to evaluate the effect of the addition of two antioxidants naturally present in olives, hydroxytyrosol (HT) and 3,4-dihydroxyphenylglycol (DHPG), to a pectin-fish gelatin edible film on the preservation of raw beef meat during refrigerated storage. A new composite film that included beeswax was also prepared, resulting in a reduction in the film's oxygen permeability. Results showed that the meat samples wrapped with film containing antioxidants reduced the formation of oxidation products in the form of thiobarbituric acid reaction substances (TBARS) compared with control film without antioxidants. HT added at 0.5% to the film with beeswax suppressed the lipid oxidation of beef meat during 7 days of storage at 4 °C, possibly by the combined effect of acting as an oxygen barrier and the specific antioxidant activity. The interference of plasticizer agents (glycerol and sorbitol) incorporated to the film on the TBARS method was showed for the first time.

Quality comparison of grass carp and salmon fillets packaged in modified atmosphere with different composite films

AbstractGrass carp fillets (without dark meat) and salmon fillets were stored in modified atmosphere packaging (MAP) with a gas mixture of 10% O2, 60% CO2, and 30% N2 for up to 12 days at 4 °C. Effects of three commercial MAP composite films, that is, F1 from Sealed Air, F2 from Amcor, and F3 from Bemis, on contents of CO2 and O2, and quality indicators including total viable count (TVC), total volatile basic nitrogen (TVB‐N), thiobarbituric acid (TBA), K value, pH, and color difference were investigated. It was observed that O2 content, pH, and TBA in grass carp fillets were higher than those of salmon fillets, while CO2 content and color difference were lower. F1 could maintain the quality of both fillets better than F2 and F3, with F3 being the worst. Principal component analysis showed the scores of F1, F2, and F3 for packaging grass carp and salmon fillets were 24.840, 26.570, and 25.162, and 24.863, 27.086, and 24.878, respectively, with F1 being the best for keeping the quality. The relationship between rate constant k and film oxygen permeability for describing kinetic change of TVC and TVB‐N during MAP storage for both fillets were also determined in the study.Practical applicationsGrass carp and salmon are very common species of fish with the largest reported production internationally. As highly perishable products, the extension of their shelf‐life is an important issue for in the industry. Modified atmosphere packaging (MAP) is an effective method for extending the shelf life of fresh foods. This study compared three commercial MAP composite films, that is, F1 from Sealed Air, F2 from Amcor, and F3 from Bemis, on contents of CO2 and O2, and quality indicators including total viable count (TVC), total volatile basic nitrogen (TVB‐N), thiobarbituric acid (TBA), K value, pH, and color difference for grass carp fillets (without dark meat) and salmon fillets stored in MAP, and indicated that F1 with composition of PP/Tie/Nylon6/EVOH/Nylon6/Tie/LLDPE was the best for keeping their quality. The current results should provide valuable information for the industry and retailers to supply high quality fresh aquatic products to the consumers.

Quality changes of fresh-cut lettuce with different oxygen permeability of films during storage

신선편의 양상추의 포장 시 산소투과율이 서로 다른 필름을 적용하여 저온저장 중 품질 변화를 조사하여 신선편의 식품의 제품설계 및 유통 중 품질 관리를 위한 기초 자료로 활용하고자 하였다. 신선편의 양상추는 산소투과율 각각 5,000, 8,000 및 10,000 cc/㎡·day·atm인 OPP 필름을 리드로 하여 용기 포장하고 10 ℃에서 7일간 저장하면서 품질변화를 조사하였다. 필름의 산소투과율에 따른 통계적 유의차는 나타나지 않았으나, 표면온도를 제외하고 모든 품질 항목이 저장일 경과에 따른 통계적 유의차를 나타내었다(p <0.05). 저장 중 신선편의 양상추의 표면 온도는 평균 13 ℃ 내외로, 산소투과율이 높을수록 표면온도는 낮게 유지되고 있었다. 저장 7일경 중량감소율은 2.8~5.4% 수준으로 산소투과율 5,000 cc/㎡·day·atm에서 가장 높았다. pH는 저장에 따라 유의적으로 증가하였으며(p <0.05), 산소투과율이 높을수록 pH의 변화는 작았다. 저장에 따라 포장 내부의 산소는 감소하고, 이산화탄소는 증가하고 있었는데, 필름의 산소 투과율이 높을수록 잔존산소 함량이 높고, 이산화탄소 함량이 낮게 나타났다. 저장에 따른 총페놀 함량 및 DPPH 라디칼 소거능은 감소하고 있었는데, 필름의 산소투과율이 높을수록 총페놀 및 항산화성도 높게 유지되고 있었다. 저장 7일경 일반세균은 5.48~6.59 log CFU/g 수준으로, 산소투과율이 높을수록 높게 나타났다. 전반기호도를 기준으로 저장 5일경까지 상업적 품질을 유지하고 있었다.