High Oxygen Transmission Rate Research Articles

Polyelectrolyte Coacervate Coatings That Dramatically Improve Oxygen Barrier of Paper

Paper-based food packaging is lightweight, low cost, and highly flexible, but it suffers from a very high oxygen transmission rate (OTR ∼ 11,100,000 cc/(m2·day·atm)). Herein, two polyelectrolyte-based coacervate coatings were studied as oxygen gas barriers on kraft builder’s paper. A single coating deposition of a polyethylenimine-poly(acrylic acid) coacervate, adding less than 20% to the paper’s weight, reduced the OTR to 164,000 cc/(m2·day·atm). This work not only demonstrates a significant OTR improvement of a poor oxygen barrier material, but also provides the foundation for polyelectrolyte-based layers to be deposited on cellulosic materials at an industrial scale.

CO2 laser perforated biodegradable films for modified atmosphere packaging of baby corn

Microperforated polylactic acid (PLA) and polybutylene succinate (PBS) films were fabricated using a CO2 laser under various pulse fluences from 37.0 to 369.8 J/cm2, corresponding to pulse durations of 20–200 μs. A hole was formed at perforation thresholds of 147.9 J/cm2 for PLA and 129.4 J/cm2 for PBS films. The area and diameter of the microhole and volume losses increased with rising laser fluence. Microperforated PLA and PBS films showed similar mechanical properties of tensile strength, Young's modulus and elongation at break to films without microholes but significant improvements in oxygen transmission rate (OTR) and carbon dioxide transmission rate (CO2TR) over non-perforated films. OTR and CO2TR through a single microhole with area of ∼20,000 μm2 on PLA were 234 ± 58 and 217 ± 57 cm3/d, respectively while OTR and CO2TR though a single microhole on PBS were 205 ± 12 and 144 ± 40 cm3/d, respectively showing that biodegradable film could achieve very high OTR at up to 77,500 cm3/m2.d. Baby corn (100g) was packed in microperforated bags. Equilibrium modified atmosphere conditions of 10%–17%O2 and 4%–7% CO2 were reached in performed film packages with very high OTR and CO2TR of 35,000–77,500 and 36,500–80,000 cm3/m2.d, respectively. Results suggested that baby corn maintained freshness qualities for more than 7 days at a storage temperature of 15 °C. The CO2 laser perforation process was successful in producing modified atmosphere packaging (MAP) with tailored gas transmission rates.

Microbiology and Quality Attributes of ‘Pione’ Grapes Stored in Passive and Active MAP

The quality of ‘Pione’ grapes was evaluated during passive and active modified atmosphere packaging (MAP) storage. In the passive MAP study, ‘Pione’ grapes were packaged in two types of films with an oxygen transmission rate (OTR) of either 440 mL/m2/d/atm (low OTR) or 1250 mL/m2/d/atm (high OTR) and stored at 25 °C or 10 °C. When the CO2 concentration in low and high-OTR films stored at 25 °C reached 10% and 3%, respectively, on day 2, grape berries showed lower bacterial counts in the low-OTR films than in the high-OTR films. At 10 °C, the packages approached an equilibrium of 12% CO2 in low-OTR films and 7% CO2 in high-OTR films during 8 days of storage, and no difference was observed in the bacterial counts between the two films. In an active MAP study, ‘Pione’ grapes were stored in low-OTR (440 mL/m2/d/atm) and high-OTR (1170 mL/m2/d/atm) films flushed with air or high CO2 (10%, 20%, and 30%) at 10 °C for 8 days. The CO2 concentration in active MAP with low-OTR films reached approximately 20% by the end of storage, while that with high-OTR films approached an equilibrium of 10% CO2 after 4 days of storage. The bacterial counts remained below the limit of detection until 4 days of storage in active MAP with high-OTR films. Although the fungal counts of berries were non-detectable or below the limit of detection in all active MAPs, Alternaria and Candida fungi and Chryseobacterium and Cutibacterium bacteria were found in the berries stored in active MAP. The firmness, soluble solid content, and surface color of the berries were not affected, regardless of the film type, in both passive and active MAP, and rachis browning due to high-CO2 injury was not observed in any samples in active MAP. These results indicate that passive MAP with low-OTR films or active MAP of 10–20% CO2 with high-OTR films at 10 °C were the optimum packing systems for ‘Pione’ grapes to control the physical and microbiological quality without high-CO2 injury, such as rachis browning.

Evolution of red wine in oak barrels with different oxygen transmission rates. Phenolic compounds and colour

Oxygen is an important factor for the quality of wine aged in barrels. The development of a tool to classify wood by its oxygen transmission rate (OTR) has made it possible to use the same batch of wood to make barrels that oxygenate twice as much as others. Therefore, the aim of this study was to evaluate the phenolic composition and colour of the same red wine aged for twelve months in barrels with a low oxygen transmission rate (LOTR) and with a high oxygen transmission rate (HOTR). The results showed that the same wine evolves differently in barrels with different oxygenation rates. Wines that received lower oxygenation (LOTR) had a higher polymeric pigment and total phenol content that were more polymerized. In these wines, the release of low molecular weight wood compounds was faster and higher than in the case of those aged in HOTR barrels. However, the wines from HOTR barrels maintained a higher level of anthocyanins and a more tannic character. Wines aged in LOTR barrels showed a higher colour intensity due to the increased formation of new pigments. These wines will maintain their red colour better than those aged in HOTR barrels.

Effect of Backsheet Properties on PV Encapsulant Degradation during Combined Accelerated Aging Tests

Long-term photovoltaic (PV) module reliability is highly determined by the durability of the polymeric components (backsheet and encapsulation materials). This paper presents the result of experiments on encapsulant degradation influenced by the backsheet permeation properties. Towards this goal, one type of ethylene/vinyl acetate copolymer (EVA) was aged in glass/EVA/backsheet laminates in accelerated aging tests (up to 4000 h for Damp-Heat (DH) and up to 480 kWh/m2 for UV and UV-DH combined). The samples contained three backsheets with different permeation properties to examine their impact on EVA degradation. Thermal and chemical characterization shows that the EVA degradation is stronger with the glass–EVA–polyamide (PA)-based backsheet than with the polyethylene terephthalate (PET)-based backsheets. The higher oxygen transmission rate (OTR) of the PA-based backsheet may increase photo-oxidation and aggravating the degradation of EVA in the laminates. Furthermore, FTIR results were used to demonstrate the effect of damp heat exposure on the EVA interfaces, showing an accelerated degradation at the glass–EVA interface. The comparison of accelerated aging stress factors reveals that EVA suffers the strongest chemical and optical degradation when high UV, high temperature and high relative humidity are combined simultaneously.

Volatile composition of oak wood from different customised oxygenation wine barrels: Effect on red wine

The compounds that the wood releases to the wine and the oxygen transmission rate (OTR) of the barrel define the final wine. The new possibility of choosing the OTR of the barrel allows the winemaker to globally control the ageing process. The aim of this work was to study the volatile composition of woods classified according to their OTR, which are used to build barrels for wine ageing. The results showed that volatile composition differs depending on wood OTR and the temperature reached during toasting. On the toasted side of the stave in contact with the wine, low OTR wood had a statistically higher content in furan compounds (5-hydroxymethylfurfural, furfural and 5-methylfurfural), acetovanillone and phenolic aldehydes (vanillin and syringaldehyde), while 4-ethylguaiacol and trans-β-methyl-γ-octalactone were significantly higher in staves with a high OTR. The same red wine aged first for three months in high and low oxygenation barrels presents different characteristics.

High Oxygen and Water-Vapor Transmission Rate and In Vitro Cytotoxicity Assessment with Illite-Polyethylene Packaging Films.

This work reports the preparation of a ceramic hybrid composite film with illite and polyethylene (illite-PE), and the evaluation of the freshness-maintaining properties such as oxygen transmission rate (OTR), water vapor transmission rate (WVTR), tensile strength, and in vitro cytotoxicity. The particle size of the illite material was controlled to within 10 μm. The illite-PE masterbatch and film were prepared using a twin-screw extruder and a blown film maker, respectively. The dispersity and contents of illite material in each masterbatch and composite film were analyzed using a scanning electron microscope (SEM) and thermogravimetric analyzer (TGA). In addition, the OTR and WVTR of the illite-PE composite film were 8315 mL/m2·day, and 13.271 g/m2·day, respectively. The in vitro cytotoxicity of the illite-PE composite film was evaluated using L929 cells, and showed a cell viability of more than 92%. Furthermore, the freshness-maintaining property was tested for a packaging application with bananas; it was found to be about 90%, as indicated by changes in the color of the banana peel, after 12 days.

Effect of packaging oxygen transmission rate on the shelf life of ready‐to‐heat foods susceptible to postcontamination during refrigerated and illuminated storage

Since more and more pressure is exerted to reduce the use of plastic packaging materials, optimizing the use of food packaging is opportune. The aim of this study was to evaluate the combined effect of packaging materials, spanning a range of oxygen transmission rates (OTR), and retail illumination, on the microbial shelf life and safety of refrigerated ready‐to‐heat foods. Cooked potato slices were packaged in OPA/PP bags with a high OTR (28.85 ccO2/m2/d) and OPA‐EVOH/PP bags with a low OTR (6.57 ccO2/m2/d). Cooked composite meals were packaged in tray and foil combinations, also spanning a range of OTR: PP trays (2.09 ccO2/tray/d) with OPA/PP foils (28.85 ccO2/m2/d), PP trays with OPA‐EVOH/PP (6.57 ccO2/m2/d) foils, and PET trays (0.07 ccO2/tray/d) with PET top foil (32.86 ccO2/m2/d) . The packages were stored in a dark environment, or under fluorescent or LED light. Due to the rapid growth of lactic acid bacteria, the microbial shelf life of both food products was largely unaffected by the type of barrier. Illumination at 1000 lux for 12 hours per day led to temperature differences significantly affecting microbial growth. Based on the results, it could be concluded that re‐evaluating packaging material choices for these foods may prove valuable, since the use of high‐barrier multilayer packaging materials may be considered as a case of overpackaging.

Application of image analysis and artificial neural networks to the prediction in-line of OTR in oak wood planks for cooperage

Oxygen Transmission Rate (OTR) is an important property of the wood employed in cooperage because of its relationship with the characteristics attained by the wine during the aging process. Nevertheless, this property has not been considered in the barrel making process because the time and systems required for measuring it do not allow its integration into a production line. This article proposes a method to classify the staves that compose each barrel in order to be able to build low-OTR barrels and high-OTR ones depending on the OTRs of the oak staves with significantly different levels among them. This method uses eight anatomical and physical parameters of the wood, which could be measured with in-line non-destructive methods, and a multilayer perceptron artificial neural network (MLP-ANN) to estimate the toasted-staves OTR value. Finally, the staves are classified according to their estimated OTR in three groups: low-OTR, high-OTR and those in between as the third group. The proposed stave classification system makes it possible to build oak barrels with different OTRs. Thus barrels with high OTRs with an average wood OTR almost three times higher than those with low OTRs could be built.

Fabrication of moth-eye gold nanostructures by nanoimprint lithography using solvent-permeable porous cross-link molds derived from hydroxypropyl-cyclodextrin

This study aims to expand the possibility of nanoimprint lithography by fabricating a high-accuracy gold (Au) nanostructure, which holds great potential in broad functional applications, using solvent-permeable porous cross-linking molds derived from hydroxypropyl-cyclodextrin. Multiple functional Au moth-eye nanostructures were imprinted 30 times using Au nanopaste, which involved volatile dilution solvents in the adjusted nanoimprint processes. The proposed method using solvent-permeable porous cross-link molds having high oxygen transmission rate could avoid the nanopattern failure due to the trapping of solvent and/or gas in the solvent-impermeable molds.

Tendency of lipid radical formation and volatiles in lose or vacuum-packed Brazil nuts stored at room temperature or under refrigeration

The Brazil nut is an important product from the Amazonian region and its productive chain is an income source for local communities. The effect of combinations of packaging atmospheres (loose or vacuum-packed) and storage temperatures (4±1 °C or 24±2 °C) on the tendency of lipid radical formation and on volatiles was investigated for the first time in shelled Brazil nut kernels. It was observed that refrigeration, whether combined with lose packing or vacuum packing, was effective to reduce the tendency for lipid radical formation, as detected by spin-trapping electron spin resonance (ESR) spectroscopy, as well as peroxides, conjugated dienes and 3-octen-2-one. However, the combination of refrigeration with vacuum packing, even using low-density polyethylene (LDPE) pouches with a high oxygen transmission rate (OTR), also reduced the formation of hexanal, which is a major off-flavor volatile, and thus should be recommended for the storage of Brazil nut kernels for the studied period.

Design and application of a passive modified atmosphere packaging for maintaining the freshness of Chinese cabbage

We designed two types of passive modified atmosphere packaging (PMAP) on the basis of mult-piece films integration design using films A (films with high water vapor transmission rate) and E (films with high oxygen transmission rate (OTR) and high carbon dioxide transmission rate) as raw materials. The two types of PMAP were evaluated for their influence on headspace gas in packaging and appearance quality, vitamin C, soluble solid content, and water loss in Chinese cabbage (Brassica rapa). Results show that PMAP can effectively delay the respiration of Chinese cabbage, thereby reducing nutrient loss, maintaining appearance quality, avoiding fog, and extending storage time from two to five days at room temperature.

Does the Oxygen Permeability affect the Equilibrium Gas Concentrations in Passive Modified Atmosphere Packaged Pomegranate Arils?

The effect of oxygen permeability of packaging material on shelf life of minimally processed and passive modified atmosphere packaged pomegranate arils, cv “Wonderful” as well as some quality attributes were investigated. Packaging materials having Oxygen transmission rate (OTR) as low as 125–290 cm3/m2/day were found to provide the gas concentration requirements of 2–5% O2 and 3–10% CO2 for passive modified atmosphere application of fresh fruits and vegetables. Although color, firmness, anthocyanin, total phenolic content and sensorial and microbial properties significantly changed there was no significant change in pH, total soluble solids and antioxidant activity during storage period at 5C. Microbial counts of total aerobic bacteria did not exceed the legal limit during storage period but sensorial values were below the limit of threshold on 11th day of storage. OTR of packaging material of pomegranate arils should be as low as 125–290 cm3/m2/day under passive modified atmosphere and its shelf life was determined as 10 days at 5C and 90% Relative humidity (RH). Practical Applications The results of this project can be utilized by producers of fresh pomegranate arils to decide on packaging material having appropriate oxygen permeability. Thus the fresh cut producers prefer to use packaging materials having higher oxygen transmission rate since minimally processed fruits and vegetables are more susceptible to microbiological and sensorial deterioration because of the higher surface area leading to enhanced respiration rate. However, this situation is not valid for fresh pomegranate arils since the respiration rate of fresh pomegranate arils is lower compared to whole pomegranates. Producers will also get the opinion that shelf life period of fresh pomegranate arils is about 10 days and sensorial properties are more potent than the microbiological properties to determine the end of shelf life due to the nature of pomegranate arils.

Oxidation-reduction potential and lipid oxidation in ready-to-eat blue mussels in red sauce: criteria for package design.

Ready-to-eat in-package pasteurized blue mussels in red sauce requires refrigerated storage or in combination with an aerobic environment to prevent the growth of anaerobes. A low barrier packaging may create an aerobic environment; however, it causes lipid oxidation in mussels. Thus, evaluation of the oxidation-reduction potential (Eh) (aerobic/anaerobic nature of food) and lipid oxidation is essential. Three packaging materials with oxygen transmission rate (OTR) of 62 (F-62), 40 (F-40) and 3 (F-3) cm3 m-2 day-1 were selected for this study. Lipid oxidation was measured by color changes in thiobarbituric acid reactive substances (TBARS) at 532 nm (TBARS@532) and 450 nm (TBARS@450). Significantly higher (P < 0.05) TBARS@532 was found in mussels packaged in higher OTR film. TBARS@450 in mussels packaged with F-62 and F-40 gradually increased during refrigerated storage (3.5 ± 0.5 °C), but remained constant after 20 days of storage for mussels packaged with F-3. The Eh of pasteurized sauce was not significantly affected (P > 0.05) by OTR and remained negative (< -80 mV) during storage. Negative Eh values can support the growth of anaerobes such as Clostridium botulinum. The headspace oxygen concentration was reduced by about 50% from its initial value during pasteurization, and then further declined during storage. The headspace oxygen concentration was higher in trays packaged with higher OTR film. Mussels packed with high OTR film showed higher lipid oxidation, indicating that high barrier film is required for packaging of mussels. Pasteurized mussels must be kept in refrigerated storage to prevent growth of anaerobic proteolytic C. botulinum spores under temperature abuse. © 2016 Society of Chemical Industry.

Super Oxygen and Improved Water Vapor Barrier of Polypropylene Film with Polyelectrolyte Multilayer Nanocoatings.

Biaxially oriented polypropylene (BOPP) is widely used in packaging. Although its orientation increases mechanical strength and clarity, BOPP suffers from a high oxygen transmission rate (OTR). Multilayer thin films are deposited from water using layer-by-layer (LbL) assembly. Polyethylenimine (PEI) is combined with either poly(acrylic acid) (PAA) or vermiculite (VMT) clay to impart high oxygen barrier. A 30-bilayer PEI/VMT nanocoating (226 nm thick) improves the OTR of 17.8 μm thick BOPP by more than 30X, rivaling most inorganic coatings. PEI/PAA multilayers achieve comparable barrier with only 12 bilayers due to greater thickness, but these films exhibit increased oxygen permeability at high humidity. The PEI/VMT coatings actually exhibit improved oxygen barrier at high humidity (and also improve moisture barrier by more than 40%). This high barrier BOPP meets the criteria for sensitive food and some electronics packaging applications. Additionally, this water-based coating technology is cost effective and provides an opportunity to produce high barrier polypropylene film on an industrial scale.

Oak Stave Oxygen Permeation: A New Tool To Make Barrels with Different Wine Oxygenation Potentials.

The aim of this study was to classify rough staves according to their permeability to oxygen by measuring their transmission rate to assess the capacity to build barrels with high and low oxygen transmission rates (OTRs). The ability to assess the OTR would be important for better understanding and controlling the aging process of wine in barrels. To accomplish this, we built a device that measures the OTR of rough staves under the same conditions as those in a full barrel, in which the stave is in contact with a liquid solution on one face and with a diffusing gas on the opposite face. A total of 69 rough staves were classified to yield a high-OTR group, with a mean 2.6 times higher than the mean of the low-OTR group. A high-OTR barrel and a low-OTR barrel were constructed, and we confirmed that the stave OTR decreased between 3- and 4.5-fold in the barrels and that the high-OTR barrel allowed the entry of twice the concentration of oxygen compared to the low-OTR barrel. These results confirmed the capacity to classify rough staves and build barrels with different OTRs.

Effect of Packaging Films on the Quality of Canola Oil under Photooxidation Conditions

The objective of this study was to evaluate the influence of packaging films on the quality of canola oil which contains high concentration of fat under photooxidation condition and get the oxidation kinetics based on measuring the oxidation intensities including peroxide value, hexanal, and photosensitizer (chlorophyll). The canola oil was packaged by PET/CPP; KPET/PE was used for experiments. The change of light and oxygen transmission rate (OTR) of PET/CPP which was considered as the typical fatty foods packaging film under different light intensities was also tested. The results show that the peroxide value increased rapidly under light conditions and fitted the zero order kinetics; also the oxygen transmission rate had great impact on it; hexanal fitted the zero order kinetic in oil whose package of low OTR generated a lot; however package in high OTR films changed very slowly that might be dependent on the performance of hexanal through plastic films. The degradation of chlorophyll fitted the first order kinetic and decreased quickly under light but was almost independent of OTR of transparent packaging material. Light reduced the oxygen barrier properties of the films, which should be considered as the photooxidation condition (and the photooxidation condition thus should be considered).

Graphene oxide and laponite composite films with high oxygen-barrier properties.

The design and fabrication of oxygen barrier films is important for both fundamental and industrial applications. We prepared three different thin films composed of graphene oxide (GO) and laponite (LN), a typical low cost inorganic clay, with the GO/LN volume ratios of 1.9/0.1, 1.7/0.3 and 1.5/0.5 together with a double layer film of the GO and LN. We found that the films with GO/LN = 1.9/0.1 and the double layers exhibited high oxygen barrier and oxygen transmission rate values that reached 0.55 and 0.37 cm(3) per m(2) per atm per day, respectively, which were much lower than those of the films prepared from the pure GO, only LN and GO/LN = 1.7/0.3 and 1.5/0.5. This study is important for the design and fabrication of a film from GO-based all inorganic nanomaterials for applications in gas-barrier membranes.

Postharvest quality and storage life of ‘Makapuno’ coconut (Cocos nucifera L.)

Makapuno is a high-value commercial coconut with distinct sensory attributes, however the postharvest conditions required to maintain quality are unknown. To address this, partially de-husked mature Makapuno coconut fruit were stored at 2, 5 or 30°C and were then evaluated after transferring to 30°C for 3 days to simulate conditions in retail markets. During storage at 30°C, the fruit showed a moderate respiration rate of 40–60mgCO2kg−1h−1, a low ethylene production rate of 0.6–0.8μLC2H4kg−1h−1 and storage life was 3 days. In contrast, storage at 2°C or 5°C markedly reduced respiration rates to 4 and 20mgCO2kg−1h−1, respectively, and storage-life increased dramatically from 3 days to 6 weeks. Generally, cold storage delayed fruit deterioration by limiting weight loss, kernel browning and malondialdehyde content, however, after the fruits were transferred to 30°C, those previously held at 2°C showed signs of chilling injury, while those held at 5°C did not. Modified atmosphere packaging (MAP) using high oxygen transmission rate (OTR) bags in combination with 5°C storage extended fruit storage-life 20-fold, from 3 days at ambient conditions to 10 weeks. The combination of MAP and 5°C storage reduced weight loss (4-fold), the incidence of surface mold and the quality parameters measured were comparable to values in freshly harvested fruit.

Porous Ultrahigh Gas-Permeable Polypropylene Film and Application in Controlling In-pack Atmosphere for Asparagus

Porous polypropylene (PP) films with greater gas permeability and lower permeability ratios (β) than existing commercial films were developed for fresh produce packaging. PP containing high content of beta-form crystal was biaxially stretched under controlled conditions. Resulting porous films with uniquely high oxygen transmission rate (OTR) of 2 659 000 cm3⋅m−2⋅d−1, water vapor transmission rate of 67 g⋅m−2⋅d−1, and β value of 0.76 was used as a “breathable window” attached to the less permeable commercial BOPP (biaxially oriented PP) lidding film. Various sizes/areas of the breathable windows were designed and tested on packaging asparagus of 400 g, at 5°C. Results demonstrated that in-pack O2 and CO2 concentrations could be practically controlled and modified by changing areas of the breathable windows. Altered porous high OTR area directly affected total gas permeation of the package. Optimum gas composition of Ο2 and CΟ2 within the recommended controlled atmosphere for asparagus, stored at 5°C, was effectively created and maintained in the package containing 25 cm2 breathable window (15% of total film lid's area). The shelf life of asparagus under optimum modified atmosphere was extended to 29 days, as compared with <3 days in the normal, low OTR tray sealed with BOPP lidding film. Clearly, these developed porous ultrahigh permeable PP films can be useful materials in designing high OTR package with desirable in-pack O2 and CO2 concentrations. Copyright © 2013 John Wiley & Sons, Ltd.