Oxygen Barrier Film Research Articles

Material properties of plasticized hardwood xylans for potential application as oxygen barrier films.

Free films based on glucuronoxylan isolated from aspen wood were prepared by casting from aqueous solutions and drying in a controlled environment. Addition of xylitol or sorbitol facilitated film formation and thus examination of the material properties of these films. The mechanical properties of the films were evaluated using tensile testing and dynamic mechanical analysis in a controlled ambient relative humidity. The strain at break increased, and the stress at break and Young's modulus of the films decreased with increasing amounts of xylitol and sorbitol due to plasticization. At high amount of plasticizer, it was found that films with xylitol gave lower extensibility. Wide-angle X-ray scattering analysis showed that xylitol crystallized in a distinct phase, which we believe contributes to the more brittle behavior of these films. The effect of the plasticizers on the glass transition temperature was determined using dynamic mechanical analysis and differential scanning calorimetry. An increased amount of plasticizer shifted the glass transition to lower temperatures. The effect of moisture on the properties of plasticized films was investigated using water vapor sorption isotherms and by humidity scans in dynamic mechanical analysis. Sorption isotherms showed a transition from type II to type III when adding plasticizer. The films showed low oxygen permeability and thus have a potential application in food packaging.

Synthesis of novel saccharide-pendant vinyl polymer and application to oxygen barrier film

Poly(vinylidene chloride) (PVDC) film, which has a high oxygen barrier property, has been widely used as packaging material, however, PVDC creates significant environmental problems. When burned, it forms chloric acid which is liberated into the atmosphere, becoming a component of the acid rain that damages forests. Therefore, many other materials have been substituted for PVDC in packaging applications. Of these alternative packaging materials, cellulose i.e., cellophane is the most environment-friendly material, and also has a high oxygen barrier property in dry conditions. Cellulose, which has been used in various matrix-forming materials, has long been developed. Although cellulose is a sustainable material, it has characteristics of rigidity derived from interand intramolecular hydrogen bonding. Therefore, cellulose shows poor workability due to thermal stability, poor controllability of chemical reactions and low solubility in water and common organic solvents [1, 2]. Cellulose derivatives such as e.g., acylate [3] and xanthate [4], or the cellulose complex with copper such as cupra [5], are required to mold cellulose. In order to overcome the poor characteristics of cellulose, we focused on a functional polymer with a constitutional unit of cellulose, namely cellobiose in the side chain, and developed the novel synthetic monovinylcellobiose. In addition, the synthetic monomer was converted into a polymer by free-radical polymerization in aqueous solution. It is important to determine whether typical cellulose properties (such as functionality, biodegradability [6] and biocompatibility [7] can be advantageously retained in this new synthetic, so in this paper we report the characterization of the synthetic monovinylcellobiose and the obtained polymer, comparing with the characteristics of the corresponding monosaccharide derivative. As a packaging material, the novel saccharidependant vinyl polymer has potential as a coating layer for oxygen barrier film. In this study, we investigated its oxygen barrier property by measuring the change of humidity. The synthesis of monovinylcellobiose monomer was carried out without the use of protecting groups for the cellobiose component, as shown in Scheme 1. As reported by Likhosherstov et al. [8], a high yield of cellobiosylamine could be obtained by reductive amination of cellobiose. Due to the reactivity difference between the amino group and the remaining hydroxyl groups of the cellobiose, the introduction of a variety of functional group to the anomeric position became possible [9]. Due to a lack of by-products, especially acid, salts and fission products, we adopted coupling with 2-(methacryloyloxy)ethy isocyanate (MOI) [10], which reacts mildly. The typical procedure for the synthesis of 2-(methacryloyloxy)ethylureido cellobiose (MOU-Cell) is described below. Cellobiose (15 g, 43.8 mmol) was dissolved in water (100 ml) and solid ammonium hydrogen carbonate (30 g, 379.7 mmol) was added at intervals of 24 h, and was stirred at 37 ◦C for 2 days. Next, the residue was diluted to 200 ml with water and concentrated to 50 ml. This procedure was repeated until the disappearance of the odor of ammonia. The purity of the freeze-dried product was 81% [11]. Cellobiosylamine (8.1 g, 23.7 mmol) was dissolved in 1.0 × 10−3 M KOH aqueous solution (100 ml). MOI (9.20 g, 59.3 mmol) was added and stirred at 3 ◦C for 12 h, producing white precipitation as a by-product. The precipitation was removed by filtration. The filtrate was washed with diethyl ether to remove traces of unreacted MOI and freeze-dried. The raw product was dissolved in water/methanol and recrystallized from acetone/diethyl ether. The yield was 8.78 g (74.5%). m.p.149.4–153.2. The structure of MOUCell is confirmed by its 1H-NMR and IR spectra. 1H-NMR (D2O, ppm): 1.95 (s, 3H, CH2 C(CH3), 3.41–4.02 (m, 12H, from sugar), 3.66 (t, 2H, CH2), 4.26 (t, 2H, CH2), 4.51 (d, 1H, H′-1), 4.85 (d,

Rinse Treatment and Oxygen Barrier Properties of Films for Improving Quality Retention in Vacuum‐Skin Packaged Fresh Chicken

ABSTRACTFresh chicken drumsticks rinsed with water or salt solution (28% NaCl) were vacuum‐skin packaged in films differing in oxygen transmission rate (OTR) (< 10, 3000, ≥ 7000 cm3/m2/24 h). Salt rinsing decreased surface lightness (CIE L*). Higher OTR films maintained surface redness (CIE a*) better than oxygen barrier film. Neither rinse nor film OTR had any effect on yellowness (CIE b*). Salt rinsing drumsticks also reduced drip loss. Counts of aerobic and coliform bacteria increased during storage for product in all films. Within each film, salt‐rinsed drumsticks had lower counts at 3 and 6 d of storage (through 12 d) for total aerobic and coliform bacteria, respectively. Product in low OTR (barrier) film generally had lower bacteria counts than product in higher OTR films.

The vitamin C content of orange juice packed in an oxygen scavenger material

A storage study of orange juice packed in oxygen scavenging (OS) film and oxygen barrier film was conducted to determine the extent of ascorbic acid loss due to oxygen as a function of time and temperature. The initial concentration of ascorbic acid in the orange juice was 374 mg/l and this was found to decrease by 74 and 104 mg/l after 3 days of storage at 25 °C in the OS and oxygen barrier film, respectively. This rapid loss in ascorbic acid correlated well with the amount of oxygen initially present in the headspace and that dissolved in the juice. The loss of ascorbic acid also correlated with an increase in the browning of the juice, where the extent of browning was found to be lower for the juice packed in the OS film than that packed in the oxygen barrier material. The rapid removal of oxygen was found to be an important factor in sustaining a higher concentration of ascorbic acid over long storage times.

Combinatorial Study and High Throughput Screening of Transparent Oxygen and Moisture Barrier Films

ABSRACTHigh throughput screening methods for evaluating oxygen and moisture barriers are described. The screening methods are based on the change in a certain optical property, such as absorbance or fluorescence, due to a chemical reaction with oxygen gas or water vapor. The results of these measurements for several cases are presented and their advantages and disadvantages are discussed.

Aroma, Oxygen and Moisture Barrier Behavior of Coated and Vacuum Coated OPP Films for Packaging

Various coated and vacuum coated, biaxially oriented polypropylene film product designs are examined in terms of their moisture, oxygen and aroma barriers. Factors that are thought to control oxygen barrier in these products are discussed and extended to aroma barrier development. The differences between the various vacuum coated and uncoated films with three organic permeants are evaluated and discussed in relationship to the impact on the polymer/coating interface and the development of aroma barrier in coated films. It is demonstrated that the existence of an evaporated barrier layer does not guarantee the existence of a chemical barrier. New combinations of film technology are described that permit the development of excellent aroma, oxygen and moisture barrier films.

PACKAGING PRESERVATION OF β‐CAROTENE IN SWEET POTATO FLAKES USING FLEXIBLE FILM AND AN OXYGEN ABSORBER

ABSTRACT Sweet potato flakes are potentially an affordable, shelf‐stable source of provitamin A β‐carotene. Because β‐carotene is susceptible to oxidative degradation, particularly in dehydrated food materials exposed to atmospheric oxygen, several packaging conditions were evaluated for enhancement of β‐carotene retention in sweet potato flakes during storage. The flakes were packaged in either a polypropylene film (high oxygen permeability) with air headspace or a nylon laminate film (low oxygen permeability) with air headspace, under vacuum, or with an Ageless oxygen absorber sachet enclosed. Packaged flakes were stored in the dark at ambient laboratory temperature (∼23C), and β‐carotene content was determined at intervals from 0 to 210 day storage using reversed‐phase liquid chromatography. Among the packaging conditions tested, β‐carotene retention was enhanced incrementally as the apparent availability of oxygen was reduced (nylon > polypropylene; oxygen absorber > vacuum > air headspace). The combined use of oxygen absorbers and flexible oxygen barrier film gave excellent retention of β‐carotene during the 210 day trial.

Quality of Raisins Treated and Stored under Different Conditions

Grapes treated using three different sample treatments before drying were dehydrated with hot air and stored under different conditions of temperature (14, 21, 28, and 35 °C), material packaging (oxygen barrier film or glass), and light. Samples were periodically analyzed in order to determine the evolution of various physical and chemical characteristics and sensory acceptability of raisins. Samples treated with sulfur dioxide as a preservative provided high-quality raisins that were deemed acceptable by a taste panel. A statistical study on pooled data showed that there were no differences between samples stored at 14 and 21 °C nor between samples stored in film and those stored in glass containers. Samples stored in darkness maintained better their quality. It has been proved that chitosan can be used as a food additive in grape preparation, although its addition did not increase grape quality. Results obtained by analytical techniques were consistent with those of the taste panel. Keywords: Storage; r...

The retail display life of steaks prepared from chill stored vacuum and carbon dioxide-packed sub-primal beef cuts

Chilled striploins and cube rolls from ten Australian steers (grain-fed for 150 days) were trimmed of external fat and cut transversely into portions approximately 10 cm thick, each weighing between 750 and 1000 g. These ‘retailer-ready’ cuts were each wrapped in drip saver pads and slid inside a plastic sleeve before being individually placed into a clear plastic high oxygen barrier film, metallized film or conventional vacuum bag. Cuts in clear plastic and metallized film packs were packaged in an oxygen-free saturated carbon dioxide atmosphere ( CO 2 -CAP), those in vacuum bags were conventionally vacuum-packed. All packs were returned to the chiller for further cooling. After 24 hr, half the clear plastic and metallized CO 2 -CAP packs were carbon dioxide master-packed in groups of eight. Retailer-ready cuts in both clear plastic and metallized film single unit and master-packed CO 2 -CAP packs were air freighted to New Zealand and sea freighted to Japan for assessment. The control vacuum packs were all consigned to New Zealand. Assessments in both countries after 39–89 days storage at between 0 °C and −1.0 °C indicated that fat colour stability limited the retail display life of steaks cut from meat in these retailer-ready packs to approximately 48 hr. In this regard, meat from single unit CO 2 -CAP, master pack CO 2 -CAP and vacuum packs performed similarly. Lean meat colour and sensory attributes remained acceptable for up to 48 hr after displayed product was rejected because of grey-green fat discoloration. The microbiological status of retailer-ready cuts removed from CO 2 -CAP packs after 89 days chilled storage was superior to that of cuts from vacuum packs. Clear plastic and metallized film CO 2 -CAP packs performed comparably.

Growth and Production of Toxin of Clostridium botulinum Type E in Rainbow Trout under Various Storage Conditions

Rainbow trout (Oncorhynchus mykiss) were inoculated with 3 to 4 1og10 spores per g of fish of a mixed pool of four strains of Clostridium botulinum type E (Beluga, Minnesota, G21-5, and 070). The trout were vacuum-skin packaged with either oxygen-barrier or oxygen-permeable films. Trout packaged with oxygen-permeable film were stored at 4°C for 21 days, while trout packaged with oxygen-barrier film were stored either at 4°C for 21 days or at 10°C for 15 days. Storage at 10°C was used to simulate commercial temperature abuse. Clostridium botulinum outgrowth was determined by a most probable-number (MPN) method using (tryptone peptone yeast extract glucose trypsin) anaerobic broth. Toxin production was evaluated using a mouse bioassay. Psychrotrophic and anaerobic populations increased with time regardless of packaging type. After 6 days at l0°C, botulinum toxin was detected in the packaged trout; however, the fish was noticeably spoiled before that time. No botulinum toxin was detected in trout packaged with either barrier or permeable films and stored at 4°C for 21 days, although the product was considered spoiled by day 12.

Clostridium botulinum type E outgrowth and toxin production in vacuum-skin packaged shrimp

White and brown shrimp (Penaeus spp.), harvested from the Georgia coast, were inoculated with log 3-4 spores of a mixed pool of four strains of Clostridium botulinum type E (Beluga, Minnesota, G21-5, and 070). Oxygen barrier film was used to vacuum-skin package the shrimp. Packaged shrimp was stored at either 4°C or 10°C. Storage at 10°C was used to simulate temperature abuse. Anaerobes were enumerated by Most Probable Number method using TPYGT broth incubated in anaerobic jars. Clostridium botulinum toxin production was evaluated using the mouse bioassay. After six days at 10°C, botulinum toxin was detected in the packaged shrimp, but the shrimp was noticeably spoiled at this point. No botulinum toxin was detected in the packaged shrimp stored at 4°C for 21 days, although spoilage was noted after 6 days.

Potential role of Proteus-Providencia-Morganella species in quality deterioration of beef

Proteeae Isolation Medium of Hawkey et al. (1986) was effective for isolation and enumeration of Proteus-Providencia-Morganella spp. from beef and beef products. On this medium colonies were brown, surrounded by a zone of clearing. In an examination of retail beef samples packaged and stored in polyvinyl chloride (PVC) film, 5% contained these bacteria in a concentration of 10 1–10 2 cells per gram or cm 2. Isolates from retail beef samples included P. vulgaris, P. alcalifaciens, P. rettgeri, and M. morganii. None of the retail samples packaged and stored in high oxygen barrier (HOB) film contained detectable Proteus-Providencia-Morganella spp. Steaks inoculated with Proteus-Providencia-Morganella spp. and packaged and stored at 4°C in PVC film (15 days) or in HOB film (42 days) usually had a reduced count of Proteus-Providencia-Morganella spp. during storage. Slight increases in counts occurred on steaks inculated with P. vulgaris and P. rettgeri and stored at 4°C for 15 days in PVC film.

Influence of packaging film permeability and residual sulphur dioxide on the quality of pre‐peeled potatoes

SummaryThe effects of sodium bisulphite concentration and gas permeability of the packaging film on the surface colour, texture, exudate production and microbial growth of pre‐peeled refrigerated potatoes were evaluated to determine shelf‐life and the lowest level of preservative which could be used.The product was packaged in polyethylene film, or in vacuo, using EVA‐SARAN‐EVA laminate and stored refrigerated. Polyethylene was not adequate in several aspects; packaging in oxygen barrier film allowed reduction of bisulphite levels, and vacuum packaging of 50 ppm bisulphite treated samples doubled the shelf‐life of the product compared with aerobic packaging.

Microbiological and sensory characteristics of pork loin chops: Role of intramuscular fat

Pork loin chops of High, Intermediate and Low intramuscular fat were trimmed free of subcutaneous fat and then packaged and stored in polyvinyl chloride (PVC) film for 0–6 days or in high oxygen barrier (HOB) film for 0–28 days at 4°C ± 1°C. In general, marbling group had no (P > 0·05) effect on the aerobic plate count (APC) and did not result in major differences in the distribution of types in the microflora of pork loin chops. During storage, Pseudomonas spp. became dominant in the microflora of PVC-wrapped chops while Lactobacillus spp. became dominant in the microflora of chops stored in HOB film. Of the sensory characteristics examined, mean surface discoloration and mean overall appearance scores of chops of Low intramuscular fat stored in HOB film were usually lower (P < 0·05) than those of chops of Intermediate and High intramuscular fat. In contrast, marbling group usually had no significant effect on mean surface discoloration and mean overall appearance scores of chops packaged in PVC film.

Effect of display lighting on fresh pork longissimus packaged in oxygen-permeable and oxygen-barrier films (1987)

Effect of display lighting on fresh pork longissimus packaged in oxygen-permeable and oxygen-barrier films (1987)

Retail Appearance, Odor and Microbiological Characteristics of Pork Loin Chops Packaged in Different Oxygen-Barrier Films as Affected by Loin Storage Treatment

Pork loins were fabricated immediately (fresh) or stored in parchment paper for 6 d or stored in vacuum packages for 8 d. Chops were packaged in either a high oxygen-permeable (PVC) film or a high oxygen-barrier film (vacuum) to be displayed 4 d or 2, 6 and 10 d, respectively. High oxygen-barrier (HOB) film was superior to PVC film in maintaining desirable visual properties of chops. Chops had less off-odor in HOB film when they were held no longer than 3 or 4 d in HOB packages compared to extended periods of display. Pork loin chops packaged in high oxygen-barrier film can be displayed up to 6 d if chops are from fresh pork loins. Although visual scores for vacuum-packaged chops were acceptable for 10 d for all storage treatments, chops from the parchment paper and vacuum-packaged storage treatments had off-odors which were limiting factors in achieving long shelf life.

Effect of Addition of Glucose, Citrate and Citrate-Lactic Acid on Microbiological and Sensory Characteristics of Steaks from Normal and Dark, Firm and Dry Beef Carcasses Displayed in Polyvinyl Chloride Film and in Vacuum Packages

Pseudomonas spp. and Brochothrix thermosphacta were a major or dominant part of the microbial flora of normal and dark, firm and dry (DFD) beef steaks with or without added glucose, citrate or citrate plus lactic acid and displayed for 3 to 6 d in polyvinyl chloride (PVC) film. When normal and DFD steaks with or without the additives were displayed in high oxygen-barrier film, Lactobacillus and/or Leuconostoc spp. were dominant. Addition of glucose (50–500 μg/g meat) had little, if any, effect on the aerobic plate count (APC), pH, lean color, odor and surface discoloration scores of both normal and DFD steaks displayed in PVC or in high-oxygen barrier film. Addition of citrate or citrate plus lactic acid also had little effect on steaks except for lowering pH values and surface discoloration scores of steaks.

Effect of Different Packaging Films and Vacuum on the Microbiology of Bacon Cured with or without Potassium Sorbate

Studies were done to determine the effects of packaging films and vacuum levels on the microbiology of bacon cured with nitrite or a combination of nitrite and sorbate in the curing salt mixture. High and low oxygen barrier films were used along with high and low vacuum levels for packaging systems. Growth of mesophilic, psychrotrophic and lipolytic organisms was restricted most with the combination of high barrier-high vacuum treatment. Vacuum level was more important than type of film in retarding bacterial growth as storage time progressed up to 28 d at 5°C. Sorbate combined with nitrite was more inhibitory than nitrite with no sorbate in the cure.

Influence of Package Construction on Stability of Potato Chips Exposed to Fluorescent Lighting

Potato chips packaged in oriented polypropylene/low-density polyethylene/polyvinylidine chloride, high-density polyethylene/ethylene vinyl acetate plus a UV-light-absorbing compound, or high-density polyethylene/ethylene vinyl acetate plus a titanium dioxide light-barrier constructions developed distinct oxidized flavors within 7 d when stored at 21°C, 55% relative humidity, and under 140–230 ft candles of continuous fluorescent lighting. Potato chips stored under the same conditions that were packaged in a high-density polyethylene plus titanium dioxide and a brown light-absorbing pigment construction or an aluminum foil/polyethylene construction were stable throughout 10 weeks of storage. Oxygen-barrier film characteristics did not influence the oxidative stability of the air-packaged potato chips.