Oxygen Requirements of Bacillus licheniformis and Bacillus subtilis in Tomato Juice; Ability to Grow in Aseptic Packages

Tomato juice was inoculated with spores of Bacillus subtilis and Bacillus licheniformis, placed in jars sealed with four polymers: oriented polypropylene (OPP), low density polypropylene with 4.5% ethyl vinyl acetate (LDPE + EVA), polyvinylidene chloride (PVDC), and polyethylene teraphthalate (PET); used in aseptic packages, serving as lids, heated in a boiling water bath for 10 min, and incubated at 35°C for up to 100 days. B. subtilis and-B. licheniformis grew at the surface of the food when OPP and LDPE + EVA were used, which caused the pH to rise above 4.6 in 60 days and above 5.0 within 100 days. The oxygen partial pressures were 0.20 and 0.18 atm per day, and the oxygen permeation ratios were 5.64 and 0.76 cc/day for LDPE + EVA and OPP, respectively.     

超高压处理对LDPE、PA6食品包装材料包装性能可逆性的研究

本文在不同条件下对LDPE、PA6进行超高压(HPP)处理,测定不同压力、保压时间及存储时间对材料拉伸强度、热封性能、阻隔性能、热性能以及包装性能可逆性的影响。实验表明:处理压力、保压时间及存储时间对2种材料的热封性均未产生显著影响,但LDPE、PA6试样的拉伸强度随压力升高明显增大;当压力300 MPa时LDPE的透湿性逐渐上升,当压力300 MPa时LDPE的透湿性又逐渐降低,对PA6来说,当压力100 MPa时,材料的透湿性明显下降由10.13 g/(m2·d)(0.1 MPa/10 min)降低到6.79 g/(m2·d)(200 MPa/10 min),但随压力增大透湿性下降的幅度并不明显;两种材料的熔融焓在HPP下均有升高,当存储24 h后,两种材料的ΔH又有所恢复;与0.1 MPa下相比,经过HPP后对异丙基甲苯在LDPE(500 MPa)和PA6(100 MPa)薄膜中的渗透率分别降低约50%和58%,但随着存储时间的延长又逐渐恢复至常压下的渗透率。研究发现实验中采用的LDPE和PA6 2种薄膜的包装性能均有可逆现象出现。     

Changes during storage of dried Moringa oleifera leaves prepared by heat pump‐assisted dehumidified air drying

Moringa oleifera leaves contain phytochemicals that are retained during heat pump‐assisted dehumidified air drying. Changes in phytochemicals, antioxidant capacity and colour were evaluated at 15–35 °C, during storage of dried leaves in polypropylene (PP) or high barrier (PET/Al/PE) packaging for up to 6 months. The a_w of samples in PP increased from 0.373 to 0.669. Decreases in total phenolics were greatest at 35 °C in PP (48%) and least at 15 °C in PET/Al/PE (19%). There were few significant changes in DPPH inhibition after 2 months storage. There was little change in kaempferol and some increase in quercetin. During storage, samples became less green, suggesting breakdown in chlorophyll had occurred. The degradation of flavonoids followed first‐order kinetics. The half‐life for total flavonoids ranged from 2.13 to 1.47 months for samples stored in PP and from 2.59 to 1.83 months for samples stored in PET/Al/PE.     

Ammonia gas permeability of meat packaging materials

Meat products are packaged in polymer films designed to protect the product from exterior contaminants such as light, humidity, and harmful chemicals. Unfortunately, there is almost no data on ammonia permeability of packaging films. We investigated ammonia permeability of common meat packaging films: low-density polyethylene (LDPE; 2.2 mil), multilayer polyolefin (MLP; 3 mil), and vacuum (V-PA/PE; 3 mil, 0.6 mil polyamide/2.4 mil polyethylene). The films were fabricated into 10 × 5 cm pouches and filled with 50 mL deionized water. Pouches were placed in a plexiglass enclosure in a freezer and exposed to 50, 100, 250, or 500 ppm ammonia gas for 6, 12, 24, and 48 h at -17 ± 3 °C and 21 ± 3 °C. At freezing temperatures, no ammonia residues were detected and no differences in pH were found in the water. At room temperature, ammonia levels and pH of the water increased significantly (P < 0.05) with increasing exposure times and ammonia concentrations. Average ammonia levels in the water were 7.77 ppm for MLP, 5.94 ppm for LDPE, and 0.89 ppm for V-PA/PE at 500 ppm exposure for 48 h at 21 ± 3 °C. Average pH values were 8.64 for MLP, 8.38 for LDPE, and 7.23 for V-PA/PE (unexposed ranged from 5.49 to 6.44) at 500 ppm exposure for 48 h. The results showed that temperature influenced ammonia permeability. Meat packaging materials have low ammonia permeability and protect meat products exposed to ammonia leaks during frozen storage.     

超高静压对食品真空复合包装膜材料性能及微观结构影响的初探

食品包装材料性能及结构变化会影响食品的质量安全及货架期,探索超高静压对食品包装材料性能及结构变化对了解超高静压对包装材料作用效应机理及包装材料选择是有益的。选择2种食品包装最为常用的未拉伸聚丙烯/尼龙/聚乙烯(CPP/nylon/PE)和聚丙烯/铝/聚乙烯(PP/Al/PE)复合包装膜为研究对象,探讨了不同超高静压强对包装材料拉伸强度、拉伸伸长率、热封强度、透气性、透湿性的变化等影响,并对超高静压对包装材料断面结构的影响进行了环境扫描电镜(ESEM)观察。试验结果表明:(1)超高静压处理对CPP/nylon/PE和PP/AL/PE复合材料拉伸强度影响变化不显著;(2)经超高静压处理后,CPP/nylon/PE伸长率及透氧系数变化显著(P<0.05);(3)经超高静压处理后,PP/Al/PE热封强度、透湿率变化显著(P<0.05)、伸长率及透氧系数变化极显著(P<0.01);(4)在一定压强的超高静压处理会使复合膜结构产生膜间裂缝及Al膜内部裂缝。对CPP/nylon/PE在300-600MPa,PP/AL/PE在200-600MPa,基本上是压强越大,裂缝就越严重。     

Effect of Pasteurization, High-Pressure Processing, and Retorting on the Barrier Properties of Nylon 6, Nylon 6/Ethylene Vinyl Alcohol, and Nylon 6/Nanocomposites Films

ABSTRACT:  This study determined the impact of pasteurization, high-pressure processing (HPP), and retorting on the barrier properties of nylon 6 (N6), nylon 6/ethylene vinyl alcohol (N6/EVOH), and nylon 6/nanocomposite (N6/nano) materials. The pasteurized and high-pressure treated films were coextruded with low-density polyethylene (PE) as the heat-sealing layer. The retorted films were coextruded with polypropylene (PP). Oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) of the samples were measured after pasteurization (75 °C for 30 min), HPP (800 MPa for 10 min at 70 °C), and retorting (121 °C for 30 min) treatments. These were compared with the thermal characteristics and morphologies of the samples using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Results showed that OTR of N6 and N6/Nano increased after HPP (16.9% and 39.7%), pasteurization (13.3% and 75.9%), and retorting (63.3% and 112.6%), respectively. For N6/EVOH, a decrease in OTR after HPP (53.9%) and pasteurization (44.5%) was observed. The HPP treatment increased the WVTR of N6 (21.0%), N6/EVOH (48.9%), and N6/Nano (21.2%). The WVTR of N6, N6/EVOH, and N6/Nano increased by 96.7%, 43.8%, and 40.7%, respectively, after pasteurization. The DSC analyses showed that the enthalpy and percent crystallinity increased (2.3% to 6.5%) in the N6/Nano when compared with the N6 material after each treatment. Retorting caused a decrease (3.5%) in the percent crystallinity of the polypropylene material. HPP did not cause major morphological changes to the samples. Results of the barrier studies were influenced by the crystallinity changes in the materials as seen in the XRD diffractograms.     

EFFECT OF PE/AG2O NANO‐PACKAGING ON THE QUALITY OF APPLE SLICES

ABSTRACT

Effects of low‐density polyethylene (LDPE) packaging and nano‐structured silver‐polyethylene (PE/Ag₂O) packaging on the overall sensory quality, color, weight and solute loss of fresh‐cut apples stored at 5 and 15C were studied in this research. Results showed that, compared with normal LDPE packaging, the PE/Ag₂O packaging helped to maintain the freshness of apple slices. Nano‐structured PE/Ag₂O bag delayed apple browning and decreased the weight loss of apple slices during storage. In addition, it can also prevent apple slices from microbial spoilage. As a result, the quality of apple slices saved at 5C in PE/Ag₂O bag was acceptable in 12 days, while those held in LDPE bag showed some deterioration in 6 days. Furthermore, considering the potential health risk resulting from silver leak, the safety of PE/Ag₂O bag was evaluated, and the result indicated an acceptable safety for food packaging.

PRACTICAL APPLICATIONS

Types of nano‐structured bags are recently commercialized for food packaging in many countries, but few documents report their performance in quality maintenance. This study indicates that nano‐structured PE/Ag₂O bag is effective in maintaining the freshness of apple slices with extended shelf‐life. Results of this work may be useful for promoting the acceptance and application of similar nano‐packaging in the quality maintenance of fresh‐cut products.     

Water absorption and oxygen barrier characteristics of ethylene vinyl alcohol films

Oxygen transmission rates (OTR) of two multilayer films containing ethylene vinyl alcohol (EVOH) were analyzed after water absorption at 121 °C. The films, referred to as film A and film B, were laminated film of PET/EVOH/PP and coextruded film of PET/PP/nylon 6/EVOH/nylon 6/PP, respectively. OTR increased with water absorption for both films. Graphical representation of data revealed two apparent linear regions describing the change of OTR with water absorption for both films. At low water contents (up to 4%) OTR were similar for the two films but differed dramatically at higher water contents. Water sorption characteristics of two monolayer EVOH barrier films (biaxially oriented and non-oriented) were determined at 25 °C using standard gravimetric method. Moisture sorption isotherms were analyzed using the Guggenheim-Anderson-de Boer model and the cluster theory of Zimm and Lundberg to evaluate the interactions between water and EVOH.     

超高压下食品组分与包装材料的相互影响

研究超高压技术对薄膜的结构和性能产生的影响及超高压作用下薄膜与食品模拟物的相互作用。对以大豆蛋白、油脂等食品组分为内容物的尼龙/聚乙烯(PA/PE)、聚酯/聚乙烯(PET/PE)两种聚合物包装材料进行超高压处理,并贮藏一定周期,测定不同压强及保压时间下食品内容物与包装材料在不同贮藏周期内的相互影响。结果表明:贮藏周期一定,经过超高压处理的两种聚合物包装材料的性能要优于未经过处理的;在保压时间一定的情况下,增加压力会提升食品组分的货架期,压力越高,效果越明显;在压力一定的条件下,保压时间的变化并未对食品组分、包装材料产生规律性的影响。压力和贮藏周期的变化对食品组分和包装材料会产生一定的影响。     

Altered Oxygen Permeation Through Packaging Polymers in Contact with Liquids—a Mathematical Model Confirmed in a Dilute Xanthan Gum Solution

The ability of liquids to reduce oxygen permeation through low density polyethylene (LDPE), oriented polypropylene (OPP), polyethylene terepthalate (PET), and polyvinylidene chloride (PVTDC) films was mathematically modeled using a water/xanthan solution as a model medium. For low barrier films (LDPE and OPP), the medium substantially reduced oxygen permeation. In PET, an intermediate barrier, the medium produced a recognizable, but minor reductions in permeation. For the highest barrier (PVDC), the medium's influence on permeation was almost unidentifiable. The effect of the medium's oxygen solubility constant and diffusion coefficient on permeation was also examined. For all films, reduction in permeation became significant only after solubility and diffusion values fell below 40% of water values.     

Effects of Rigor Status during High‐Pressure Processing on the Physical Qualities of Farm‐Raised Abalone (Haliotis rufescens)

High‐pressure processing (HPP) is used to increase meat safety and shelf‐life, with conflicting quality effects depending on rigor status during HPP. In the seafood industry, HPP is used to shuck and pasteurize oysters, but its use on abalones has only been minimally evaluated and the effect of rigor status during HPP on abalone quality has not been reported. Farm‐raised abalones (Haliotis rufescens) were divided into 12 HPP treatments and 1 unprocessed control treatment. Treatments were processed pre‐rigor or post‐rigor at 2 pressures (100 and 300 MPa) and 3 processing times (1, 3, and 5 min). The control was analyzed post‐rigor. Uniform plugs were cut from adductor and foot meat for texture profile analysis, shear force, and color analysis. Subsamples were used for scanning electron microscopy of muscle ultrastructure. Texture profile analysis revealed that post‐rigor processed abalone was significantly (P < 0.05) less firm and chewy than pre‐rigor processed irrespective of muscle type, processing time, or pressure. L values increased with pressure to 68.9 at 300 MPa for pre‐rigor processed foot, 73.8 for post‐rigor processed foot, 90.9 for pre‐rigor processed adductor, and 89.0 for post‐rigor processed adductor. Scanning electron microscopy images showed fraying of collagen fibers in processed adductor, but did not show pressure‐induced compaction of the foot myofibrils. Post‐rigor processed abalone meat was more tender than pre‐rigor processed meat, and post‐rigor processed foot meat was lighter in color than pre‐rigor processed foot meat, suggesting that waiting for rigor to resolve prior to processing abalones may improve consumer perceptions of quality and market value.     

QUALITY CHANGES IN FRESH‐CUT SPINACH (SPINACIA OLERACEA) UNDER MODIFIED ATMOSPHERES WITH PERFORATIONS

ABSTRACT

Fresh‐cut spinach leaves were stored for 4 days at 15C and 75% relative humidity under modified atmosphere packaging to assess the impact of differential in‐pack gas atmospheres generated through different packaging films and variable in‐pack weight on the quality of stored produce. After 4 days of storage, retention of chlorophyll, β‐carotene and ascorbic acid was better in low‐density polyethylene (LDPE) packages than in polypropylene (PP) packages. LDPE film‐packaged samples had higher phenolic content than PP film‐packaged samples. Low in‐pack O₂ (1–2 kPa) along with the buildup of CO₂ (8–10 kPa) seems to have enhanced the retention of antioxidant components, i.e., β‐carotene and ascorbic acid, in LDPE packages. This helped in chlorophyll retention and also prevented formation of oxidation compounds of phenols that otherwise caused browning of cut surfaces. Thus, O₂ and CO₂ permeability of packaging film or in‐pack weight of produce might be such that equilibrated O₂ partial pressures remain near to 1–2 kPa so as to affect a beneficial increase in the phenolic content along with concomitant retention of chlorophyll.

PRACTICAL APPLICATIONS

Fresh‐cut spinach leaves have received an enormous demand due to their utility in various traditional Indian preparations. Shelf life and quality of fresh‐cut produce may be greatly reduced due to high rates of respiration. Traditional packaging and handling techniques reduce the shelf life and sensory quality of fresh‐cut spinach. Temperature control and atmospheric modifications help to maintain produce quality by reducing respiration rate and enhance shelf life by minimizing the adverse effects of cutting. This research focused on evaluation of respiratory behavior of fresh‐cut spinach leaves at a temperature commonly encountered during transportation and retail distribution, i.e., 15C, and the effect of different polymeric films and in‐pack weights on produce quality. The results of the study suggest that packaging of fresh‐cut spinach in polymeric film packages could maintain the sensory quality and reduce degradation of various physicochemical constituents. Utilization of the results for proper design of modified atmosphere packages for this highly perishable produce can prove to be extremely beneficial for safe storage and transportation to urban retail markets.     

Release property and antioxidant effectiveness of tocopherol-incorporated LDPE/PP blend films

Low-density polyethylene (LDPE)/polypropylene (PP) blend films in various blending ratios containing 3000?mg?kg^?1 of tocopherol were manufactured by an extrusion process. Tocopherol release properties were characterised and correlated with antioxidant effectiveness in retarding the oxidation of linoleic acid contacting the films at 40°C. The conditions without tocopherol (control) and with instant tocopherol addition corresponding to the amount included in the films were also prepared and compared with the film-contacting solutions. The effect of tocopherol inclusion and the blending ratio on their physical properties was also examined. A wide range of tocopherol diffusivity in 6.6?×?10^?16–4.6?×?10^?14?m^2?s^?1 were obtained by blend films. As PP content increases, the diffusivity decreased sharply at the beginning and levelled off later. The slower release of tocopherol in LDPE/PP blend films corresponding to lower tocopherol diffusivity retained the higher tocopherol concentration in the linoleic acid system providing better antioxidant effectiveness of the extended induction period in oxidation. The tocopherol inclusion reduced tensile strength and transparency significantly in an affordable range with higher tensile strength given by a higher PP ratio. LDPE/PP blending can be a useful tool to modulate the release profile of tocopherol and thus the antioxidant effectiveness of the tocopherol-incorporated antioxidant packaging film.     

Sensory and microbiological quality of shiitake mushrooms in modified‐atmosphere packages

The aim of the present work was to study the influence of modified‐atmosphere packaging on the microbiological and sensory quality of shiitake mushrooms (Lentinula edodes). Mushrooms were packaged under atmospheric air (passive modified atmosphere) and an initial gas mixture of 5% O₂ and 2.5% CO₂ (active modified atmosphere), in bags of two different films: low‐density polyethylene (PE) and polypropylene (PP). As control, mushrooms were packaged in macroperforated PP films. Bags were stored at 5 °C for 20 days. Package atmosphere composition, mushroom respiration rate, weight loss, microbiological counts and sensory quality were determined during storage. Risk assays were also performed. Under the studied conditions, shiitake mushroom deterioration was not due to microorganism growth, and therefore the shelf‐life of this product might be defined by changes in its sensory characteristics. Sensory analysis showed that mushrooms stored under modified atmosphere (active and passive) had a higher deterioration rate than those stored in PP macroperforated films, and lower sensory quality values during the entire storage time. These results suggest that mushroom deterioration was probably due to shiitake mushrooms' sensitivity to high CO₂ concentrations. Copyright © 2007 Society of Chemical Industry     

Effect of high‐pressure processing on the migration of antioxidant Irganox 1076 from polypropylene film into a food simulant

The effect of high‐pressure processing (HPP) on the migration behaviour of a typical antioxidant, Irganox 1076, from polypropylene (PP) flexible structures was studied. Initial concentrations of Irganox 1076 in polypropylene (PP) were 2.0 and 5.0 mg g^?1. The migration experiments were carried out on high‐pressure treated and non‐treated polypropylene pouches containing either 95 or 10% ethanol aqueous food simulating liquids (FSL) for 20 days at 40 and 60 °C. After the contact period, concentrations of Irganox in PP and FSL were measured to determine migration behaviour. The results showed that there was no significant difference in the concentration of Irganox 1076 migrating from PP, and into the FSL for pressure‐treated vs non‐treated samples. No significant concentration differences were found in non‐treated (control) samples and those treated for 5 and 10 min. However, there was a storage time effect on the migration level. There was also a significant migration effect on the migration of Irganox between the two different food simulants, and an increase in the HPP temperature increased the rate of migration. Copyright © 2004 Society of Chemical Industry     

A comparative study on the effect of packaging material and storage environment on shelf life of fresh bell-pepper

The effect of packaging materials [low density polyethylene (LDPE), polypropylene (PP)] and storage environment [modified atmospheric packaging (MAP)] on shelf life enhancement of bell pepper in terms of quality attributes such as physiological weight loss, ascorbic acid, texture, surface colour and subjective quality analysis have been studied at ambient and refrigerated condition. Different packaging techniques used for the experiment were MAP with LDPE, MAP with PP, MAP in perforated LDPE films, MAP in perforated PP films, shrink packaging with bi-axially oriented PP (BOPP) film and vacuum packaging with PP film. The in-pack bell pepper created a suitable headspace environment with low O₂ and high CO₂ concentrations, which resulted in a better retention of freshness of the vegetables and its marketability. Shrink packaging with BOPP film could not yield better result under ambient storage because of high water vapor transmission rate of the film and consequently loss of turgidity of the vegetables. Among different packaging techniques and storage conditions, MAP with PP film in refrigerated condition was found to be the best followed by vacuum pack with PP film in refrigerated condition and could be used to store for 20 days for bell pepper with maintenance of texture, colour, ascorbic acid and marketability. It is also inferred that under ambient conditions, bell pepper could be stored for 4 days using ventilated LDPE and PP as MAP storage. Further studies are needed to evaluate the sensory aspects, as well as to microbiological evaluation to characterize the fresh bell pepper during storage.     

A probabilistic model for the permeation of gases through microporous membranes

A probabilistic model for the motion of gas molecules through pores of microporous membranes is proposed. The interaction energy between the gas molecules and the surface of membrane pores is investigated using molecular modeling and results are used as input to the probabilistic model. The proposed model was used to evaluate the effect of surface coating on gas permeation of air and ammonia through single- and double-layer microporous membranes. Gas transmission experiments were conducted on uncoated polyethylene terephthalate (PET), nylon and PP/PE, coated PET, and double-layer PET microporous membranes at different pressure levels. Model results were compared with experimental data and a reasonable conclusion was drawn.     

Insect‐Resistant Food Packaging Film Development Using Cinnamon Oil and Microencapsulation Technologies

Insect‐resistant films containing a microencapsulated insect‐repelling agent were developed to protect food products from the Indian meal moth (Plodia interpunctella). Cinnamon oil (CO), an insect repelling agent, was encapsulated with gum arabic, whey protein isolate (WPI)/maltodextrin (MD), or poly(vinyl alcohol) (PVA). A low‐density polyethylene (LDPE) film was coated with an ink or a polypropylene (PP) solution that incorporated the microcapsules. The encapsulation efficiency values obtained with gum arabic, WPI/MD, and PVA were 90.4%, 94.6%, and 80.7%, respectively. The films containing a microcapsule emulsion of PVA and CO or incorporating a microcapsule powder of WPI/MD and CO were the most effective (P < 0.05) at repelling moth larvae. The release rate of cinnamaldehyde, an active repellent of cinnamaldehyde, in the PP was 23 times lower when cinnamaldehyde was microencapsulated. Coating with the microcapsules did not alter the tensile properties of the films. The invasion of larvae into cookies was prevented by the insect‐repellent films, demonstrating potential for the films in insect‐resistant packaging for food products. Practical Application : The insect‐repelling effect of cinnamon oil incorporated into LDPE films was more effective with microencapsulation. The system developed in this research with LDPE film may also be extended to other food‐packaging films where the same coating platform can be used. This platform is interchangeable and easy to use for the delivery of insect‐repelling agents. The films can protect a wide variety of food products from invasion by the Indian meal moth.     

Extending shelf life of desalted cod by high pressure processing

Salted fish need to be rehydrated before eaten, but rehydrated fish have a relatively short shelf life. To increase the shelf life the products can e.g. be frozen, packed in modified atmosphere or processed by high pressure (HPP). Here, rehydrated cod was packed with different packaging regimes; in vacuum, with CO₂ emitter or in modified atmosphere [MAP], either alone or in combination with HPP. A shelf life study was performed, and headspace gas composition, drip loss, pH, colour, texture and microbial counts were assessed in the packaged and processed portions. The results showed that a shelf life of minimum 49 days can be obtained by treating the rehydrated cod by HPP or by combining HPP with modified atmosphere or in combination with a CO₂ emitter. The results of this study have shown that different packaging and processing methods can increase the shelf life of desalted cod.Industrial relevanceThe growing trend and availability of “ready to cook” products are forcing the food industry to increase production of convenience products. Today desalted saltfish or clipfish need to be consumed immediately, stored chilled for a few days, stored frozen or being packed and/or processed to extend its shelf life. The use of high pressure processing represents a promising strategy to enhance the shelf-life of fish products. This study shows that HPP alone or combined with CO₂ can extend the shelf life of rehydrated cod. Hence, these results can open up for new products.     

Influence of selected packaging materials on some quality aspects of pressure-assisted thermally processed carrots during storage

Role of packaging barrier properties and storage conditions on pressure-assisted thermally processed (PATP) carrot quality were investigated. Samples were packaged in pouches fabricated using three packaging materials (Nylon/EVOH/EVA, Nylon/EVA and MetPET/PE) and processed at 600 MPa and 110 °C for 10 minutes. Processed pouches were stored at 25 and 37 °C, and withdrawn over 12 weeks. Samples were analyzed for color, β-carotene and total plate count. Oxygen and water vapor transmission rates (OTR, WVTR), melting point and enthalpy of fusion of the packages were evaluated. PATP treatment resulted in product shelf-stability during storage. Packaging type and storage conditions significantly influenced the product color and β-carotene content. Nylon/EVOH/EVA package best preserved carrot quality. PATP increased OTR of the MetPET/PE and degraded carrot color and β-carotene during storage. Raw carrots had 11.13 mg/100g β-carotene content. PATP treatment followed by 12 weeks storage at 37 °C reduced the β-carotene content of carrots packaged in Nylon/EVOH/EVA, Nylon/EVA and MetPET/PE to 7.19, 0.04 and 0.06 mg/100g, respectively. Similarly, the red color of carrot samples (25.51 for raw carrots) decreased to 19.85, 3.44 and 7.20 for Nylon/EVOH/EVA, Nylon/EVA and MetPET/PE, respectively. The study demonstrated the importance of high barrier packaging materials in preserving PATP-treated carrot quality.