Types Of Packaging Films Research Articles

Rheological Properties of Film-Forming Dispersions of Selected Biopolymers Used for Packaging Films or Food Coating

Film-forming solutions based on four types of biopolymers were prepared and their rheological properties were determined. High methylated apple pectin and sodium alginate were used at the concentrations 1%, 1.5%, and 2%, whereas soy protein isolate and pork gelatin were obtained at 4%, 8%, and 12%. The parameters determining the production of the appropriate type of packaging film or edible coating are the setting time on the substrate, regardless of its type, and the gelation temperature, which were analyzed in the study by determination of flow curves and rheological parameters of prepared dispersions. The Newtonian model was used to describe the flow curves of the gelatin and sodium alginate solutions, while the Ostwald–de Waele model was used to describe the flow curves of the soy protein isolate and high methylated apple pectin solutions. The apparent viscosity of all solutions increased with increasing biopolymer concentrations, from 0.0042 to 0.0061 Pa·s and from 0.0187 to 0.0884 Pa·s for high-methylated apple pectin and sodium alginate, respectively; whereas, for a protein-based solution the viscosity increase was from 0.024 to 0.100 Pa·s and from 0.0018 to 0.0056 Pa·s for soy and gelatin, respectively. Modulus of elasticity curves appeared only at the highest concentrations, which means that the formation of the continuous structure of film or coating occurs by different mechanisms depending on the biopolymer type and its amount dispersed in aqueous solutions.

HS-SPME-GC-MS technique for FFA and hexanal analysis in different cheese packaging in the course of long term storage

The present study sought to develop a headspace solid-phase microextraction (HS-SPME) gas chromatography–mass spectrometry (GC-MS) method to quantify free fatty acids (FFAs) and hexanal in cheese, and to track theirs levels over time. The developed method was applied on Fresh Asiago and Grana Padano cheeses, and FFAs and hexanal levels were monitored over 4 and 12 weeks respectively. Their evolutions were also compared from two types of packaging films: a high-density polyethylene (HDPE) package and a packaging bag named Ideabrill®. The later allowed a lower increase of these analytes (11.6-fold increase for Grana Padano and 5.9 for Fresh Asiago) compared to the HDPE packaging (21.5-fold increase for Grana Padano and 7.4 for Fresh Asiago). This method can contribute to the optimization of analytical methods in food industry for studies on shelf life, quality control or food packaging.

The Use of Chloride, Citric and Ascorbic Acid Dip and Packaged Film to Extend the Shelf Life of Pejerrey (<i>Odonthested bonaerensis</i>) during Storage at Different Temperatures

The objective of this study was to analyze the effect of chloride, citric and ascorbic acid dip treatments in conjunction with two types of packaging films (with high and low gas permeability) on microbial growth in samples of pejerrey fillets (Odonthestes bonaerensis) at three storage temperatures (4°C, 0°C and -1.5°C). Colour, pH, texture modification and chemical changes were also studied. Psychrotrophic microorganisms, sp. were modelled by the Gompertz’ equation. Lag phase duration, specific growth rate and maximum population density were calculated. The activation energy (Eµ) was calculated reaching values of 147 and 177 kJ/mol when the low permeability packaging films were employed. We used psychrotrophic microorganisms, sp., as a predictor of the shelf life of product. The application of treatment with chloride, citric and ascorbic acids, extended 1 - 2 days the storage life of the product (time to reach 106 CFU/g) when the packaging material used was polyethylene. The use of chloride, citric and ascorbic acids and vacuum packaging produced shelf life values of 7.7, >25 and >25 days at 4°C, 0°C and -1.5°C respectively. The products had very good organoleptic characteristics, maintained their colour and texture appropriate, and absence of pathogenic microorganisms. These values indicated that the growth models were acceptable for expressing the growth of microorganisms on pejerrey fillets, which can be applied to ensure the safety of fish and to establish standards for avoiding microbial contamination.

Comparison of Various Packaging Films for Mango Export

This study compared the effects of the use of various types of packaging films in maintaining quality, preserving bioactive compounds and extending shelf life of the ‘Nam Dok Mai’ mango. The principal techniques for maintaining the quality of mangoes are based on modified atmosphere packaging using highly gas‐permeable films and an ethylene‐removing mechanism. The films studied were non‐perforated highly gas‐permeable film, non‐perforated ethylene‐absorbing highly gas‐permeable film (HNPE), micro‐perforated highly gas‐permeable films (HMP) and common non‐perforated polyethylene film (LNP). These films were compared with non‐packaging treatment, which served as a control (C). Gas composition (O2, CO2 and C2H4) in the package headspace was monitored during storage at 12°C. The quality of mangoes were assessed by weight loss, colour (L* a* b*), texture, total soluble solids, titratable acidity, total phenolics, total flavonoids, ethanol concentration and sensory quality. Equilibrium‐modified atmospheres of 5 kPaO2 + 5 kPaCO2 and 4 kPaO2 + 5 kPaCO2 were achieved in the non‐perforated highly gas‐permeable film and HNPE packs, respectively. Carbon dioxide accumulation was observed in the HMP and LNP packs where CO2 reached 17 and 10 kPa, respectively, after storage for 10 days. The shelf life of mangoes was extended to 40 days with HNPE, 35 days with HNP, and 30 days with HMP, as compared with 20 days with control and 5 days with LNP. HNPE, the film incorporated with fine particles of mordenite framework inverted‐type zeolite with ethylene‐absorbing ability, could further extend the shelf life of mangoes in addition to modified atmosphere packaging alone. Copyright © 2011 John Wiley & Sons, Ltd.

Barrier Properties of Coated and Laminated Polyolefin Films for Food Packaging

The food packaging industry demands polymer films possessing a defined barrier against permeation of gases, moisture and flavor. The objective of this study was to assess the differences between the barrier properties of coated and un-coated polyolefine films. Eight types of packaging films are prepared by standard industrial procedure by cast film extrusion processing with chill rollers: biaxially oriented polypropylene (BOPP), BOPP coated by acrylic copolymer, metallized BOPP by aluminum, and low-density polyethylene (LDPE). The influence of lamination and metallization on the gas molecules (CO2, O2 and N2) was determined by Lyssy’s method. The moisture transparency was assessed according to the gravimetric method. The substantial differences between the barrier properties of the coated and un-coated films were estimated. It was estimated that the lamination process improves the oxygen barrier but not necessarily the moisture barrier, due to the different mechanisms for oxygen and moisture permeability. The obtained barrier properties data were considered from a practical point of view. It was concluded that films based on metallized BOPP has excellent barrier properties and can be used to over wrap food products.

Control of spoilage microorganisms in minced pork by a self-developed modified atmosphere induced by the respiratory activity of meat microflora

The changes in microbial flora of minced pork during aerobic storage at 0, 5, 10 and 15 °C were studied. Minced pork samples (100 g) were packed using two types of packaging films: (a) a common food film with high permeability (HPF) and (b) a film with low permeability (LPF). The respiratory activity of meat microflora and the use of a LPF resulted in a modified atmosphere in the package headspace developed during storage. Oxygen concentration decreased from 18.7% (after packaging) to 7% (after 15 days of storage) in packages with LPF, stored at 0 °C, while CO 2 increased from 3% to 10.5%, respectively. On the contrary, no significant atmosphere changes were observed during storage of HPF packages. The self-developed modified atmosphere in LPF packages resulted in a significant inhibition of pseudomonad growth which was more pronounced at low storage temperatures. For example, during storage at 0 °C, the growth rate of pseudomonads in meat packed with LPF was reduced by 48.7% compared to HPF. At 10 °C the latter reduction decreased to 13.7%. LPF packaging was also found to inhibit the growth of Brochothrix thermosphacta but this inhibition was weaker compared to pseudomonads. The effect of storage temperature on the growth rate of pseudomonads and B. thermosphacta in minced pork packed with the different films was modeled using an Arrhenius equation. For both bacteria, the activation energy was higher for LPF packaging. This can be attributed to the increased inhibitory effect of the modified atmosphere at lower storage temperature. The Arrhenius model was further used to evaluate the effect of temperature on the time required by the two bacteria to reach a spoilage level of 10 7 CFU/g. The results showed that when LPF packaging is combined with effective temperature control the time-to-spoilage can be significantly extended compared to HPF packaging.

Connection between Hot Tack Force and Form-Fill-Seal Performance of Packaging Films

Recently, most packaging with plastic film for liquids such as soap, sauce and ketchup is performed on vertical automatic form-fill-seal packaging systems. The major technical issue for form-fill-seal packaging has been the packaging speed, which is restricted by leakage at the horizontal seals due to insufficient heat sealing. It has been known that the packaging speed depends on the type of packaging film and the hot tack force of the packaging film has been regarded as a main controlling factor of the leakage. However, a quantitative correlation between the hot tack force of the packaging film and the leakage at the horizontal seals has not been determined yet, and the means to improve the packaging speed are unknown.By means of hot tack force measurements and actual form-fill-seal packaging tests for several packaging films, we studied the quantitative correlations between the hot tack force and the leakage at the horizontal seals. We also developed a method to predict and compare the form-fill-seal packaging performance (proper range of heat seal temperature and heat seal time: packaging speed) for various packaging films by utilizing the quantitative correlation obtained in the above study. As samples for the study, we used laminate films of bi-axially oriented nylon (15μm)/polyethylene type sealants (50μm). The sealant resins used were metallocene plastomer, low density polyethylene, ethylene copolymers of EVA and EMAA and ethylene ionomers.The following results were obtained:1. It was confirmed that the leakage at the horizontal seals arises in the range of heat seal conditions (heat seal temperature and heat seal time: packaging speed) where the hot tack force of the seal is less than the stress to peel the horizontal seal part. A quantitative correlation between the hot tack force of the packaging film and the leakage at form-fill-seal packaging was determined.2. The agreement in the predictions for the proper range of packaging conditions (heat seal temperature and heat seal time: packaging speed) based on hot tack force measurements as a function of heat seal time and with those obtained by actual form-fill-seal packaging tests was confirmed. A method to predict and compare the packaging performance (proper range of heat seal conditions) for various packaging films was developed.3. It was reconfirmed that the hot tack property of various packaging films depends on the type of sealant resin, which results in a difference in form-fill-seal packaging performance among various films that differ in sealant resin type.• m-plastomer: hot tack force develops with very short heat seal time, which results in good performance under high speed packaging.• ionomer: has very large hot tack force both at very short heat seal time and under a wide range of heat seal temperatures, resulting in superior performance.• LDPE & EVA: small hot tack and slow hot tack force development speed, resulting in inferior packaging performance.

Mesophilic Aerobic Population of Fresh‐cut Spinach as Affected by Chemical Treatment and Type of Packaging Film

ABSTRACT: Fresh‐cut spinach was treated with citric acid and ascorbic acid solutions and packaged in mono‐oriented polypropylene bags or low‐density polyethylene bags. Response surface methodology was used to study the simultaneous effect of chemical treatment and refrigerated storage time on headspace gas composition, mesophilic aerobic population (AP), and pH of fresh‐cut spinach. Type of film affected %CO2, %O2, and pH but did not influence AP. Chemical treatment reduced initial pH values and initial microbial counts. AP and pH increased during refrigerated storage. The model developed for AP enabled finding acid concentrations that lowered AP below any proposed microbiological criterion at production and consumption stages of fresh‐cut spinach stored at 4 °C.

APPLICATION OF ETHYLENE ADSORBERS IN COMBINATION WITH HIGH OXYGEN ATMOSPHERES FOR THE STORAGE OF STRAWBERRIES AND RASPBERRIES

Different possibilities (combination of gas composition and packaging film) of consumer-size modified atmosphere packages for highly perishable strawberries and raspberries, stored at 7degreesC, were evaluated. All proposed closed packaging systems resulted in a prolonged shelf life compared to the nowadays applied macro-perforated packaging films. A selective permeable film was selected based on the required oxygen and ethylene permeability in order to obtain 3-5% O-2, 5-10% CO2 and a limited ethylene accumulation. High Oxygen Atmosphere (HOA) (95% O-2 - 5% N-2) in combination with a high barrier film for strawberries and a semi-barrier film for raspberries resulted in too high CO2-levels resulting in poorer evaluation of the organoleptical properties (fermentation and softening) but an inhibition of mould development was noticed. The combination of a HOA in a selective permeable type of packaging film was evaluated as an optimal packaging system based on the checked quality assessment parameters: moisture loss, loss of marketable fruit based on visual defects and mould development, sensorial and microbiological quality. For raspberries, the addition of an ethylene adsorbing film in the system is favourable to prevent a too high accumulation of ethylene.

Shelf life of fresh-cut spinach as affected by chemical treatment and type of packaging film

Abstract - Fresh-cut vegetables are an important and rapidly developing class of convenience foods. Theirstorage life may be greatly reduced due to their high rates of respiration and transpiration and the possibilityof enzymatic and microbiological deterioration. Consequently, the objective of this work was to determine theshelf life and the failure attribute that conditioned the shelf life of fresh-cut spinach treated with chemicalsolutions and packaged in bags with different permeabilities. The shelf life of fresh-cut vegetables wasdefined as the time of refrigerated storage at which any one of the sensory attributes scored below 7 or whenthe microbiological counts exceeded 5.10 7 CFU/g. Fresh-cut spinach was treated with citric acid and ascorbicacid solutions and packaged in mono-oriented polypropylene (OPP) bags or low-density polyethylene (LDPE)bags. Sensory attributes and total microbial counts were evaluated throughout refrigerated storage. Responsesurface methodology (RSM) was used to study the simultaneous effect of chemical treatment and refrigeratedstorage time on sensory and microbiological quality of fresh-cut spinach. A quadratic polynomial regressionmodel was assumed for predicting off-odor, general appearance, wilting, browning, color, and mesophilicaerobic population. Type of packaging film only influenced development of off-odor (p≤0.001) and had noeffect on visual sensory attributes or microbiological counts (p>0.05). Development of off-odor was theattribute that limited shelf life of fresh-cut spinach packaged in OPP bags. On the other hand, shelf life ofsamples packaged in LDPE bags was dependent on a decrease in general appearance or an increase inmicrobiological counts, depending on the chemical treatment used.

Modeling respiration–transpiration in a modified atmosphere packaging system containing blueberry

A respiration–transpiration model was developed by applying simultaneous heat and mass transfer principles along with known physiological behavior for the design of MAP systems containing fresh produce. The model equations were solved numerically using Adams–Moulton method to predict gas compositions, RH, and temperature in model packages. The applicability of the model to packages containing blueberry at 15 and 25 °C was successfully verified using different types of packaging films. The difference between the experimental and predicted headspace gas composition was less than 1%. The predicted and experimental values were in agreement for RH (within 2%) and temperature (within 0.5 °C).

Multivariate Analysis of the Organic Acids Content of Gouda type Cheese during Ripening

Gouda cheeses from a local plant were subjected to different ripening conditions and analyzed. The effects of ripening temperature, type of packaging film and storage period before packaging on the organic acids content of Gouda cheese were studied. A factorial design of 23×5 was used, where the three factors selected in two levels were: (1) time of storage before packaging, 4 and 10 days, (2) ripening temperature, 10 and 20°C, and (3) plastic film (BK1 and BK5; Grace, Argentina). Ripening time was the fourth factor considered; sampling times were 15, 25, 35, 49 and 70 days after production. At the beginning of the experiment (4 days of ripening), mean water content of samples was 44.0±0.9%. At 70 days of ripening, humidities were 39.7±0.6 and 40.8±0.6% for cheeses stored at 20 and 10°C, respectively. Nine organic acids (formic, orotic, uric, lactic, acetic, citric, pyruvic, propionic and butyric) were analyzed in each sample by HPLC. Samples of the same batch with four days of ripening and cheeses traditionally ripened (without packaging) were also studied. None of the factors affected the orotic and uric acid concentrations and butyric acid was not detected in any sample. The remaining acids content increased linearly with ripening time. Increasing storage temperature accelerated the maturation processes. The corresponding Q10for each acid was calculated as the ratio between the rate of increase at 20 and 10°C, obtaining values between 1.2 and 5.8. Three PCA factors interpreted 87% of the total variation in the samples. Discriminant analysis classified cheeses according to their age.

Behaviour of Listeria monocytogenes and autochthonous flora on meat stored under aerobic, vacuum and modified atmosphere packaging conditions with or without the presence of oregano essential oil at 5 oC

The effect of aerobic, modified atmosphere packaging (MAP; 40% CO2/30% O2/30% N2) and vacuum packaging (VP) on the growth/survival of Listeria monocytogenes on sterile and naturally contaminated beef meat fillets was studied in relation to film permeability and oregano essential oil. The dominant micro-organism(s) and the effect of the endogenous flora on the growth/survival of L. monocytogenes were dependent on the type of packaging film. The fact that L. monocytogenes increased whenever pseudomonads dominated, i.e. aerobic storage and MAP/VP in high-permeability film, and even earlier than on sterile tissue, suggests that this spoilage group enhanced growth of the pathogen. Brochothrix thermosphacta constituted the major proportion of the total microflora in MAP/VP within the low-permeability film, where no growth of L. monocytogenes was detected either on naturally contaminated or sterile meat fillets. The addition of 0.8% (v/w) oregano essential oil resulted in: (i) an initial reduction of 2-3 log10 of the majority of the bacterial population, with lactic acid bacteria and L. monocytogenes indicating the most apparent decrease in all gaseous environments, and (ii) limited growth aerobically and survival/death of L. monocytogenes in MAP/VP, regardless of film permeability.

Effects of ripening conditions on the texture of Gouda cheese

Summary The effects of ripening temperature, type of packaging film and storage period before packaging were related to the degree of proteolysis and the texture of Gouda cheese, so as to determine the optimum ripening conditions. Gouda cheeses from a local plant were subjected to different ripening conditions. A factorial design of 23× 5 was used, where the three factors selected in two levels were: (1) time of storage before packaging, 4 and 10 days, (2) ripening temperature, 10 and 20 °C and (3) plastic film, BK1 and BK5 (Grace, Quilmes, Argentina). Ripening time was a fourth factor analyzed; sampling times were 15, 25, 35, 49 and 70 days after production. Cheeses traditionally ripened (without packaging) were also analyzed. Water content and pH were determined. Nonprotein nitrogen (soluble in 12% trichloracetic acid (TCA)) was quantified by the Kjeldhal method. Cheese texture was analyzed by compression and relaxation tests which were done by using an Instron Universal Testing Machine (Instron Corp., Canton, MA, USA). The pH and water content of cheeses which ripened at 20 °C were lower than the corresponding ones ripened at 10 °C. Only ripening time and temperature had a significant effect on water content, nonprotein nitrogen concentration and rheological parameters. Results show that texture properties of Gouda cheese ripened in plastic films with low gaseous permeability are similar to those of traditionally ripened Gouda. Texture development was accelerated by increasing the storage temperature.

Problemes de l'electricite statique dans l'industrie des films d'emballage

A brief review is given of the different types of packaging films, methods for their manufacture, as well as the electrostatic problems that can arise. This is followed by a discussion of research aimed at finding an antistatic suitable for films of low, medium and high density polyethylene and of an ethylene-vinyl acetate copolymer. The influence of the corona effect on the surface properties is treated. Proof is given that in certain cases the corona effect brings about hydrolysis of the antistatic molecules, which improves the conductivity of the surface.

Studies on the Relation Between Water Activity and Sensory Qualities as well as Chemical Changes of Coriander (Coriandrun sativum) Powder in Flexible Packaging Films

Selection of suitable packaging film is necessary to minimize the deteriorative changes of foods. Packaging films differ for different food products. Flexible packaging films are now widely used instead of hard packages for processed dry food products. In this study attempt has been made to select a suitable packaging film for dry coriander powder at ambient temperature. Three types of packaging films like heat sealable laminated aluminium foil, high density polythene (HDPE) and poly propylene (PP) were chosen. The changes in water activity, total ash, acid insoluble ash and consequent effect on sensory qualities like texture, colour, flavour and appearance of coriander powder were investigated at an interval of two months during one year storage period. 
 
 Bangladesh J. Sci. Ind. Res. 42(1), 53-58, 2007