Effect of carboxymethyl cellulose-based coatings incorporated with Zataria multiflora Boiss. essential oil and grape seed extract on the shelf life of rainbow trout fillets

The applications of Lactobacillus plantarum-derived extracellular vesicles as a novel natural antibacterial agent for improving quality and safety in tuna fish

Bacteria release membrane vesicles into the extracellular environment but which activity is unclear. We investigated the applications of extracellular vesicles (EVs) isolated from probiotic Lactobacillus plantarum to protect tuna fish against spoilage and quality loss in this study. A significant difference was found in EVs size obtained from L. plantarum after 8, 24, and 48 hr incubation. The L. plantarum-derived EVs were collected and used to confirm the anti-bacterial activity versus Shewanella putrefaciens. Finally, the tuna fish was stored at 4 °C for 5 days after coating with EVs or sodium erythorbate, and the quality indexes were assayed. Results indicated that EVs markedly inhibited oxidation reaction, total volatile base nitrogen (TVBN), peroxide value (PV), malondialdehyde (MDA), and bacteria levels. These results finding out that EVs from L. plantarum may have potential for application in food storage technology. Overall, we indicated this new material may be developed as an anti-bacterial agent for prolonging the shelf life of tuna fish.

Characterization of carboxymethyl cellulose-based antimicrobial films incorporated with plant essential oils

The aim of this study was to investigate the effect of essential oil (EO) addition (1, 2, and 3% v/v) obtained from different plants (Santolina chamaecyparissus (SC), Schinus molle (SM), and Eucalyptus globulus (EG) on the antimicrobial, physical, water vapor permeability, mechanical, optical and microstructural properties of the carboxymethyl cellulose (CMC) films. The films containing EO at the concentration of 3% showed the highest antimicrobial activity on tested microorganisms. The EO content increase from 1% to 3% in films decreased the moisture content and water solubility of all films. The water vapor permeability also decreased in films with EGEO but it increased in films with SCEO and SMEO. While the tensile strength (TS) of films containing EO (29.43 ± 3.28-77.05 ± 0.02 MPa) was determined higher than the TS of the control (24.60 ± 0.54 MPa), the elongation at break (E%) of films (14.41 ± 0.02-33.01 ± 0.01%) were lower than E% of the control (37.06 ± 0.85%). The microstructures of films were homogeneous in the films containing 1% and 2% EOs. CMC films gained a significant antimicrobial property and improved its characteristic properties with the incorporation of EOs presenting a good potential for applying to foods.

Chitosan-Based Coatings Incorporated with Cinnamon and Tea Extracts to Extend the Fish Fillets Shelf Life: Validation by FTIR Spectroscopy Technique

The aim of this study was to evaluate the effect of active coatings prepared from the chitosan on the quality parameters of fish fillets. Antimicrobial and antioxidant properties were improved by addition of tea and cinnamon extracts. Different quality parameters including free fatty acids (FFA), thiobarbituric acid value (TBA), trimethylamine (TMA), total volatile basic nitrogen (TVBN), whiteness, and pH of coated and noncoated samples were evaluated during storage for 20 d at 5 ± 1°C. Moreover, FTIR characterization (i.e., wavenumber and absorbance values) was used to investigate the oxidative stability. Extracts addition to chitosan coating had noticeable influence on reducing FFA and TBA. Moreover, modified chitosan coating decreased TVBN and TMA significantly. Based on FTIR finding, control sample showed the highest oxidation value, while the treated samples with chitosan\incorporated with tea and cinnamon extracts (CTCECS) had the lowest oxidation. The results showed that FTIR technique could be successfully applied to monitor the lipid oxidation of fish fillet. Therefore, FTIR provides a fast approach to study the compositional changes of food products rather than conventional chemical analysis. The findings of our research showed that chitosan coating modified with tea and cinnamon extracts could be used as a novel active packaging to prolong the shelf life quality of fish fillet.

Application an edible active coating based on chitosan- Ferulago angulata essential oil nanoemulsion to shelf life extension of Rainbow trout fillets stored at 4 °C

The present study was undertaken to evaluate the feasibility of nanoemulsification for improving the efficiency of chitosan- Ferulago angulata essential oil coating (CH + EO) on extending the shelf life of Rainbow trout fillets during 16 days storage at 4 °C. The average droplet size of coarse emulsions was dramatically reduced after nanoemulsification which was accompanied by a significantly more positive ζ-potential and lower polydispersity index. In vitro antibacterial potential of CH + EO against two fish specific spoilage organisms, Shewanella putrefaciens and Pseudomonas fluorescens, and its antioxidant activity improved significantly (p < 0.05) when nanoemulsions were fabricated. The CH + EO nanoemulsion (3% EO) treatment exhibited a significantly better inhibitory effect on bacterial growth of refrigeration stored Rainbow trout fillets. Moreover, nanoemulsification potentiated the efficacy of CH + EO in retarding the increase of TVB-N and lipid peroxidation in fish fillets. Texture, colour, and overall acceptability of CH + EO nanoemulsion treated samples were significantly (p < 0.05) better than those of other samples. Results suggest nanoemulsification as a potential approach to enhance the efficacy of the active coating.

Antimicrobial Activity of Polylactic Acid Film Incorporated With Marjoram and Clove Essential Oils on Microbial and Chemical Properties of Minced Beef During Refrigerated Storage

Background: Active packaging is one of the new packaging technologies which causes interaction between packaging material and food with the aim of food shelf life extension while maintaining food safety and quality. Biodegradable films like polylactic acid (PLA) can be good alternatives to non-biodegradable plastics because of environmental pollution and concerns about the limitations of petroleum resources. Objective: This study was conducted to evaluate the efficacy of PLA film incorporated with marjoram and clove essential oils (EOs) (0.5 and 1% v/v) in maintaining the microbial and chemical quality of minced beef during refrigerated storage. Materials and Methods: Minced beef was packaged with PLA film incorporated with marjoram and clove EOs (0.5 and 1% v/v) alone and in combination and stored at refrigerator temperature for 10 days. Then, microbiological and chemical analyses were done at 0, 2, 4, 7 and 10 days of examination. Results: A reduction of 1 log CFU/g in total count was observed between groups with simultaneous use of EOs and control group (P<0.05) at day 7; however, there was not any significant difference between the mentioned groups at day 10. Active packaging with marjoram and clove EOs decreased the number of psychrotrophs in comparison to the control group and it was more evident at days 7 and 10. The number of Enterobacteriaceae in control and 1% clove EO/1% marjoram EO groups showed a difference of 3 log units at day 10. TVB-N of 1% clove EO/1% marjoram EO and 0.5% clove EO/1% marjoram EO showed significant differences from control at day 10 (P<0.05). Conclusion: The results of the current study have shown that the active PLA films can be a promising approach in order to maintain microbial and chemical quality of minced beef at refrigerator temperature for 10 days.

Effect of grape seed extract combined with modified atmosphere packaging on the quality of roast chicken

The purpose of this study was to screen out the appropriate concentration of grape seed extract solution and study the effects of grape seed extract combined with modified atmosphere packaging on the physical and chemical properties of roasted chicken during storage at 4°C. Samples were stored in 3 different packages: A (air packaging), M (modified atmosphere packaging, CO₂/N₂ = 40%/60%), and P (0.5% grape seed extract solution treatment combined with modified atmosphere packaging, CO₂/N₂ = 40%/60%). Microbiological analysis, pH, headspace composition, color, and lipid oxidation of roasted chicken were measured. The results showed that 0.5% is the suitable concentration of grape seed extract preservative for the storage of modified atmosphere packaged roast chicken. Compared with normal packaging (A) and single modified atmosphere packaging (M), 0.5% grape seed extract solution combined with modified atmosphere packaging (P) could effectively reduce the growth rate of total aerobic bacteria, Pseudomonas spp., mold, and yeast in roast chicken during low-temperature storage, reduce the lipid oxidation rate in roast chicken, and maintain the color stability of the product. This result could help the roast poultry processing industry to find more efficient ways to store and sell products.

Shelf-life extension of whole shrimp using an active coating containing fish skin gelatin hydrolysates produced by a natural protease

This study was focused on shelf-life extension of whole shrimp (Penaeus merguiensis) using an active coating containing gelatin hydrolysates. Gelatin extracted from Scomberomorus commerson skin was hydrolyzed using actinidin extracted from kiwifruit. Some important physicochemical characteristics of fish skin gelatin including viscosity, gelling and melting points, and temperatures were examined. The whole shrimp was coated with four coating agents including fish skin gelatin (FG), commercial gelatin (CG), fish skin gelatin containing 1 mg/ml fish gelatin hydrolysates (FG + GH), and commercial bovine gelatin containing 1 mg/ml fish gelatin hydrolysates (CG + GH). Chemical, microbial, and sensorial properties of samples were monitored for 12 days at 4°C with 3-day intervals (0-12 days). The pH value of samples coated with FG + GH and CG + GH showed the lowest changes during 12 days of storage (1.68 ± 0.00 and 1.70 ± 0.09, respectively). The free fatty acid content (FFA), total volatile base nitrogen (TVB-N), lipid oxidation, and carbonyl content of samples coated with FG + GH and CG + GH were significantly lower than that of control, CG, and FG samples. The results of this study showed that the gelatin hydrolysates could be used as a preservative costing agent for whole shrimp.

Prospect of Polysaccharide-Based Materials as Advanced Food Packaging

The use of polysaccharide-based materials presents an eco-friendly technological solution, by reducing dependence on fossil resources while reducing a product's carbon footprint, when compared to conventional plastic packaging materials. This review discusses the potential of polysaccharides as a raw material to produce multifunctional materials for food packaging applications. The covered areas include the recent innovations and properties of the polysaccharide-based materials. Emphasis is given to hemicelluloses, marine polysaccharides, and bacterial exopolysaccharides and their potential application in the latest trends of food packaging materials, including edible coatings, intelligent films, and thermo-insulated aerogel packaging.

The effects of gelatin-CMC films incorporated with chitin nanofiber and Trachyspermum ammi essential oil on the shelf life characteristics of refrigerated raw beef

The effects of gelatin-carboxymethyl cellulose (Gel-CMC) based films containing chitin nano fiber (CHNF) and Trachyspermum ammi essential oil (Ajowan), on the shelf life extension of the raw beef at refrigerated temperature (4 °C) over a 12-day period were evaluated. Ajowan essential oil (AJEO) and CHNF were added to the films at 0.24, 0.64 and 1% v/v; and 2 and 4 wt%, respectively. The microbiological (total viable count, psychrotrophic count, Pseudomonas spp., Staphylococcus aureus, lactic acid bacteria, molds and yeasts), the chemical (pH, thiobarbituric acid and total volatile basic nitrogen), color and sensory properties of the packaged samples were evaluated periodically. Bacteria grew the most quickly in the control samples, followed by those wrapped with the Gel-CMC films; The lowest microbial counts, the least change in the chemical properties and the highest sensory scores after 12 days of storage were obtained for the samples wrapped in the films incorporated with 1% AJEO and 4 wt% CHNF.

Preparation of multifunctional carboxymethyl cellulose-based films incorporated with chitin nanocrystal and grapefruit seed extract

Chitin nanocrystals (ChNC) were isolated from shrimp shells powder using acid hydrolysis and ammonium persulfate methods. Multifunctional carboxymethyl cellulose (CMC) composite films were prepared by adding ChNC and grapefruit seed extract (GSE), and their effects on the optical, mechanical, water vapor barrier, and antibacterial properties of CMC film were investigated. The isolated ChNC had a needle-like structure with a length of 340-370 nm and a diameter of 18-20 nm depending on the isolation method. The CMC films prepared with ChNC and GSE were transparent with high UV barrier properties. The addition of GSE reduced the strength (TS) and stiffness (EM) of CMC films by 10.4% and 30.3%, respectively, while the flexibility (EB) increased by 17.7%. However, when the ChNC was added, the TS and EM of CMC film increased by 19.7% and 58.7%, respectively, and the EB remained the same. The addition of ChNC reduced the water vapor permeability (WVP) of the CMC film by 27%. CMC films containing GSE also showed strong antibacterial activity against foodborne pathogenic bacteria, E. coli and L. monocytogenes.

Shelf-Life Enhancement in Fresh and Frozen Rainbow Trout Fillets by the Employment of a Novel Active Coating Design

The goal of this study was to determine the effect of incorporating ethanolic Prosopis farcta extract (PFE, 0 and 0.5%) and curcumin nanoparticles (CCM, 0, 0.1 and 0.2%) into sodium alginate (SA) coating on shelf-life of refrigerated and frozen rainbow trout fillets during storage lasting for 12 days and 6 months, respectively. Antioxidant and antibacterial properties of designated coatings were examined using 2, 2-diphenyl-1-picrylhydrazyl hydrate free radical scavenging activity and broth microdilution methods, respectively. The highest antioxidant and antibacterial activities were found in CCM 0.2% + PFE 0.5% and CCM 0.1% + PFE 0.5%. The CCM 0.2% + PFE 0.5% and CCM 0.1% + PFE 0.5% treatments could significantly extend the shelf-life of fresh trout fillets for 12 days during refrigerated storage evidenced by the 3.6 to 4.3 and 3 to 3.7 log CFU/g decrease in the microbial population in comparison with the untreated group, respectively. At the end of refrigerated storage time, the chemical change in all treated fillets was significantly lower than the untreated group (P < 0.05). The treatments of frozen trout fillets with SA + different concentrations of PFE and CCM resulted in better microbial and chemical properties than of the untreated group at the end of storage period (P < 0.05). PRACTICAL APPLICATION: Antimicrobial edible coatings from natural renewable resources have been found to be very useful in the food preservation field owing to the increasing consumer interest for the improvement of shelf-life property and appearance of fresh foodstuffs. Rainbow trout fillets without chemical preservatives have a limited shelf-life due to its biological properties. This study indicates the possibility of application of sodium alginate coatings containing Prosopis farcta extract and curcumin nanoparticles to increase shelf-life and maintain the quality of refrigerated trout fillets.

Identification of key genes involved in the biosynthesis of triterpenic acids in the mint family

Triterpenic acids (TAs), a large group of natural compounds with diverse biological activity, are produced by several plant taxa. Betulinic, oleanolic, and ursolic acids are the most medicinally important TAs and are mainly found in plants of the mint family. Metabolic engineering is strongly dependent on identifying the key genes in biosynthetic pathways toward the products of interest. In this study, gene expression tracking was performed by transcriptome mining, co-expression network analysis, and tissue-specific metabolite-expression analysis in order to identify possible key genes involved in TAs biosynthetic pathways. To this end, taxa-specific degenerate primers of six important genes were designed using an effective method based on the MEME algorithm in a phylogenetically related group of sequences and successfully applied in three members of the Lamiaceae (Rosmarinus officinalis, Salvia officinalis, and Thymus persicus). Based on the results of in-depth data analysis, genes encoding squalene epoxidase and oxido squalene cyclases are proposed as targets for boosting triterpene production. The results emphasize the importance of identifying key genes in triterpene biosynthesis, which may facilitate genetic manipulation or overexpression of target genes.

Review on Natural Preservatives for Extending Fish Shelf Life

Fish is extremely perishable as a result of rapid microbial growth naturally present in fish or from contamination. Synthetic preservatives are widely used in fish storage to extend shelf life and maintain quality and safety. However, consumer preferences for natural preservatives and concerns about the safety of synthetic preservatives have prompted the food industry to search natural preservatives. Natural preservatives from microorganisms, plants, and animals have been shown potential in replacing the chemical antimicrobials. Bacteriocins and organic acids from bacteria showed good antimicrobial activities against spoilage bacteria. Plant-derived antimicrobials could prolong fish shelf life and decrease lipid oxidation. Animal-derived antimicrobials also have good antimicrobial activities; however, their allergen risk should be paid attention. Moreover, some algae and mushroom species can also provide a potential source of new natural preservatives. Obviously, the natural preservatives could perform better in fish storage by combining with other hurdles such as non-thermal sterilization processing, modified atmosphere packaging, edible films and coatings.

Prediction of various freshness indicators in fish fillets by one multispectral imaging system

In current study, a simple multispectral imaging (430–1010 nm) system along with linear and non-linear regressions were used to assess the various fish spoilage indicators during 12 days storage at 4 ± 2 °C. The indicators included Total-Volatile Basic Nitrogen (TVB-N) and Psychrotrophic Plate Count (PPC) and sensory score in fish fillets. immediately, after hyperspectral imaging, the reference values (TVB-N, PPC and sensory score) of samples were obtained by traditional method. To simplify the calibration models, nine optimal wavelengths were selected by genetic algorithm. The prediction performance of various chemometric models including partial least-squares regression (PLSR), multiple-linear regression (MLR), least-squares support vector machine (LS-SVM) and back-propagation artificial neural network (BP-ANN) were compared. All models showed acceptable performance for simultaneous predicting of PPC, TVB-N and sensory score (R²_P ≥ 0.853 and RPD ≥ 2.603). Non-linear models were considered better quantitative model to predict all of three freshness indicators in fish fillets. Among the three spoilage indices, the best predictive power was obtained for PPC value and the weakest one was acquired for TVB-N content prediction. The best model for prediction TVB-N (R²_p = 0.862; RMSEP = 3.542 and RPD = 2.678) and sensory score (R²_p = 0.912; RMSEP = 1.802 and RPD = 3.33) belonged to GA-LS-SVM and for prediction of PPC value was BP-ANN (R²_p = 0.921; RMSEP = 0.504 and RPD = 3.64). Therefore, developing multispectral imaging system based on LS-SVM model seems to be suitable for simultaneous prediction of all three indicators (R²_P > 0.862 and RPD > 2.678). Further studies needed to improve the accuracy and applicability of HSI system for predicting freshness of rainbow-trout fish.

Tartary Buckwheat Extract and Chitosan Coated Tilapia (Oreochromis Niloticus) Fillets Determine Their Shelf Life

The preservation effects of tartary buckwheat extract (T) and chitosan (C) coatings on the physicochemical (pH value, thiobarbituric acid value, Peroxide value (PV), total volatile basic nitrogen (TVB-N), K value, surface color and the texture profiles), bacteriological (total viable counts (TVC) and psychrotrophic bacteria counts (PBC)), and sensory characteristics of tilapia (Oreochromis niloticus) fillets storage at 0 °C for 18 days were evaluated. The fillets coated with 0.5% T + 1.0% C, 1.0% T + 1.0% C and 1.5% T + 1.0% C maintained better quality and had longer shelf life with respect to samples coated with chitosan alone and the control. Base on the limit values of TVB-N, K value, TVC and sensory preference scores, the shelf life of control fillets was 6 days. By contrast, shelf life of 9 days for 0.5% T + 1.0% C-coated fillets, 12 days for 1.0% T + 1.0% C treated-fillets, and 15 days for 1.5% T + 1.0% C-treated fillets were obtained. Therefore, TBE combined with chitosan coatings have the potential to extend the shelf life of tilapia fillets during storage at 0 °C. PRACTICAL APPLICATION: This study provides basic theory regarding the application of TBE to fish preservation. The edible coating of TBE combined with chitosan has potential use in developing activity food preservation coating.

Efficiency of Tragacanth gum coating enriched with two different essential oils for deceleration of enzymatic browning and senescence of button mushroom (Agaricus bisporus)

The effect of Tragacanth gum (T) coating containing (100, 500, and 1,000 mg/L) Satureja khuzistanica essential oil (S), Zataria multiflora Boiss. essential oil (Z), and (1,000 mg/L) sodium metabisulfite (M) on mushroom (Agaricus bisporus) enzymatic browning and postharvest quality was examined throughout 16 days of cold storage. Mushroom respiration rate, soluble solids content (SSC), percentage of open caps, and sensory quality as well as factors related to browning such polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), and peroxidase (POD) activities were figured out. The significant decrease in respiration rate, cap opening delay, and SSC enhancement was observed after treating mushrooms with TZ and TS. Moreover, TZ- and TS-treated mushrooms prevented enzymatic browning through inhibiting PPO and POD activities and increasing activity of PAL over the storing term. Additionally, the influence of TZ5 and TS5 (containing 500 mg/L essential oil) coatings was validated by sensory evaluation through protecting the overall quality of button mushrooms over the storage. Thus, Tragacanth coating enriched with essential oils might be an encouraging nomination for improving the modality of button mushroom and expanding its shelf life.

Physicochemical responses and microbiological changes of bream (Megalobrama ambycephala) to pectin based coatings enriched with clove essential oil during refrigeration

The effectiveness of pectin coatings enriched with clove essential oil (CEO), as new edible coatings were investigated to preserve bream (Megalobrama ambycephala) fillets during refrigeration over a period of 15 days. All samples were analyzed for physicochemical (pH, PV, TBA and TVB-N), microbiological (Total viable count, Psychrophilic bacteria, Lactic acid bacteria, Enterobacteriaceae, Pseudomonas spp., H₂S producing bacteria) and organoleptic attributes. The results revealed that the CEO incorporation reduced the extent of lipid oxidation, as judged by PV, TBA and TVB-N, thus extending the shelf life of bream fillets by at least 15 days. Moreover, the application of pectin coatings with CEO improved the weight loss, water holding capacity, textural and color attributes of the bream samples significantly compared to untreated sample. Pectin coating along with CEO was effective in inhibiting bacterial growth especially in gram-negative bacteria, while the growth of lactic acid bacteria remained constant for most of the storage period. The effect on the microorganisms during storage was in accordance with biochemical indexes of the quality, representing the viability of these coatings for bream preservation. Thus, the coatings developed in present study could inhibit the development of lipid oxidation during cold storage, representing an option as a seafood preservative.

Quality and sensory acceptability of fish fillet (Oreochromis niloticus) with alginate-based coating containing essential oils

The quality and sensory acceptability of fish fillet (Oreochromis niloticus) with alginate-based coating containing ginger and oregano essential oils (EO) were evaluated. The antioxidant activity of essential oil, coating, and fish were also investigated. In relation to lipid oxidation, a decrease was observed in fish with the edible coatings compared to the control being the coating with oregano EO the most effective and also with the highest antioxidant activity. Loss in color and weight were significantly lower with coating. Fish with coating maintained firmness whereas fish without coating became softer. Fish with edible coating and oregano essential oils showed higher sensory acceptability regarding to odor evaluated by consumers. Thus, edible coatings with essential oils as natural antioxidant improved the product quality and sensory acceptability.

Effect of a Sodium Alginate Coating Infused with Tea Polyphenols on the Quality of Fresh Japanese Sea Bass (Lateolabrax japonicas) Fillets

Sodium alginate (SA) and tea polyphenols (TP) are natural preservatives commonly used in the food industry, including the production of fish products. The effect of SA coating infused with TP on the quality of fresh Japanese sea bass (Lateolabrax japonicas) fillets was evaluated over a 20-day period at 4 °C. SA (1.5%, w/v) or TP (0.5%, w/v) treatment alone, and the SA coating infused with TP (SA-TP) all reduced microbial counts, with the SA-TP providing the greatest effect. Fish fillet samples treated with SA-TP had significantly lower levels of total volatile basic nitrogen, lipid oxidation, and protein decomposition during the storage period, relative to the remaining treatments. The samples treated with SA-TP had the highest sensory quality rating as well. Collectively, sodium alginate coating infused with tea polyphenols may represent a promising treatment for preservation of Japanese sea bass fillets during cold storage.

PRACTICAL APPLICATION

The sodium alginate-tea polyphenols composite coating has strong potential to be used as a new biopreservative for maintaining fish fillet quality.

Development of a novel colorimetric sensor based on alginate beads for monitoring rainbow trout spoilage

Alginate is a non-toxic, renewable, and linear copolymer obtained from the brown algae Laminaria digitata that can be easily shaped into beads. Its good gel forming properties have made it useful for entrapping food and pharmaceutical ingredients. In this study, alginate beads were used in a novel application as a colorimetric sensor in food intelligent packaging. Colorimetric sensor was developed through entrapping red cabbage extract as a pH indicator in alginate beads. The pH indicator beads were used in rainbow trout packaging for monitoring fillets spoilage. Color change of beads during fish storage was measured using the CIELab method. The alginate bead colorimetric sensor is validated by measuring total volatile basic nitrogen (TVB-N) levels and microbial populations in fish samples. Moreover, peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) were evaluated during storage. Results indicated that increasing the bacterial population during storage and production of proteolytic enzymes resulted in protein degradation, accumulation of volatile amine compounds, increase in the pH and finally color change of alginate beads. The values of TVB-N, pH, PV and TBARS increased with time of storage. The results of TVB-N and microbial growth were in accordance with color change of beads and CIELab data. Therefore, the proposed system enjoys a high sensitivity to pH variations and is capable of monitoring the spoilage of fish or other protein-rich products through its wide range of color changes. The alginate beads containing the red cabbage extract can, thus, be used as a low-cost colorimetric sensor for intelligent packaging applications.