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An easy-to-use food packaging label with pH and ammonia sensitivity was developed by adding betacyanin (5, 10 and 15 mg per g of starch) from flowers of paperflower (Bougainvillea glabra) to potato starch film made using the solvent casting method. The betacyanin was well dispersed into the starch matrix and formed new interactions with it as revealed by FTIR. The film containing 15 mg/g of betacyanin showed a color change from light pink to yellow as a response to pH adjustment of between 2 to 13. It was also able to detect the presence of ammonia in a range of 0.1 and 0.01 mg of ammonia per ml of water. Surface hydrophobicity and water vapor barrier capacity of the starch film increased by addition of the betacyanin, yet their mechanical strength decreased in the presence of the betacyanin. The ability of the film in the real-time indication of fish quality as a label was also evaluated during the storage of Caspian sprat at 4 °C. A visual change in the color of the packaging label from pink to yellow in parallel with the increase in the total volatile basic nitrogen (TVB-N), microbial count of the fish samples was detected. The starch/betacyanin film could be a novel intelligent label for application in food packaging., (Copyright © 2021. Published by Elsevier B.V.)

Multi-layer film structures of poly(lactic acid) (PLA) and fish gelatin (FG), prepared using the solvent casting technique, were studied in an effort to produce bio-based films with low oxygen (OP) and water vapor permeability (WVP). The scanning electron microscopy (SEM) images of triple-layer film showed that the outer PLA layers are being closely attached to the inner FG layer to make continuous film. The OP of multi-layer film (5.02cm 3 /m 2 daybar) decreased more than 8-fold compared with that of the PLA film, and the WVP of multi-layer film (0.125gmm/kPah m 2 ) also decreased 11-fold compared with that of the FG film. Lamination with PLA profoundly increased the water resistance of the bare gelatin film. Meanwhile, the tensile strength of the triple-layer film (25±2.13MPa) was greater than that of FG film (7.48±1.70MPa). At the same time, the resulting film maintains high optical clarity. Differential scanning calorimetry (DSC) analysis also revealed that the materials were compatible showing only one T g which decreased with FG deposition. This material exhibits an environmental-friendliness potential and a high versatility in food packaging., (Copyright © 2016 Elsevier B.V. All rights reserved.)

With the goal of improving the physico-chemical performance of fish gelatin-based films, composite films were prepared with increasing concentrations of chitosan (Ch) (100G:0Ch, 80G:20Ch, 70G:30Ch, 60G:40Ch and 0G:100Ch, gelatin:Ch), and some of their main physical and functional properties were characterised. The results indicated that the addition of Ch caused significant increase (p<0.05) in the tensile strength (TS) and elastic modulus, leading to stronger films as compared with gelatin film, but significantly (p<0.05) decreased the elongation at break. Ch drastically reduced the water vapour permeability (WVP) and solubility of gelatin films, as this decline for the blend film with a 60:40 ratio has been of about 50% (p<0.05). The light barrier measurements present low values of transparency at 600 nm of the gelatin-chitosan films, indicating that films are very transparent while they have excellent barrier properties against UV light. The structural properties investigated by FTIR and DSC showed a clear interaction between fish gelatin and Ch, forming a new material with enhanced mechanical properties., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The effects of turmeric extract (T), shallot extract (Sh), and their combination (T + Sh) on the quality of vacuum-packaged rainbow trout (Oncorhynchus mykiss) were examined during refrigerated storage (4 ± 1 °C) over a period of 20 d. Fish samples were divided into 4 batches; 3 batches were treated by dipping for 30 min in aqueous solution of turmeric extract (1.5%; v/v), shallot extract (1.5%; v/v), or turmeric and shallot extract combination (1.5%+ 1.5% v/v), while the fourth batch was dipped in distilled water as a control sample. The control and the treated fish samples were analyzed periodically for microbiological (total viable count, psychrotrophic count), chemical (total volatile base nitrogen [TVB-N], peroxide value [PV], and thiobarbituric acid [TBA] value), and sensory characteristics. The results indicated that the effect of the T, Sh, and T + Sh on the fish samples were to enable the good quality characteristics to be retained longer and to extend the shelf life during the refrigerated storage., (© 2011 Institute of Food Technologists®)

Abstract: Montmorillonite (MMT) nanoclay and rosemary essential oil (REO) were incorporated into chitosan film to improve its physical and mechanical properties as well as antimicrobial and antioxidant behavior. The MMT weight percent relative to chitosan was varied from 1 to 5 and was activated by three REO levels (0.5%, 1%, and 1.5% v/v), and their impact on physical, mechanical, and barrier properties of the chitosan films was investigated. Total phenolic and antimicrobial activity were also evaluated. Microstructure of chitosan/MMT–REO nanocomposites was characterized through X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results showed that incorporating MMT and REO into chitosan improves water gain, water vapor permeability, and solubility of the chitosan film by more than 50%. It was also shown that the combined effect of clay and REO improves significantly the tensile strength and elongation of chitosan (p <0.05). The XRD and FTIR results confirmed that the improvements are related to the MMT exfoliation and good interaction between chitosan and MMT in the presence of REO. Antimicrobial properties of the films also improved by REO incorporation in 1.5% v/v. [Copyright &y& Elsevier]

Summary Rosemary essential oil (REO) was used to develop an active film from chitosan. The effects of REO concentration (0.5, 1.0 and 1.5% v/v) on film properties were studied by measuring the physical, mechanical and optical properties of the REO-loaded films. Scanning electron microscopy and Fourier transform infrared (FTIR) spectroscopy were used to study microstructure and the interaction of the chitosan-based films. The solubility and water gain of the chitosan film decreased about 25% and 85%, respectively, by REO incorporation, up to 1.5% v/v, because of the interaction between hydrophilic groups of chitosan and REO as confirmed by FTIR. It was determined that REO improved the transparency of the films from 4.97 in neat chitosan up to 7.61; moreover, it reduced the films' light transmission in UV light more than 25%. Films containing REO showed more antibacterial activity and total phenol content. The films containing REO showed potential to be used as active film in food preservation. [ABSTRACT FROM AUTHOR]

Edible coating is a novel food packaging technology for controlling the growth of spoilage bacteria and chemical changes in ready-to-eat food products. Fresh fish are highly perishable foodstuffs and are very susceptible to spoilage. A sodium alginate coating was used to maintain the quality of rainbow trout fillets in chilled storage over a period of 20 days. Fillet samples were coated with an aqueous solution of 3% sodium alginate and then stored at chilled temperature (4 ± 2°C). The control and coated samples were analyzed periodically (every 5 days) for microbial (aerobic plate count and psychrotrophic count), chemical (total volatile basic nitrogen, thiobarbituric acid, peroxide value), and sensory characteristics. The results indicated that the sodium alginate coating helped protect the quality characteristics of treated fresh fish fillets and prolonged the shelf life during chilled storage of rainbow trout fillets. [ABSTRACT FROM AUTHOR]

The main shortcoming of poly(lactic acid) (PLA) for food packaging applications is its brittleness. The aim of this work was to evaluate the potential use of Origanum vulgare L. essential oil (OEO) in PLA-based matrices to obtain developed bio-based films with enhanced mechanical properties as well as antimicrobial performance. The PLA-essential oil composite films were more flexible than neat PLA films; so that up to 6-fold increase in the elongation-at-break values (2.82–16.78%) were acquired when 0.5% (w/w) oil was added to the polymer matrix. The addition of essential oil decreased the PLA glass transition temperature ( T g ), as the result of the polymer plasticization, and led to modification of the tensile behavior. AFM results confirmed that the PLA surface microstructure was drastically influenced in terms of roughness parameters ( R a and R q ) when OEO was added. The films’ antimicrobial activities were induced by incorporating essential oil, which were more effective against the bacteria in direct contact method than a vapor phase. However, in both of test methods, Staphylococcus aureus was the most sensitive bacterium to OEO-containing films, while Escherichia coli was the most resistant. Then, efficacy of bioactive film included with 1.5% (w/w) essential oil to reduce microbial growth of rainbow trout during chilled storage was evaluated; the results indicated that antimicrobial PLA film was effective against all the microorganisms tested in this study. These results suggest that the developed PLA films with active substance could be used in designing antimicrobial packaging materials. [ABSTRACT FROM AUTHOR]

Abstract: Montmorillonite (MMT) and cellulose nanoparticles (CNP) were added to alginate biopolymer to compare the properties of bionanocomposites reinforced with different organic and inorganic nanofillers in various loading contents (1, 3, and 5 wt%). Both MMT and CNP decreased the water solubility (WS) of the films. However, at all filler contents the WS of the alginate/MMT (84–61%) nanocomposites was significantly (P < 0.05) lower than that of alginate/CNP films (95–77%). Surface hydrophobicity of the nanocomposites showed a great improvement (83%) with crystalline hydrophobic CNP addition, while MMT made films' surface more hydrophilic. The addition of both nanoreinforcements similarly caused a reduction in the water vapor permeability of the alginate-based nanocomposites. Due to the similar polysaccharide structures and good interfacial interactions, the TS and E of the nanocomposite films improved with an increase in CNP content and reached a maximum at the highest loading level (5 wt%). However, when the content of MMT went beyond 1 wt% nanocomposites, a decrease in the TS was observed. Finally, these results propose that organic CNP more than ability to make a fully renewable and natural nanocomposites may also introduce some other advantages compared to inorganic nanoclay fillers when added to carbohydrate biopolymers. [Copyright &y& Elsevier]

Abstract: A bio-based nanocomposite was developed by incorporation of cellulose nanoparticles (CN) obtained from sulfuric acid hydrolysis into alginate biopolymer using solution casting method. The effect of CN loading content (1, 3, 5 and 10wt%) on microstructural, physical, mechanical and optical properties of the nanocomposites were characterized. The results showed that water solubility and water vapor permeability of the nanocomposites decreased by about 40% and 17%, respectively, upon increasing the CN content to 10%. In addition, the crystalline structure of the CN increased surface hydrophobicity of the alginate film by about 98%. The tensile strength value of the composite films increased from 18.03 to 22.4MPa with increasing NC content from 0 to 5%; but, it decreased with further increase of the filler content. Nevertheless, film transparency decreased with CN incorporation, especially in high level (10%), which suggested the occurrence of partial agglomeration of the fillers at 10% that coincided with microstructural and mechanical results. [Copyright &y& Elsevier]