Fast dissolving, hermetically sealable, edible whey protein isolate-based films for instant food and/or dry ingredient pouches

Plant polysaccharide-derived edible film packaging for instant food: Rapid dissolution in hot water coupled with exceptional mechanical and barrier characteristics

A comprehensive multiscale analysis was conducted to explore the effects of different ratios of these materials on its properties. The results show that KC played a crucial role in controlling solution viscosity and gel and sol temperatures. The dissolution time at high water temperatures primarily decreased with an increase in SA content. Higher KC and CS content increased tensile strength (TS) and elongation at break (ε), while also exhibiting better thermal stability. Water vapor transmission (WVT) and permeability (PV) initially decreased, then increased with the increase of SA and CS contents. Finally, an SA:KC:CS ratio of 1:3:2 showed optimal comprehensive properties, with a dissolution time of about 60.0 ± 3.8 s, TS of 23.80 ± 0.29 MPa, ε of 18.61 ± 0.34 %, WVT of 21.74 ± 0.62 g/m2·24h, and PV of 5.39 ± 0.17 meq/kg. Meanwhile, the SA:KC:CS edible food packaging only introduced minimal effects on food after dissolution, and the total bacterial count met regulatory standards.

Effect of Drying Conditions and Jojoba Oil Incorporation on the Selected Physical Properties of Hydrogel Whey Protein-Based Edible Films

Edible hydrogel coatings or films in comparison to conventional food packaging materials are characterized as thin layers obtained from biopolymers that can be applied or enveloped onto the surface of food products. The use of lipid-containing hydrogel packaging materials, primarily as edible protective coatings for food applications, is recognized for their excellent barrier capacity against water vapor during storage. With the high brittleness of waxes and the oxidation of different fats or oils, highly stable agents are desirable. Jojoba oil obtained from the jojoba shrub is an ester of long-chain fatty acids and monovalent, long-chain alcohols, which contains natural oxidants α, β, and δ tocopherols; therefore, it is resistant to oxidation and shows high thermal stability. The production of hydrogel films and coatings involves solvent evaporation, which may occur in ambient or controlled drying conditions. The study aimed to determine the effect of drying conditions (temperature from 20 to 70 °C and relative humidity from 30 to 70%) and jojoba oil addition at the concentrations of 0, 0.5, 1.0, 1.5, and 2.0% on the selected physical properties of hydrogel edible films based on whey protein isolate. Homogenization resulted in stable, film-forming emulsions with bimodal lipid droplet distribution and a particle size close to 3 and 45 µm. When higher drying temperatures were used, the drying time was much shorter (minimum 2 h for temperature of 70 °C and relative humidity of 30%) and a more compact structure, lower water content (12.00-13.68%), and better mechanical resistance (3.48-3.93 MPa) of hydrogel whey protein films were observed. The optimal conditions for drying hydrogel whey protein films are a temperature of 50 °C and an air humidity of 30% over 3 h. Increasing the content of jojoba oil caused noticeable color changes (total color difference increased from 2.00 to 2.43 at 20 °C and from 2.58 to 3.04 at 70 °C), improved mechanical elasticity (the highest at 60 °C from 48.4 to 101.1%), and reduced water vapor permeability (the highest at 70 °C from 9.00·10-10 to 6.35·10-10 g/m·s·Pa) of the analyzed films. The observations of scanning electron micrographs showed the heterogeneity of the film surface and irregular distribution of lipid droplets in the film matrix.

Tailoring Pectin-PLA Bilayer Film for Optimal Properties as a Food Pouch Material

This study focuses on developing a biodegradable film using a novel hybrid citrus peel pectin. A bilayer approach with PLA was proposed and optimized using Response Surface Methodology (RSM) to complement pectin films' mechanical and barrier property limitations. The optimized film composition (2.90 g PLA and 1.96 g pectin) showed enhanced mechanical strength with a tensile strength (TS) of 7.04 MPa and an elongation at break (EAB) of 462.63%. In addition, it demonstrated lower water vapor (1.45 × 10-10 g/msPa), oxygen (2.79 × 10-7 g/ms) permeability, and solubility (23.53%). Compared to single-layer pectin films, the optimized bilayer film had a 25% increased thickness, significantly improved water barrier (3806 times lower) and oxygen barrier (3.68 times lower) properties, and 22.38 times higher stretchability, attributed to hydrogen bond formation, as confirmed by FTIR analysis. The bilayer film, effectively protected against UV and visible light, could be a barrier against light-induced lipid oxidation. Moreover, it demonstrated superior seal efficiency, ensuring secure sealing in practical applications. The bilayer pouch containing mustard dressing exhibited stable sealing with no leakage after immersion in hot water and ethanol, making it suitable for secure food pouch packaging.

Revolutionizing single-use food packaging: a comprehensive review of heat-sealable, water-soluble, and edible pouches, sachets, bags, or packets

Edible food packaging has emerged as a critical focal point in the discourse on sustainability, prompting the development of innovative solutions, notably in the realm of edible pouches. Often denoted as sachets, bags, or packets, these distinct designs have garnered attention owing to their water-soluble and heat-sealable attributes, tailored explicitly for single-use applications encompassing oils, instant or dry foods, and analogous products. While extant literature extensively addresses diverse facets of edible films, this review addresses a conspicuous void by presenting a consolidated and specialized overview dedicated to the intricate domain of edible pouches. Through a meticulous synthesis of current research, we aim to illuminate the trajectory of advancements made thus far, delving into critical aspects, including materials, production techniques, functional attributes, consumer perceptions, and regulatory considerations. By furnishing a comprehensive perspective on the potential, challenges, and opportunities inherent in edible pouches, our overarching aim is to stimulate collaborative endeavors in research, innovation, and exploration. In doing so, we aspire to catalyze the broader adoption of sustainable packaging solutions tailored to the exigencies of single-use applications.

High-Barrier, Biodegradable Films with Polyvinyl Alcohol/Polylactic Acid + Wax Double Coatings: Influence of Relative Humidity on Transport Properties and Suitability for Modified Atmosphere Packaging Applications

Polyvinyl alcohol (PVOH) exhibits outstanding gas-barrier properties, which favor its use as a biodegradable, high-barrier coating on food-packaging films, possibly in combination with modified atmospheres. Nonetheless, its high sensitivity to water can result in a severe loss of barrier properties, significantly limiting its applications with fresh foods and in high-humidity conditions. In this work, the water vapor (PWV) and oxygen permeability (PO2) of high-barrier biodegradable films with PVOH/PLA + wax double coatings were extensively characterized in a wide range of relative humidity (from 30 to 90%), aimed at understanding the extent of the interaction of water with the wax and the polymer matrices and the impact of this on the permeation process. What is more, a mathematical model was applied to the PWV data set in order to assess its potential to predict the permeability of the multilayer films by varying storage/working relative humidity (RH) conditions. The carbon dioxide permeability (PCO2) of the films was further evaluated, and the corresponding permselectivity values were calculated. The study was finally augmented through modified atmosphere packaging (MAP) tests, which were carried out on double-coated films loaded with 0 and 5% wax, and UV-Vis analyses. The results pointed out the efficacy of the PLA + wax coating layer in hampering the permeation of water molecules, thus reducing PVOH swelling, as well as the UV-shielding ability of the multilayer structures. Moreover, the MAP tests underlined the suitability of the double-coated films for being used as a sustainable alternative for the preservation of foods under modified atmospheres.

Xanthoceras sorbifolia Husk Extract Incorporation for the Improvement in Physical and Antioxidant Properties of Soy Protein Isolate Films

With the increasing awareness of ecological and environmental protection, the research on eco-friendly materials has experienced a considerable increase. The objective of our study was to explore a novel soy protein isolate (SPI) film functionalized with antioxidants extracted from Xanthoceras sorbifolia husk (XSHE) as bio-based active packaging films. The films were evaluated in light of their structure, physical machinery, and antioxidant performance using advanced characterization techniques. The FTIR and microscopy results revealed the hydrogen-bond interaction between the SPI and XSHE and their good compatibility, which contributed to the improvement in various properties of the composite films, such as tensile strength (TS), UV blocking, and the water barrier property. As the XSHE content increased to 5%, the TS of the films dramatically increased up to 7.37 MPa with 47.7% and the water vapor permeability decreased to 1.13 × 10-10 g m m-2 s-1 Pa-1 with 22.1%. Meanwhile, the introduction of XSHE caused further improvement in the antioxidant capacity of films, and the release of active agents from films was faster and higher in 10% ethanol than it was in a 50% ethanol food simulant. Overall, SPI-based films functionalized with XSHE demonstrated promising potential applications in food packaging.

Whey protein isolate/jujube polysaccharide-based edible nanocomposite films reinforced with starch nanocrystals for the shelf-life extension of banana: Optimization and characterization

The formulation of new bionanocomposite (BNC) films using whey protein isolates (WPI, 3.3-11.7 %)-jujube polysaccharide (JPS, 1.59-18.41 %)/starch nanocrystals (SNCs, 0.32-3.68 %) blends was optimized. The ultrasound-assisted acid hydrolysis produced ~63.1 nm SNCs from native starch with -24.3 mV ζ-potential. The extracted JPS purification led to a single symmetrical peak for galactoarabinan-rich fraction (1.35 × 10⁵ Da). The optimal levels of barrier (oxygen (11.85 cm³ m^-2 d^-1 atm^-1) and water vapor (3.22 × 10^-10 g m^-1 s^-1 Pa^-1) permeability rate), optical (opacity index (2.7 AU μm^-1), total color difference (18.69), and whiteness index (77.40)), and thermal (glass transition temperature (-8.29 °C) and melting point (110.38 °C)) properties were obtained at 5.0 % WPI, 15.0 % JPS, and 3.0 % SNCs. The film-forming solution of optimal BNCs had a significant antibacterial effect against Staphylococcus aureus and Escherichia coli. The improved crystallinity of BNCs at an optimal SNC level was confirmed by the XRD. The AFM and SEM images confirmed a continuous and uniform network for the optimal BNCs without any pores or cracks accompanied by low surface roughness. The FTIR spectroscopy proved covalent interaction and hydrogen bonding among chemical functional groups of WPI and JPS reinforced with SNCs. The optimal BNC could preserve banana fruits with favorable physicochemical and microbial quality during storage.

Effect of whey protein isolate-based edible films containing amino acids on the PhIP level and physicochemical properties of pan-fried chicken breasts

This study was conducted to investigate the inhibitory effects of edible films containing amino acids (AAs) on the formation of 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP) in chicken breasts and to evaluate the physicochemical properties of the edible films. Heated whey protein isolate (HWPI) solution was made by heating 5 g whey protein isolate (WPI) solution at 90°C for 30 min in a water bath and subsequently mixed with 2.5 g glycine, and tryptophan (Trp) or lysine (Lys) at 0.25%, 0.5%, and 0.75% concentrations. Unheated whey protein isolate (UHWPI)-based casting solution was prepared with the same method but without heating of WPI solution. Chicken breasts were cut at the same weights and were covered with the prepared edible films. For edible films, total soluble matter (TSM%), color (calorimeter), radical scavenging activity (DPPH), and Fourier transform infrared spectroscopy (FTIR) were conducted. For chicken breasts, PhIP level, color before and after frying (calorimeter), cooking loss percentage (weigh loss before after frying), and tenderness (texture analyzer) were evaluated. The average PhIP level decreased from 78.47 ppb to 6.69-8.31 ppb for chicken covered with Lys-containing HWPI edible films, and to 25.82-46.80 ppb for chicken covered with Trp-containing ones. For chicken covered with UHWPI edible films, the PhIP decreased 28.4-56.04 ppb for Trp-containing ones and 19.67-40.32 ppb for Lys-containing ones. Moreover, chicken breasts covered with HWPI edible films had lower cooking loss and improved tenderness compared to the chicken breasts with no edible film. This study provides a new approach to decrease the PhIP levels in fried chicken breast.

The Effect of Whey Protein Films with Ginger and Rosemary Essential Oils on Microbiological Quality and Physicochemical Properties of Minced Lamb Meat

Consumers’ constant search for high-quality and safe products, with the least possible preservatives and additives, as well as extended shelf life, has led industries to research and develop alternative forms of food preservation and packaging. The purpose of this research was the study of the effect of natural antimicrobials and, in particular, the essential oils of ginger (Zingiber Officinale Roscoe) and rosemary (Rosmarinus officinalis L.) on strengthening whey protein films’ properties. Whey protein isolate (WPI) films, alone and with incorporated essential oils (WPI + EO) at different concentrations were prepared and then examined for their possible effect on delaying the deterioration of minced lamb meat. Microbiological and physicochemical measurements were carried out to examine the meat’s shelf life. Results showed that films with 1% EO significantly improved the microbiological quality of meat. On day 11, total viable counts, Pseudomonas spp., Br. thermosphacta, lactic acid bacteria, Enterobacteriaceae, and yeasts remained low for films with 1% concentration of essential oil compared with 0.5%. Regarding, physicochemical properties the same pattern was observed for pH while oxidation degree was significantly reduced. Finally, color attributes measurements recorded fluctuations between samples, but overall, no considerable discoloration was observed.

Fabrication and characterization of fast dissolving glycerol monolaurate microemulsion encapsulated gelatin nanofibers with antimicrobial activity

BACKGROUND

Electrospun fibers are a good candidate for the delivery of bioactive compounds in the food industry because of their advantages that include a tunable diameter, high porosity and a high specific surface area. In the present study, we fabricated gelatin/glycerol monolaurate (GML) microemulsion nanofibers by solubilizing GML in Tween-80 followed by mixing with gelatin solution for electrospinning. We hypothesized that the addition of GML microemulsions affects the properties of the gelatin solution and modifies the physical and antimicrobial properties of the resulting nanofibers.

RESULTS

Both pure gelatin solution and gelatin/GML microemulsions showed shear-thinning behavior. However, electrospinnability was not affected by the addition of GML microemulsions. A significantly higher average diameter of nanofibers (1147 nm) with 5% GML was observed compared to the gelatin fiber diameter of 560 nm. Fourier transform infrared spectroscopy showed hydrogen bonding between gelatin molecules and GML microemulsions. Thermal analysis and X-ray diffraction indicated an amorphous structure of gelatin/GML microemulsion nanofibers, although a small amount of crystalline GML existed in the nanofibers with high GML content. Gelatin/GML microemulsion nanofibers showed high thermal stability and improved hydrophilicity. Nanofibers with 5% GML (weight with respect to nanofiber) (D64 nanofibers) showed effective antimicrobial activity against Escherichia coli and Staphylococcus aureus.

CONCLUSION

Gelatin/GML microemulsion nanofibrous films demonstrate superhydrophilicity and fast dissolution properties as a result of the high surface-to-volume ratio, amorphous structure and improved hydrophilicity of the nanofiber surface. The results indicate the potential application of gelatin/GML microemulsion nanofibrous films as edible antimicrobial food packaging. © 2021 Society of Chemical Industry.

Physicochemical and Microstructural Characterization of Whey Protein Films Formed with Oxidized Ferulic/Tannic Acids

Protein-based biodegradable packaging films are of environmental significance. The effect of oxidized ferulic acid (OFA)/tannic acid (OTA) on the crosslinking and film-forming properties of whey protein isolate (WPI) was investigated. Both of the oxidized acids induced protein oxidation and promoted WPI crosslinking through the actions of quinone carbonyl and protein sulfhydryl, and amino groups. OTA enhanced the tensile strength (from 4.5 MPa to max 6.7 MPa) and stiffness (from 215 MPa to max 376 MPa) of the WPI film, whereas OFA significantly increased the elongation at break. The water absorption capability and heat resistance of the films were greatly improved by the addition of OTA. Due to the original color of OTA, the incorporation of OTA significantly reduced light transmittance of the WPI film (λ 200–600 nm) as well as the transparency, whereas no significant changes were induced by the OFA treatment. Higher concentrations of OTA reduced the in vitro digestibility of the WPI film, while the addition of OFA had no significant effect. Overall, these two oxidized polyphenols promoted the crosslinking of WPI and modified the film properties, with OTA showing an overall stronger efficacy than OFA due to more functional groups available.

Methods of Incorporating Plant-Derived Bioactive Compounds into Films Made with Agro-Based Polymers for Application as Food Packaging: A Brief Review

Plastic, usually derived from non-renewable sources, is among the most used materials in food packaging. Despite its barrier properties, plastic packaging has a recycling rate below the ideal and its accumulation in the environment leads to environmental issues. One of the solutions approached to minimize this impact is the development of food packaging materials made from polymers from renewable sources that, in addition to being biodegradable, can also be edible. Different biopolymers from agricultural renewable sources such as gelatin, whey protein, starch, chitosan, alginate and pectin, among other, have been analyzed for the development of biodegradable films. Moreover, these films can serve as vehicles for transporting bioactive compounds, extending their applicability as bioactive, edible, compostable and biodegradable films. Biopolymer films incorporated with plant-derived bioactive compounds have become an interesting area of research. The interaction between environment-friendly biopolymers and bioactive compounds improves functionality. In addition to interfering with thermal, mechanical and barrier properties of films, depending on the properties of the bioactive compounds, new characteristics are attributed to films, such as antimicrobial and antioxidant properties, color and innovative flavors. This review compiles information on agro-based biopolymers and plant-derived bioactive compounds used in the production of bioactive films. Particular emphasis has been given to the methods used for incorporating bioactive compounds from plant-derived into films and their influence on the functional properties of biopolymer films. Some limitations to be overcome for future advances are also briefly summarized. This review will benefit future prospects for exploring innovative methods of incorporating plant-derived bioactive compounds into films made from agricultural polymers.