Water vapor barrier and mechanical properties of konjac glucomannan–chitosan–soy protein isolate edible films

Preparation and characterization of Baijiu Jiuzao cellulose nanofibers-kafirin composite bio-film with excellent physical properties

Jiuzao is the main solid by-products of Baijiu industry, which contain a high amount of underutilized cellulose and proteins. In recent years, cellulose nanofibers mixed with proteins to prepare biodegradable bio-based film materials have received widespread attention. In this study, we propose a novel method to simultaneously extract kafirin and cellulose from strong-flavor type of Jiuzao, and modify cellulose to prepare cellulose nanofibers by the TEMPO (2,2,6,6-tetramethylpiperidine-1-oxide) oxidation-pressure homogenization technique, and finally mix kafirin with cellulose nanofibers to prepare a new biodegradable bio-based composite film. Based on the analysis of one-way and response surface experiments, the highest purity of cellulose was 82.04 %. During cellulose oxidation, when NaClO was added at 25 mmol/g, cellulose nanofibers have a particle size of 80-120 nm, a crystallinity of 65.8°. Finally, kafirin and cellulose nanofibers were mixed to prepare films. The results showed that when cellulose nanofibers were added at 1 %, the film surface was smooth, the light transmittance was 60.8 %, and the tensile strength was 9.17 MPa at maximum, which was 104 % higher than pure protein film. The contact angle was 34.3°. This paper provides new ideas and theoretical basis for preparing biodegradable bio-based composite film materials, and improves the added value of Jiuzao.

Insights into recent innovations in barrier resistance of edible films for food packaging applications

The utilization of biopolymer-based food packaging holds significant promise in aligning with sustainability goals and enhancing food safety by offering a renewable, biodegradable, and safer alternative to traditional synthetic polymers. However, these biopolymer-derived films often exhibit poor barrier and mechanical properties, potentially limiting their commercial viability. Desirable barrier properties, such as moisture and oxygen resistance, are critical for preserving and maintaining the quality of packaged food products. This review comprehensively explores different traditional and advance methodologies employed to access the barrier properties of edible films. Additionally, this review thoroughly examines various approaches aimed at enhancing the barrier properties of edible films, such as the fabrication of multilayer films, the selection of biopolymers for composite films, as well as the integration of plasticizers, crosslinkers, hydrophobic agents, and nanocomposites. Moreover, the influence of process conditions, such as preparation techniques, homogenization, drying conditions, and rheological behavior, on the barrier properties of edible films has been discussed. The review provides valuable insights and knowledge for researchers and industry professionals to advance the use of biopolymer-based packaging materials and contribute to a more sustainable and food-safe future.

Structure, Merits, Gel Formation, Gel Preparation and Functions of Konjac Glucomannan and Its Application in Aquatic Food Preservation

Konjac glucomannan (KGM) is a natural polysaccharide extracted from konjac tubers that has a topological structure composed of glucose and mannose. KGM can be used as a gel carrier to load active molecules in food preservation. The three-dimensional gel network structure based on KGM provides good protection for the loaded active molecules and allows for sustained release, thus enhancing the antioxidant and antimicrobial activities of these molecules. KGM loaded with various active molecules has been used in aquatic foods preservation, with great potential for different food preservation applications. This review summarizes recent advances in KGM, including: (i) structural characterization, (ii) the formation mechanism, (iii) preparation methods, (iv) functional properties and (v) the preservation of aquatic food.

Changes in microstructure and rheological properties of konjac glucomannan/zein blend film-forming solution during drying

During film formation at 60 °C, the microstructure and rheological properties of konjac glucomannan (KGM) film-forming solution and KGM/zein blend film-forming solution were investigated. The drying process of film-forming solutions was divided into two stages according to the drying curves. Scanning electron microscopy showed that KGM chains in the blend solution aggregated into thicker chains and formed a molecular network with larger pores. Zein particles grew larger but were homogeneously distributed during drying as observed by confocal laser scanning microscopy. The addition of zein improved the thermal stability of the film-forming solution. As the drying proceeded (up to 8 h), KGM solution exhibited a typical concentrated solution behavior due to molecular entanglement; whereas the blend solution gradually formed a weak gel after 2 h. Complex viscosity data for the film-forming solutions were well-fitted by the power-law model. The information obtained from the study is important for understanding the film-forming mechanism.

Application of different carbohydrates to produce squash puree based edible sheet

The production possibility of squash puree-containing edible sheet and its improvement by different hydrocolloids were studied. In this study, two hydrocolloids [carboxymethyl cellulose (CMC) and tragacanth gum] and also one plasticizer (glycerol) were used to produce squash puree-based edible sheets and optimization was performed to produce an edible sheet sample with the optimum properties. The results revealed that the CMC increased the tensile strength, elongation, and water vapor transition (WVT) of the edible sheets, whilst decreased their moisture content. The tragacanth increased the edible sheets elongation, oxygen transition (OT) and opacity. The glycerol also increased the elongation, density, OT, WVT, opacity and water solubility of the edible sheets; whereas the water activity, tensile strength, elastic modulus, and swelling capacity were decreased. The optimum quality of edible sheets was obtained from a combination of 0.14 g of CMC, 0.25 g of tragacanth and 1.88 g of glycerol.

Preparation, properties, and structural characterization of β-glucan/pullulan blend films

This study investigates the physico-mechanical and structural properties of β-glucan (BG)/pullulan (PUL) composite edible films successfully prepared with 0-0.3 g of BG. Results demonstrated that BG addition significantly increases the elongation at break (p < 0.05), tensile strength, and water dissolution time of the resulting films. The transparency of the 0.2PUL:0.1BG film and the oxygen barrier property of the 0.15PUL:0.15BG film decreased remarkably compared with those of the plain films (0.3PUL:0BG and 0PUL:0.3BG) and other composite films (p < 0.05). FTIR indicated hydrogen bonding interactions between PUL and BG molecules, and microstructural observations showed that aggregated BG is homogeneously dispersed in the PUL continuous matrix. Among the films tested, the thermal stability of the 0.15PUL:0.15BG film was the best. A PUL:BG mixing ratio of 0.15:0.15 is thus suggested to provide the best film properties. This research offers an alternative method to improve PUL-based edible films.

Composite edible films and coatings from food-grade biopolymers

The development of edible films and coatings from food-grade biopolymers has advanced significantly during the past decade. The current state-of-the-art lies in the formulation of composite edible films and coatings from such biomolecules. Composite films and coatings refer to systems where multiple biopolymers have been combined to achieve beneficial properties. Carbohydrate, protein, and lipids have been preferred for developing such systems. Binary films and coatings have been prepared from multiple combinations including protein-protein, carbohydrate-carbohydrate and protein-carbohydrate. Similarly, ternary films and coatings have been prepared from protein-protein-carbohydrate combinations. In addition, several active ingredients including antimicrobial compounds have been loaded to these systems for the preparation of functional films and coatings. Therefore, the goal of this manuscript is to review the multitude of composite systems that are currently available for food packaging purposes. In addition, we discuss the application of composite coatings to fruits and vegetables, dairy, meat and seafood as model food systems.

Edible Gum-Phenolic-Lipid Incorporated Gluten Films for Food Packaging

The aim of this investigation was to improve the barrier and mechanical properties of gluten films and further explore their application in the packaging of seasonings. The effects of flaxseed gum (FG), oligomeric procyanidins (OPCs), and lauric acid (LA) on the water vapor permeability (WVP), mechanical properties, and peroxide value (POV) were determined. FG and OPCs improved the WVP properties of the gluten films, whereas LA significantly improved the oxygen-barrier properties. The FG/OPCs/LA/GP composite film was then optimized, and the morphological, microstructural, and thermal properties of the composite gluten film were investigated by scanning electron microscopy, atomic force microscopy, surface hydrophobicity analysis; Fourier transform infrared spectroscopy; thermal gravimetric analysis, respectively. The results confirmed that gluten is compatible with FG, OPCs, and LA, thereby leading to the formation of a more uniform, dense, and hydrophobic film. The changes in the preservation properties (appearance, POV, and acid value) of the composite gluten film for oil, salt, and vegetable packaging were also examined. The composite gluten film maintained some degree of seasoning packaging capacity over a 75-day storage period, indicating its potential for uses as a packaging material for seasonings in food production.

PRACTICAL APPLICATION

The edible composite film will be produced in industry according to the data provided in our paper; the film can be used as packaging material for seasonings in food production.

Effect of different animal fat and plant oil additives on physicochemical, mechanical, antimicrobial and antioxidant properties of chitosan films

Practical application of chitosan-essential oil blend films is limited due to the uneconomical extraction procedure of essential oils from plants. This study aimed to produce chitosan films blended with low cost and commercially available oils and fats consumed in daily human diet (olive, corn and sunflower oils, butter and animal fats). The study also focused on how physicochemical, biological and mechanical properties of chitosan blend films were influenced by the incorporation of oils and fats with varying unsaturation degrees. Possible interactions of chitosan film matrix with incorporated oils or fats were investigated. Chitosan-olive oil film showed better surface morphology and higher thermal stability than the films with other unsaturated oils. Tensile strength, Young's modulus and elongation at break were improved by 57.2%, 25.1% and 31.7% for chitosan-olive oil film, respectively. Chitosan-olive oil blend film had the highest antibacterial activity (almost equal to that of commercial antibiotic gentamicin). Edible films obtained from by incorporation of natural oils and fats into chitosan can help produce an environmentally friendly packaging material that is low cost and easily manufactured.

Preparation and Characterization of Chitosan/Soy Protein Isolate Nanocomposite Film Reinforced by Cu Nanoclusters

Soy protein isolate (SPI) based films have received considerable attention for use in packaging materials. However, SPI-based films exhibit relatively poor mechanical properties and water resistance ability. To tackle these challenges, chitosan (CS) and endogenous Cu nanoclusters (NCs) capped with protein were proposed and designed to modify SPI-based films. Attenuated total reflectance-Fourier transform infrared spectroscopy and X-ray diffraction patterns of composite films demonstrated that interactions, such as hydrogen bonds in the film forming process, promoted the cross-linking of composite films. The surface microstructure of CS/SPI films modified with Cu NCs was more uniform and transmission electron microscopy (TEM) showed that uniform and discrete clusters were formed. Compared with untreated SPI films, the tensile strength and elongation at break of composite films were simultaneously improved by 118.78% and 74.93%, respectively. Moreover, these composite films also exhibited higher water contact angle and degradation temperature than that of pure SPI film. The water vapor permeation of the modified film also decreased. These improved properties of functional bio-polymers show great potential as food packaging materials.

Síntesis y propiedades de filmes basados en quitosano/lactosuero

El quitosano es un polímero natural derivado de la desacetilación de la quitina con propiedades tales como biocompatibilidad, biodegradabilidad y formación de filmes, de gran aplicación en el campo de la industria, alimentación y medicina. Los filmes a base de quitosano y lactosuero fueron preparados teniendo en cuenta la concentración de la solución de quitosano (1; 1.5 y 2% v/v), la relación en volumen de lactosuero (4:20, 6:20 y 8:20 v/v) y el tiempo de secado de 4.5, 5.0 y 5.5 horas. Estas condiciones de preparación se optimizaron empleando la metodología de la superficie de respuesta. La quitina extraída previamente de los exoesqueletos de camarón fue tratada con una solución acuosa de NaOH al 50% en masa, hasta obtener quitosano con un grado de desacetilación de 80.72%. El quitosano obtenido fue disuelto en ácido acético para obtener las distintas soluciones que posteriormente fueron combinadas con lactosuero. Los filmes sintetizados fueron caracterizados por espectroscopia en la región del infrarrojo y se evaluaron los parámetros de espesor, densidad, solubilidad, transparencia, hinchamiento y degradación. La degradación de los filmes quitosano/lactosuero disminuye con el aumento de la concentración de quitosano. El porcentaje de hinchamiento de los filmes se ve afectado por las proporciones de lactosuero. La concentración de lactosuero incide en el aumento del espesor y la densidad de los filmes.

Application of soy protein coatings and their effect on the quality and shelf-life stability of beef patties

There was no significant change in lipid oxidation up to day 10 of storage for soy-protein-coated samples.

Investigation of Regenerated Cellulose/Poly(acrylic acid) Composite Films for Potential Wound Healing Applications: A Preliminary Study

Regenerated cellulose/poly(acrylic acid) composite films have been synthesized for wound dressing applications. The water absorbency of these films was studied as a function of amount of cross-linker N,N′-methylenebisacrylamide and cellulose contents in the feed mixture. The samples, having different compositions, showed tensile strength and percent elongation in the range of 9.98×105 to 13.40×105 N/m2 and 110 to 265, respectively. The water vapor transmission rate (WVTR) for various films was found to be in the range of 2.03 to 7.18 mg/cm2/h. These films were loaded with antibacterial drug miconazole nitrate and their release was studied in the physiological pH at 37°C. The release data was found to fit well the diffusion controlled Higuchi model. Finally the films demonstrated fair antibacterial and antifungal action, thus establishing their strong candidature as wound dressing materials.