Effect of protein concentrations on the properties of fish myofibrillar protein based film compared with PVC film

Synergistic Effects of High-Intensity Ultrasound Combined with L-Lysine for the Treatment of Porcine Myofibrillar Protein Regarding Solubility and Flavour Adsorption Capacity

This study aimed to investigate the synergistic effects of high-intensity ultrasound (0, 5, 10, 15, and 20 min) in combination with L-lysine (15 mM) on improving the solubility and flavour adsorption capacity of myofibrillar proteins (MPs) in low-ion-strength media. The results revealed that the ultrasound treatment for 20 min or the addition of L-lysine (15 mM) significantly improved protein solubility (p < 0.05), with L-lysine (15 mM) showing a more pronounced effect (p < 0.05). The combination of ultrasound treatment and L-lysine further increased solubility, and the MPs treated with ultrasound at 20 min exhibited the best dispersion stability in water, which corresponded to the lowest turbidity, highest absolute zeta potential value, and thermal stability (p < 0.05). Based on the reactive and total sulfhydryl contents, Fourier transform infrared spectroscopy, and fluorescence spectroscopy analysis, the ultrasound treatment combined with L-lysine (15 mM) promoted the unfolding and depolymerization of MPs, resulting in a larger exposure of SH groups on the surface, aromatic amino acids in a polar environment, and a transition of protein conformation from α-helix to β-turn. Moreover, the combined treatment also increased the hydrophobic bonding sites, hydrogen-bonding sites, and electrostatic effects, thereby enhancing the adsorption capacity of MPs to bind kenone compounds. The findings from this study provide a theoretical basis for the production and flavour improvement of low-salt MP beverages and the utilisation of meat protein.

Advances of blend films based on natural food soft matter: Multi-scale structural analysis

The blend films made of food soft matter are of growing interest to the food packaging industries as a pro-environment packaging option. The blend films have become a novel pattern to replace traditional plastics gradually due to their characteristics of biodegradability, sustainability, and environmental friendliness. This review discussed the whole process of the manufacturing of food soft matter blend films from the raw material to the application due to multi-scale structural analysis. There are 3 stages and 12 critical analysis points of the entire process. The raw material, molecular self-assembly, film-forming mechanism and performance test of blend films are investigated. In addition, 11 kinds of blend films with different functional properties by casting are also preliminarily described. The industrialization progress of blend films can be extended or facilitated by analysis of the 12 critical analysis points and classification of the food soft matter blend films which has a great potential in protecting environment by developing sustainable packaging solutions.

Development of antifogging double-layer film using cellulose nanofibers and carboxymethyl chitosan for white Hypsizygus marmoreus preservation

Films with simultaneously excellent mechanical and anti-fog properties are of great importance for food packaging. A novel strategy is described here to prepare long-lasting anti-fog film with antibacterial and antioxidant capabilities via a simple, green approach. The CMC (carboxymethyl chitosan) gel was integrated with CNF/TA (cellulose nanofibers/tannic acid) composite solution based on layer-by-layer assembly to form a membrane with a bilayer structure. The anti-fog performance of the bilayer film could be adjusted by regulating the CNF/TA layer thickness. On the whole, the developed anti-fog film had high mechanical strength and excellent UV shielding properties, as well as good antibacterial and antioxidant properties, and could be non-fogging for a long time under water vapor (40 °C). The effect of double layer anti-fog film (3%CmFT-3) on the fresh-keeping effect of white Hypsizygus marmoreus was compared at room temperature (28 °C) with commercially available anti-fog PVC film. The results showed that the bilayer anti-fog film could effectively prevent the generation of fog, delay the Browning, inhibit mildew, improve the overall acceptability, and effectively extend the shelf life of white Hypsizygus marmoreus. This biomass-based anti-fog film offers great potential for the development of multifunctional green food packaging.

Packaging films based on biopolymers from seafood processing wastes: Preparation, properties, and their applications for shelf-life extension of seafoods-A comprehensive review

Biopolymers derived from seafood processing byproducts are used to prepare active and biodegradable films as the packaging of food products. These films possess bioactivities to enhance the shelf life of packed foods by proactively releasing antimicrobial/antioxidative agents into the foods and providing sufficient barrier properties. Seafood processing byproducts are an eminent source of valuable compounds, including biopolymers and bioactive compounds. These biopolymers, including collagen, gelatin, chitosan, and muscle proteins, could be used to prepare robust and sustainable food packaging with some antimicrobial agents or antioxidants, for example, plant extracts rich in polyphenols or essential oils. These active packaging are not only biodegradable but also prevent the deterioration of packed foods caused by spoilage microorganisms as well as chemical deterioration. Seafood discards have a promising benefit for the development of environmentally friendly food packaging systems via the appropriate preparation methods or techniques. Therefore, the green packaging from seafood leftover can be better exploited and replace the synthetic counterpart.

A natural blue colorant from butterfly pea (Clitoria ternatea) petals for traditional rice cooking

Butterfly pea (Clitoria ternatea) flowers are widely used for culinary purposes in southern Asian countries. We assessed the optimal level of a butterfly pea petal extract (BPPE) to produce blue rice. Dried butterfly pea petals were extracted with water at 0.2, 0.4, 0.6, and 0.8% (w/v), and the extract was used to color boiled rice before cooking was completed. Rice cooked with BPPE acquired various shades of blue from light to dark. Significantly decreased lightness/darkness (L*), redness/greenness (a*), yellowness/blueness (b*), and color difference (∆E*) were observed in response to BPPE levels, while hue (h*) and chroma (C*) were significantly increased (p < 0.05). Total phenolic (TPC) and total anthocyanin (TAC) contents of cooked rice increased with BPPE levels (p < 0.05), and both constituents contributed significant radical scavenging activity (r = 0.886 to 0.994, p < 0.01, n = 20). Sensory evaluation by consumers indicated a suitable level of BPPE at 0.6%. The color of blue cooked rice was stable under an opaque cover for 8 days, whereas TPC and TAC decreased significantly with storage time. Findings from the current study can be used to produce blue rice in traditional cooking, and to produce other ready-to-use BPPE products.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05752-w.

Development of Films from Spent Coffee Grounds' Polysaccharides Crosslinked with Calcium Ions and 1,4-Phenylenediboronic Acid: A Comparative Analysis of Film Properties and Biodegradability

Most polymeric materials are synthetic and derived from petroleum, hence they accumulate in landfills or the ocean, and recent studies have focused on alternatives to replace them with biodegradable materials from renewable sources. Biodegradable wastes from food and agroindustry, such as spent coffee grounds (SCGs), are annually discarded on a large scale and are rich in organic compounds, such as polysaccharides, that could be used as precursors to produce films. Around 6.5 million tons of SCGs are discarded every year, generating an environmental problem around the world. Therefore, it was the aim of this work to develop films from the SCGs polysaccharide fraction, which is comprised of cellulose, galactomannans and arabinogalactans. Two types of crosslinking were performed: the first forming coordination bonds of calcium ions with polysaccharides; and the second through covalent bonds with 1,4-phenylenediboronic acid (PDBA). The films with Ca²⁺ ions exhibited a greater barrier to water vapor with a reduction of 44% of water permeability vapor and 26% greater tensile strength than the control film (without crosslinkers). Films crosslinked with PDBA presented 55-81% higher moisture contents, 85-125% greater permeability to water vapor and 67-150% larger elongations at break than the films with Ca²⁺ ions. Film biodegradability was demonstrated to be affected by the crosslinking density, with the higher the crosslinking density, the longer the time for the film to fully biodegrade. The results are promising and suggest that future research should focus on enhancing the properties of these films to expand the range of possible applications.

Physical and Mechanical Characteristics of Gelatin-Based Films as a Potential Food Packaging Material: A Review

This review discusses the potential application of gelatin-based film as biodegradable food packaging material from various types of gelatin sources. The exploitation of gelatin as one of the biopolymer packaging in the food industry has rising interest among researchers as the world becomes more concerned about environmental problems caused by petroleum-based packaging and increasing consumer demands on food safety. Single gelatin-based film properties have been characterized in comparison with active and intelligent gelatin-based composite films. The physical properties of gelatin-based film such as thickness, color, and biodegradability were much influenced by total solid contents in each film. While, for mechanical and light barrier properties, poultry-based gelatin films have shown better properties compared to mammalian and marine gelatin films. This paper detailed the information on gelatin-based film characterization in comparison with active and intelligent gelatin-based composite films. The physical properties of gelatin-based film such as color, UV-Vis absorption spectra, water vapor permeability, thermal, and moisture properties are discussed along with their mechanical properties, including tensile strength and elongation at break.

Recent Applications of Biopolymers Derived from Fish Industry Waste in Food Packaging

Fish waste is attracting growing interest as a new raw material for biopolymer production in different application fields, mainly in food packaging, with significant economic and environmental advantages. This review paper summarizes the recent advances in the valorization of fish waste for the preparation of biopolymers for food packaging applications. The issues related to fishery industry waste and fish by-catch and the potential for re-using these by-products in a circular economy approach have been presented in detail. Then, all the biopolymer typologies derived from fish waste with potential applications in food packaging, such as muscle proteins, collagen, gelatin, chitin/chitosan, have been described. For each of them, the recent applications in food packaging, in the last five years, have been overviewed with an emphasis on smart packaging applications. Despite the huge industrial potential of fish industry by-products, most of the reviewed applications are still at lab-scale. Therefore, the technological challenges for a reliable exploitation and recovery of several potentially valuable molecules and the strategies to improve the barrier, mechanical and thermal performance of each kind of biopolymer have been analyzed.

Effect of Different Polyalcohols as Plasticizers on the Functional Properties of Squid Protein Film (Dosidicus Gigas)

Conventional plastic materials accumulation has led to a constant search to develop friendly packaging, edible coatings from biopolymers are an example. Since different proteins have different behavior and plastizicer compatibility, in this work, the effect of different polyalcohols (glycerol, sorbitol, maltitol, mannitol, and xylitol) as plasticizers on squid protein films behavior was studied. The results show that except for mannitol, transparent, and flexible films can be obtained. None of them showed transmission to light on the ultraviolet (UV) spectrum. However, only glycerol and sorbitol were sufficiently flexible to evaluate their mechanical properties, in which glycerol had a more elastic behavior with an elongation at a break of 920% and tensile strength (TS) of 0.94 MPa, while sorbitol exhibited a more plastic behavior with an elongation at break of 511% and a TS of 4.41 MPa. Water-vapor transmission rate was higher in glycerol, with 194.41 g·m−2d−1, while sorbitol had 44.27 g·m−2d−1 but presented blooming. This could be due to low interaction between sorbitol and the protein matrix, correlating with the film-solubility results. Amide I band of the Fourier transform infrared (FT-IR) spectra demonstrated higher denaturation and loss of alpha helical structure in glycerol film, followed by maltitol/sorbitol, xylitol, mannitol, and the control film. This in accordance with thermogravimetric analysis (TGA) results. The results of this study prove that only glycerol and sorbitol are suitable to obtain a see-through flexible film.

Use of sodium alginate in the preparation of gelatin-based hard capsule shells and their evaluation in vitro

Using only type B gelatin produces hard capsule shells which are too brittle. This study examines the blending of type B bovine gelatin with sodium alginate to produce hard capsule shells and through evaluation of their in vitro physicochemical properties provides a reflection on the role of gelatin and sodium alginate in the blend. The compositions and formulation of the capsule shells in this study comprised gelatin (10%, 20% and 30%), sodium alginate (1%, 2%, 3%, 4% and 5%), water, and opacifying agents (titanium dioxide; TiO₂) and polyethylene glycol (PEG) whose concentrations were kept constant. From the 15 films prepared, five were found to form hard capsule shells. Increased concentrations of sodium alginate increased the viscosity of the blends accompanied by capsule thickening. There was a good molecular compatibility between gelatin and sodium alginate. Increased gelatin and sodium alginate concentrations increased the water-holding capacity of the film, which decreased the redness (a*), lightness (L*), blueness (b*), variation in the color parameters (ΔE*) and the whiteness index (WI). The weight of the capsule shells ranged between 0.080 g and 0.25 g and the moisture content was between 5% and 11%. Ash contents for all the formulations were below 5% and the sensitivity of capsules at pH 7 was higher than that at acidic pH. Highest rupture times were observed with simulated gastric fluid (SGF, pH 1) for all formulations. Increased gelatin concentration decreased the resistance of the capsule to force while increased sodium alginate concentration had no effect on resistance to force.

Using only type B gelatin produces hard capsule shells which are too brittle.

Effects of plasticizers on the properties of fish myofibrillar protein film

This study investigated the effects of various plasticizer types [glycerol (GLY), sorbitol (SOR), and polyethylene glycol (PEG)] on the properties of fish myofibrillar protein (FMP) film. FMP films plasticized with GLY showed the greatest elongation at break (116.53%). It also showed the greatest water vapor permeability (1.43 × 10-10 g m-1 s-1 Pa-1). The film plasticized with SOR exhibited the highest tensile strength (12.56 MPa) and film solubility (62.59%). PEG plasticized film showed to have yellowish colour as indicated by the high b* value and low light transmission at 280 nm. Furthermore, FMP films containing PEG and SOR possessed lower moisture content than films with GLY. FT-IR and electrophoretic properties were not affected by any types of plasticizer. The appearance of the FMP film was similar to that of the PVC film. It was concluded that plasticizers had major effects on FMP films. They not only plasticize the protein film, but also affected other major film properties.

A High-Performance Soy Protein Isolate-Based Nanocomposite Film Modified with Microcrystalline Cellulose and Cu and Zn Nanoclusters

Soy protein isolate (SPI)-based materials are abundant, biocompatible, renewable, and biodegradable. In order to improve the tensile strength (TS) of SPI films, we prepared a novel composite film modified with microcrystalline cellulose (MCC) and metal nanoclusters (NCs) in this study. The effects of the modification of MCC on the properties of SPI-Cu NCs and SPI-Zn NCs films were investigated. Attenuated total reflectance-Fourier transformed infrared spectroscopy analyses and X-ray diffraction patterns characterized the strong interactions and reduction of the crystalline structure of the composite films. Scanning electron microscopy (SEM) showed the enhanced cross-linked and entangled structure of modified films. Compared with an untreated SPI film, the tensile strength of the SPI-MCC-Cu and SPI-MCC-Zn films increased from 2.91 to 13.95 and 6.52 MPa, respectively. Moreover, the results also indicated their favorable water resistance with a higher water contact angle. Meanwhile, the composite films exhibited increased initial degradation temperatures, demonstrating their higher thermostability. The results suggested that MCC could effectively improve the performance of SPI-NCs films, which would provide a novel preparation method for environmentally friendly SPI-based films in the applications of packaging materials.