Gelatin/chitosan based films loaded with nanocellulose from soybean straw and activated with "Pitanga" (Eugenia uniflora L.) leaf hydroethanolic extract in W/O/W emulsion

Improving the Properties of Gelatin-Based Films by Incorporation of "Pitanga" Leaf Extract and Crystalline Nanocellulose

Biopolymer-based films can be activated by the incorporation of active compounds into their matrix. Plant extracts are rich in phenolic compounds, which have antimicrobial and/or antioxidant properties. The aim of this study was to produce gelatin-based active films and nanocomposite films incorporated with "pitanga" (Eugenia uniflora L.) leaf extract (PLE) and/or crystalline nanocellulose extracted from soybean straw (CN), and to study the physicochemical, functional, microstructural, thermal, UV/Vis light barrier, and antioxidant properties of these materials. PLE enhanced some film properties, such as tensile strength (from 30.2 MPa to 40.6 MPa), elastic modulus (from 9.3 MPa to 11.3 MPa), the UV/Vis light barrier, and antioxidant activity, in addition to affecting the microstructural, surface, and color properties. These improvements were even more significant in nanocomposites simultaneously containing PLE and CN (59.5 MPa for tensile strength and 15.1 MPa for elastic modulus), and these composites also had lower moisture content (12.2% compared to 13.5-14.4% for other treatments) and solubility in water (from 48.9% to 44.1%). These improvements may be the result of interactions that occur between PLE's polyphenols and gelatin, mainly in the presence of CN, probably due to the formation of a stable PLE-CN-gelatin complex. These results are relevant for the food packaging sector, as the activated nanocomposite films exhibited enhanced active, barrier, and mechanical properties due to the presence of PLE and CN, in addition to being entirely produced with sustainable components from natural and renewable sources.

Release kinetic modeling of Satureja Khuzestanica Jamzad essential oil from fish gelatin/succinic anhydride starch nanocomposite films: The effects of temperature and nanocellulose concentration

Fish gelatin (FG) and octenyl succinic anhydride starch (OSAS) composite films loaded with 1, 2, 3 and 4 wt% bacterial nanocellulose (BNC) and Satureja Khuzestanica Jamzad essential oil (SKEO) were achieved successfully and their physicochemical and release properties were investigated. The results revealed that incorporation of BNC improved the tensile strength which was associated with FE-SEM, FTIR and XRD. Moreover, this study focused on the release modeling of SKEO in 4, 25 and 37 °C from nanocomposite films using different release kinetic and Arrhenius models. Also, analysis of variance-simultaneous component analysis (ASCA) and exploratory data visualization by principal component analysis (PCA) were carried out to investigate the effects of two controlled factors. Consequently, the Peleg model showed the best fitting of experimental data. The activation energies decreased by increasing the BNC concentration. This research demonstrated the nanocomposite film containing SKEO would be a suitable candidate for active food packaging.

Improvement of cross-linked films based on chitosan/diepoxy-poly (ethylene glycol) incorporating trans-cinnamaldehyde essential oil: Preparation, properties, and application in banana storage

In this study, development of bioactive coatings containing 1 % (w/v) chitosan (CS), 0.6 % (w/v) diepoxy-polyethylene glycol (PEG), and trans-cinnamaldehyde (CIN) was achieved. The physicochemical and biological properties of the coatings were investigated. The tensile strength, light transmission, water vapor permeability (WVP), and antibacterial properties were enhanced by the incorporation of CIN. The CIN-containing films appeared compact and rough, as observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). In addition, the quality attributes of the bananas were evaluated at room temperature for 24 days, and the results showed that the CS/PEG/CIN coating delayed the respiration peak, weight loss, sugar content loss, and maintained firmness, color, total soluble solids (TSS), titratable acid (TA), and the appearance of the bananas. Principal component analysis (PCA) revealed that the bioactive coating significantly affected the respiration rate and weight loss of bananas.

An Updated Comprehensive Overview of Different Food Applications of W1/O/W2 and O1/W/O2 Double Emulsions

Double emulsions (DEs) present promising applications as alternatives to conventional emulsions in the pharmaceutical, cosmetic, and food industries. However, most review articles have focused on the formulation, preparation approaches, physical stability, and release profile of encapsulants based on DEs, particularly water-in-oil-in-water (W1/O/W2), with less attention paid to specific food applications. Therefore, this review offers updated detailed research advances in potential food applications of both W1/O/W2 and oil-in-water-in-oil (O1/W/O2) DEs over the past decade. To this end, various food-relevant applications of DEs in the fortification; preservation (antioxidant and antimicrobial targets); encapsulation of enzymes; delivery and protection of probiotics; color stability; the masking of unpleasant tastes and odors; the development of healthy foods with low levels of fat, sugar, and salt; and design of novel edible packaging are discussed and their functional properties and release characteristics during storage and digestion are highlighted.

Development of Eco-Friendly Biocomposite Films Based on Opuntia ficus-indica Cladodes Powder Blended with Gum Arabic and Xanthan Envisaging Food Packaging Applications

Currently, food packaging is facing a critical transition period and a major challenge: it must preserve the food products' quality and, at the same time, it must meet the current requirements of the circular economy and the fundamental principles of packaging materials eco-design. Our research presents the development of eco-friendly packaging films based on Opuntia ficus-indica cladodes (OFIC) as renewable resources. OFIC powder (OFICP)-agar, OFICP-agar-gum arabic (GA), and OFICP-agar-xanthan (XG) blend films were eco-friendlily prepared by a solution casting method. The films' properties were investigated by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (X-RD), and differential scanning calorimeter (DSC). Water solubility and moisture content were also determined. Morphology, thickness, molecular interactions, miscibility, crystallinity, and thermal properties, were affected by adjusting the gums (GA and XG) content and glycerol in the blend films. Moisture content increased with increasing glycerol and XG content, and when 1.5 g of GA was added. Water solubility decreased when glycerol was added at 50% and increased with increasing GA and XG content. FTIR and XRD confirmed strong intermolecular interactions between the different blend film compounds, which were reflected in the shifting, appearance, and disappearance of FTIR bands and XRD peaks, indicating excellent miscibility. DSC results revealed a glass transition temperature (Tg) below room temperature for all prepared blend films, indicating that they are flexible and soft at room temperature. The results corroborated that the addition of glycerol at 30% and the GA to the OFICP increased the stability of the film, making it ideal for different food packaging applications.

Films Based on Biopolymers Incorporated with Active Compounds Encapsulated in Emulsions: Properties and Potential Applications-A Review

The rising consumer demand for safer, healthier, and fresher-like food has led to the emergence of new concepts in food packaging. In addition, the growing concern about environmental issues has increased the search for materials derived from non-petroleum sources and biodegradable options. Thus, active films based on biopolymers loaded with natural active compounds have great potential to be used as food packaging. However, several lipophilic active compounds are difficult to incorporate into aqueous film-forming solutions based on polysaccharides or proteins, and the hydrophilic active compounds require protection against oxidation. One way to incorporate these active compounds into film matrices is to encapsulate them in emulsions, such as microemulsions, nanoemulsions, Pickering emulsions, or double emulsions. However, emulsion characteristics can influence the properties of active films, such as mechanical, barrier, and optical properties. This review addresses the advantages of using emulsions to encapsulate active compounds before their incorporation into biopolymeric matrices, the main characteristics of these emulsions (emulsion type, droplet size, and emulsifier nature), and their influence on active film properties. Furthermore, we review the recent applications of the emulsion-charged active films in food systems.

Bio-Nanocomposite Based on Edible Gelatin Film as Active Packaging from Clarias gariepinus Fish Skin with the Addition of Cellulose Nanocrystalline and Nanopropolis

This study develops bio-nano composite gelatin-based edible film (NEF) by combining nanogelatin, cellulose nanocrystal (CNC), and nanopropolis (NP) fillers to improve the resulting film characteristics. The NEF was characterized in terms of thickness, swelling, pH, water content, solubility, vapor and oxygen permeability, mechanical properties, heat resistance, morphology, transparency, and color. The results showed that the thickness and swelling increased significantly, whilst the pH did not significantly differ in each treatment. The water content and the water solubility also showed no significant changes with loadings of both fillers. At the same time, vapor and oxygen permeability decreased with addition of the fillers but were not significantly affected by the loading amounts. The heat resistance properties increased with the filler addition. Tensile strength and Young’s modulus increased for the films loaded with >3% CNC. The elongation at break showed a significant difference together with transparency and color change. The greater the CNC concentration and NP loading were, the darker the resulting transparency and the color of the NEF. Overall results show a considerable improvement in the properties of the resulting NEFs with the incorporation of CNC and NP fillers.

Moth Bean, Gelatin, and Murraya Koenigii Leaves Extract-Based Film and Coating: Effect of Coating on Shelf and Quality of Solanum Melongena

Moth bean starch (MS), gelatin (GA), and Murraya koenigii leaves extract (ME) are blended at different compositions to prepare film and coating according to casting and dipping approaches. Different MS, GA, and ME compositions were used to synthesize films and coating. The film compositions (MS : GA: ME: 60 : 20 : 20 and MS : GA: ME:20 : 60 : 20) were represented in terms of F3 and F4, respectively. The results showed that F3 exhibited better physicochemical properties than other films. In addition, SEM images showed that all components of the films were uniformly mixed and formed smooth surface morphology without cracks and bubbles. FTIR results indicate that ME in the films induces interactions between the film components, causing an improvement in compactness. Moreover, an optimized film-forming solution was tested as a coating. Parameters such as skin tightness, weight loss, pH, titratable acidity, and sensory analysis were considered to check the quality of coated Solanum melongena during storage. The results show that the formulation effectively maintains the quality parameters during storage. Furthermore, it also notices that coating extends the shelf life of Solanum melongena by one week.

Rheological and Viscoelastic Properties of Chitosan Solutions Prepared with Different Chitosan or Acetic Acid Concentrations

Chitosan (Ch) is a partially crystalline biopolymer, insoluble in pure water but soluble in acid solutions. It has attracted interest from researchers to prepare solutions using different acid types and concentrations. This research aims to study both the effect of chitosan (Ch) or acetic acid (Ac) concentrations, at different temperatures, on rheological and viscoelastic properties of Ch solutions. To study the effect of Ch, solutions were prepared with 0.5−2.5 g Ch/100 g of solution and Ac = 1%, whereas to study the effect of Ac, the solutions were prepared with 2.0 g of Ch/100 g of solution and Ac = 0.2−1.0%. Overall, all analyzed solutions behaved as pseudoplastic fluid. The Ch strongly affected rheological properties, the consistency index (K) increased and the index flow behavior (n) decreased as a function of Ch. The activation energy, defined as the energy required for the molecule of a fluid to move freely, was low for Ch = 0.5%. The effect of Ac was less evident. Both K and n varied according to a positive and negative, respectively, parabolic model as a function of Ac. Moreover, all solutions, irrespective of Ch and Ac, behaved as diluted solutions, with G” > G’. The relaxation exponent (n”) was always higher than 0.5, confirming that these systems behaved as a viscoelastic liquid. This n” increased with Ch, but it was insensitive to Ac, being slightly higher at 45 °C.

Advances in biopolymeric active films incorporated with emulsified lipophilic compounds: a review

The attention towards active films has increased due to consumer demand for high-quality foods without chemical additives. Active biopolymer-based films have shown great potential for active films by impacting food safety, acting as the carriers of various natural antioxidant and antimicrobial compounds, and decreasing environmental pollution from petrol-derived packaging materials. However, there is a wide range of challenges concerning the different characteristics of biopolymers and plasticizers, often hygroscopic/hydrophilic, compared to numerous lipophilic bioactive compounds. Therefore, recent studies have focused on applying oil-in-water emulsion-based systems to enhance the lipophilic bioactive compounds' dispersibility into the film matrix, improving their performance. It is worth emphasizing that resulting complex systems give rise to new challenges such as (i) dispersion technology of the bioactive compounds with minimum adverse effects on its bioactivities, (ii) interactions between different components of the active films, giving rise to new physicochemical properties, and (iii) the change of the diffusion properties of bioactive compounds into the active films, resulting in different release properties. These challenges are profound and critically discussed in this review, as well as the encapsulation techniques employed in preparing emulsions loaded with lipophilic bioactive compounds for the active film development. An outlook of future directions in the research, development, and application of these active films are given.

The attention towards active films has increased due to consumer demand for high-quality foods without chemical additives.