Physical and antioxidant properties of starch/gelatin films incorporated with Garcinia atroviridis leaves

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Research background

Nowadays, there is a growing interest in active packaging with the addition of natural extracts due to safety concerns and consumer preferences. Physalis angulata is a medicinal and edible species of the Solanaceae family and is rich in phenolic compounds. Phenolic compounds, the secondary metabolites, are synthesised and stored in all plant tissues. They can be used as plasticizers or fillers to improve the interfacial interaction between the two biopolymers and prevent the transfer of moisture and gas from the food product and extend the shelf life to some degree.

Experimental approach

The effect of a three-layer (P/G/B) film based on polylactic acid (P), gelatine (G) and polybutylene adipate-co-terephthalate (B) incorporated or not with Physalis leaf extract (PLE) on the quality changes of fish meat powder (sample) stored at 27-30 °C (30 days) was investigated in comparison with control (uncovered), polyethylene (PE), polylactic acid, polybutylene adipate-co-terephthalate and gelatine films. The samples were sealed in a cylindrical bottle covered with the prepared films. The storage properties such as moisture content, pH, peroxide value (PV), thiobarbituric acid reactive substances (TBARS), total volatile basic nitrogen (TVB-N), changes in colour, sensory properties and volatile compounds of samples packed with the developed films were analysed.

Results and conclusions

The moisture content was lower in the sample covered with the P/G/B-PLE-7 % film throughout the storage period. However, the sample covered with PE film had the highest PV (p<0.05). TBARS, TVB-N and volatile compounds decreased in the sample covered with P/G/B-PLE-7 % on day 30 of storage. The incorporation of Physalis leaf extract into the three-layer film improved the properties of the film and extended the shelf life of fish meat powder. Thus, the addition of Physalis leaf extract to the three-layer film could serve as a biodegradable active packaging and be a promising substitute for commercial plastic films.

Novelty and scientific contribution

This is the first report on the study of chemical changes of fish meat powder covered with a three-layer (P/G/B) film incorporated with Physalis leaf extract. This will lead to a better understanding of the role of the three-layer (P/G/B) film containing Physalis leaf extract on the extension of shelf life of fish meat powder.

An Antibacterial and Antioxidant Food Packaging Film Based on Amphiphilic Polypeptides-Resveratrol-Chitosan

Antimicrobial and antioxidant packaging films play a crucial role in extending food shelf life, maintaining quality, and enhancing safety by inhibiting microbial growth and slowing oxidation processes. However, most commercial preservative films suffer from limited antimicrobial and antioxidant properties. Moreover, these films are made from petroleum-based materials that degrade into microplastics, resulting in environmental contamination and potential health risks for humans. Herein, an antibacterial and antioxidant food packaging film (CS-SAP@R) is developed by integrating star-shaped amphiphilic polypeptides (SAP) and resveratrol (R) into the chitosan (CS) matrix. The incorporation of SAP not only effectively addresses the existing compatibility issues between the highly hydrophobic resveratrol and water-soluble CS film, but also significantly enhances the antimicrobial properties of CS. Additionally, the well-integrated resveratrol molecules endow the film with superior antioxidant properties. Furthermore, CS-SAP@R has achieved bacterial killing rates of 97.31% against E. coli and 99.05% against S. aureus. The enhanced characteristics of the CS-SAP@R film contribute to its exceptional preservation performance, effectively extending the shelf life of perishable products by ≈3 days when stored at 4 °C. These remarkable attributes underscore the benefits of polypeptide-based biopolymers and demonstrate the potential applicability of the CS-SAP@R film in effectively safeguarding perishable products.

A novel gelatin composite film with melt extrusion for walnut oil packaging

Gelatin have excellent film-forming and barrier properties, but its lack of biological activity limits its application in packaging. In this study, fish gelatin incorporated with apple polyphenol/cumin essential oil composite films were successfully prepared by melt extrusion. The cross-linking existed in gelatin and apple polyphenol improved the thermal stability and oxidation resistance of the film. The synergistic effect of apple polyphenols and cumin essential oil decreased the sensitivity of the film to water, especially the water solubility decreased from 41.60 % to 26.07 %. The plasticization of essential oil nearly doubled the elongation at break while maintaining the tensile strength of the film (11.45 MPa). Furthermore, the FG-CEO-AP film can inhibit peroxide value to extend the shelf life about 20 days in the walnut oil preservation. In summary, the apple polyphenol/cumin essential oil of FG film exhibits excellent comprehensive properties and high preparation efficiency for utilization as an active packaging material.

Development of a Multifunctional Chitosan-Based Composite Film from Crab Shell (Portunus segnis) and Algae (Ulva lactuca) with Enhanced Antioxidant and Antimicrobial Properties for Active Food Packaging

Eco-friendly, bioactive and edible films from renewable resources are increasingly regarded as viable replacements for petroleum-based packaging. This study investigates the application of Ulva lactuca macroalgae powder (ULP) as an active additive in crab (Portunus segnis) chitosan-based films for natural food packaging. Films with ULP concentrations of 0.5, 1.5, and 2.5% were prepared using a solvent-casting method with glycerol as a plasticizer. Their physicochemical, mechanical, functional, and biological properties were evaluated comprehensively. Fourier-transform infrared spectroscopy revealed intermolecular interactions between ULP's polyphenolic compounds and the chitosan matrix, enhancing the films' structural integrities. ULP's incorporation reduced the moisture content, water solubility, lightness (L*), redness (a*), and whiteness index values while significantly (p < 0.05) increasing the yellowness (b*), total color difference (ΔE), yellowness index (YI), tensile strength (TS), and elongation at break (EB). The antioxidant activity improved in a concentration-dependent manner, as evidenced by the high free-radical scavenging capacity. Moreover, antimicrobial tests showed significant inhibitory effects against pathogenic strains. Biodegradability tests confirmed that the films decomposed entirely within 12 days under soil burial conditions, reinforcing their environmental compatibility. These results highlight the multifunctional potential of chitosan-ULP composite films, combining enhanced mechanical properties, bioactivity, and sustainability. By utilizing renewable and biodegradable materials, this work contributes to reducing waste and promoting resource efficiency, aligning with the principles of a circular economy and environmental preservation.

Extraction of Bioactive Compounds From Centella asiatica and Enlightenment of Its Utilization Into Food Packaging: A Review

Centella asiatica is a medicinal herb, well known for its phytochemical activities because of the presence of terpenoids and polyphenols, which contribute to the bioactivity of herb extract that can be effectively utilized in the packaging industry. Biopolymers infused with C. asiatica extract could be a promising solution in the food sector. The antibacterial and antioxidant qualities of C. asiatica can help preserve the quality and lengthen the freshness of food products, thereby preventing food loss. Selection of a suitable extraction method is essential to retain the yield and properties of the bioactive compounds of C. asiatica extract. Many research has been conducted on the separation of C. asiatica by using conventional and novel extraction techniques and its execution in packaging as a functional component. This review provides an overview of the extraction of phytochemicals from C. asiatica and its utilization in biopolymer film as an active component to modify the packaging film characteristics.

Novel Biodegradable Nanoparticulate Chain-End Functionalized Polyhydroxybutyrate-Caffeic Acid with Multifunctionalities for Active Food Coatings

The bioactivities of polyhydroxyalkanoates have been curtailed owing to the lack of bioactive functional groups in their backbones. In this regard, polyhydroxybutyrate (PHB) produced from new locally isolated Bacillus nealsonii ICRI16 was chemically modified for enhancing its functionality, stability as well as solubility. First, PHB was transformed to PHB-diethanolamine (PHB-DEA) by transamination. Subsequently, for the first time, the chain ends of the polymer were substituted by caffeic acid molecules (CafA), generating novel PHB-DEA-CafA. The chemical structure of such a polymer was confirmed by Fourier-transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (¹H NMR). The modified polyester demonstrated improved thermal behavior compared to PHB-DEA as was shown by thermogravimetric analysis, derivative thermogravimetry, and differential scanning calorimetry analyses. Interestingly, 65% of PHB-DEA-CafA was biodegraded in a clay soil environment after 60 days at 25 °C, while 50% of PHB was degraded within the same period. On another avenue, PHB-DEA-CafA nanoparticles (NPs) were successfully prepared with an impressive mean particle size of 223 ± 0.12 nm and high colloidal stability. The nanoparticulate polyester had powerful antioxidant capacity with an IC₅₀ of 32.2 mg/mL, which was the result of CafA loading in the polymer chain. More importantly, the NPs had a considerable effect on the bacterial behavior of four food pathogens, inhibiting 98 ± 0.12% of Listeria monocytogenes DSM 19094 after 48 h of exposure. Finally, the raw polish sausage coated with NPs had a significantly lower bacterial count of 2.11 ± 0.21 log cfu/g in comparison to other groups. When all these positive features are recognized, the polyester described herein could be considered as a good candidate for commercial active food coatings.

3D Printed gelatin film with Garcinia atroviridis extract

Active packaging, such as edible film with antibacterial properties, can help extend the shelf life of food. The research aimed to develop a 3D printed gelatin edible film by using glycerol and Garcinia atroviridis extract (GAE). Mechanical properties of gelatin gel, physical, mechanical, and antimicrobial properties of edible film with glycerol and GAE were determined. Water solubility, total colour difference, and elongation of break of gelatin edible film increased as glycerol concentration increased (0-25% w/w), whereas tensile strength and Young's modulus value decreased from 26.5 to 4.64 MPa and 3.04 to 0.13 MPa, respectively. On the other hand, increasing GAE from 1 to 4% (w/w) increases elongation at break from 40.83 to 98.27%, while decreasing edible film tensile strength and gelatin gel hardness value from 8.94 to 6.21 MPa and 1848.67 to 999.67 g, respectively. Using 20% (w/w) glycerol and 4% (w/w) GAE, the best 3D printed film with low tensile strength (6.21 MPa), high elongation at break (98.27%), and antibacterial activity against S. aureus with 7.23 mm zone of inhibition was developed. It seems to have a great potentiality as an active packaging material for 3D printed gelatin edible film.

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.

Effect on the Properties of Edible Starch-Based Films by the Incorporation of Additives: A Review

At present, people more actively pursuing biodegradable-based food packaging to lower the environmental problems of plastic-based packaging. Starch could become a promising alternative to plastic because of its properties (easily available, nontoxic, tasteless, biodegradable, ecofriendly, and edible). This review article is focused mainly on the impact of the properties of starch-based biodegradable films, such as their thickness, morphology, and optical, water-barrier, mechanical, oxygen-barrier, antioxidant, and antimicrobial properties, after the incorporation of additives, and how such films fulfill the demands of the manufacturing of biodegradable and edible food-based film with preferable performance. The incorporation of additives in starch-based films is largely explained by its functioning as a filler, as shown via a reduction in water and oxygen permeability, increased thickness, and better mechanical properties. Additives also showed antimicrobial and antioxidant properties in the films/coatings, which would positively impact the shelf life of coated or wrapped food material.

Synthesis, Characterization, and Optimization Studies of Starch/Chicken Gelatin Composites for Food-Packaging Applications

The indiscriminate use of plastic in food packaging contributes significantly to environmental pollution, promoting the search for more eco-friendly alternatives for the food industry. This work studied five formulations (T1–T5) of biodegradable cassava starch/gelatin films. The results showed the presence of the starch/gelatin functional groups by FT-IR spectroscopy. Differential scanning calorimetry (DSC) showed a thermal reinforcement after increasing the amount of gelatin in the formulations, which increased the crystallization temperature (Tc) from 190 °C for the starch-only film (T1) to 206 °C for the film with 50/50 starch/gelatin (T3). It also exhibited a homogeneous surface morphology, as evidenced by scanning electron microscopy (SEM). However, an excess of gelatin showed low compatibility with starch in the 25/75 starch/gelatin film (T4), evidenced by the low Tc definition and very rough and fractured surface morphology. Increasing gelatin ratio also significantly increased the strain (from 2.9 ± 0.5% for T1 to 285.1 ± 10.0% for T5) while decreasing the tensile strength (from 14.6 ± 0.5 MPa for T1 to 1.5 ± 0.3 MPa for T5). Water vapor permeability (WVP) increased, and water solubility (WS) also decreased with gelatin mass rising in the composites. On the other hand, opacity did not vary significantly due to the films’ cassava starch and gelatin ratio. Finally, optimizing the mechanical and water barrier properties resulted in a mass ratio of 53/47 cassava starch/gelatin as the most appropriate for their application in food packaging, indicating their usefulness in the food-packaging industry.

Antioxidant Films from Cassava Starch/Gelatin Biocomposite Fortified with Quercetin and TBHQ and Their Applications in Food Models

Edible and active packaging are attractive for use in food packaging applications due to their functionality and sustainability. This research developed new antioxidant active food packaging materials from cassava starch/gelatin (7:3 w/w) composite films with varied antioxidant types (quercetin and tertiary butylhydroquinone (TBHQ)) and concentrations (0–200 mg/200 mL film-forming solution) and evaluated their properties. Antioxidant addition altered the mechanical and barrier properties of the films. At 34% relative humidity (RH), increasing the concentration of quercetin increased the tensile strength and decreased the elongation at break of the composite films. Increasing quercetin and TBHQ contents increased the film water solubility and water vapor transmission rate. Intermolecular interactions between the antioxidants and films, as found in Fourier transform infrared (FT-IR) spectra and XRD micrographs, were related to the changed film functionalities. In food application studies, the cassava starch/gelatin films containing quercetin and TBHQ retarded the oxidation of lard (more than 35 days) and delayed the redness discoloration of pork. Cassava starch/gelatin composite films integrated with quercetin and TBHQ can be utilized as active packaging that delays oxidation in foods.