Corn starch and methylcellulose edible films incorporated with fireweed (Chamaenerion angustifolium L.) extract: Comparison of physicochemical and antioxidant properties

3D printed cinnamon essential oil/banana peel carbon dots loaded corn starch/gelatin bilayer film with enhanced functionality for food packaging application

Using 3D printing technology, a gelatin-polyvinyl alcohol‑carbon dots (GPC) layer+corn starch-polyvinyl alcohol-cinnamon essential oil (CPC) layer active bilayer film with an external barrier function and an internal controlled-release effect was successfully produced for food preservation. The GPC film was provided with potent antioxidant and UV blocking properties by the banana peel carbon dots (CDs). The cinnamon essential oil (CEO) had the strongest interaction with the film matrix at 3% (w/w), causing the CPC film having the lowest surface wettability, good integrity, and lowest crystallinity. The CEO's stability and releasing effectiveness were greatly enhanced by the creation of a bilayer film. At 60% filling rate of the CPC layer, the bilayer film showed the highest CEO retention after drying and the best CEO release performance. Finally, the created active bilayer film was found to significantly improve the sensory quality stability of the spicy essential oil microcapsule powders. It also successfully extended the mangoes' shelf life by delaying browning and rot.

A comprehensive review on starch-based sustainable edible films loaded with bioactive components for food packaging

Biopolymers like starch, a renewable and widely available resource, are increasingly being used to fabricate the films for eco-friendly packaging solutions. Starch-based edible films offer significant advantages for food packaging, including biodegradability and the ability to extend shelf life. However, they also present challenges such as moisture sensitivity and limited barrier properties compared to synthetic materials. These limitations can be mitigated by incorporating bioactive components, such as antimicrobial agents or antioxidants, which enhance the film's resistance to moisture and improve its barrier properties, making it a more viable option for food packaging. This review explores the emerging field of starch-based sustainable edible films enhanced with bioactive components for food packaging applications. It delves into fabrication techniques, structural properties, and functional attributes, highlighting the potential of these innovative films to reduce environmental impact and preserve food quality. Key topics discussed include sustainability issues, processing methods, performance characteristics, and potential applications in the food industry. The review provides a comprehensive overview of current research and developments in starch-based edible films, presenting them as promising alternatives to conventional food packaging that can help reduce plastic waste and environmental impact.

Carbon dot/g-C3N4-mediated self-activated antimicrobial nanocomposite films for active packaging applications

A novel carbon dot/g-C3N4 nanocomposite (CCN) exhibiting enhanced photocatalytic activity was developed and used as a photoactive nanofiller to construct corn starch/carboxymethyl cellulose (CS/CMC)-based functional films. The morphologies and structures of the CCN-CS/CMC composite films were investigated with scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The effects of the CCN on the physicochemical properties and antibacterial activities of the films were analyzed. The properties of the films were optimized with the addition of CCN (0.20 mg/mL), and the tensile strength of the film was increased to 11.9 MPa and the water contact angle was increased to 103.39°. The optimal active film showed > 99.9 % antibacterial efficiencies against Escherichia coli and Staphylococcus aureus under visible light and prolonged the shelf lives of bananas for more than four days compared to the 4-day shelf life of the control. This work provides a novel route for developing antimicrobial active packaging.

Phytochemical Profiling and Pharmacological Evaluation of Leaf Extracts of Ruellia tuberosa L.: An In Vitro and In Silico Approach

The present study was designed to appraise the photoprotective, antioxidant, and antibacterial bioactivities of Ruellia tuberosa leaves extracts (RtPE, RtChl, RtEA, RtAc, RtMe, and RtHMe). The results showed that, RtHMe extracts of R. tuberosa was rich in total phenolic content, i. e., 1.60 mgGAE/g dry extract, while highest total flavonoid content was found in RtAc extract, i. e., 0.40 mgQE/g. RtMe showed effective antioxidant activity (%RSA: 58.16) at the concentration of 120 μL. RtMe, RtEA and RtHMe exhibited effective in vitro antibacterial activity against Gram-negative bacteria (E. coli). In silico docking studies revealed that paucifloside (-11.743 kcal/mol), indole-3-carboxaldehyde (-7.519 kcal/mol), nuomioside (-7.275 kcal/mol), isocassifolioside (-6.992 kcal/mol) showed best docking score against PDB ID 2EX8 [penicillin binding protein 4 (dacB) from Escherichia coli, complexed with penicillin-G], PDB ID 6CQA (E. coli dihydrofolate reductase protein complexed with inhibitor AMPQD), PDB ID 2Y2I [Penicillin-binding protein 1B in complex with an alkyl boronate (ZA3)] and PDB ID 2OLV (from S. aureus), respectively. Docked phytochemicals also showed good drug likeness properties.

Determination of Pentacyclic Triterpenoids in Plant Biomass by Porous Graphitic Carbon Liquid Chromatography-Tandem Mass Spectrometry

Pentacyclic triterpenoids (PCTs), which possess a number of bioactive properties, are considered one of the most important classes of secondary plant metabolites. Their chromatographic determination in plant biomass is complicated by the need to separate a large number of structurally similar compounds belonging to several classes that differ greatly in polarity (monools, diols, and triterpenic acids). This study proposes a rapid, sensitive, and low-cost method for the simultaneous quantification of ten PCTs (3β-taraxerol, lupeol, β-amyrin, α-amyrin, betulin, erythrodiol, uvaol, betulinic, oleanolic, and ursolic acids) by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) using porous graphitic carbon (Hypercarb) as a stationary phase capable of hydrophobic retention and specific interactions with analytes. Revealing the effects of the mobile phase composition, pH, ionic strength, and column temperature on retention and selection of chromatographic conditions on this basis allowed for the effective separation of all target analytes within 8 min in gradient elution mode and attaining limits of detection in the range of 4-10⁴ µg L^-1. The developed method was fully validated and successfully tested in the determination of PCTs in common haircap (Polytrichum commune) and prairie sphagnum (Sphagnum palustre) mosses, and fireweed (Chamaenerion angustifolium) stems and leaves.

The physiochemical and photodynamic inactivation properties of corn starch/erythrosine B composite film and its application on pork preservation

This study explored the effect of erythrosine B (EB) as a photosensitizer in corn starch (CS) film and its physicochemical properties and photodynamic bacteriostatic ability against Staphylococcus aureus, Escherichia coli, and Salmonella both in vitro and inoculated on pork under the irradiation of D65 light-emitting diode (LED) (400-800 nm). The study revealed that the physiochemical properties of CS films: moisture content, water solubility, and water vapor transmission were improved with the addition of EB. In addition, the elasticity and the thermal stability of the film were enhanced. The results showed that the CS-EB films stimulated a maximum of 26.36 μg/mL hydrogen peroxide and 74.5 μg/g hydroxyl radical under irradiation. The CS composite films with a 5 % concentration of EB inhibited the bacterial growth by 4.7 Log CFU/mL in vitro after 30 min of illumination, and 2.4 Log CFU/mL on the pork samples under the same experimental condition. Moreover, the antibacterial ability was enhanced with the increase in EB concentration. Overall, the CS-EB composite films can inhibit the growth of bacteria through photodynamic inactivation and has the potential to become a new type of environmentally friendly packaging material.

The Impact of Solid-Phase Fermentation on Flavonoids, Phenolic Acids, Tannins and Antioxidant Activity in Chamerion angustifolium (L.) Holub (Fireweed) Leaves

At present, the consumption of medical plants and functional foods is growing across the whole world. Fireweed (Chamerion angustifolium (L.) Holub), an important medicinal plant that has various pharmacological effects (antioxidant, anti-inflammatory, anticancer and others), can improve the state of health and well-being and reduce the risk of various diseases. The aim of this work was to investigate polyphenols (flavonoids, phenolic acids and tannins) and antioxidant activity in fireweed leaves fermented for 24, 48 and 72 h in solid-phase fermentation under aerobic and anaerobic conditions. High-performance liquid chromatography (HPLC) for polyphenols and the spectrophotometric method based on quenching of stable colored radical (ABTS•+) for antioxidant activity determinations were used. The results showed that the highest amounts of total polyphenols, total flavonoids and tannin oenothein B in the dried matter were found after 72 h and the highest total phenolic acids after 48 h of anaerobic solid-phase fermentation. The highest antioxidant activity was found after 72 h of solid-phase fermentation under aerobic conditions.

Influence of Dielectric Barrier Discharge Cold Plasma Treatment on Starch, Gelatin, and Bacterial Cellulose Biodegradable Polymeric Films

The environmental damage caused by plastic packaging and the need to reduce pollution requires actions to substitute plastic materials for more sustainable and biodegradable materials. Starch, gelatin, and bacterial cellulose films are three potential biodegradable polymeric films for use in packaging. However, these materials need improvements in their physical, chemical, and mechanical properties to be used in packaging. In this work, these films were treated with cold plasma to evaluate the effects of treatment conditions on several physical, chemical, and mechanical properties. The dielectric barrier discharge plasma technology was applied with varying treatment times (0 to 20 min) and excitation frequencies (50 to 900 Hz) at 20 kV. The optimal excitation frequency for starch films (50 Hz) was different from the optimal frequency for gelatin and bacterial cellulose films (900 Hz), indicating a high dependency on the treatment in this variable that is often neglected. Plasma treatment improved the hydrophobicity, surface morphology, water resistance, and mechanical properties of all three films, with the advantage of not recurring to chemical or biological additives.

Biodegradable Active Packaging Material Containing Grape Seed Ethanol Extract and Corn Starch/κ-Carrageenan Composite Film

An active film composed of corn starch/κ-carrageenan and ethanolic grape seed extract (0, 1, 3, and 5 wt% of GSE on corn starch basis) were successfully prepared using the solvent casting technique. The effects of the different concentrations of ethanolic grape seed extract (GSE) on the physicochemical properties, antioxidant properties, and antibacterial properties of CS/κC films were analyzed. The results showed that the addition of GSE inhibited the recrystallization of starch in the composite film. The glass transition temperature of composite film is 121.65 °C. With the addition of GSE, the surface roughness of the composite film increased, and the cross-section displayed a stratification phenomenon. Meanwhile, when GSE was added to the composite film, the tensile strength of the composite film decreased (3.50 ± 0.27 MPa), the elongation at break increased (36.87 ± 2.08%), and the WVP increased (1.58 ± 0.03 g mm/m2·d· kPa). With the increase of the concentration of GSE in the composite film, the a* value and b* value of the composite film increase, the L* value decreases, and the opacity increases. The lipid oxidation test proved that the composite films containing 1% GSE has a significant inhibitory effect on the oxidation of lard (p < 0.05). The above results indicate that the GSE can be used as a food-grade packaging material and has a good application prospect in the food industry.

A Comprehensive Study on Gelatin- and Whey Protein Isolate-Based Edible Films as Carriers of Fireweed (Epilobium angustifolium L.) Extract

Gelatin (GEL) and whey protein isolate (WPI) are often taken into account as carriers of phytoantioxidants for developing active packaging. The materials obtained, however, have not yet been systematically compared to demonstrate their potential benefits and drawbacks. Fireweed extract (FE) is a rich source of polyphenols with high antioxidant activity. Therefore, in this study, the structural, physicochemical, and antiradical properties of GEL and WPI films incorporated with freeze-dried fireweed extract (FE; 0, 0.0125, 0.025, 0.05%) were simultaneously evaluated. As verified by X-ray diffraction, the GEL-based films were more crystalline and, consequently, mechanically stronger (~ 9–11 vs. ~ 6 MPa) and less permeable to water vapor than the WPI films (44.95–52.02 vs. 61.47–70.49 g mm m−2 day−1 kPa−1). Furthermore, GEL offered a bit more transparent, less yellow, and more stretchable films (~ 50–59% vs. ~ 26%). In turn, the WPI films had superior UV-protective potential. The higher FE concentration yielded more yellow films with improved UV-blocking ability. The FE (0.05%) made the GEL cryogel denser. Based on the half-time reduction of 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (tABTS50%), the 0.025, and 0.05% FE-supplemented WPI films exhibited ~ 1.6 and ~ 1.9 times better antiradical potential than the GEL counterparts. This result implies that the WPI-based films, being more soluble (35.12–36.74 vs. 31.51–33.21%) and less swellable (192.61–205.88 vs. 1056.93–2282.47%), ensured faster release of FE into aqueous medium. The slower building up of the antiradical activity of the FE-supplemented GEL films suggests that GEL could be more useful in the development of slow/less migratory active packaging systems for high moisture food.

Fabrication and characterization of pullulan-based composite films incorporated with bacterial cellulose and ferulic acid

Pullulan-based composite films incorporated with bacterial cellulose (BC) and ferulic acid (FA) were prepared by solution casting method. The rheological, morphological, barrier, optical, anti-fogging, and antioxidant properties of pullulan-based composite films doped with BC and FA were investigated. The rheological results showed that all film-forming solution was pseudoplastic fluid and its viscosity increased with the increase of BC content. An appropriate BC (2 %) and FA were uniformly dispersed in pullulan to form uniform and dense composite films. With the increase of BC content, the roughness and opacity of composite films increased while their UV-vis barrier performance was improved by incorporating BC and FA. Fourier transform infrared spectrometer analysis demonstrated that hydrogen bond interactions among pullulan, BC, and FA were found, and incorporating BC could increase the crystallinity of the composite films, thus enhancing their mechanical, barrier, hydrophobic, and thermal stability properties. Pullulan-based composite films incorporated with 2 % BC and FA (P-BC2-FA) showed better mechanical properties, water, oxygen, and carbon dioxide barrier performances, and its water contact angle value also increased compared with control, respectively. P-BC2-FA film showed superior anti-fogging and antioxidant activities. These results indicate that the P-BC2-FA film are expected to be a potential target of bioactive packaging.

Preparation of corn starch/rock bean protein edible film loaded with d-limonene particles and their application in glutinous rice cake preservation

Glycerol hydrogenated rosin (GEHR) and d-limonene were prepared for micro-particles by electrostatic spray method. When the GEHR/d-limonene ratio is 5.5:4.5 and the electrostatic spray extrusion speed is 1 mL/h, the best particle size (177.24 ± 17.09 μm) and embedding rate of d-limonene (41.74 ± 9.88%) are achieved. Then, rock bean protein (RP) was extracted from wild rock beans and combined with GEHR/d-limonene particles and corn starch (CS) to prepare a new type of edible film. The prepared film was characterized using Fourier transform infrared spectroscopy in terms of structural changes and physical, optical, mechanical, and thermal properties. The results show that the edible film with a ratio of 1:1 exhibited more optimized thermal (179.2 °C) and mechanical properties (TS 0.88 MPa, EAB 54.36%). Studies on freshly prepared glutinous rice cake as an object for preservation using edible film show that the films can prolong shelf life by ~2-4 d. Through this experiment, it can serve as a reference for the development of a new type of edible film.