Release of fireweed extract (Epilobium angustifolium L.) from corn starch- and methylcellulose-based films - A comparative study

Assessment of the Phenolics Content in Epilobium angustifolium and Epilobium hirsutum Extracts and Their Pharmacological Activity

The recent outbreak of Omicron strains of coronavirus disease urged the search for novel treatments from natural products such as Epilobium species. The present work reports a comparative HPLC-DAD study of the polyphenolic composition of the crude extracts of Epilobium angustifolium and Epilobium hirsutum. Oenothein B, gallic acid, hyperoside, and isoquercitin were the dominant phenolic compounds. E. hirsutum methanol extract showed a high radical scavenging activity as demonstrated by the HPLC-ABTS assay due to its richness in phenolic compounds. The polysaccharide-rich extracts and water extracts of E. hirsutum showed potent anti-coronavirus SARS-CoV-2 activity against the Omicron strain at 10 μg/mL with inhibition percentages of 38.4% and 46.1%, respectively. In contrast, the methanol (50% v/v) extract was inactive. Rutin and chlorogenic acid docked well into the binding pocket of the coronavirus spike protein. Emerging evidence suggests that suppressing excessive neutrophilic inflammation during the late stage of coronavirus infection benefits patients' survival. The methanol extracts of both plants completely inhibited fMLF/CB-induced elastase release in human neutrophils at 10 μg/mL (IC50 2.44 μg/mL), while the water extract showed an IC50 of 5.67 μg/mL. While several compounds docked well into the spike protein, the major and marker compound oenothein B showed promising in vitro anti-coronavirus activity with an IC50 of 6.08 µM in hACE2-overexpressing HEK293 cells, mimicking the entry of wild-type SARS-CoV-2 into human host cells. The results indicated that E. hirsutum might be helpful in the treatment of coronavirus infections and related inflammatory syndromes.

An antioxidant composite film based on loquat seed starch incorporating resveratrol-loaded core-shell nanoparticles

A Novel bioactive food packaging film was prepared from non-grain sourced loquat seed starch (LSS) incorporated with resveratrol-loaded nanoparticles (NRs) based on a zein/pectin core-shell system, where the NRs were prepared using the anti-solvent method. The chemical constitution of the LSS was analyzed. The film was characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The physical, optical, and antioxidant properties of the films were also identified. The results showed that incorporating NRs into the films significantly increased antioxidation activity, although simultaneously decreasing light transmission, water content, and elongation at break properties. Furthermore, NRs (15 %) facilitated strong hydrogen bonding interactions with the LSS matrix, improving the barrier properties and tensile strength. The resveratrol release behavior of the composite films in ethanol solutions (10 % and 95 % in water, v/v) as a food simulant was also investigated. The LSS/NRs composite film is effective in delaying unwanted oxidation during the storage of soybean oil. In conclusion, LSS could be applied as a good film-forming matrix, and LSS films containing NRs exhibit excellent physical properties and antioxidant activity, making them ideal for convenience foods containing a grease mixture of spices and grease-class packaging.

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.

Chitosan/zein-based sustained-release composite films: Fabrication, physicochemical properties and release kinetics of tea polyphenols from polymer matrix

This study investigated the properties of chitosan/zein/tea polyphenols (C/Z/T) films and analyzed the release kinetics of tea polyphenols (TP) in various food simulants to enhance the sustainability and functionality of food packaging. The results revealed that TP addition enhanced the hydrophilicity, opacity and mechanical properties of film, and improved the compatibility between film matrix. 1.5 % TP film showed the lowest lightness (76.4) and the highest chroma (29.1), while 2 % TP film had the highest hue angle (1.5). However, the excessive TP (above 1 % concentration) led to a decrease in compatibility and mechanical properties of film. The TP concentration (2 %) resulted in the highest swelling degree in aqueous (750.6 %), alcoholic (451.1 %), and fatty (6.4 %) food simulants. The cumulative release of TP decreased to 16.32 %, 47.13 %, and 5.87 % with the increase of TP load in the aqueous, alcoholic, and fatty food simulants, respectively. The Peleg model best described TP release kinetics. The 2 % TP-loaded film showed the highest DPPH (97.13 %) and ABTS (97.86 %) free radical scavenging activity. The results showed TP release influenced by many factors and obeyed Fick's law of diffusion. This study offered valuable insights and theoretical support for the practical application of active films.

Preparation, characterization and application of pH-responsive smart film based on chitosan/zein and red radish anthocyanin

This research was aimed at developing a novel pH-responsive smart film made of chitosan, zein and red radish anthocyanin (RRA). The morphology, interaction, crystallization, thermal stability, physiochemical properties and pH sensitivity of films were analyzed. The smart film was applied to monitor the freshness of mushroom (Agaricus bisporus). The results of morphology (SEM) and spectrum (FT-IR and XRD) indicated that the incorporation of RRA could enhance the interaction between polymer matrix. The addition of RRA had no significant effect on the thermal stability of films. The chitosan/zein/red radish anthocyanin (C/Z/R) films exhibited higher tensile strength, Young's modulus, hydrophobicity, antioxidant activity and lower elongation at break. The C/Z/R films had stronger water vapor and gas barrier capacity. The C/Z/R films showed a pH-sensitive color variation from red (pH 2) to green (pH 12) and good reversibility under alkaline and acidic environment. The prepared smart film could be successfully used for the quality monitoring of mushroom.

Influence of Epilobium parviflorum Herbal Extract on Physicochemical Properties of Thermoplastic Starch Films

In this study, for the first time, Epilobium parviflorum Schreb. (E, hoary willowherb) aqueous extract was introduced into edible biopolymer films and its influence on physicochemical properties of the final products were investigated. Potato starch was gelatinized in the herbal tea to obtain thermoplastic starch (TPS) films via the casting method. The characterization of the films included mechanical, antioxidative, water (WVTR, contact angle, swelling degree) and UV radiation barrier properties as well as microstructure analysis (SEM). Obtained results indicated that the presence of the extract (rich in phenolic compounds) in the films acted as a co-plasticizer for starch and led to a higher elongation at break, up to 70%, with a parallel increase in tensile strength up to ca. 9 MPa. Moreover, TPS films with E exhibited lower WVTR values and absorption of UV light in comparison with the control TPS film. DPPH scavenging activity of TPS E films immersed in methanol was ca. 92%, and it was related to the release of the extract into liquid media. Novel TPS E films are characterized by multifunctional properties that can be used, e.g., in the active packaging sector.

Effects of NaCl on the Physical Properties of Cornstarch-Methyl Cellulose Blend and on Its Gel Prepared with Rice Flour in a Model System

This study investigated the impact of NaCl on the physical properties of cornstarch-methyl cellulose (CS-MC) mixtures and their gels prepared with rice flour in a model system. Opposite trends were observed, showing that NaCl led to decreased viscosity of the CS-MC mixtures (liquid-based), whereas a more stable and robust structure was observed for the rice-flour-added gels (solid-based) with the addition of NaCl. The interference of NaCl with the CS-MS blend's ability to form a stable gel network resulted in a thinner consistency, as the molecules of the CS-MS blend may not bind together as effectively. On the contrary, NaCl showed the potential to enhance the protein network within CS-MC gels prepared with rice flour, thereby contributing to an augmentation in the stability or firmness of the cooked gels. Careful utilization of NaCl to optimize the physical properties of the CS-MC blends, as well as the gels based on rice flour, should be performed.

Antioxidant polysaccharide/gelatin blend films loaded with curcumin - A comparative study

Curcumin (CUR; 0, 0.005, 0.01, 0.02 %) was loaded into binary 75/25 blend films based on polysaccharides (carboxymethyl cellulose (CMC), gum Arabic (GAR), octenyl succinic anhydride modified starch (OSA), water-soluble soy polysaccharides (WSSP)) and gelatin (GEL). The GAR-based system was the least rough and, consequently, the most transparent of the films. An opposite result was found for the WSSP-based film. Despite the phase separation, the CMC75/GEL25 film exhibited excellent mechanical strength and stiffness. CUR improved the UV/VIS light-barrier characteristics of the films, but did not affect most of other physiochemical properties. X-ray diffractograms revealed that CUR provoked the rearrangement of the triple helical structure of GEL. As highly erodible, the CMC75/GEL25 carrier ensured the fastest and the most complete release of CUR. The OSA75/GEL25 system exhibited an opposite behavior. The kinetic profiles of the antiradical activity of the films did not reflect CUR release. A comparison of 2,2-diphenyl-1-picrylhydrazyl (DPPH*) scavenging on the plateau revealed that the CUR-supplemented films had quite comparable antiradical potential. The CMC75/GEL25 system exhibited the highest colorimetric stability, likely as a result of complete encapsulation of CUR in the GEL-rich microspheres. Weak symptoms of physical aging (enthalpy relaxation) were found in the films.

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.

Epilobium angustifolium L. as a Potential Herbal Component of Topical Products for Skin Care and Treatment-A Review

Epilobium angustifolium L. (EA) has been used as a topical agent since ancient times. There has been an increasing interest in applying EA as a raw material used topically in recent years. However, in the literature, there are not many reports on the comprehensive application of this plant to skin care and treatment. EA contains many valuable secondary metabolites, which determine antioxidant, anti-inflammatory, anti-aging, and antiproliferative activity effects. One of the most important active compounds found in EA is oenothein B (OeB), which increases the level of ROS and protects cells from oxidative damage. OeB also influences wound healing and reduces inflammation by strongly inhibiting hyaluronidase enzymes and inhibiting COX-1 and COX-2 cyclooxygenases. Other compounds that play a key role in the context of application to the skin are flavonoids, which inhibit collagenase and hyaluronidase enzymes, showing anti-aging and anti-inflammatory properties. While terpenes in EA play an important role in fighting bacterial skin infections, causing, among other things cell membrane, permeability increase as well as the modification of the lipid profiles and the alteration of the adhesion of the pathogen to the animal cells. The available scientific information on the biological potential of natural compounds can be the basis for the wider use of EA in skin care and treatment. The aim of the article is to review the existing literature on the dermocosmetic use of E. angustifolium.

Epilobium angustifolium L. Essential Oil-Biological Activity and Enhancement of the Skin Penetration of Drugs-In Vitro Study

Epilobium angustifolium L. is a popular medicinal plant found in many regions of the world. This plant contains small amounts of essential oil whose composition and properties have not been extensively investigated. There are few reports in the literature on the antioxidant and antifungal properties of this essential oil and the possibility of applying it as a potential promoter of the skin penetration of drugs. The essential oil was obtained by distillation using a Clavenger type apparatus. The chemical composition was analyzed by the GC-MS method. The major active compounds of E. angustifolium L. essential oil (EOEa) were terpenes, including α-caryophyllene oxide, eucalyptol, β-linalool, camphor, (S)-carvone, and β-caryophyllene. The analyzed essential oil was also characterized by antioxidant activity amounting to 78% RSA (Radical Scavenging Activity). Antifungal activity against the strains Aspergillus niger, A. ochraceus, A. parasiticum, and Penicillium cyclopium was also determined. The largest inhibition zone was observed for strains from the Aspergillus group. The EOEa enhanced the percutaneous penetration of ibuprofen and lidocaine. After a 24 h test, the content of terpene in the skin and the acceptor fluid was examined. It has been shown that the main compounds contained in the essential oil do not penetrate through the skin, but accumulate in it. Additionally, FTIR-ATR analysis showed a disturbance of the stratum corneum (SC) lipids caused by the essential oil application. Due to its rich composition and high biological activity, EOEa may be a potential candidate to be applied, for example, in the pharmaceutical or cosmetic industries. Moreover, due to the reaction of the essential oil components with SC lipids, the EOEa could be an effective permeation enhancer of topically applied hydrophilic and lipophilic drugs.

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

The properties of edible films derived from corn starch (CS) and methylcellulose (MC) supplemented with fireweed extract (FE; 0.0125-0.05% w/w) were analyzed. Due to their more crystalline structure, the MC films were significantly stronger (~26 MPa) than the CS films (~4 MPa). In turn, CS produced films with lower water vapor permeability (WVP, 50.12-51.74 vs. 56.52-59.10 g mm m^-2 d^-1 kPa^-1). The hydrothermally-disrupted starch granules contributed to high roughness and opacity of the CS films. The FE-supplemented films exhibited an intensive yellow color and improved the UV-absorbing effect. FE delayed starch retrogradation, as indicated by the reduced crystallinity and slightly improved transparency of the CS films. Incorporation of FE significantly enhanced the released radical scavenging activity (RSA) of the films, while did not affect the WVP and mechanical properties. Due to better FE-trapping capacity, the CS-based films exhibited lower antioxidant activity (RSA_60min = 2.21-19.75%) as compared to the MC counterparts (RSA_60min = 4.87-38.31%).

Functional effectiveness of double essential oils@yam starch/microcrystalline cellulose as active antibacterial packaging

In this work, two combinations of double EOs, i.e., α-terpineol: eugenol (α-T:Eu) and carvacrol:eugenol (CA:Eu), are used to develop the active antibacterial films of double EOs@yam starch/microcrystalline cellulose (EOs@SC). The hydrogen-bonded networks in SC matrix are conducive to thermostability enhancement and the film of SC25 is determined for EO incorporation. The interactions between EOs and SC matrix are also hydrogen bonds and the double EOs@SC are smooth at ratio of ≤2:2 for α-T:Eu or CA:Eu. The ultimate film properties are dependent on the incorporated EOs. The release of EOs is well controlled by two mechanisms of diffusion (predominant) and swelling (secondary). Synergetic antibacterial activity occurs on double EOs@SC. The shelf life of pork can be extended by 1 day at 25 °C by the two typical films of α-T₂:Eu₂@SC and CA₂:Eu₂@SC. Moreover, EOs@SC can be well degraded in humus soil. Thereby, the target films will have great potential in active packaging to extend the shelf life of food.