Characterization of new biodegradable edible film made from basil seed (Ocimum basilicum L.) gum

Nanoemulsion and emulsion vitamin D3 fortified edible film based on quince seed gum

In this research, emulsions and nanoemulsions containing two concentrations of vitamin D were added to quince seed gum film and its properties were examined. Incorporation of emulsified oil droplets to the films structure was confirmed by FTIR. It was observed that presence of emulsion and nanoemulsion in the films, increased their thickness, opacity, and hydrophobicity and interaction of the gum chains with water molecules was decreased and so, water vapor permeability, water solubility, and moisture content decreased. Due to the penetration of oil molecules to the chain, the resultant films had higher elongation at break and lower tensile strength. SEM micrographs of samples showed instability of the oil droplets within the matrix. Vitamin content during 14 days of storage showed that it was more stable at lower concentration and in the nanoemulsion compared to emulsion. So, quince seed gum films containing vitamin can be introduces as an ideal edible packaging.

Prospects of Polymeric Nanofibers Loaded with Essential Oils for Biomedical and Food-Packaging Applications

Essential oils prevent superbug formation, which is mainly caused by the continuous use of synthetic drugs. This is a significant threat to health, the environment, and food safety. Plant extracts in the form of essential oils are good enough to destroy pests and fight bacterial infections in animals and humans. In this review article, different essential oils containing polymeric nanofibers fabricated by electrospinning are reviewed. These nanofibers containing essential oils have shown applications in biomedical applications and as food-packaging materials. This approach of delivering essential oils in nanoformulations has attracted considerable attention in the scientific community due to its low price, a considerable ratio of surface area to volume, versatility, and high yield. It is observed that the resulting nanofibers possess antimicrobial, anti-inflammatory, and antioxidant properties. Therefore, they can reduce the use of toxic synthetic drugs that are utilized in the cosmetics, medicine, and food industries. These nanofibers increase barrier properties against light, oxygen, and heat, thereby protecting and preserving the food from oxidative damage. Moreover, the nanofibers discussed are introduced with naturally derived chemical compounds in a controlled manner, which simultaneously prevents their degradation. The nanofibers loaded with different essential oils demonstrate an ability to increase the shelf-life of various food products while using them as active packaging materials.

Seed coat mucilages: Structural, functional/bioactive properties, and genetic information

Seed coat mucilages are mainly polysaccharides covering the outer layer of the seeds to facilitate seed hydration and germination, thereby improving seedling emergence and reducing seedling mortality. Four types of polysaccharides are found in mucilages including xylan, pectin, glucomannan, and cellulose. Recently, mucilages from flaxseed, yellow mustard seed, chia seed, and so on, have been used extensively in the areas of food, pharmaceutical, and cosmetics contributing to stability, texture, and appearance. This review, for the first time, addresses the similarities and differences in physicochemical properties, molecular structure, and functional/bioactive properties of mucilages among different sources; highlights their structure and function relationships; and systematically summarizes the related genetic information, aiming with the intent to explore the potential functions thereby extending their future industrial applications.

Extraction, purification, physicochemical properties and antioxidant activity of a new polysaccharide from Ocimum album L. seed

In this study, a novel polysaccharide fraction from Ocimum album seed was extracted and then purified by Cellulose DEAE-52 and Sephadex G-200 anion exchange chromatography. The structural, physicochemical and antioxidant properties of the main polysaccharide fraction (OAP-1A) were evaluated. The purified polysaccharide contained 94.3% carbohydrate, 3.56% moisture and 2.14% ash and result of gel permeation chromatography (GPC) showed average molecular weight of 593 kDa. The results of high-performance liquid chromatography (HPLC) showed that OAP-1A was a neutral hetero-polysaccharide composed of mannose (35.7%), glucose (33.32%), galactose (19.6%) and rhamnose (11.38%). In addition, GC-MS data, nuclear magnetic resonance (NMR) spectrum and Fourier transform infrared (FT-IR) analysis revealed that the backbone of OAP-1A consists of →3)-β-D-Manp-(1→, →3,4)-β-D-Manp-(1→, →3,6)-β-D-Manp-(1→, →3)-α-D-Glcp-(1→, →6)-β-D-Galp-(1→, →4)-α-L-Rhap-(1→ and α-D-Glcp-(1→. X-ray diffraction (XRD) analysis showed semi-crystalline structure in OAP-1A. Differential scanning colorimeter (DSC) and thermo-gravimetry analysis (TGA) indicated that OAP-1A had relatively high thermal stability. Moreover, OAP-1A showed strong scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals.

Use of Chia by-Products Obtained from the Extraction of Seeds Oil for the Development of New Biodegradable Films for the Agri-Food Industry

Chia oil production and consumption have increased in recent years, producing a large number of by-products that had low utility or economic value for the industry. In this study, a biodegradable film was successfully prepared from mucilage extracted from defatted chia flour. The physical-chemical, optical, water vapor permeability (WVP), and mechanical properties of films made with two different types of chia matrixes (defatted flour and whole seeds) were determined. In general, defatted chia flour films exhibited a slightly reddish and yellowish color but still transparent in appearance, were good visible light barriers, and had better mechanical properties than films made with whole seeds. They also have greater WVP values than synthetic films such as low-density polyethylene. The results of the present study demonstrated that defatted chia flour can be used in producing edible films with improved quality characteristics.

Edible Films and Coatings as Food-Quality Preservers: An Overview

Food preservation technologies are currently facing important challenges at extending the shelf-life of perishable food products (e.g., meat, fish, milk, eggs, and many raw fruits and vegetables) that help to meet the daily nutrient requirement demand. In addition, food preservation has gone beyond only preservation; the current techniques are focused on the fulfillment of two additional objectives, the suitability of the used processes and generation of environmentally friendly products with non-presence of any side effect on health. Moreover, they are also looking for additional nutritional properties. One of these preservation protocols deals with the use of edible films and coatings. Therefore, this review shows an overview of synthetic materials (e.g., glass, aluminum, plastic, and paperboard), as well as the regulations that limit their application in food packaging. Further, this review releases the current-state-of-the-art of the use of films and edible coatings as an alternative to conventional packaging, providing the main features that these biodegradable packaging should meet towards specific uses for the conservation and improvement of various food products. Herein, particular attention has been paid to the main used components (e.g., biopolymers, additives, bioactive, and probiotic components), manufacturing methods (for edible films or coatings) and their application to specific products. In addition, an outlook of the application of edible films and coatings as quality indicators of perishable products is shown.

Characteristics of karaya gum based films: Amelioration by inclusion of Schisandra chinensis oil and its oleogel in the film formulation

This research was focused to develop novel karaya gum films, modified by adding Schisandra chinensis oil and its oleogel. The films produced were assessed for physicochemical, mechanical, thermal and structural characteristics. Glass transition temperature (Tg) of control karaya gum films was recorded as 145.70 °C. Insignificant (p < 0.05) changes occurred in Tg of films in which oil was incorporated, irrespective of the concentration. However, Tg decreased significantly (p < 0.05) as oleogel was added to the karaya gum films and lowest Tg occurred for the KGOG3 films which contained highest concentration of oleogel. X-ray diffraction test depicted an obsolete amorphous behavior of control karaya gum film whereas some peaks appeared in other film samples. Scanning electron micrography (SEM) revealed a reduction in roughness and grainy morphology when oil or oleogel was added to the films. Addition of oil/oleogel enhanced the phenolic content and DPPH radical scavenging activity of the films.

Extraction of basil seed mucilage using ionic liquid and preparation of AuNps/mucilage nanocomposite for catalytic degradation of dye

Basil seeds are widely cultivated throughout the world because of their extensive applications in various fields of life. The Basil seeds mucilage (BSM) exhibits remarkable physical and chemical properties like high water absorbing capacity, emulsifying, and stabilizing properties. The extraction of this mucilage from the seed surface has always been done by physical and chemical methods, which has certain drawbacks. Here, we report for the first time a chemical method for the effective extraction of this mucilage using ionic liquids (ILs); the green solvents. Pyridinium chloride based ILs were investigated for the effective extraction of mucilage and the process was optimized for various variables i.e. time, temperature, basil seed loading, co-solvents, anti-solvents. The extraction yield (up to 25% w/w of mucilage per basil seeds dry weight) was obtained at optimum conditions. Extracted mucilage was characterized by analytical techniques. The extracted BSM was used to prepare AuNps/BSM nanocomposite by stabilizing the gold nanoparticles. The AuNps/BSM nanocomposite was applied for the catalytic degradation of dyes (congo red; 12 min, methyl orange; 4 min, whereas 4-nitrophenol; 6 min).

Structure and properties of edible packaging film prepared by soy protein isolate-eggshell membrane conjugates loaded with Eugenol

In this study, we reported a facile and economical strategy for producing a functional protein-based composite film that was based on soybean protein isolate (SPI), eggshell membrane (ESM) and eugenol (Eu). The composite films were also characterized by mechanical, water vapor permeability (WVP), UV barrier, water resistance, hydrophobicity, antioxidant and antimicrobial activity. The results suggested the appropriate content of ESM could significantly enhance the mechanical, barrier, water resistance and hydrophobicity performances of the film. The addition of Eu into the SPI/ESM film could improve not only these properties, but also antimicrobial and antioxidant properties. The intermolecular interaction between SPI, ESM and Eu was mainly hydrogen bond confirmed by the Fourier-transform infrared spectroscopy (FTIR). The scanning electron microscopy (SEM) and X-ray diffraction (XRD) indicated a good compatibility existed between SPI and ESM, and the Eu could be well emulsified and dispersed into the SPI/ESM film matrices network. Such edible films carried potentially developed in active packaging applications.

The efficacy of edible film from Konjac glucomannan and saffron petal extract to improve shelf life of fresh-cut cucumber

The efficacy of saffron petal extract (SPE; 1%-4%) incorporated into Konjac glucomannan (KGM) edible films on the quality and shelf life of fresh-cut cucumbers was evaluated. Changes in chemical, physical, and microbial properties, antioxidant activity, and total soluble phenolic contents of sliced cucumbers during storage at 4°C for 5 days were investigated. Results showed that the addition of SPE markedly reduced the water vapor permeability features of produced films, whereas the moisture content and transparency of them increased (p < .05). All the formulated films containing 1%-4% of SPE exhibited significant antimicrobial properties against the examined pathogens (Escherichia coli, Shigella sonnei, Salmonella Typhi, Staphylococcus aureus, and Bacillus cereus) both in vitro and in vivo conditions. KGM films incorporated SPE were successful in reducing mesophilic bacteria and fungi populations so that the microbial load significantly decreased as the concentrations of SPE increased and KGM + 4% of SPE was considered as the most effective treatment in decreasing the microbial content of sliced cucumbers. Total soluble solids of the treated cucumbers were significantly increased at the end of the storage in refrigerator, compared to the control sample. Moreover, antioxidant activity (DPPH assay) and total soluble phenols in treated fruit increased with storage time, while these parameters decreased with increasing concentrations of SPE incorporated into KGM film. So according to the findings, the introduced film with KGM and SPE could be considered as an edible film and be applied to preserve the fruit and vegetables quality and extend the shelf life of sliced cucumbers.

Synthesis of chemically cross-linked hydrogel films based on basil seed (Ocimum basilicum L.) mucilage for wound dressing drug delivery applications

The present study aims toward the preparation of pH-sensitive hydrogel films based on basil seed mucilage (OBM) biopolymer as a novel drug delivery system for wound dressing. Various contents of polyvinyl alcohol (PVA), glutaraldehyde (GA) as cross-linker, and glycerol as a plasticizer were incorporated to have an optimal combination of softness and resilience. OBM hydrogel films characterized by FT-IR, thermogravimetric analysis (TGA), morphological analysis by scanning electron microscope (SEM) and their physical properties were discussed on the reportage of the results of several tests: rheology, mechanical tests (stress at maximum load and Young's modulus), O₂ permeability and water vapor permeability, gel fraction, water retention capacity and swelling degree measurements. The best results for this work were Mu-Gly2, which has the acceptable swelling degree and gel fraction leading to functional water retention capacity, as well as the selected formulations, which were non-toxic and biocompatible according to the result of cytotoxicity test. The optimized formulations of films were used for loading of Tetracycline hydrochloride (TH) as a model drug, and the release studies showed better results at pH = 8.5 and pH = 7.4 rather than acidic pH.

Seed mucilages as the functional ingredients for biodegradable films and edible coatings in the food industry

In recent years, environmental problems, consumer health concerns, and economic limitations associated with synthetic plastics have led to the application of renewable, biodegradable, and edible resources for developing food packaging. Edible packaging can be important in maintaining the food quality and preventing the microbial and chemical spoilage of foods. Several seeds can produce 'seed-based mucilage' with different techno-functional properties for application in various food products. In the field of packaging, these mucilages can be extruded into coatings and films and improve the barrier properties against the transfer of oxygen and moisture. Likewise, bioactive ingredients can also be incorporated into these mucilages which will extend the shelf life of food products. This study gives an overview of various seed mucilages, their production and characteristics of the films/coatings prepared with them for successful applications in different food products.

Tuning the physicochemical properties of apple pectin films by incorporating chitosan/pectin fiber

Various biodegradable or edible films were designed to deal with the environmental threats from plastic films. To overcome the defects of pectin film, the feasibility for the incorporation of CH/PE fiber was explored. Micron-scale novel artificial CH/PE fibers in needle, spindle or whisker shape with a diameter around 25 μm were fabricated via a shearing regime in virtue of electrostatic complexing. The incorporation of CH/PE fiber (mixture) and its size-fractioned portions (small and large) substantially changed PE films in diverse ways. Structurally, the fiber-incorporated films were heterogeneous with the fibers concentrated in the upper layer, although they presented similar FT-IR spectra and XRD pattern to PE film. Regarding the film performance, the incorporation of CH/PE fibers, especially the small portion, rendered the PE film with higher values in water-proof ability, thermal stability, break resistibility, stretchability and UV blocking capacity. More importantly, this work provided an innovative strategy to improve the performance of edible films.

Morphological and physical properties of kefiran-whey protein isolate bionanocomposite films reinforced with Al2O3 nanoparticles

Considering environmental pollution caused by the non-biodegradable polymers used in food packaging, developing and enhancing the properties of biodegradable films seem to be necessary. For this aim, in the present study, kefiran-whey protein isolate bionanocomposite films were prepared and the impact of different concentrations (1, 3 and 5% w/w) of Al₂O₃ (alumina) nanoparticles on their physical, morphological, thermal and mechanical properties was studied. Based on the obtained results, an increase in the nanoparticles content led to a significant decrease (p < 0.05) in the water vapor permeability, moisture absorption, moisture content, and water solubility. Scanning electron microscope images showed a homogeneous structure, confirming the good dispersion of alumina nanoparticles with smooth surface up to concentration of 3%. In addition, both thermal stability and mechanical properties of the films were improved by the increased concentrations of alumina. The results of X-ray diffraction indicated that the intensity of the crystalline peaks of film increased with the addition of Al₂O₃ to kefiran-whey protein isolate matrix. By considering all results, the concentration of 3% was proposed as the appropriate concentration of Al₂O₃ for the nano-reinforcement of kefiran-whey protein isolate bionanocomposites.

Development and characterization of elephant foot yam starch-hydrocolloids based edible packaging film: physical, optical, thermal and barrier properties

The study aimed at the development of elephant foot yam starch (EFYS) based edible film through blending of Xanthan (XG) and agar-agar (AA). Film thickness and density increased with increase in concentration of hydrocolloids and the respective highest value 0.199 mm and 2.02 g/cm³ were found for the film possessing 2% AA. The film barrier properties varied with hydrocolloids and the lowest value of water vapour transmission rate (1494.54 g/m²) and oxygen transmission rate (0.020 cm³/m²) was observed for the film with 1% XG and 1.5% AA, respectively. Mechanical and thermal properties also improved upon addition of hydrocolloid. Highest tensile strength (20.14 MPa) and glass transition temperature (150.6 °C) was observed for film containing 2% AA. Fourier transform infrared spectroscopy demonstrated the presence of -OH, C-H, and C=O groups. The change in crystallinity was observed through peak in X-ray diffraction analysis, which increased with increase in the hydrocolloids' concentration.

Development, modification and characterization of new biodegradable film from basil seed (Ocimum basilicum L.) mucilage

BACKGROUND

Biodegradable films from basil seed mucilage (BSM) were formed and modified with several di-carboxylic acid crosslinkers; i.e. tartaric acid (TA), malic acid (MA) and succinic acid (SA) with varying acidity and chemical structures, to enhance mechanical properties and water barrier ability. Basil seeds have a reasonable mucilage content and valuable properties; thus, it has the potential to develop valuable new biodegradable films.

RESULT

We characterized BSM films with the three crosslinkers using Fourier-transform infrared (FTIR) spectra and observed a 1730 cm^-1 CO stretching peak, which confirmed ester linkage between the mucilage and crosslinkers. The crosslinked films showed higher gel fraction than native films. The crosslinked films showed better swelling and water vapor permeability with SA than with TA and MA. Crosslinking led to significant improvement in strain at maximum load. Further, the stress maximum load was comparable to that of commercial low-density polyethylene (LDPE) film. Crosslinked films showed additional homogeneous morphology and an increase in thermal degradation temperatures.

CONCLUSION

Crosslinking with dicarboxylic acids improved all the key properties of BSM films, including excellent stress and strain at maximum load, improved barrier capability and thermal properties. Thus, these films showed good potential as biodegradable films, especially for food packaging. © 2019 Society of Chemical Industry.

Electrospun Gelatin Nanofibers Encapsulated with Peppermint and Chamomile Essential Oils as Potential Edible Packaging

Natural and edible materials have attracted increasing attention in food packaging, which could overcome the serious environmental issues caused by conventional non-biodegradable synthetic packaging. In this work, gelatin nanofibers incorporated with two kinds of essential oil (EO), peppermint essential oil (PO) and chamomile essential oil (CO), were fabricated by electrospinning for potential edible packaging application. Electron microscopy showed that smooth and uniform morphology of the gelatin/EOs was obtained, and the diameter of nanofibers was mostly enlarged with the increase of the EO content. The proton nuclear magnetic resonance spectrum confirmed the existence of PO and CO in nanofibers after electrospinning. The addition of EOs led to an enhancement of the water contact angle of nanofibers. The antioxidant activity was significantly improved for the nanofibers loaded with CO, while the antibacteria activity against Escherichia coli and Staphylococcus aureus was better for the fibers with PO addition. The combination of half PO and half CO in nanofibers compensated for their respective limitations and exhibited optimum bioactivities. Finally, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay with NIH-3T3 fibroblasts demonstrated the absence of cytotoxicity of the gelatin/EO nanofibers. Thus, our studies suggest that the developed gelatin/PO/CO nanofiber could be a promising candidate for edible packaging.

Mechanical and moisture barrier properties of corn distarch phosphate film influenced by modified microcry stalline corn straw cellulose

BACKGROUND

In this paper, a novel modified microcrystalline corn straw cellulose (MMCSC) was prepared by ultrasonic/microwave-assisted treatment. Effective incorporation of MMCSC into corn distarch phosphate (CDP)-based composite films was investigated.

RESULTS

As the proportion of MMCSC was increased, tensile strength increased initially before decreasing, and the elongation at break always decreased. The composite film of MMCSC20 showed the lowest water vapor permeability (2.917 × 10^-7 g m^-1 h^-1 Pa^-1 ). The measurement of surface color showed that by the increasing of the MMCSC proportion in composite films, the L^* and b^* values and the total color difference (ΔE^* ) increased, while a^* values decreased. Fourier transform infrared spectroscopy and X-ray diffraction analysis indicated that, with the incorporation of MMCSC, the stable structure of the films was enhanced through cross-linking and the crystallinity was increased. A scanning electron microscopy study revealed the surface microstructure of films (MMCSC0-MMCSC30) was smooth and homogeneous, and there was no distinct separation in the matrix of composite films.

CONCLUSION

The incorporation of suitable MMCSC could improve the properties of composite films. The CDP-MMCSC films, which are completely biodegradable and environmental friendly, have a high potential to be used for food packaging. © 2018 Society of Chemical Industry.

Development and characterization of edible films based on eggplant flour and corn starch

In this study, biodegradable and edible films based on eggplant flour (EF) and corn starch (CS) were prepared using casting method at proportion of 0-100, 25-75, 50-50, 75-25 and 100-0%, w/w. The mechanical, barrier, physical, and biodegradability properties were evaluated. Tensile strength, elongation at break, Young's modulus, thickness, density and L^⁎ parameter of pure starch films were higher than those of other films. Solubility, water vapor permeability (WVP), moisture content and swelling index of films were augmented with the substitution of CS by EF. Color measurement of the edible films indicated that increasing the proportion of EF increased a^⁎, b^⁎ and opacity values. The highest amount of water sorption was obtained for pure EF films. Moreover, the incorporation of EF accelerated films biodegradability compared to ones with only starch. In general, EF is a promising material for the formulation of edible and biodegradable films with adequate physical properties for food applications by direct contact.

Preparation and Properties of Sodium Carboxymethyl Cellulose/Sodium Alginate/Chitosan Composite Film

A sodium alginate/chitosan solution was prepared by dissolving sodium alginate, chitosan, and glycerol in an acetic acid solution. This solution was then combined with a sodium carboxymethyl cellulose solution and the mixture was cast onto a glass plate and dried at a constant temperature of 60 °C. Then, a carboxymethyl cellulose/sodium alginate/chitosan composite film was obtained by immersing the film in a solution of a cross-linking agent, CaCl2, and air-drying the resulting material. First, the most advantageous contents of the three precursors in the casting solution were determined by a completely random design test method. Thereafter, a comprehensive orthogonal experimental design was applied to select the optimal mass ratio of the three precursors. The composite film obtained with sodium alginate, sodium carboxymethyl cellulose, and chitosan contents of 1.5%, 0.5%, and 1.5%, respectively, in the casting solution displayed excellent tensile strength, water vapor transmission rate, and elongation after fracture. Moreover, the presence of chitosan successfully inhibited the growth and reproduction of microorganisms. The composite film exhibited antibacterial rates of 95.7% ± 5.4% and 93.4% ± 4.7% against Escherichia coli and Staphylococcus aureus, respectively. Therefore, the composite film is promising for antibacterial food packaging applications.