Development of a high methoxyl pectin edible film for retention of l-(+)-ascorbic acid

The Increase in the Plasticity of Microcrystalline Cellulose Spheres' When Loaded with a Plasticizer

Compaction pressure can induce an undesirable solid-state polymorphic transition in drugs, fragmentation, loss of coated pellet integrity, and the decreased viability and vitality of microorganisms. Thus, the excipients with increased plasticity can be considered as an option to decrease the undesirable effects of compaction pressure. This study aims to increase the plasticity (to reduce the mean yield pressure; Py) of dried microcrystalline cellulose (MCC) by loading it with a specially selected plasticizer. Diethyl citrate (DEC), water, and glycerol were the considered plasticizers. Computation of solubility parameters was used to predict the miscibility of MCC with plasticizers (possible plasticization effect). Plasticizer-loaded MCC spheres with 5.0 wt.% of water, 5.2 wt.% of DEC, and 4.2 wt.% glycerol were obtained via the solvent method, followed by solvent evaporation. Plasticizer-loaded formulations were characterised by TGA, DSC, pXRD, FTIR, pressure-displacement profiles, and in-die Heckel plots. Py was derived from the in-die Heckel analysis and was used as a plasticity parameter. In comparison with non-plasticized MCC (Py = 136.5 MPa), the plasticity of plasticizer-loaded formulations increased (and Py decreased) from DEC (124.7 MPa) to water (106.6 MPa) and glycerol (99.9 MPa), and that was in full accordance with the predicted miscibility likeliness order based on solubility parameters. Therefore, water and glycerol were able to decrease the Py of non-plasticized MCC spheres by 16.3 and 30.0%, respectively. This feasibility study showed the possibility of modifying the plasticity of MCC by loading it with a specially selected plasticizer.

Fabrication and Characterization of Pectin Films Containing Solid Lipid Nanoparticles for Buccal Delivery of Fluconazole

Fluconazole (FZ) is a potential antifungal compound for treating superficial and systemic candidiasis. However, the use of conventional oral drug products has some limitations. The development of buccal film may be a potential alternative to oral formulations for FZ delivery. The present study involved the development of novel FZ-loaded solid lipid nanoparticles (FZ-SLNs) in pectin solutions and the investigation of their particle characteristics. The particle sizes of the obtained FZ-SLNs were in the nanoscale range. To produce pectin films with FZ-SLNs, four formulations were selected based on the small particle size of FZ-SLNs and their suitable polydispersity index. The mean particle sizes of all chosen FZ-SLNs formulations did not exceed 131.7 nm, and the mean polydispersity index of each formulation was less than 0.5. The properties of films containing FZ-SLNs were then assessed. The preparation of all FZ-SLN-loaded pectin films provided the mucoadhesive matrices. The evaluation of mechanical properties unveiled the influence of particle size variation in FZ-SLNs on the integrity of the film. The Fourier-transform infrared spectra indicated that hydrogen bonds could potentially form between the pectin-based matrix and the constituents of FZ-SLNs. The differential scanning calorimetry thermogram of each pectin film with FZ-SLNs revealed that the formulation was thermally stable and behaved in a solid state at 37 °C. According to a drug release study, a sustained drug release pattern with a burst in the initial stage for all films may be advantageous for reducing the lag period of drug release. All prepared films with FZ-SLNs provided a sustained release of FZ over 6 h. The films containing FZ-SLNs with a small particle size provided good permeability across the porcine mucosa. All film samples demonstrated antifungal properties. These results suggest the potential utility of pectin films incorporating FZ-SLNs for buccal administration.

Alginate Films Enriched in Raspberry and/or Black Currant Seed Oils as Active Food Packaging

Alginate films plasticized with glycerol and enriched in raspberry and/or black currant seed oils were prepared via casting solution techniques. The intention was to create active films for food packaging where antioxidants in a film would deactivate oxidants in a packed product or its surroundings, improving conditions inside packaging and extending the shelf life of such a product. The prepared materials were characterized by physicochemical, spectroscopic, mechanical, water vapor transmission (WVTR), and antioxidant activity analysis. Infrared spectra of the alginate films with oils were similar to those without the additive; the band with a maximum at about 1740 cm-1 stood out. The prepared materials with oils were thicker, contained less water, were more yellow, and were less permeable to water vapor. Moreover, the presence of the oil in the films resulted in a slightly lower Young's modulus and lower stress at break values but higher strain at break. The antioxidant capacity of raspberry seed oil itself was about five times higher than that of black currant seed oil, and a similar trend was noticed for films modified with these oils. The results indicated that both oils could be used as active substances with antioxidant properties in food packaging.

Keratin-based bioplastics extracted from chicken feathers: Effect of chitosan concentration on the structural, chemical bonding, and mechanical properties of bioplastics

Keratin was synthesized by alkaline hydrolysis from chicken feathers and then continue by casting method for producing bioplastics with additional various amounts of chitosan as a filler, polyvinyl alcohol (PVA) and glycerol as a plasticizer. The main purpose is analysis the effect of chitosan on the structural properties using quantitative analysis of X-ray diffraction (XRD) spectra, chemical bonding by Fourier transforms infrared (FTIR) spectra, and mechanical properties by texture analyser to the keratin-based bioplastics. Biodegradation of bioplastics was analysed from the loss of weight by burying in the soil. It's found that, the additional of chitosan (0 %, 2 %, 5 %, and 8 %) increased the crystallinity of bioplastics by 11.83 %, 11.12 %, 18.99 %, and 17.03 %, respectively, but decreasing tensile strength and elasticity of bioplastics. Degradation of bioplastic keratin-based shows that the addition of chitosan can reduce the degradation time which is directly proportional to the loss of CO bonds. The highest degradation rate is 89.29 % in 49 days for keratin-based bioplastics with 8 % chitosan, indicated that high potential for future production.

A Novel Hydrocolloid Film Based on Pectin, Starch and Gunnera tinctoria and Ugni molinae Plant Extracts for Wound Dressing Applications

BACKGROUND

The biodegradable and biocompatible nature of pectin-based films is of particular interest in wound dressing applications, due to its non-toxicity, pH-sensitivity and gelling activity. An approach to improve the mechanical properties, the release profile of bioactive compounds as well as the performance in wet environments of pectin-based films is mixing with other biopolymers.

OBJECTIVE

To prepare hydrocolloid films based on crosslinked pectin / starch blend loaded with bioactive extracts from leaves of G. tinctoria and U. molinae with controlled release of bioactive compounds and healing property.

METHODS

The hydrocolloid films were characterized by FTIR, SEM, and TGA-FTIR techniques and their tensile properties, water uptake, and polyphenolic release profile in aqueous media were evaluated. The dermal anti inflammatory activity of the hydrocolloid films was assessed by the mouse ear inflammation test. The wound healing property of the loaded hydrocolloid films was explored in a rat model and in a clinical trial (sacrum pressure ulcer).

RESULTS

The films showed an adequate water-uptake capacity between 100-160%. The release of active compounds from the hydrocolloid films followed the Korsmeyer-Peppas equation. The mechanical properties of hydrocolloid films were not affected by the plant extracts within the concentration range used. The incorporation of the bioactive extracts in the polysaccharide films inhibited the topical edematous response by about 50%. The topical application of the loaded hydrocolloid film on the pressure ulcer is completely closed after 17 days without showing any adverse reaction.

CONCLUSION

A novel hydrocolloid matrix was produced from crosslinked starch-pectin, which exhibited suitable chemical-physical properties to be used as a carrier of plant extracts with wound healing properties.

Layer-by-Layer Alginate and Fungal Chitosan Based Edible Coatings Applied to Fruit Bars

Food waste is currently being generated at an increasing rate. One proposed solution would be to convert it to biopolymers for industrial applications. We recovered chitin from mushroom waste and converted it to chitosan to produce edible coatings. We then used layer-by-layer (LbL) electrostatic deposition of the polycation chitosan and the polyanion alginate to coat fruit bars enriched with ascorbic acid. The performance of the LbL coatings was compared with those containing single layers of fungal chitosan, animal origin chitosan and alginate. Bars containing alginate-chitosan LbL coatings showed increased ascorbic acid content, antioxidant capacity, firmness and fungal growth prevention during storage. Also, the origin of the chitosan did not affect the properties of the coatings.

PRACTICAL APPLICATION

Mushroom stalk bases could be an alternative source for isolating chitosan with similar properties to animal-based chitosan. Also, layer-by-layer assembly is a cheap, simple method that can improve the quality and safety of fruit bars.

Preparation and characterization of antibacterial, eco-friendly edible nanocomposite films containing Salvia macrosiphon and nanoclay

Nowadays, food security is a vital issue and antimicrobial packaging could play an important role in this matter. In this regard, Salvia macrosiphon seed mucilage (SSM) and nanoclay, as new sources for the production of food-grade edible films were investigated. These edible films were prepared by incorporation of SSM with glycerol and different percentage of nanoclay. Upon addition of nanoclay up to 2% physical, mechanical and thermal properties were considerably improved and the composite films showed the lowest water vapor permeability (WVP), as well as highest elongation at break and tensile strength. The nanocomposite edible films also showed antibacterial activity due to the SSM nature. Addition of nanoclay, increased the hydrophobicity, which makes the films great alternatives for food packaging. This study revealed that these novel antimicrobial edible films could be a promising packaging option for a wide range of food products.

Effect of Plasticizer Type on Tensile Property and In Vitro Indomethacin Release of Thin Films Based on Low-Methoxyl Pectin

This study developed the interests of low-methoxyl pectin (LMP) together with plasticizers for the preparation of elastic thin films. The effect of different plasticizer types (glycerol: Gly; sorbitol: Sor; propylene glycol: PG; and polyethylene glycol 300: PEG 300) and concentrations (20–40% w/w) on mechanical and thermal properties of LMP films as well as on in vitro release of indomethacin were evaluated. Without any plasticizer, a brittle LMP film with low tensile strength and % elongation at break was obtained. Addition of plasticizers from 20% to 40% caused reduction in the tensile strength and Young’s modulus values, whereas percent elongation was increased. Forty percent Gly-plasticized and PG-plasticized films were selected to deliver indomethacin in comparison with non-plasticized film. No significant difference in indomethacin release profiles was displayed between the films. The analysis of indomethacin release model indicated that more than one drug release mechanism from the film formulation was involved and possibly the combination of both diffusion and erosion. Even though indomethacin incorporated in non-plasticized film showed similar release profile, Gly or PG should be added to enhanced film flexibility and decrease film brittleness.

Physicochemical properties of pectin from green jelly leaf (Cyclea barbata Miers)

The water extract of Green Jelly leaves (GJL) obtained by crushing the leaves in water (1:40) was capable of forming a gel at room temperature. The composition of GJL consisted mainly of carbohydrate (∼70w/w), protein (∼13% w/w) and minerals (∼6% w/w). The mineral portion consisted of mainly calcium (∼1.2% w/w), zinc (∼0.12% w/w) and magnesium (∼0.11% w/w). The isolated polysaccharide fraction (∼42.6% w/w) consisted of mainly galacturonic acid (∼35.8% w/w) and neutral sugars (∼6.8% w/w), with a weight-average molecular weight of ∼4.4×10⁵g/mol. The results obtained by Fourier Transform Infra-Red (FTIR) showed that GJL polysaccharide fraction had a fairly similar FTIR fingerprint as the commercial low-methoxyl pectin (LMP). The degree of esterification of the polysaccharide changed drastically (from 97% to 10%) depending on the temperature used during the extraction process. The zeta potential of the extracted polysaccharide showed high negative charged as compared to the commercial LMP but close to sodium alginate. The study showed that the gelation was divalent cation-mediated and probably facilitated by the low degree of esterification which reduced steric hindrance from the methyl ester groups.

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

It is well known that the market for edible films is experiencing remarkable growth and expected to continue. This study investigated the using of basil seed gum (BSG) as a new film-forming material under the influence of addition of glycerol (GLY) as plasticizer. Edible films based on BSG and three different concentrations of GLY (25%, 35%, and 50% w/w BSG) were developed, and their water vapor permeability (WVP), as well as physical, thermal and mechanical properties were measured. The addition of glycerol significantly increased water vapor permeability and solubility of the film (p<0.05). As expected, the increase in GLY concentration from 25% to 50% (w/w) increased the extensibility, but decreased tensile strength. This suggests weaker mechanical strength and higher mobility of polymer chains by plasticizing effect of GLY. The color measurement values showed that increasing the glycerol concentration in polymer matrix caused the b and L values increased while ΔE value decreased. The electron scanning micrograph showed plasticized films as smooth, and uniform which lacked pores or cracks compared with those were not plasticized. This study revealed that the BSG had a good potential to be used in producing edible films for various food applications.

Triggering mechanisms for oxygen-scavenging function of ascorbic acid-incorporated whey protein isolate films

BACKGROUND

Incorporation of ascorbic acid (AA) into whey protein isolate (WPI) films has been shown to increase the film's ability to protect foods from oxidation. The O₂-scavenging function of AA-WPI films could be triggered upon being placed in contact with food products. Several food-related factors hypothesized to act as triggering mechanisms for activating the O₂-scavenging function of AA-WPI films were investigated, including change of water activity (a(w)), pH and/or metal catalyst presence.

RESULTS

Rate of O₂ scavenging of AA-WPI films was observed to most closely follow first-order kinetics. The film a(w) level was found to control the O₂-scavenging rate. At high a(w) levels, O₂ scavenging occurred at a desirably rapid rate. Food models with pH 7.4 produced the fastest O₂-scavenging rate. The slowest rate at pH 3.0 was due to the lower concentration of O₂-sensitive ascorbate monoanion. The presence of Cu²⁺ accelerated AA oxidation at high a(w) level.

CONCLUSION

The desirable activation of oxygen scavenging in AA-WPI film at high a(w) and neutral pH in the presence of metal catalyst suggests that such AA-WPI films can be used to protect foods that have the highest vulnerability to oxidation.

Apple pomace is a good matrix for phytochemical retention

Phytochemical content and color changes in dried apple pomace and pulp (mixture of Red Delicious and Golden Delicious varieties) were studied during 9 months storage in the water activity (a(w)) range 0.11-0.75 at 30 °C. Water mobility was measured at various a(w) levels by (1)H NMR. During storage, antioxidant degradation (including flavonols, flavanols, dihydrochalcones, anthocyanins, and hydroxycinnamic acids) followed first-order kinetics, whereas color changes followed zero-order kinetics. These changes were accelerated by increasing a(w). Phytochemical and color were more stable in the pomace than in the pulp over the entire a(w) range, having 2-6 times smaller degradation rates. These results were related to the lower water mobility found in apple pomace as compared to the pulp. The overall results show that apple pomace can be exploited as a food ingredient with good phytochemical retention, and may help in the development of new matrices with maximum phytochemical retention.

Hydrolytic and oxidative stability of L-(+)-ascorbic acid supported in pectin films: influence of the macromolecular structure and calcium presence

The hydrolytic and oxidative stability of L-(+)-ascorbic acid (AA) into plasticized pectin films were separately studied in view of preserving vitamin C activity and/or to achieve localized antioxidant activity at pharmaceutical and food interfaces. Films were made with each one of the enzymatically tailored pectins (50%, 70%, and 80% DM; Cameron et al. Carbohydr. Polym.2008, 71, 287-299) or commercial high methoxyl pectin (HMP; 72% DM). Since AA stability was dependent on water availability in the network, pectin nanostructure affected the AA kinetics. Higher AA retention and lower browning rates were achieved in HMP films, and calcium presence in them stabilized AA because of higher water immobilization. Air storage did not change AA decay and browning rates in HMP films, but they significantly increased in Ca-HMP films. It was concluded that the ability of the polymeric network to immobilize water seems to be the main factor to consider in order to succeed in retaining AA into film materials.