Pomegranate peel pectin films as affected by montmorillonite

Ecologically sustainable biodegradable polymers fabricated from banana peel pectin reinforced with silver zeolite nanoparticles (Ag/zeolite NPs)

In the present investigation, the formulation and thorough assessment of biodegradable composite films were conducted, utilizing pectin extracted from banana peel in conjunction with synthesized silver zeolite nanoparticles. The evaluation of physical properties, microstructural investigation, mechanical characteristics, and barrier properties was done providing valuable insights into various attributes of the film. The amalgamation of silver zeolite nanoparticles with the extracted pectin from banana peel results in biodegradable composite films exhibiting distinct physical, mechanical, barrier, and thermal properties. Optimal mechanical characteristics were recorded in films containing 0.75 % Ag-ZY, demonstrating a tensile strength of 43.22 ± 0.12 MPa and a Young's modulus of 829.61 ± 0.71 MPa, while the elongation at break exhibited a decline as the filler concentration escalated. The barrier properties were enhanced with the integration of Ag-ZY. At a concentration of 0.75 % Ag-ZY, the water vapor transmission rate (WVTR) and water vapor permeability (WVP) reached their lowest measurements. The thermal stability increased, with the glass transition temperature (Tg) increasing from 70.31 °C in the baseline film to 135.53 °C when 0.75 % Ag-ZY was added. These results elucidate that the incorporation of 0.75 % silver zeolite nanoparticles into banana peel pectin films significantly improved mechanical, barrier, and thermal properties.

Development and Characterization of Potato Starch-Pectin-Based Active Films Enriched With Juniper Berry Essential Oil for Food Packaging Applications

The increasing demand for sustainable food packaging has driven the development of films based on biopolymers. However, enhancing their functional properties remains a challenge. In the current study, potato starch-pectin (PSP) composite films were fabricated and enriched with juniper berry essential oil (JBEO) to improve their physicochemical properties. The effects of incorporating different concentrations of JBEO (0.1%-1% v/v) on various properties of PSP-based films were evaluated, including surface color, transparency, barrier properties, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA and DTA), antioxidant activity, and antimicrobial effectiveness. Increasing the level of JBEO led to a significant decrease in the moisture content, film transparency, and mechanical attributes, while an increase in thickness, water permeability, and film elongation was observed. SEM analysis also revealed morphological properties such as some spherical, bubble-like configuration and cracks on the surface due to an increase in JBEO concentration. TGA and DTA revealed lower weight loss in the initial cycles due to the addition of JBEO, and the thermal stability of the films improved. The antioxidant assays revealed a concentration-dependent increase in the radical scavenging capacity of the films from 11.31% to 17.28% for DPPH and from 3.06% to 25.53% for ABTS. Moreover, significant antibacterial and antifungal activity of the bioactive films was observed against P. aeruginosa, S. aureus, and C. albicans. These findings suggest that JBEO enhances the functional properties of PSP films, making them suitable for active food packaging applications.

Punica granatum L. polysaccharides: A review on extraction, structural characteristics and bioactivities

Punica granatum L., commonly known as pomegranate, is native to Afghanistan and Iran, and today widely cultivated all over the world. Pomegranate polysaccharides are one of the most important bioactive components of P. granatum, which have a wide range of beneficial biological activities, such as anticancer, immunostimulatory, hepatoprotection, anti-psoriasis and antioxidation. Hot water extraction is currently the most commonly used method to isolate pomegranate polysaccharides. The structural characteristics of pomegranate polysaccharides have been extensively investigated through various advanced modern analytical techniques. This review focuses on the extraction, purification, structural characteristics, biological activities and structure-activity relationships of polysaccharides from Punica granatum. The aim of this article is to comprehensively and systematically summarize recent information of polysaccharides from Punica granatum and to serve as a basis for further research and development as therapeutic agents and functional foods.

Pectin extracted from red dragon fruit (Hylocereus polyrhizus) peel and its usage in edible film

Pectin was extracted from red dragon fruit (Hylocereus polyrhizus) peel using two different extraction methods: subcritical water extraction (SCWE) and conventional acid extraction (AE), from two different types of peels, fresh peel puree and dried peel powder. SCWE method on fresh peel puree showed an ∼18.88 % increase in pectin yield compared to AE. Extracted pectin is classified as low methoxyl pectin (DE: 8.51-50.64 %), with an average molecular weight ranging from 115.23 kDa to 577.84 kDa and a Gal-A content of 44.09 % - 53.90 %. The potential of pectin from fresh peel puree to be applied as a biodegradable film was further explored. Different pectin concentrations (3-5 % w/v) were used to prepare the films. Regarding the film performance, PF-S5, which was produced from SCWE with 5 % of pectin concentration, exhibits better thermal stability (Tdmax 250 °C, residue of 28.69 %) and higher moisture barrier (WVP 5.59 × 10-11 g.cm-1.s-1.Pa-1). In comparison, PF-A showed lower water solubility (45.14-69.15 %), higher water contact angle (33.01° - 44.35°), and better mechanical properties (TS: 2.12-4.11 MPa, EB: 48.72-61.39 %). Higher molecular weight accompanied by higher DE and Gal-A content contributes to better pectin film properties.

Nanofillers in Novel Food Packaging Systems and Their Toxicity Issues

Background: Environmental concerns about petroleum-based plastic packaging materials and the growing demand for food have inspired researchers and the food industry to develop food packaging with better food preservation and biodegradability. Nanocomposites consisting of nanofillers, and synthetic/biopolymers can be applied to improve the physiochemical and antimicrobial properties and sustainability of food packaging. Scope and approach: This review summarized the recent advances in nanofiller and their applications in improved food packaging systems (e.g., nanoclay, carbon nanotubes), active food packaging (e.g., silver nanoparticles (Ag NPs), zinc oxide nanoparticles (ZnO NPs)), intelligent food packaging, and degradable packaging (e.g., titanium dioxide nanoparticles (e.g., TiO2 NPs)). Additionally, the migration processes and related assessment methods for nanofillers were considered, as well as the use of nanofillers to reduce migration. The potential cytotoxicity and ecotoxicity of nanofillers were also reviewed. Key findings: The incorporation of nanofillers may increase Young's modulus (YM) while decreasing the elongation at break (EAB) (y = -1.55x + 1.38, R2 = 0.128, r = -0.358, p = 0.018) and decreasing the water vapor (WVP) and oxygen permeability (OP) (y = 0.30x - 0.57, R2 = 0.039, r = 0.197, p = 0.065). Meanwhile, the addition of metal-based NPs could also extend the shelf-life of food products by lowering lipid oxidation by an average of approx. 350.74% and weight loss by approx. 28.39% during the longest storage period, and significantly increasing antibacterial efficacy against S. aureus compared to the neat polymer films (p = 0.034). Moreover, the migration process of nanofillers may be negligible but still requires further research. Additionally, the ecotoxicity of nanofillers is unclear, as the final distribution of nanocomposites in the environment is unknown. Conclusions: Nanotechnology helps to overcome the challenges associated with traditional packaging materials. Strong regulatory frameworks and safety standards are needed to ensure the appropriate use of nanocomposites. There is also a need to explore how to realize the economic and technical requirements for large-scale implementation of nanocomposite technologies.

Comparative study on effect of pomegranate peel powder as natural preservative and chemical preservatives on quality and shelf life of muffins

This research aims to investigate the potential of utilizing pomegranate peel powder (PPP) as a natural preservative in muffin preparation. Pomegranate peel is a rich source of bioactive compounds, including phenolics, flavonoids, and tannins, which possess high antioxidant and antimicrobial properties. The In-Vitro antifungal activity of pomegranate peel powder (8% PPP), potassium sorbate (0.1% PS) and calcium propionate (0.5% CP) was assessed against Penicillium sp. and Aspergillus sp. using poison food technique. The PPP showed the anti-fungal activity by delaying the growth of microorganism on media plate similar to the PS and CP. The effect of utilization of PPP on quality characteristics of muffins were compared with the muffins with chemical preservatives (0.1% PS and 0.5% CP). The viscosity and specific gravity of batter significantly increased from 7.98 to 11.87 Pa s and 1.089-1.398 respectively on addition of 8% PPP. The optical microscopic structure of PPP added batter revealed the decrease in the number of air cells from 24 to 12 with radius range of 6.42-72.72 μm and area range of 511.03-15,383.17 µm2. The functional properties of flour with PPP had higher water absorption capacity, foaming stability, emulsification activity and emulsion stability than others. The addition of PPP significantly increase the weight (32.83 g), and decrease the height (31.3 mm), volume (61.43 cm3), specific volume (1.67 cm3/g) and baking loss (10.19%). The 418.36% increase in fibre content, 14.46% and 18.46% decrease in carbohydrates and energy value was observed in muffin with 8% PPP as compared to control respectively. The total phenols was increased from 0.92 to 12.5 mg GAE/100 g, total tannin from 0.2 to 8.27 mg GAE/100 g, In-vitro antioxidant activity by DPPH from 6.97 to 29.34% and In-vitro antioxidant activity by FRAP from 0.497 to 2.934 mg AAE/100 g in muffins added with 8% PPP. The muffin with PPP was softer than control and muffin with 0.1% PS. The addition of PPP resulted to improve in muffin texture but taste slightly bitter. During the storage of muffins at room temperature (27-30 °C), the moisture content of muffin with PPP was reduced from 17.04 to 13.23% which was higher than the rest of the treatments. Similarly, the hardness of sample with PPP was higher than the sample with 0.5% CP, but lowers than control and sample with 0.1% PS throughout the storage period. The results suggest that pomegranate peel powder can be successfully used as a natural preservative in place of chemical preservatives in muffins, to extend the shelf life. This study provides the opportunity to use PPP as functional ingredient and natural preservative in different bakery products.

Development of fiber-enriched muffins using pomegranate peel powder and its effect on physico-chemical properties and shelf life of the muffins

BACKGROUND

Pomegranate peel is a by-product from the pomegranate processing industries and is a rich source of dietary fibers and bioactive compounds. It has good antioxidant and antimicrobial properties. In the present study, the effects of substitution of refined wheat flour with pomegranate peel powder (PPP) at a rate of 2%, 4%, 6%, 8% and 10% on the physico-chemical and sensorial properties as well as on the oxidative and microbial stability of muffins were investigated.

RESULTS

A significant reduction in specific volume (1.99 to 1.57 cm3  g-1 ), weight loss (11.73 to 10.14 g 100 g-1 ) and an increase in crumb hardness (633.06 to 2311.5 g) of muffins were observed on addition of PPP. Moreover, the nutritional value was improved by a significant increase in the fiber content (4.39 to 10.66%), total phenols (0.443 to 48.53 mg GAE 100 g-1 ), antioxidant activity (75.94% to 99.36%), calcium (200.33 to 294.33 mg 100 g-1 ), potassium (227.33 to 425.33 mg 100 g-1 ) and magnesium (96.33 to 288.33 mg 100 g-1 ). The pasting and rheological properties of muffin batter showed a significant decrease in the final and peak viscosity, as well as increase in storage, loss and complex modulus. The muffin samples were organoleptically acceptable up to a level of 8% PPP. Free fatty acid content, peroxide value and microbial count of the muffin with 8% PPP were significantly lower compared to the control sample and more oxidatively and microbially stable for a storage period of 21 and 28 days at ambient and refrigerated temperatures, respectively.

CONCLUSION

The present study provides the opportunity to use PPP as functional ingredients and natural preservative in the preparation of muffins. © 2023 Society of Chemical Industry.

Application of combined Box-Behnken design with response surface methodology and desirability function in optimizing pectin extraction from fruit peels

BACKGROUND

This study aimed to extract pectin from various fruit peels, namely apple, orange, green citron, and pomegranate, and to evaluate the effects of various experimental conditions. The extraction was conducted at temperatures of 50-90 °C, with a solid-liquid ratio of 0.03-0.08 g/mL, for 120-180 min. The Box-Behnken design was applied in a three-level and four-factor factorial approach, including 29 experiments for each extraction, with varying conditions. The interaction effects were investigated. Each experiment's conditions were optimized.

RESULTS

The percentage yield varied (11.70-37.37%). The maximum yield was found in apples, whereas the lowest was in pomegranates.

CONCLUSION

Under optimized experimental conditions,high-quality pectin was extracted from pomegranate, orange, green citron, and apple peel waste. The extract was considered to be high methyl ester pectin with a degree of esterification greater than 50% and with an Anhydrouronic acid (AUA) content greater than 65%. The peel pectin that was studied could therefore be a food additive with numerous uses. The procedure developed here reuses waste resources effectively and contributes to a novel concept for exploring natural assets for use in food and pharmaceutical applications. © 2023 Society of Chemical Industry.

Optimization of citron peel pectin and glycerol concentration in the production of edible film using response surface methodology

Pectin-based edible film plasticized with glycerol has been developed, and the effect of pectin and glycerol concentration was optimized using response surface methodology for better mechanical properties and transparency. The upper and lower concentration of pectin (3-5 g) and glycerol (15%-25%) concentration ranges were considered in this study based on the preliminary experiment. The responses of the edible film determined were tensile strength, elongation at break and elastic modulus and opacity. The interaction effects of glycerol and pectin concentrations on edible film properties significantly affected the film properties. Tensile strength and opacity were positively affected by pectin concentrations; however, elastic modulus and elongation at break were negatively affected. Glycerol concentration negatively affected the edible film's tensile strength and elastic modulus. The decrease in the opacity of the biofilm was observed as the pectin concentration increased; however, glycerol had not shown a significant influence on opacity. The numerical optimization provided 4 g of pectin, and 20% of glycerol showed a strong and transparent edible film. The TGA curve showed that the maximum weight loss occurred between the temperatures 250-400 °C due to the loss of polysaccharides. From FTIR analysis, observed peaks around 1037 cm-1 represented the C-O-C stretching vibrations of the saccharide found in pectin and glycerol.

Novel Biocomposite Films Based on High Methoxyl Pectin Reinforced with Zeolite Y for Food Packaging Applications

Pectin is a natural biopolymer with broad applications in the food industry and it is suitable to prepare edible films to prolong food shelf-life. However, the main limitation of pectin-based films is their poor mechanical and barrier properties. Zeolite Y is a hydrophobic clay that can be used as film reinforcement material to improve its physicochemical and mechanical properties. In this work, the influence of high methoxyl citrus and apple pectin on physicochemical properties of biopolymer films modified with zeolite Y (0.05–0.2 wt%) was investigated. The films were characterized by FTIR, TGA, WAXD, mechanical analysis, and water vapor permeability analysis, and a potential film application is presented. The WAXD and FTIR analysis demonstrated that the strongest interaction between pectin chains and zeolite Y occurred when citrus high methylated pectin was used. Adding 0.2 wt% of zeolite Y into citrus high methylated pectin matrix enhanced the tensile strength by 66%, thermal stability by 13%, and water vapor barrier by 54%. In addition, fruit shelf-life test was performed, where strawberries were sealed in film. It was shown that sealed strawberries maintained a better color and healthy appearance than the control treatment after 7 days at 10 °C. This study enabled the development of biocomposite films with improved properties for potential application in food packaging.

Strategies to Improve the Barrier and Mechanical Properties of Pectin Films for Food Packaging: Comparing Nanocomposites with Bilayers

Traditional food packaging systems help reduce food wastage, but they also produce environmental impacts when not properly disposed of. Bio-based polymers are a promising solution to overcome these impacts, but they have poor barrier and mechanical properties. This work evaluates two strategies to improve these properties in pectin films: the incorporation of cellulose nanocrystals (CNC) or sodium montmorillonite (MMT) nanoparticles, and an additional layer of chitosan (i.e., a bilayer film). The bionanocomposites and bilayer films were characterized in terms of optical, morphological, hygroscopic, mechanical and barrier properties. The inclusion of the nanofillers in the polymer reduced the water vapor permeability and the hydrophilicity of the films without compromising their visual properties (i.e., their transparency). However, the nanoparticles did not substantially improve the mechanical properties of the bionanocomposites. Regarding the bilayer films, FTIR and contact angle studies revealed no surface and/or chemical modifications, confirming only physical coating/lamination between the two polymers. These bilayer films exhibited a dense homogenous structure, with intermediate optical and hygroscopic properties. An additional layer of chitosan did not improve the mechanical, water vapor and oxygen barrier properties of the pectin films. However, this additional layer made the material more hydrophobic, which may play an important role in the application of pectin as a food packaging material.

Novel trends in extraction and optimization methods of bioactives recovery from pomegranate fruit biowastes: Valorization purposes for industrial applications

Pomegranate biowastes present potential economic value worldwide owing to their several health benefits mediated by a complex mixture of unique bioactives. The exploitation of these bioactives has motivated the exploration of eco-friendly, efficient, and cost-effective extraction techniques to maximize their recovery. The current review aims to provide updated technical information about bioactives extraction mechanisms from pomegranate wastes (seeds and peel), their advantages and disadvantages, and factors towards optimization. A comparative overview of the modern green extraction techniques viz., supercritical fluid extraction, ultrasound-assisted extraction, microwave-assisted extraction, pressurized liquid extraction, and eutectic solvent mixture as alternatives to conventional extraction methods for seeds and peel is presented. Approaches focused on biowastes modification for properties improvement are also discussed. Such comprehensive review shall provide the best valorization practices of pomegranate biowastes and its application in food and non-food areas focusing on original methods, innovation, protocols, and development to be considered for other fruit biowastes.

pH-sensitive soluble soybean polysaccharide/SiO2 incorporated with curcumin for intelligent packaging applications

In the present work, the effect of various concentrations of SiO2 nanoparticles (5, 10, and 15%) on physicochemical and antimicrobial properties of soluble soybean polysaccharide (SSPS)-based film was investigated. Then, the migration of SiO2 nanoparticles to ethanol as a food simulant was evaluated. Subsequently, curcumin was added to the nanocomposite formulation to sense the pH changes. Finally, the cytotoxicity of the developed packaging system was investigated. With increasing nanoparticle concentration, the film thickness, water solubility, and water vapor permeability decreased and mechanical performance of the films improved. SSPS/SiO2 nanocomposite did not show antibacterial activity. SEM analysis showed that SiO2 nanoparticles are uniformly distributed in the SSPS matrix; however, some outstanding spots can be observed in the matrix. A very homogeneous surface was observed for neat SSPS film with R a and R q values of 3.48 and 4.26, respectively. With the incorporation of SiO2 (15%) into SSPS film, R a and R q values increased to 5.67 and 5.98, respectively. Small amount of SiO2 nanoparticles was released in food simulant. The nanocomposite incorporated with curcumin showed good physical properties and antibacterial activity. A strong positive correlation was observed between TVBN content of shrimp and a* values of the films during storage time (Pearson's correlation = 0.985).

Nutritional and Bioactive Components of Pomegranate Waste Used in Food and Cosmetic Applications: A Review

Pomegranate (Punica granatum L.) is a fruit that is rich in bioactive compounds that has a biowaste (rind and seed) with the potential to be converted into value-added products in a wide variety of applications. Recent studies have demonstrated the potent antioxidant and antimicrobial effects of using pomegranate rind and seed as natural food additives, thus making researchers incorporate them into bioplastics and edible coatings for food packaging. Additionally, these components have shown great plasticizing effects on packaging materials while extending the shelf life of food through active packaging. Even within skin health applications, pomegranate seed oil and its bioactive compounds have been particularly effective in combating UV-induced stresses on animal skin and in-vitro models, where cells and microorganisms are separated from the whole organism. They have also aided in healing wounds and have shown major anti-inflammatory, analgesic, and anti-bacterial properties. This review highlights all of the relevant and recent food and skin health applications found in the value-added conversion of pomegranate biowaste. The lack of research in particular areas and future outlook are also discussed.

Starch-based antimicrobial films functionalized by pomegranate peel

In this work, pomegranate peel (PGP) as an antimicrobial agent as well as a reinforcing agent was utilized in developing starch-based films. Hydroxypropyl high-amylose starch plasticized by water and glycerol was used in this work. The microstructure and performance of films were investigated using scanning electron microscope (SEM), optical microscope (OM), X-ray diffraction (XRD), dynamic mechanical analyzer, tensile testing, drop impact testing and disc diffusion test. Results clearly demonstrated that PGP inhibited the growth of both gram-positive (S. aureus) and gram-negative (Salmonella) bacteria. Meanwhile, PGP also increased Young's modulus, tensile strength and stiffness of the starch-based films. Both OM and SEM observations indicated reasonably good compatibility between starch and PGP particles. The XRD results indicated that PGP retained its semi-crystalline structure in the film, which can be used to explain the mechanism of mechanical reinforcement. Since all the components are food ingredients, so it is expected that the developed material can be used as an edible film and food grade packaging material.

Recent Developments in Food Packaging Based on Nanomaterials

The increasing demand for high food quality and safety, and concerns of environment sustainable development have been encouraging researchers in the food industry to exploit the robust and green biodegradable nanocomposites, which provide new opportunities and challenges for the development of nanomaterials in the food industry. This review paper aims at summarizing the recent three years of research findings on the new development of nanomaterials for food packaging. Two categories of nanomaterials (i.e., inorganic and organic) are included. The synthetic methods, physical and chemical properties, biological activity, and applications in food systems and safety assessments of each nanomaterial are presented. This review also highlights the possible mechanisms of antimicrobial activity against bacteria of certain active nanomaterials and their health concerns. It concludes with an outlook of the nanomaterials functionalized in food packaging.

Application of cold plasma to develop carboxymethyl cellulose-coated polypropylene films containing essential oil

This study was aimed to develop and characterize carboxymethyl cellulose-coated polypropylene (PP/CMC) films with Zataria multiflora essential oil (ZEO) as a new antimicrobial food packaging. For better attachment of CMC on polypropylene (PP) film surface, atmospheric plasma pretreatment was used. Results showed the formation of polar groups such as CO and OH in the PP surface following the plasma treatment. Plasma-treated PP had rougher surfaces and their contact angle reduced from 88.92° to 52.15° indicating increased surface hydrophilicity. Plasma-treated PP/CMC films showed lower water vapor permeability (WVP) and higher tensile strength compared to untreated bilayer films. Results revealed that antimicrobial PP/CMC films with higher content of ZEO had lower WVP, but was more sensitive to breakage. Antimicrobial characteristics in the direct contact and vapor phase represented great inhibition for all the tested bacteria. Our findings suggest that plasma-treated PP/CMC films have the potential for application in food antimicrobial packaging.

An assessment of lactobiopolymer-montmorillonite composites for dip coating applications on fresh strawberries

BACKGROUND

The use of biopolymer coatings appears as a good alternative to preserve highly perishable fruits, as well as the environment. Proteins generally produce films with good mechanical properties, although their highly hydrophilic nature limits the use in many applications. Nanoparticles, such as nanoclays, can play a critical role in improving barrier properties. The present study evaluated the effect of the addition of montmorillonite (MMT)-nanoparticles to a lacto-biopolymer coating, focusing on: (i) the morphological, thermal and barrier properties of the material and (ii) the shelf life of coated fresh strawberries.

RESULTS

The addition of MMT improved the water vapor barrier property. Morphological and thermal analysis indicated a good interaction between the milk protein and the nanoclay, which was intercalated within the milk protein base (MPB) matrix, offering a more tortuous path to diffusing migrants. The MMT-MPB coating helped to significantly (P ≤ 0.05) reduce the weight loss, as well as oxygen uptake and the release of carbon dioxide, and improved the fruit firmness and reduced mould and yeast load compared to the uncoated fruits. The addition of MMT gave statistical difference (P ≤ 0.05) in terms of weight loss, subjective global appearance and purchase intention of coated fresh strawberries.

CONCLUSION

The addition of nanofillers, such as MMT, into protein-based coating could improve its water vapour barrier and could affect, positively, some parameters of the shelf life of coated strawberries. © 2016 Society of Chemical Industry.