Valorization of Food Industry Waste: Synthesis and Fabrication of an Antibacterial and Barrier Paper Coating from Pomegranate Polyphenol-Grafted Silane.

Pomegranate peel (Punica granatum L.) is commonly disregarded as a byproduct in the juice industry despite its rich content of bioactive compounds. This study investigates the impact of incorporating pomegranate peel extract at concentrations of 0%, 1%, 2%, and 3% into rice starch-pectin-based films. Characterization of the films was conducted using Fourier Transform Infrared Spectroscopy (FTIR) and Field Emission Scanning Electron Microscopy (FESEM). Physicochemical properties including thickness, color, opacity, moisture content, water solubility, and water vapor permeability were assessed. The results demonstrate that the incorporation of pomegranate peel extract significantly enhanced the properties of the rice starch-pectin-based films (p < 0.05). Moreover, antimicrobial assays revealed substantial inhibition of Escherichia coli by films containing 3% pomegranate peel extract. Furthermore, the efficacy of these films was evaluated using real tomato samples to assess their potential to extend the shelf life of perishable foods. The findings suggest that the inclusion of pomegranate peel extract in the film matrix contributes to natural pigment preservation, mitigates microbial contamination, and maintains the organoleptic attributes of tomatoes, thereby potentially enhancing their shelf life. These results underscore the promising applications of pomegranate peel extract in the development of sustainable and functional food packaging materials.

Antimicrobial and UV-resistant coatings are important finishing materials for making specialty wood products. In the current work, anti-bacterial and UV-resistant coatings were prepared from nitrocellulose (NC) and pomegranate peel extract (PGE). Different ratios of PGE were added to NC solution (up to 10 wt.% of NC) and the effect of PGE on the viscosity of NC solution, optical, UV-absorption, mechanical, moisture sorption, and antibacterial properties of NC films was studied. Finally, the NC/PGE solution with the appropriate antibacterial activity was sprayed onto the surface of beechwood and its surface was evaluated and compared to neat NC coating regarding gloss, color, change in color due to daylight and thermal aging, and wettability by water. The results showed that PGE reduced the viscosity of NC solution even at low concentrations. All the NC/PGE films had good homogeneity, transparency, UV light absorption, film flexibility, and good antibacterial properties against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria at PGE content 6% or higher. PGE moderately increased the moisture sorption of NC films at high relative humidity (98%). Beechwood was sprayed with NC/8% PGE solution in ethyl acetate; the presence of PGE in NC didn’t affect the visual appearance or light indices (L, a, and b) of the coated wood when compared to the coating with neat NC. The NC/8%PGE coating had high stability against daylight aging while there was no difference in color change between the wood coated with NC and NC/8%PGE after thermal aging. The study showed the potential of PGE as a renewable and safe anti-bacterial and UV-resistant additive for nitrocellulose lacquers used in furniture.Graphical abstract

Substantial increase in the production of agri-food commodities over the past years has resulted in the generation of enormous volumes of wastes and by-products, thus contributing to increased environmental pollution. Being an under-exploited raw material which are rich in bioactive compounds (e.g., polyphenols, dietary fibre, oils, essential vitamins, minerals, etc), novel strategies and initiatives have been proposed and implemented for the effective management and valorization of these wastes and by-products. The proposed initiatives and strategies support the concepts of EU circular economy and green biorefinery, thus promoting sustainability. One of the strategies of management of waste and by-products includes the effectual development of nutritious low-cost sustainable animal feed. Currently, in the world market, there are a range of fruit and vegetable wastes and by-products that have been effectively introduced in animal diets. Within this context, this systematic review focuses on a diversified group of agri-food wastes (and the industrial by-products), their bioactive components, the opportunities for the development of animal feed or feed supplements (for Ruminants, Non-Ruminants and as Poultry feed) and conclusively the health benefits imparted. In addition, the safety issues and regulations aspects are also covered.

Pomegranate peel extract (PPE), a by-product of the pomegranate juice industry with potential health effects, was explored for use to fortify reconstituted apple juice in the concentration range 0.5 to 2.0% (w/w). Radical scavenging and antioxidative capacities of the fortified apple juices were evaluated using (i) electron spin resonance (ESR) to quantify their ability to scavenge the stable radical Fremy's salt and (ii) the Trolox equivalent antioxidant capacity (TEAC) assay and compared to apple juice without fortification as control. The highest antioxidative capacity was found in the apple juice fortified with the highest percentage of pomegranate peel extract, while the optimal sensory quality was found by addition of 0.5 g PPE per 100 mL. The Artemia salina assay was used as a fast screening method for evaluating overall toxicity, and showed little toxicity with up to 1.0 g per 100 mL addition of PPE, but increasing toxicity at higher concentrations. Accordingly, it is important to balance addition of PPE, when used for enrichment of apple juice in order to obtain a healthier product, without compromising the sensorial quality or toxicological safety of the apple juice. Concentrations between 0.5 and 1.0 g PPE per 100 mL seem to be acceptable.

Development and characterization of pomegranate peel extract-infused carboxymethyl cellulose composite films for functional, sustainable food packaging

Food by-products and waste are a boundless source of bioactives, nutraceuticals, and naturally occurring substances that are good for human health. In fact, a lot of by-products and wastes are generated by several food businesses. Therefore, waste management and by-product utilization are the most important aspects of the food sector. According to various studies, many bioactive compounds such as phenolics, carotenoids, and proteins can be recovered as feed stock from various industries' by-products and wastes using potential technologies. As a result, current trends are shifting attention to the sustainable valorisation of food sector waste management and by-products utilization. Thus, the circular economy principles have been applied to the field of food science. The aim of the circular economy is to ensure environmental protection and promote economic development while minimizing the environmental impact of food production. All of these aspects of the circular economy, at present, have become a challenging area of research for by-product valorisation as well. Hence, this review aims to highlight the emerging trends in the efficient utilization of food industry waste and by-products by focusing on innovative encapsulation techniques and controlled release mechanisms of bioactive compounds extracted from food industry waste and by-products. This review also aims to suggest future research directions, and addresses regulatory and toxicity considerations, by fostering knowledge dissemination and encouraging eco-friendly approaches within the food industry. This review reveals the role of encapsulation strategies for the effective utilization of bioactive compounds extracted from food industry waste and by-products. However, further research is needed to address regulatory and toxicity considerations of encapsulated bioactive compounds and health-related concerns.

Although the Green Revolution was a milestone in agriculture, it was accompanied by intensive use of synthetic pesticides, which has raised serious concerns due to their impact on human and environmental health. This is increasingly stimulating the search for safer and more eco-friendly alternative means to control plant diseases and prevent food spoilage. Among the proposed alternatives, pomegranate peel extracts (PPEs) are very promising because of their high efficacy. In the present review, we discuss the complex mechanisms of action that include direct antimicrobial activity and induction of resistance in treated plant tissues and highlight the importance of PPE composition in determining their activity. The broad spectrum of activity, wide range of application and high efficiency of PPEs against bacterial, fungal and viral plant pathogens suggest a potential market not only restricted to organic production but also integrated farming systems. Considering that PPEs are non-chemical by-products of the pomegranate industry, they are perceived as safe by the public and may be integrated in circular economy strategies. This will likely encourage agro-pharmaceutical industries to develop commercial formulations and speed up the costly process of registration.

The sustainable use of pomegranate peel, a by-product of the food industry, is gaining importance in developing pharmaceutical bio-inputs, aligning with circular economy practices and waste reduction. This study explores the application of dry crude pomegranate peel extract (PPE) as a bio-input for medicinal gels with wound healing properties. PPE was extracted via percolation in ethanol and freeze-dried. High-performance liquid chromatography and mass spectrometry identified key bioactive compounds: gallic acid, punicalagin, punicalin, ellagic acid, and citric acid, recognized for their antioxidant, antimicrobial, and healing properties. In vitro assays revealed low hemolytic activity, non-cytotoxicity, significant fibroblast proliferation, and robust antioxidant activity (95.99% 2,2-diphenyl-1-picrylhydrazyl scavenging at 100µg/mL). A carbomer gel containing 2.5% w/w of the extract effectively promoted wound healing in rats, with performance comparable to that of silver sulfadiazine ointment, while demonstrating no microbial contamination during the process. These findings position PPE as a promising, sustainable, and effective alternative for wound-care pharmacotherapy, addressing both medical needs and environmental sustainability.

This study investigated the potential use of two edible coatings, chitosan (CH) and locust bean gum (LBG), which incorporated chemically characterized water pomegranate peel extract (WPPE) or methanol pomegranate peel extract (MPPE) and the biocontrol agent (BCA) Wickerhamomyces anomalus, to control the growth of Penicillium digitatum and to reduce the postharvest decay of oranges.CH and LBG including pomegranate peel extracts (PPEs) at different concentrations were tested in vitro against P. digitatum to determine their antifungal efficacy; at the same time, the tolerance of viable cells of W. anomalus to increasing concentrations of WPPE and MPPE extracts was assessed. The potential application of selected bioactive coatings was evaluated in vivo on oranges, which had been artificially inoculated with P. digitatum, causal agent of green mold decay. CH incorporating MPPE or WPPE at all concentrations was able to inhibit in vitro P. digitatum, while LBG was active only at the highest MPPE or WPPE concentrations. W. anomalus BS91 was slightly inhibited only by MPPE-modified coatings, while no inhibition was observed by WPPE, which was therefore selected for the in vivo trials on oranges artificially inoculated with P. digitatum. The experimental results proved that the addition of 0.361 g dry WPPE/mL, both to CH and LBG coatings, significantly reduced disease incidence (DI) by 49 and 28% respectively, with respect to the relative controls. Besides the combination CH or LBG + WPPE, the addition of W. anomalus cells to coatings strengthened the antifungal effect with respect to the relative controls, as demonstrated by the significant reduction of DI (up to 95 and 75% respectively). The findings of the study contribute to the valorization of a value-added industrial byproduct and provide a significant advancement in the development of new food protectant formulations, which benefit from the synergistic effect between biocontrol agents and natural bioactive compounds.

Background: Effective post-tooth extraction bleeding management and the alleviation of patient discomfort hinge upon the careful choice and judicious application of suitable hemostatic agents. Purpose: In this study, we developed a biodegradable, porous hemostatic sponge composed of gelatin (GE) and chitosan (CS), enhanced by the incorporation of pomegranate peel extract (PE), which was designed for use in dental applications, with a focus on antibacterial properties and infection prevention. Methods: The sponge was synthesized using an environmentally friendly (green) foaming approach without a foaming agent and was fabricated by freeze-drying. The efficiency of the hemostatic sponge was evaluated using various tests, including structural analysis, mechanical strength, water absorption capacity, hydrophilicity, blood clotting time (BCT), in vitro antibacterial effectiveness, and biodegradability. Results: The calcium chloride–crosslinked CS-GE and PE-immersed (CS-GE-PE) sponges exhibited adequate tensile strengths, with CS-GE-PE at 0.776 ± 0.025 MPa. The CS-GE-PE sponge showed significant water absorption (927.1% ± 37.55%). Hydrophilicity was evident (contact angle: 45°) and decreased slightly with the addition of PE. The BCT was shorter for the CS-GE sponge (161 ± 9.644 s), and both sponges exhibited minimal hemolysis, indicating biocompatibility. The CS-GE-PE sponge exhibited slightly enhanced antibacterial properties. Conclusion: This study has successfully developed a composite sponge consisting of CS, GE, and PE that exhibits a balanced level of biodegradability, antibacterial and anti-inflammatory properties, and blood absorption properties that reduce clotting time. This innovative material has great potential for a wide range of clinical applications in dental procedures and wound care.

Sugarcane is a lignocellulosic crop which is used to produce sugar in sugarcane processing industries. Globally, sugarcane processing industries generate solid and liquid wastes amounting to more than 279 million tons per annum and by-products; namely, trash, bagasse, mill mud, and molasses. The valorisation of waste and by-products has recently increased and is playing a significant role in achieving policies and goals associated with circular bioeconomy and sustainable development. For the valorisation of sugarcane processing industry waste and by-products, a number of technologies are well established and in use, while other innovative technologies are still ongoing through research and development with promising futures. These by-products obtained from sugarcane processing industries can be converted into biofuels like hydrogen and methane via anaerobic digestion. Molasses belongs to the first-generation (1G) waste, while trash, bagasse, and mill mud belong to second-generation (2G) waste. Various studies have been carried out in converting both first- and second-generation sugarcane processing industry wastes into renewable energy, exploiting anaerobic digestion (AD) and dark fermentation (DF). This review emphasises the various factors affecting the AD and DF of 1G and 2G sugarcane processing industry wastes. It also critically addresses the feasibility and challenges of operating a two-stage anaerobic digestion process for hydrogen and methane production from these wastes.

Using more sustainable materials and products, the textile sector has been able to contribute to the circular economy. Moreover, the textile industry is witnessing a paradigm shift for more sustainable production methods due to enhanced environmental restrictions and rising consumer preferences for eco-friendly textile products by using the natural fibres and natural dyes. Petroleum-derived synthetic colourants are being used extensively in the textile industry due to their wide colour range, fastness, and affordability which resulted utilisation of significant amounts of fossil fuels and resources. In result, synthetic colours contribute to pollution problems and some of them are even hazardous. Industries are actively seeking alternate approaches to mitigate the detrimental impact of manufactured colourants and chemicals on the environment and human health. This article comprehensively reviews the significant developments in the dyeing of hemp with natural dyes. Several plants like inula, agro-food industry leftovers (chestnut and onion), and logwood and madder have been used for dyeing hemp textiles and examined colour strength and the UV protection characteristics which is the growing demand of "eco-friendly" market. Further, Various natural dye extracts such as calendula (Calendula Officialis), common madder (Rubia Tinctorum L.), pomegranate peel extracts (Punica granatum) and dried Buddleja officinalis flower extracts have been utilised for dyeing the hemp fabrics with various metallic, natural mordants with different mordanting condition and assessed the various parameters like colour strength (K/S), colour fastness properties. The dyed fabrics from pomegranate peel extracts have shown significant antibacterial activity and good colour fastness against laundering, water, sea water, and perspiration. Efforts are underway to utilise natural dyes in order to achieve comparable outcomes to those achieved with synthetic dyes. Understanding the various natural materials for dyeing the Hemp and their characteristics provides a new insight for the dyeing industry and inspiring to carry out the research in similar natural materials.

To maintain the overall quality of fisheries products, functional edible coatings from natural ingredients including fish gelatin (Gf), k-carrageenan (Cr), and extract of pomegranate peels (PPE) were composed. The Gf was extracted from blue tilapia (Oreochromis aureus), microencapsulated with Cr, and then loaded with PPE (at concentrations of 0.5%, 1.0%, 1.5% and 2.0%). The Fourier transform infrared (FTIR) spectra of Gf/Cr composites verified their cross-linkage and functionality; the Gf/Cr microcapsules had a mean particle size of 36.2 µm with good distribution and homogeneity. The coating of Nile tilapia (Oreochromis niloticus) fillets, with constructed solutions from Gf/Cr/PPE, revealed their positive effects on fillet quality attributes; the effectiveness was dependent on the supplemented PPE concentration. The Gf/Cr/PPE solutions could effectively reduce the microbial counts of total aerobics, psychrotrophs, yeast and molds, and enterobacteriaceae groups throughout 30 days of refrigerated storage. Additionally, the analysis of spoilage chemical parameters (total volatile basic nitrogen, peroxide value, and thiobarbituric acid reactive substances) in coated samples indicated that formulated solutions could hinder the increase of their values during storage. The sensorial evaluation indicated the acceptability and validity of coated samples for up to 30 days of storage. Gf/Cr/PPE coating is recommended for overall quality maintenance of fish fillets and prolongation of storage using safe and healthy biopreservatives.

This chapter addresses sustainable environmental remediation by valorization of wastes and their by-products obtained from agro-food industries. The agro-food industry generates a huge amount of agro-food waste and by-products from fruit and vegetable processing which are well known for their excellent source of valuable constituents such as bioactives (secondary metabolites). The antioxidative, anti-carcinogenic, anti-inflammatory, anti-allergic, and anti-atherogenic properties of bioactive compounds have a very positive impact on health and are also known to modulate metabolic processes as well as help in cellular activities for human health, depending on the pathway and their bioavailability in the body. Consequently, this chapter highlights an overview of current trends and future prospects in the conversion of residues from various food sections into value-added products.

Biologically produced silver nanoparticles are becoming a more appealing option than chemically produced antioxidants and antimicrobial agents, because they are safer, easier to manufacture and have medicinal properties at lower concentrations. In this work, we employed the aqueous pomegranate peel extract (PPE) to synthesize silver nanoparticles (PPE-AgNPs), as peel extract is a rich source of phytochemicals which functions as reducing agent for the synthesis of PPE-AgNPs. Additionally, the PPE was examined quantitatively for total phenolics and total flavonoids content. PPE-AgNPs were characterized using analytical techniques including UV–Vis spectroscopy, DLS, FTIR, XRD, HRTEM and FESEM, evaluated in vitro against the plant pathogenic microbes and also for antioxidant activities. Analytical techniques (HRTEM and FESEM) confirmed the spherical shape and XRD technique revealed the crystalline nature of synthesized PPE-AgNPs. Quantitative analysis revealed the presence of total phenolics (269.93 ± 1.01 mg GAE/g) and total flavonoids (119.70 ± 0.83 mg CE/g). Biosynthesized PPE-AgNPs exhibited significant antibacterial activity against Klebsiella aerogenes and Xanthomonas axonopodis, antifungal activity against Colletotrichum graminicola and Colletotrichum gloesporioides at 50 µg/mL concentration. The antioxidant potential of biosynthesized PPE-AgNPs was analysed via ABTS (IC50 4.25 µg/mL), DPPH (IC50 5.22 µg/mL), total antioxidant (86.68 g AAE/mL at 10 µg/mL) and FRAP (1.93 mM Fe(II)/mL at 10 µg/mL) assays. Cytotoxicity of PPE-AgNPs was valuated using MTT assay and cell viability of 83.32% was determined at 100 µg/mL concentration. These investigations suggest that synthesized PPE-AgNPs might prove useful for agricultural and medicinal purposes in the future.