Stabilization Techniques of Essential Oils by Incorporation into Biodegradable Polymeric Materials for Food Packaging

Biopolymer-polyphenol conjugates: Novel multifunctional materials for active packaging

The development of natural active packaging materials and coatings presents a promising alternative to petroleum-based packaging solutions. These materials are engineered by incorporating functional ingredients with preservative capabilities. Concurrently, research has highlighted the diverse physicochemical, functional, and health-promoting properties of protein-polyphenol, polysaccharide-polyphenol, and protein-polysaccharide-polyphenol conjugates within various food formulations. However, a critical gap exists regarding the exploration of these biopolymers as active packaging materials. In contrast to conventional approaches for developing active packaging materials, this review presents a novel perspective by focusing on biopolymer-polyphenol conjugates. In this work, we delve into the realm of active packaging materials and coatings constructed from these conjugates, highlighting their potential as multifunctional active components in food packaging and preservation. This review comprehensively investigates the physicochemical properties, functionalities, and health-promoting activities associated with biopolymer-polyphenol conjugates. Their emulsification, antioxidant, and antimicrobial activities, coupled with enhancements in mechanical strength and permeability properties, contribute to their multifunctional nature. Furthermore, we explore the potential advantages and limitations of utilizing these conjugates in active packaging applications. Finally, the review concludes by proposing crucial research avenues for further exploration of biopolymer-polyphenol conjugates within the domain of active food packaging.

Enhanced stability of encapsulated lemongrass essential oil in chitosan-gelatin and pectin-gelatin biopolymer matrices containing ZnO nanoparticles

The use of essential oils is widespread in various fields such as pharmacy, pest control, and active packaging. However, their instability and short-term effects require methods to enhance their durability and effectiveness. Encapsulation in biopolymer matrices appears to be a promising approach due to the environmental safety and cost-effectiveness of such formulations. In this study, different oil-in-water emulsions were prepared by mixing chitosan-gelatin (C-G) or pectin-gelatin (P-G) solutions with lemongrass essential oil (LG). ZnO NPs were used as an additional active component. Encapsulation in biopolymer matrices resulted in stable emulsions with a significantly slower release of LG, and ZnO NPs further suppressed LG release, particularly in the P-G emulsion. They also contributed to the stability of the emulsions and a decrease in the average droplet size of LG. Furthermore, the presence of LG and ZnO NPs improved the smoothness of the films prepared from the emulsions and dispersions using the casting technique. SEM/EDS analysis confirmed the homogeneous distribution of ZnO NPs in both C-G and P-G films. By adjusting the type and content of the biopolymers and NPs, such emulsions could be effectively utilized in various applications where controlled release of active components is required.

Formulization and characterization of guar gum and almond gum based composite coating and their application for shelf-life extension of okra (Hibiscus esculentus)

The current novel study aims was to development and characterization of gum based (guar gum: almond gum) composite formulations with or without addition of oregano essential oils to extend the shelf life of okra at ambient condition. In this study, the optimized composite of guar gum: almond gum (75:25 V/V) prepared with addition of different concentrations (0.05, 0.1 and 0.15 % (V/V) of oregano essential oils to study their physicochemical, rheological, antimicrobial and particle size & zeta potential distribution. In addition, the effects of prepared edible coatings on shelf-life of okra vegetables were also investigated by assessing their postharvest quality attributes at ambient (23 °C) storage up to 7 days storage. The results revealed, increasing concentration of essential oils in composite coating significantly increased in pH, TSS, particle size, antimicrobial (Apergillus. niger, Escherichia coli, Staphylococcus aureus) activity respectively. Furthermore, the increasing EOs improved viscosity (n) and stability of the coatings matrix. In addition, the applications of guar gum (0.25 %): almond gum (0.5 %) composite ratio (75,25) with oregano essential oils exhibited excellent properties and potential to maintain the postharvest characteristics of okra throughout the storage period. The results of this study revealed that the addition of higher concentration (0.15 %) of essential oils in composite formulation of 75 % guar gum +25 % almond gum (03) showed higher value of pH (5.45), antioxidant activity (20.87 %), particle size (899.1 nm), zeta potential (-8.6 mV), polydispersity index (50.6 %) and higher antimicrobial activity against E.coli (19 mm), S. aureus (29 mm) and A. niger (35 mm) as compared to other formulations. Therefore, the lower composite formulation (01) with lower concentration (0.05 %) of oregano essential oil was found most effective formulation to maintain the shelf life of okra for up to 4 days as compared to other treated and control okra samples at ambient temperature by retarded the weight loss (12.74 %), maintained higher firmness (0.998 N), lower respiration rate (484.32 ml Co2/kg/h) respectively on 7 days of storage. The microbial load in the okra samples treated with different guar gum: almond gum composite showed lower microbial load in terms of total plate count and yeast & mold counts as compared to control samples. Samples treated with O3 coating showed lowest TPC (0.1 × 108 cfu/g) and YMC (6.63 × 106 cfu/g) followed by O2 (0.48 × 108 cfu/g, 7.9 × 106 cfu/g) and O1 (0.78 × 108 cfu/g, 9.45 × 106 cfu/g) respectively on 6rd day of storage, overall results indicated that the application of composite coating with different concentrations of oregano essential oils were effective to maintained postharvest shelf life of okra up to 4 days at ambient condition.

Electrospun Nanofibers for Functional Food Packaging Application

With the strengthening of the public awareness of food safety and environmental protection, functional food packaging materials have received widespread attention. Nanofibers are considered as promising packaging materials due to their unique one-dimensional structure (high aspect ratio, large specific surface area) and functional advantages. Electrospinning, as a commonly used simple and efficient method for preparing nanofibers, can obtain nanofibers with different structures such as aligned, core-shell, and porous structures by modifying the devices and adjusting the process parameters. The selection of raw materials and structural design of nanofibers can endow food packaging with different functions, including antimicrobial activity, antioxidation, ultraviolet protection, and response to pH. This paper aims to provide a comprehensive review of the application of electrospun nanofibers in functional food packaging. Advances in electrospinning technology and electrospun materials used for food packaging are introduced. Moreover, the progress and development prospects of electrospun nanofibers in functional food packaging are highlighted. Meanwhile, the application of functional packaging based on nanofibers in different foods is discussed in detail.

Essential Oils: Recent Advances on Their Dual Role as Food Preservatives and Nutraceuticals against the Metabolic Syndrome

Essential oils (EO) are compounds synthesized by plants as secondary products and are a complex mixture of volatile molecules. Studies have demonstrated their pharmacological activity in the prevention and treatment of metabolic syndrome (MetS). Moreover, they have been used as antimicrobial and antioxidant food additives. The first part of this review discusses the role of EO as nutraceuticals to prevent metabolic syndrome-related disorders (i.e., obesity, diabetes, and neurodegenerative diseases), showing results from in vitro and in vivo studies. Likewise, the second part describes the bioavailability and mechanisms of action of EO in preventing chronic diseases. The third part presents the application of EO as food additives, pointing out their antimicrobial and antioxidant activity in food formulations. Finally, the last part explains the stability and methods for encapsulating EO. In conclusion, EO dual role as nutraceuticals and food additives makes them excellent candidates to formulate dietary supplements and functional foods. However, further investigation is needed to understand EO interaction mechanisms with human metabolic pathways and to develop novel technological approaches to enhance EO stability in food systems to scale up these processes and, in this way, to overcome current health problems.

Preparation and Characterization of New Bioplastics Based on Polybutylene Succinate (PBS)

Sea and environmental pollution due to microplastics are global problems that in recent years have attracted particular interest in the scientific community. The increase in the world population and the consequent consumerism of non-reusable materials are amplifying these problems. In this manuscript, we present novel bioplastics, which are completely biodegradable, for their potential use in food packaging, to replace fossil-fuel-derived plastic films and slow food degradation due to oxidative processes or microbial contamination. In this study, thin films based on polybutylene succinate (PBS) were prepared to reduce pollution, and different percentages by weight (1, 2 and 3 wt%) of extra virgin olive oil (EVO) and coconut oil (CO) were included to improve the chemico-physical properties of the polymer and possibly improve the functionality of the films in terms of prolonged food preservation. Attenuated total reflectance Fourier transform infrared (ATR/FTIR) spectroscopy was used to evaluate the interactions between the polymer and the oil. Furthermore, the mechanical properties and thermal behavior of the films were evaluated as a function of the oil content. A scanning electron microscopy (SEM) micrograph showed the surface morphology and the thickness of the materials. Finally, apple and kiwi were selected for a food-contact test, and the wrapped sliced fruit was monitored and evaluated for 12 days to macroscopically evaluate the oxidative process and/or eventually occurring contamination. The films were shown to reduce the browning of sliced fruit due to oxidation, and no molds were evidenced up to 10/12 days of observation with the addition of PBS, with 3 wt% of EVO achieving the best outcomes.

Essential oil for the control of fungi, bacteria, yeasts and viruses in food: an overview

This review begins with a general introduction to essential oils (EO) and their relation to food and microorganisms. Classification and characteristics of EO, addressing the major compounds with antimicrobial action. Subsequently, the main microorganisms followed by a collection of the main works published in recent years that approached the influence of the EO on the protection against microorganisms and food decontamination. At last, the major gaps and future perspectives on the subject. Using EO for fighting food contamination is a way of sustainably supplying the need for new antimicrobials to ensure microbial safety and is a viable source to solve the problem of current microbial resistance. Form of application, EO composition and microbiological load are reported as the responsible factors for the treatment's success. The EO's effects on fungi and bacteria are already well known, but its effect on viruses and yeasts is something to be explored.

Synthesis of Bioactive Materials by In Situ One-Step Direct Loading of Syzygium aromaticum Essential Oil into Chitosan-Based Hydrogels

Hydrogel conjugates based on chitosan and an essential oil were synthetized by an ultrasound-assisted emulsification approach. Rheology studies revealed a gel-type structure with pronounced compactness and flexibility while SEM showed the formation of a two-level ordered network with highly interconnected pores. The swelling studies indicated a pH-dependent behavior with a significant overshooting effect. The synergistic effects of the components in clove essential oil led to a strong antioxidant character and an enhanced antimicrobial activity of the conjugate hydrogels. The bioactivity was maintained for 6 months, despite a slight decrease in the antimicrobial effect. Hydrogel conjugates were found to be very stable even after two months immersed in acidic solutions that would otherwise dissolve the chitosan matrix. Ultrasound emulsification was proved as an efficient one-step loading method of hydrophobic clove essential oil into hydrophilic chitosan matrix. It was found that clove oil and its components have a double role. Besides providing bioactivity, they also behave as gelation-inducing agents, acting as an alternative to the classical chemical cross-linkers to ensure the good physical and chemical stabilization of chitosan.