Recovery of Bioactive Compounds from Jaboticaba Peels and Application into Zein Ultrafine Fibers Produced by Electrospinning

Antimicrobial activity of geranium (Pelargonium graveolens) essential oil and its encapsulation in carioca bean starch ultrafine fibers by electrospinning

Geranium (Pelargonium graveolens) is known for being an aromatic plant rich in bioactive compounds with antibacterial properties. In this study, geranium essential oil (GEO) was extracted and encapsulated in ultrafine bean starch fibers produced by electrospinning as an antibacterial agent. GEO revealed a composition rich in volatile compounds, including citronellol, cis-geraniol, β-linalool, citronellyl formate, and linalool formate. In its free form, GEO exhibited high antibacterial activity against pathogenic bacteria strains (L. monocytogenes, S. aureus, and E. coli). The bean starch fibers, produced with and without the addition of GEO, were uniform and continuous, with an average diameter ranging from 249 to 373 nm. Confocal analysis indicated a uniform distribution of GEO in the fibers, with a loading capacity of 54.0 %, 42.9 %, and 36.5 % for 20 %, 30 %, and 40 % GEO concentrations, respectively. Remarkably, fibers containing 40 % GEO showed a significant reduction in tested bacteria (L. monocytogenes, S. aureus, and E. coli), suggesting promising applications in preventing losses and extending the shelf life of food through active packaging.

Starch extraction from avocado by-product and its use for encapsulation of ginger essential oil by electrospinning

Starches from alternative sources, such as avocado seed, have potential for application in the encapsulation of essential oils. This study aimed to extract starch from avocado seeds and its use as wall material to encapsulate ginger essential oil (GEO), at different concentrations. The fibers were produced by electrospinning and evaluated by morphology, size, infrared spectra, thermogravimetric properties, contact angle, loading capacity, and antibacterial activity. The major compounds in GEO were α-zingiberene, β-sesquiphellandrene, α-farnesene, and α-curcumene. The starch-GEO fibers presented a higher diameter (∼553 nm) than those without GEO (345 nm). Encapsulation of GEO in starch fibers increased their thermal degradation temperatures from 165.8 °C (free GEO) to 257.6 °C (40 % GEO fibers). The starch-GEO fibers presented characteristic bands of their constituents by infrared spectra. Loading capacity ranged from 44 to 54 %. The fibers showed hydrophilic character, with a contact angle of <90°. Free GEO and the fibers with 50 % of GEO displayed antibacterial activity against Escherichia coli, proving the bioactivity of the starch-GEO fibers and its possible applicability for food packaging. Avocado seed starch showed to be a great wall material for GEO encapsulation.

Obtaining of a rich-cellulose material from black wattle (Acacia mearnsii De Wild.) bark residues

Black wattle (Acacia mearnsii De Wild.) barks are residues produced by tannin industries in huge quantities, which are normally discharged on environmental or used for energy production. Therefore, this study aimed to evaluate the use of black wattle bark residues as a raw material on obtaining of a rich-cellulose material by alkaline (MET1), acetosolv (MET2), and organosolv (MET3) procedures. The results obtained indicated that the alkaline methodology, followed by a bleaching step (MET1), promoted klason lignin and hemicellulose removals more efficiently. It was possible to observe that better results were achieved using NaOH concentration of 6% (wt%), at 65 °C for 2.5 h, presenting a yield of 63.24 ± 1.25%, and a reduction on klason lignin content of almost 90.45%. Regarding the bleaching step, it was possible to obtain a material free of non-cellulosic compounds with a yield of 78.28 ± 1.48%. Thermogravimetric analysis indicated the removal of lignin and hemicellulose as well as an increase in cellulose degradation temperature, due to changes in crystalline phases. According to X-ray diffraction (XRD), the procedures employed have led to an increase in crystallinity from 66.27 to 91.78% due to the removal of non-cellulosic compounds. Scanning electron microscopy (SEM) showed morphological alterations in accordance with the removal of non-cellulosic compounds.

Optimization of the Green Extraction of Red Araçá (Psidium catteyanum Sabine) and Application in Alginate Membranes for Use as Dressings

In this research, the aim was to introduce innovation to the pharmaceutical field through the exploration of an underutilized plant matrix, the red araçá, along with the utilization of sodium alginate for the development of membranes designed for active topical dressings. Within this context, optimal extraction conditions were investigated using the central composite rotational statistical design (CCRD) to obtain a red araçá epicarp extract (RAEE) rich in bioactive compounds utilizing the maceration technique. The extract acquired under the optimized conditions (temperature of 66 °C and a hydroalcoholic solvent concentration of 32%) was incorporated into a sodium alginate matrix for the production of active membranes using a casting method. Characterization of the membranes revealed that the addition of the extract did not significantly alter its morphology. Furthermore, satisfactory results were observed regarding mechanical and barrier properties, as well as the controlled release of phenolic compounds in an environment simulating wound exudate. Based on these findings, the material produced from renewable matrices demonstrates the promising potential for application as a topical dressing within the pharmaceutical industry.

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.

Novel Adsorbent Material from Plinia cauliflora for Removal of Cationic Dye from Aqueous Solution

The food industry is responsible for the generation of large amounts of organic residues, which can lead to negative environmental and economic impacts when incorrectly disposed of. The jaboticaba peel is an example of organic waste, widely used in industry due to its organoleptic characteristcs. In this study, residues collected during the extraction of bioactive compounds from jaboticaba bark (JB) were chemically activated with H₃PO₄ and NaOH and used to develop a low-cost adsorbent material for the removal of the cationic dye methylene blue (MB). For all adsorbents, the batch tests were carried out with the adsorbent dosage of 0.5 g L^-1 and neutral pH, previously determined by 2² factorial design. In the kinetics tests, JB and JB-NaOH presented a fast adsorption rate, reaching equilibrium in 30 min. For JB-H₃PO₄, the equilibrium was reached in 60 min. JB equilibrium data were best represented by the Langmuir model and JB-NaOH and JB-H₃PO₄ data by the Freundlich model. The maximum adsorption capacities from JB, JB-NaOH, and JB-H₃PO₄ were 305.81 mg g^-1, 241.10 mg g^-1, and 122.72 mg g^-1, respectively. The results indicate that chemical activations promoted an increase in the volume of large pores but interacted with functional groups responsible for MB adsorption. Therefore, JB has the highest adsorption capacity, thus presenting as a low-cost and sustainable alternative to add value to the product, and it also contributes to water decontamination studies, resulting in a zero-waste approach.

Trends in Bioactive Multilayer Films: Perspectives in the Use of Polysaccharides, Proteins, and Carbohydrates with Natural Additives for Application in Food Packaging

The harmful effects on the environment caused by the indiscriminate use of synthetic plastics and the inadequate management of post-consumer waste have given rise to efforts to redirect this consumption to bio-based economic models. In this sense, using biopolymers to produce materials is a reality for food packaging companies searching for technologies that allow these materials to compete with those from synthetic sources. This review paper focused on the recent trends in multilayer films with the perspective of using biopolymers and natural additives for application in food packaging. Firstly, the recent developments in the area were presented concisely. Then, the main biopolymers used (gelatin, chitosan, zein, polylactic acid) and main methods for multilayer film preparation were discussed, including the layer-by-layer, casting, compression, extrusion, and electrospinning methods. Furthermore, we highlighted the bioactive compounds and how they are inserted in the multilayer systems to form active biopolymeric food packaging. Furthermore, the advantages and drawbacks of multilayer packaging development are also discussed. Finally, the main trends and challenges in using multilayer systems are presented. Therefore, this review aims to bring updated information in an innovative approach to current research on food packaging materials, focusing on sustainable resources such as biopolymers and natural additives. In addition, it proposes viable production routes for improving the market competitiveness of biopolymer materials against synthetic materials.

Antimicrobial Bilayer Film Based on Chitosan/Electrospun Zein Fiber Loaded with Jaboticaba Peel Extract for Food Packaging Applications

This work focused on developing an active bilayer film based on natural extract. Thus, the jaboticaba peel extract (JPE) was produced and characterized and showed promising application as a natural additive in biopolymeric materials. The zein fiber and bilayer films were produced using a chitosan film (casting) and zein fiber (electrospinning), with and without JPE. All samples were evaluated according to thickness, solubility in water, water vapor permeability, and main diameter, and for these, zein fiber, chitosan/zein fiber, and chitosan/zein fiber + 3% JPE showed values of 0.19, 0.51, and 0.50 mm, 36.50, 12.96, and 27.38%, 4.48 × 10^-9, 1.6 × 10^-10, and 1.58 × 10^-10 (g m^-1 Pa^-1 s^-1), and 6.094, 4.685, and 3.620 μm, respectively. These results showed that the addition of a second layer improved the barrier properties of the material when compared to the monolayer zein fiber. The thermal stability analysis proved that the addition of JPE also improved this parameter and the interactions between the components of the zein fiber and bilayer films; additionally, the effective presence of JPE was shown through FTIR spectra. In the end, the active potential of the material was confirmed by antimicrobial analysis since the bilayer film with JPE showed inhibition halos against E. coli and S. aureus.

Promising New Material for Food Packaging: An Active and Intelligent Carrageenan Film with Natural Jaboticaba Additive

This research focused on the development of active and intelligent films based on a carrageenan biopolymer incorporated with jaboticaba peels extract (JPE). The bioactive extract was obtained by maceration extraction and showed high concentrations of total phenolic content (TP), total anthocyanin (TA), cyanidin-3-glucoside (Cn-3-Glu), antioxidant activity (AA), and microbial inhibition (MI) against E. coli, being promising for use as a natural additive in food packaging. The carrageenan films were produced using the casting technique, incorporating different concentrations of JPE, and characterized. The results of the thickness and Young’s modulus of the film increased in the films supplemented with JPE and the addition of the extract showed a decrease in elongation capacity and tensile strength, in water vapor permeability, and a lower rate of swelling in the water. In addition, the incorporation of JPE into the polymeric matrix promotes a change in the color of the films when compared to the control film and improves the opacity property. This is a positive effect as the material has a UV-vis light barrier which is interesting for food packaging. The increase in the active potential of the films was directly proportional to the concentration of JPE. The films results showed visible changes from purple to brown when in contact with different pH, which means that films have an intelligent potential. Accordingly, this novel carrageenan based-film incorporated with JPE could be a great strategy to add natural additives into packaging material to obtain an active potential and also an indicator for monitoring food in intelligent packaging.

Microencapsulation of Anthocyanins—Critical Review of Techniques and Wall Materials

Anthocyanins are value-added food ingredients that have health-promoting impacts and biological functionalities. Nevertheless, there are technological barriers to their application in the food industry, mainly because of their poor stability and susceptibility to harsh environmental conditions, such as oxygen, temperature, pH, and light, which could profoundly influence the final food product′s physicochemical properties. Microencapsulation technology is extensively investigated to enhance stability, bioaccessibility, and impart controlled release properties. There are many varieties of microencapsulation methods and diverse types of wall materials. However, choosing a proper approach involves considering the processing parameters, equipment availability, and application purposes. The present review thoroughly scrutinizes anthocyanins′ chemical structure, principles, benefits, and drawbacks of different microencapsulation methods, including spray drying, freeze drying, electrospinning/electrospraying, inclusion complexes, emulsification, liposomal systems, ionic gelation, and coacervation. Furthermore, wall materials applied in different techniques plus parameters that affect the powders′ encapsulation efficiency and physicochemical properties are discussed. Future studies should focus on various processing parameters and the combination of different techniques and applications regarding microencapsulated anthocyanins in functional foods to assess their stability, efficiency, and commercialization potentials.