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Jussara pulp (Euterpe edulis Mart.) is rich in bioactive compounds known to be protective mediators against several diseases. In this context, nevertheless, anthocyanins, the most abundant natural pigment in jussara, are sensitive to temperature, pH, oxygen, and light conditions, leading to instability during food storage or digestion, and, thus jeopardizing the antioxidant proprieties retained by these flavonoids and limiting industrial application of the pulp. The production of nanostructures, from synthetic and natural polymers, containing natural matrices rich in bioactive compounds, has been widely studied, providing satisfactory results in the conservation and maintenance of the stability of these compounds. The current work aimed to compare uniaxial and coaxial electrospinning operation modes to produce core-shell jussara pulp nanofibers (NFs). Additionally, the parameters employed in the electrospinning processes were optimize using response surface methodology in an attempt to solve stability issues for the bioactive compounds. The best experimental conditions provided NFs with diameters ranging between 110.0 ± 47 and 121.1 ± 54 nm. Moreover, the coaxial setup improved jussara pulp NF formation, while further allowing greater integrity of NFs structures.

The development of processes for stabilization of the properties of bioactive compounds has been studied in recent years, and the use of nanotechnology is among the most discussed routes. The present work addressed the assembly of nanostructures using polyethylene oxide (PEO), the production of core-shell nanofibers (NFs) with bioactive compounds, and the evaluation of their microscopic and physical characteristics. Aqueous solutions of PEO were electrospun by varying different process and solution parameters (PEO and NaCl concentrations, feeding rate, the tip-to-collector distance (TCD), and applied voltage) in order to optimize production of nanostructures. The best condition obtained was evaluated to form core-shell NFs composed by jussara pulp as a source of anthocyanins. To assess the production of NFs with PEO and jussara pulp, feed solutions were prepared in acetate buffer (pH 4.5) with 6% PEO and 10% lyophilized jussara pulp, at a feeding rate of 150 μL·h−1 and TCD of 15 cm using an applied voltage of 10 kV to form core-shell NFs. The results revealed the formation of core-shell NFs with a diameter of 126.5 ± 50.0 nm. The outcomes achieved represent a crucial step in the application of anthocyanins in food systems as pigments, establishing a basis for further research on the incorporation of nanomaterials into foodstuff.

Electrospinning can produce a new composite for coating sensitive bioactive compounds, such as anthocyanins, and the product obtained from this process presents characteristics that potentialize the application of natural pigments in foodstuffs. The present work aimed to develop a new nanofiber composite with incorporated anthocyanins from jussara pulp using polyethylene oxide through electrospinning. A decay in the percentage of anthocyanins during digestion was observed. However, the polymeric solution and composites produced maintained the antioxidant activity, showing their protective effect on bioactive compounds; furthermore, both nanofibers and polymer solution improved the thermal stability of the anthocyanins. Thus, the results obtained potentiate electrospinning composites in processed food products since the nanofibers presented superior thermal stability and antioxidant activity, even after the digestion process in vitro.