Thermal and irradiation resistance of folic acid encapsulated in zein ultrafine fibers or nanocapsules produced by electrospinning and electrospraying

Abstract

The objectives of this study were to characterize zein fibers and capsules prepared by electrospinning and electrospraying techniques, respectively, and then use them to encapsulate folic acid. Folic acid containing fibers and capsules (0.5, 1.0, and 1.5%, w/v) were submitted to thermal treatment (100, 140, and 180°C) and ultraviolet A light (UVA) irradiation to evaluate the resistance of folic acid. Zein fibers and capsules containing folic acid showed high encapsulation efficiency (> 80%). Unencapsulated folic acid showed a reduction in folic acid content from 17.17 μg/mL to 5.44 μg/mL (approximately 70%) when exposed to 180°C. Photodegradation of unencapsulated folic acid lowered its concentration from 17.17 μg/mL to 12.58 μg/mL (~26% of reduction), when exposed for 1 h to UVA irradiation. However, folic acid concentration when encapsulated in fibers (1.5%) was maintained or only slightly reduced from 9.73 μg/mg to 8.88 μg/mg after thermal treatment at 180°C. The capsules containing 1.5% of folic acid also presented a slight reduction in folic acid concentration from 8.84 μg/ mg to 7.88 μg/mg when exposed to 24 h of UVA irradiation. Zein fibers and capsules containing folic acid present promising characteristics for application in foods that require thermal processing or exposure to irradiation.

Gallic Acid‐Loaded Zein Nanoparticles by Electrospraying Process

“…Similar studies that have reported distances of 10 cm for zein nanoparticles were those of do Evangelho et al. () and Gómez‐Mascaraque et al. ().…”

“…Studies report that needle distance of the collector and solvent evaporation exert a significant impact on particle size and distribution with three behaviors as follows: the first behavior, were at short distance (<10 cm) and high solvent evaporation, a smaller diameter is obtained; the second, if the collector distance is very short (5 cm), it will not be possible to evaporate all of the solvent; thus, the particle will be unstable and the size will be larger (Costamagna et al, 2017;Ghayempour, & Mortazavi, 2013), and, in the third behavior, if the collector distance is long (>10 cm) with low solvent evaporation, it can volatilize the solvent and the polymer particle encourages fission Tapia-Hernández et al, 2017). Similar studies that have reported distances of 10 cm for zein nanoparticles were those of do Evangelho et al (2018) and Gómez-Mascaraque et al (2018).…”

“…In this study, the electrosprayed solution with a lower concentration of GA (1% w/v) had high electrical conductivity (369 ± 4.3 µs/cm), which is related to the smaller particle size and to the similar morphology obtained and is demonstrated in Figure . The electrical conductivity of the GA‐zein electrosprayed solution is influenced by the type and concentration of the components, the solvent, and the availability of ionizable compounds (do Evangelho et al., ).…”

“…Electrical conductivity. Electrical conductivity was determined from the methodology described by Prietto et al (2018). Electrical conductivity was determined for all zein solutions at different concentrations of GA (1 to 5% w/v).…”

Free and encapsulated orange essential oil into a β‐cyclodextrin inclusion complex and zein to delay fungal spoilage in cakes

“…The suspension obtained from the previous section was pumped at a flow rate of 1 ml/h by an infusion pump to a 16‐gauge blunt end stainless steel needle that acted as a spinneret, in accordance with the methodology described by Evangelho et al () for capsules production with some modifications. The spinneret was connected to the positive electrode of a 20 kV direct current power supply.…”