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, ß-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.

Absorbent bioactive aerogels based on germinated wheat starch and grape skin extract.

This study aimed to produce water-absorbent bioactive aerogels using biodegradable raw materials, wheat starch and poly ethylene oxide (PEO), and derived from agro-industrial residues (grape skin) obtained in the wine industry. The aerogels were produced using germinated wheat starch (GWS), with and without PEO, and incorporating grape skin extract (GSE) at concentrations of 5 and 10 % (w/w). The GSE was evaluated for total and individual phenolic compounds, anthocyanins, and antioxidant activity. The starch aerogels were characterized for morphology, density, porosity, functional groups by FT-IR, relative crystallinity and diffraction pattern, water absorption capacity, antioxidant activity, and in vitro release profile of phenolic compounds in food simulant medium. The total phenolic compounds in GSE was 226.25 ± 0.01 mg equivalent of gallic acid/g GSE. The aerogels showed low density and high porosity. All aerogels demonstrated high water absorption capacity (581.4 to 997.5 %). The antioxidant activity of the aerogels increased with increasing GSE concentration and the addition of PEO. The aerogels could release GSE gradually for up to 120 days in the hydrophilic simulant medium and 240 h for the hydrophobic medium. Starch-based aerogels with GSE showed potential to be applied as exudate absorbers with antioxidant activity to develop active food packaging.

Curcumin encapsulation in capsules and fibers of potato starch by electrospraying and electrospinning: Thermal resistance and antioxidant activity.

The aim of this work was to encapsulate curcumin at different concentrations in capsules and fibers of native potato starch by electrospraying and electrospinning. The best conditions for the production of capsules and fibers were obtained by varying the polymer concentration and resting time of the polymer solution. The best conditions were used for the encapsulation of curcumin. The curcumin-loaded capsules and fibers had an average diameter of 1373 nm to 1787 nm and 108 nm to 142 nm, respectively, and had a high curcumin loading capacity with values ranging from 79.01 % to 97.09 %. Curcumin encapsulated in starch capsules and fibers showed higher thermal stability at 180 °C for 2 h compared to unencapsulated curcumin. The antioxidant activity of starch fibers containing 1 % of curcumin had the greatest ability to inhibit the ABTS radical (45 % inhibition). These materials are promising for use in food or active packaging.

Characterization and quantification of bioactive compounds from Ilex paraguariensis residue by HPLC-ESI-QTOF-MS from plants cultivated under different cultivation systems.

Ilex paraguariensis is a perennial plant used in the production of mate tea, "chimarrão" and "tererê," cosmetics, and other food products. Its leaves are harvested every 12 or 18 months. Approximately 2 to 5 tons of residue are generated per hectare during the harvest. The bioactive composition of this residue has not been characterized to date. Therefore, this paper presents for the first time, the simultaneous characterization of the bioactive compounds of the leaves, thin branches, and thick branches (residue) from I. paraguariensis grown under two cultivation systems: "full sun" and "shaded." The identification and quantification of the compounds was performed using high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight mass spectrometer (HPLC-ESI-QTOF-MS). Consequently, 35 compounds were identified. The average dry weight of phenolic compounds in the residue was 4.1 g/100 g, whereas that in the bark of the residue was 12.9 g/100 g, which was similar to the content found in leaves. The same compounds were identified in the two cultivation systems but with a difference in their contents. While the "full sun" cultivation had a higher content of phenolic acids, the "shaded" cultivation had a higher content of flavonoids and saponins. It was found that the I. paraguariensis residue, particularly the bark, is rich in bioactive compounds, such as quinic, 3-caffeoylquinic, 5-cafefoylquinic, 3,5-dicaffeoylquinic, and 4,5-dicaffeoylquinic acids as well as rutin, and their contents vary according to the cultivation system. Therefore, this residue is an underutilized natural resource with a potential for industrial applications. PRACTICAL APPLICATION: Yerba mate producers will be able to choose the best cultivation system ("full sun" or "shaded") to increase the content of bioactive compounds. New products may be developed with yerba mate residue due to its high concentration of compounds that are beneficial to the human health. New destinations may be applied to yerba mate residue from the harvest pruning, adding commercial value to this unexplored natural resource.

The postharvest ripening of strawberry fruits induced by abscisic acid and sucrose differs from their in vivo ripening.

In this study, we compared the chemical composition of strawberry (Fragaria × ananassa) fruits that were ripened in vivo (attached to plant) to those ripened during postharvest storage. The effects of the application of abscisic acid (ABA) and sucrose on the postharvest ripening were also evaluated. The results suggested that the postharvest ripening process was dependent on the signal triggered by ABA and differed from in vivo ripening, resulting in fruits with altered chemical composition and firmness. The application of sucrose in unripe strawberries resulted in the induction of ripening, which is dependent on ABA and its derivatives. This induction was more pronounced during the first days of storage and associated with the application of mannitol rather than water, suggesting that mannitol negatively regulated the postharvest strawberry ripening. These results provide further insights into the role of ABA and sucrose in the regulation of postharvest ripening of strawberry.

Genome-wide identification, and characterization of the CDPK gene family reveal their involvement in abiotic stress response in Fragaria x ananassa.

Calcium-dependent protein kinases (CDPKs) are encoded by a large gene family and play important roles against biotic and abiotic stresses and in plant growth and development. To date, little is known about the CDPK genes in strawberry (Fragaria x ananassa). In this study, analysis of Fragaria x ananassa CDPK gene family was performed, including gene structures, phylogeny, interactome and expression profiles. Nine new CDPK genes in Fragaria x ananassa were identified based on RNA-seq data. These identified strawberry FaCDPK genes were classified into four main groups, based on the phylogenetic analysis and structural features. FaCDPK genes were differentially expressed during fruit development and ripening, as well as in response to abiotic stress (salt and drought), and hormone (abscisic acid) treatment. In addition, the interaction network analysis pointed out proteins involved in the ABA-dependent response to plant stress via Ca2+ signaling, especially RBOHs. To our knowledge, this is the first report on CDPK families in Fragaria x ananassa, and it will provide valuable information for development of biofortified fruits and stress tolerant plants.

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

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.

ABA-dependent salt and drought stress improve strawberry fruit quality.

Strawberry crop is very sensitive to osmotic stress conditions. We investigated the effect of the stress induced by mild drought (DS) and salt (SS) stresses, on molecular, physiological, and metabolic processes in the strawberry crop (Fragaria ananassa), cv. Camarosa. The results showed that the fruit yield was not affected. Mild DS and SS also resulted in an increased content of phenolics, anthocyanins, and l-ascorbic acid, and an increased antioxidant activity. These effects were accompanied by increased levels of ABA and its derivatives (phaseic and dehydrophasic acids), alongside the upregulation of several genes involved on their synthesis. Therefore, the results obtained in this study suggest that mild DS and SS improve the functional quality of strawberry fruits through and ABA-dependent mechanism.

Improvement of the characteristics of fish gelatin - gum arabic through the formation of the polyelectrolyte complex.

The aim of this study was to evaluate and characterize the interaction between fish gelatin (FG) and Gum Arabic(GA) and its effects in obtaining optimal atomization conditions. The optimal conditions (D = 0.866) founded in this paper were: Gum Arabic concentration of 33.4% and inlet air temperature of 130 °C. These conditions afforded 6.62 g/h yield, 0.27 aw and 247 g of Gel Strength, that are considered as suitable characteristics for food grade gelatin. The complex formed (FG-GA) was successfully obtained, as demonstrated by the results of amino acid profile, SDS-PAGE, FTIR spectroscopy, zeta potential and morphology. It was also verified that the formation of FG-GA promotes positive changes, such as higher atomization yield, adequate Gel Strength, low hygroscopicity and high solubility. The technological properties of FG-GA shown high potential to be applied in the food industry as well in other industrial fields like chemical and pharmaceutical areas.

Production, Characterization, and Stability of Orange or Eucalyptus Essential Oil/ß-Cyclodextrin Inclusion Complex.

The aim of this study was to produce and characterize inclusion complexes (IC) between ß-cyclodextrin (ß-CD) and orange essential oil (OEO) or eucalyptus essential oil (EEO), and to compare these with their pure compounds and physical mixtures. The samples were evaluated by chemical composition, morphology, thermal stability, and volatile compounds by static headspace-gas chromatography (SH-GC). Comparing the free essential oil and physical mixture with the inclusion complex, of both essential oils (OEO and EEO), it was observed differences occurred in the chemical composition, thermal stability, and morphology. These differences show that there was the formation of the inclusion complex and demonstrate the necessity of the precipitation method used to guarantee the interaction between ß-CD and essential oils. The slow loss of the volatile compounds from both essential oils, when complexed with ß-CD, showed a higher stability when compared with their physical mixtures and free essential oils. Therefore, the results showed that the chemical composition, molecular size, and structure of the essential oils influence the characteristics of the inclusion complexes. The application of the ß-CD in the formation of inclusion complexes with essential oils can expand the potential applications in foods.