Percorrer por autor "Rosales-Conrado, Noelia"
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- A biorefinery approach for the simultaneous obtention of essential oils, organic acids and polyphenols from citrus peels: Phytochemical characterization and bioactive potentialPublication . Gómez-Mejía, Esther; Dias, Maria Inês; Pereira, Carla; Pires, Tânia C.S.P.; Palá-Paúl, Jesús; Rosales-Conrado, Noelia; León-González, María Eugenia; Calhelha, Ricardo C.; Roriz, Custódio Lobo; Pereira, CarlaThis investigation evaluates the valorization of citrus peels (lemon, tangerine, and orange) to recover both on-polar and polar fractions simultaneously. Citrus essential oils, abundant in limonene (74.4–33.7 %), exhibited great antioxidant activity (IC50 = 2.002 mg/mL) and Campylobacter jejuni halo inhibition (2.9 cm), particularly in tangerine and orange essential oils. The aqueous extracts were rich in quinic and malic acid (10–78.8 g/100 g), along with polyphenols (22.7–5.2 mg/g), such as diosmetin, luteolin, and eriodictyol glycosides. Tangerine’s aqueous fraction showed the highest inhibition of oxidative hemolysis (IC50 = 102 μg/mL) and Staphylococcus aureus (MIC = 2.5 mg/mL). Whereas lemon was most effective against lipid peroxidation (IC50 = 1.33 mg/mL) and gastric adenocarcinoma proliferation (IG50 = 83 μg/mL). Principal component analysis correlated the in vitro bioactivities with each compound and citrus type, underscoring the potential of citrus peels as a cost- effective, sustainable source of value-added compounds with tailored commercial applications.
- Chemical characterization and bioactivity evaluation of black mulberry and grape seedsPublication . Gómez-Mejía, Esther; Roriz, Custódio Lobo; Heleno, Sandrina A.; Calhelha, Ricardo C.; Dias, Maria Inês; Pinela, José; Rosales-Conrado, Noelia; León-González, María Eugenia; Ferreira, Isabel C.F.R.; Barros, LillianCircular economy is increasingly seen as a crucial way to reduce food by- products and residues and obtain valuable raw materials. There is a growing demand for industrial products with clean labels and bio benefits, where natural bioactive compounds play an important role. Among these natural biomolecules, polyphenols stand out for their health benefits against diseases such as cancer or diabetes. Thus, the use of agro-industrial bioresidues as a rich source of polyphenols for the development of new natural preservatives, colorants and nutraceuticals is in the spotlight [1,2]. The aim of this work was the recovery of polyphenols from grape and mulberry seeds, usually considered as biowaste. Polyphenols were characterized by HPLC-DAD- ESI/MSn, and the obtained polyphenol-rich extracts were analysed for their bioactive properties, namely antimicrobial and antioxidant capacities. Grape seeds were richer in catechin oligomers (36.0 ± 0.3 mg/g), and mulberry seeds in ellagic acid derivatives (3.14 ± 0.02 mg/g). In addition, both extracts exhibited high antimicrobial activity against multi-resistant Staphylococcus aureus. On the other hand, mulberry seeds showed the strongest antioxidant activity by the lipid peroxidation inhibition (IC50 = 23 ± 2 μg/mL) and oxidative haemolysis inhibition (IC50 at a 60 min Δt = 46.0 ± 0.8 μg/mL) methods [2]. Both by-products could be exploited for the recovery of added-value bioactive polyphenols and further application in the industry [2].
- A green alternative approach to citrus peel bio-waste disposal: characterisation and bioactive potentialPublication . Gómez-Mejía, Esther; Palá-Paúl, Jesús; Lobo Roiz, Custódio; Heleno, Sandrina A.; Calhelha, Ricardo C.; Dias, Maria Inês; Rosales-Conrado, Noelia; León-González, María Eugenia; Barros, Lillian; Madrid, YolandaCurrently, there is a great interest in promoting circular economy perspectives for the recovery of value-added bioactive compounds, potentially exploitable as bioactive natural ingredients, from agri-food bioresidues that causes serious environmental problems. The citrus juice industry is a powerful manufacturing industry that generates huge amounts of waste, mainly peels [1-2]. Material & Methods: A hydrodistillation system was used for the extraction of essential oils, polyphenols and organic acids from lemon, clementine and orange peels, subsequently analysed by GC-MS, UPLC-DAD-ESIMSn and UFLC-PDA respectively. Antioxidant, antimicrobial and/or cytotoxic activities were assessed. Results: The aqueous extract was rich in polyphenols such as hesperidin and sinapoil-O-glucosido. It showed antioxidant (IC50 TBARS = 0.98–1.4 mg/mL), antimicrobial (Staphylococcus aureus MIC = 2.5 mg/mL), and cytotoxic (AGS GI50 = 83 ± 4 mg/mL) activities, especially lemon peels. The essential oils recovered from lemon and clementine peels were rich in limonene (63.6-33,7%), nerol (10,9%) and linalool (5,3%), showing the most antioxidant (IC50 DPPH = 2.0 mg/mL) and antimicrobial (Campylobacter jejuni inhibition halo = 2.8 cm) potential.
- Valorisation of black mulberry and grape seeds: Chemical characterization and bioactive potentialPublication . Gómez-Mejía, Esther; Roriz, Custódio Lobo; Heleno, Sandrina A.; Calhelha, Ricardo C.; Dias, Maria Inês; Pinela, José; Rosales-Conrado, Noelia; León-González, María Eugenia; Ferreira, Isabel C.F.R.; Barros, LillianGrape (Vitis vinifera L. var. Albariño) and mulberry (Morus nigra L.) seeds pomace were characterized in terms of tocopherols, organic acids, phenolic compounds and bioactive properties. Higher contents of tocopherols (28 ± 1 mg/100 g fw) were obtained in mulberry, whilst grape seeds were richer in organic acids (79 ± 4 mg/100 g fw). The phenolic analysis of hydroethanolic extracts characterised grape seeds by catechin oligomers (36.0 ± 0.3 mg/g) and mulberry seeds by ellagic acid derivatives (3.14 ± 0.02 mg/g). Both exhibited high antimicrobial activity against multiresistant Staphylococcus aureus MIC = 5 mg/mL) and no cytotoxicity against carcinogenic and non-tumour primary liver (PLP) cells. Mulberry seeds revealed the strongest inhibition (p lt 0.05) against thiobarbituric reactive substances (IC50 = 23 ± 2 µg/mL) and oxidative haemolysis (IC50 at 60 min = 46.0 ± 0.8 µg/mL). Both seed by-products could be exploited for the developing of antioxidant-rich ingredients with health benefits for industrial application.