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- On the valorization of Arbutus unedo L. Pomace: Polyphenol extraction and development of novel functional cookiesPublication . Duarte, Hugo; Carrera, Ceferino; Aliaño-González, M.J.; Gutiérrez-Escobar, Rocío; Jiménez-Hierro, María Jesús; Palma, Miguel; Galego, Ludovina; Romano, Anabela; Medronho, BrunoThe fruits of Arbutus unedo L. have a crimson colour and are enriched with remarkable concentrations of bioactive compounds such as anthocyanins and polyphenols. These fruits are commonly used in the production of a Portuguese Protected Geographical Indication distillate called “Aguardente de Medronho”. During this process, a solid pomace is generated and presently discarded without valuable applications. In this work, two strategies have been developed for the valorisation of A. unedo pomace. The first approach considers the extraction of polyphenols from this by-product through the optimization of an ultrasound-assisted method using a Box-Behnken design coupled with response surface methodology. The results indicate that the temperature and the percentage of methanol, along with their interaction, significantly influence the total concentration of polyphenols and the antioxidant activity of the extracts obtained. The optimal conditions identified consider the extraction of 0.5 g of sample with 20 mL of a solvent containing 74% MeOH (aq), at a pH of 4.8, maintained at 70 ◦C for 15 min. On the other hand, the second valorisation strategy considered the use of A. unedo pomace in the development of functional cookies. The incorporation of 15–20% pomace in the cookie formulation was well-received by consumers. This incorporation results in an intake of ca. 6.55 mg of polyphenols per gram of cookie consumed, accompanied by an antioxidant activity of 4.54 mg Trolox equivalents per gram of cookie consumed. Overall, these results encourage the employment of A. unedo pomace either as a reliable source of extracts enriched in polyphenols or as a nutraceutical active ingredient in functional cookies, thereby positively impacting human health.
- A sustainable extraction approach of phytochemicals from date (Phoenix dactylifera L.) fruit cultivars using ultrasound-assisted deep eutectic solvent: A comprehensive study on bioactivity and phenolic variabilityPublication . Djaoudene, Ouarda; Bachir-Bey, Mostapha; Schisano, Connie; Djebari, Sabrina; Tenore, Gian Carlo; Romano, AnabelaThe present study aimed to evaluate the efficacy of natural deep eutectic solvents (NADESs) on the extraction of phytochemicals from eight Algerian date fruit cultivars (Phoenix dactylifera L.). In this study, lactic acid/sucrose-based NADESs were used as an alternative to conventional chemical solvents using the ultrasound-assisted extraction (UAE) method. The obtained extracts were assessed for the determination of bioactive compound contents, phenolic composition, antioxidant activity, and enzyme inhibitory potential. The results showed a considerable variation in phytochemical compositions and related activities between cultivars, where the greatest contents of total phenolics (1288.7 mg GAE/100 g), total flavonoids (53.8 mg QE/100 g), proanthocyanidins (179.5 mg CE/g), and total triterpenoids (12.88 mg OAE/100 g) were detected in the fruits of the Ourous cultivar. The same cultivar displayed the highest antioxidant capacity against DPPH• free radical (595 mg AAE/100 g), ABTS•+ cation radical (839 mg TE/100 g), and ferric reducing antioxidant potential (704 mg AAE/100 g). All extracts manifested moderate antioxidant activities tested by phosphomolybdenum, NO• , and linoleic acid lipid peroxidation assays. These extracts also exhibited interesting levels of in vitro enzyme inhibition; the Ourous cultivar gave the best inhibitory activity against α-amylase and acetylcholinesterase with 45 and 37%, respectively. HPLC-DAD-MS detected a total of five compounds, with phenolic acids and flavonoids being the main phenolics identified in the extract. The phenolic composition exhibited significant variability among cultivars. Notably, the highest amounts were revealed in the Tazizaout cultivar, with the predominance of gallic acid. The results confirmed that the combination of UAE and NADESs provides a novel and important alternative to chemical solvents for sustainable and environmentally friendly extraction and can represent a good alternative in food and pharmaceutical industry applications.
- Impact of metallic nanoparticles on In vitro culture, phenolic profile and biological activity of two mediterranean lamiaceae species: Lavandula viridis L’Hér and Thymus lotocephalus G. López and R. MoralesPublication . Gonçalves, Sandra; Mansinhos, Inês; Rodríguez-Solana, Raquel; Pereira-Caro, Gema; Moreno-Rojas, José Manuel; Romano, AnabelaNanoparticles (NPs) recently emerged as new chemical elicitors acting as signaling agents affecting several processes in plant metabolism. The aim of this work was to investigate the impact of the addition of copper oxide (CuO), zinc oxide (ZnO) and iron oxide (Fe3O4 ) NPs (<100 nm) at different concentrations (1, 5 and 10 mg/L) to the culture media on several morphological, physiological and -biochemical parameters of in vitro shoot cultures of Lavandula viridis L’Hér and Thymus lotocephalus G. López and R. Morales (Lamiaceae), as well as on phenolic profile and bioactivity (antioxidant and enzyme inhibition capacities). Although some decreases in shoot number and length were observed in response to NPs, biomass production was not affected or was improved in both species. Most NPs treatments decreased total chlorophyll and carotenoid contents and increased malondialdehyde levels, an indicator of lipid peroxidation, in both species. HPLC-HR-MS analysis led to the identification of thirteen and twelve phenolic compounds, respectively, in L. viridis and T. lotocephalus extracts, being rosmarinic acid the major compound found in all the extracts. ZnO and Fe3O4 NPs induced an increase in total phenolic and rosmarinic acid contents in T. lotocephalus extracts. Additionally, some NPs treatments also increased antioxidant activity in extracts from this species and the opposite was observed for L. viridis. The capacity of the extracts to inhibit tyrosinase, acetylcholinesterase and butyrylcholinesterase enzymes was not considerably affected. Overall, NPs had a significant impact on different parameters of L. viridis and T. lotocephalus in vitro shoot cultures, although the results varied with the species and NPs type.
- Thymus lotocephalus wild plants and in vitro cultures produce different profiles of phenolic compounds with antioxidant activityPublication . Costa, Patrícia; Gonçalves, Sandra; Valentão, Patrícia; Andrade, Paula B.; Coelho, Natacha; Romano, AnabelaWe compared the phenolic metabolites and antioxidant activities of Thymus lotocephalus G. López & R.Morales wild plants and in vitro cultures using different extraction solvents. HPLC–DAD analysis allowed the identification and quantification of phenolic (caffeic and rosmarinic) acids and flavones (luteolin and apigenin) in extracts from both sources. The in vitro cultures accumulated large amounts of rosmarinic acid. However, extracts from both sources were able to neutralise free radicals in different test systems(TEAC and ORAC assays), to form complexes with Fe2+ and to protect mouse brains against Fe2+-induced lipid peroxidation. The solvent significantly influenced the phenolic content and antioxidant activity of the extracts, water/ethanol being the most efficient for the extraction of antioxidant phytochemicals. We conclude that in vitro cultures of T. lotocephalus represent a promising alternative for the production of valuable natural antioxidants and an efficient tool for the in vitro biosynthesis of rosmarinic acid, therefore avoiding the need to exploit populations of wild plants.
- Sapwood of carob tree (Ceratonia siliqua L.) as a potential source of bioactive compoundsPublication . Custódio, Luísa; Escapa, Ana Luísa; Patarra, João; Aligué, Rosa; Alberício, Fernando; Neng, Nuno Rosa; Nogueira, José Manuel F.; Romano, AnabelaMethanol (ME) and hot water extracts (WE) of carob tree sapwood (Ceratonia siliqua L.) exhibited high antioxidant activity and were rich in phenolic compounds, with the main compounds identified by HPLC/DAD as gentisic acid and (-)-epicatechin. The ME displayed a high in vitro antitumor activity against human tumoural cell lines and reduced intracellular ROS production by HeLa cells after treatment with H2O2. (-)-Epicatechin was shown to contribute to the cytotoxic activity of the ME. This is the first report on the biological activity of carob tree sapwood.
- Influence of wine pH and ethanol content on the fining efficacy of proteins from winemaking by-productsPublication . Baca-Bocanegra, Berta; Gonçalves, Sandra; Nogales-Bueno, Julio; Mansinhos, Inês; Heredia, Francisco José; Hernández-Hierro, José Miguel; Romano, A.Wine color and limpidity are important aspects of consumer preferences. The alteration of these parameters can damage wine’s appearance but also its mouthfeel characteristics due to its relationship with attributes such as bitterness and astringency. Fining is a practice usually used in enology to modulate undesirable wine organoleptic attributes. However, there are several factors that influence this technique. In this study, the influence of wine pH and ethanol content on grape seed protein fining efficacy has been assessed. Wine clarification, total phenolic and flavanol contents, antioxidant activity, and chromatic parameters have been investigated before and after fining process. The most noticeable clarifying effects were observed for the experimental wines with a lower pH and ethanol content. Control of these factors will make it possible to modulate the main organoleptic properties of the wine, also avoiding the addition of large amounts of fining agents and thus providing greater versatility to wineries during winemaking. Furthermore, our findings indicated that grape seed protein is a potential alternative to other plant-based fining proteins commonly used in winemaking. Its effects on clarification and color quality have been found to be comparable to those of potato protein and significantly better than those of pea protein.
- Antioxidant and anti-cholinesterase activities of Lavandula viridis L’Hér extracts after in vitro gastrointestinal digestionPublication . Costa, Patrícia; Grevenstuk, Tomás; Costa, Ana M. Rosa da; Gonçalves, Sandra; Romano, AnabelaLavandula viridis L’Hér is an aromatic shrub with relevant biological activities associated to the presence ofphenolic compounds. However, these compounds must be bioavailable to exert their biological function.Therefore, in this study, we investigated the influence of the L. viridis extract matrices on the digestion ofthe main component rosmarinic acid and their antioxidant and anti-cholinesterase activities after in vitrogastrointestinal digestion. Overall, the antioxidant and anti-cholinesterase activities were assured afterin vitro gastrointestinal processes and we observed that the L. viridis extract matrices have an importantrole in the bioactive effects of their main compound, rosmarinic acid. The L. viridis extracts and rosmarinicacid did not show any toxic effect on colon adenocarcinoma Caco-2 cell viability. Finally, the compoundsfrom L. viridis extracts were not metabolized by Caco-2 cells and were not able to permeate into them.
- Ultrasound-assisted extraction of Polyphenols from maritime pine residues with deep eutectic solventsPublication . Duarte, Hugo; Gomes, Valentim; Aliaño-González, María José; Faleiro, Maria Leonor; Romano, Anabela; Medronho, BrunoDeep eutectic solvents represent an important alternative in the field of green solvents due to their low volatility, non-toxicity, and low synthesis cost. In the present investigation, we propose the production of enriched polyphenolic extracts from maritime pine forest residues via an ultrasound-assisted approach. A Box–Behnken experimental design with a response surface methodology was used with six variables to be optimized: solid-to-solvent ratio, water percentage, temperature and time of extraction, amplitude, and catalyst concentration. The mixture of levulinic and formic acids achieved the highest extraction yield of polyphenols from pine needle and bark biomass. In addition, the solid-to-solvent ratio was found to be the only influential variable in the extraction (p-value: 0.0000). The optimal conditions were established as: 0.1 g of sample in 10 mL of LA:FA (70:30%, v/v) with 0% water and 0 M H2SO4 heated to 30 ◦C and extracted during 40 min with an ultrasound amplitude of 80% at 37 kHz. The bioactive properties of polyphenol-enriched extracts have been proven with significant antioxidant (45.90 ± 2.10 and 66.96 ± 2.75 mg Trolox equivalents/g dw) and antimicrobial activities. The possibility to recycle and reuse the solvent was also demonstrated; levulinic acid was successfully recovered from the extracts and reused in novel extractions on pine residues. This research shows an important alternative to obtaining polyphenolenriched extracts from forest residues that are commonly discarded without any clear application, thus opening an important window toward the valorization of such residues.
- Ultrasonic-assisted extraction and natural deep eutectic solvents combination: A green strategy to improve the recovery of phenolic compounds from Lavandula Pedunculata subsp. Lusitanica (Chaytor) FrancoPublication . Mansinhos, Inês; Gonçalves, Sandra; Rodríguez Solana, Raquel; Ordóñez-Díaz, José Luis; Moreno-Rojas, José Manuel; Romano, A.The present study aimed at evaluating the effectiveness of different natural deep eutectic solvents (NADES) on the extraction of phenolic compounds from Lavandula pedunculata subsp. lusitanica (Chaytor) Franco, on the antioxidant activity, and acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase (Tyr) inhibitory capacities. Ten different NADES were used in this research and compared with conventional solvents. Ultrasound-assisted extraction (UAE) for 60 min proved to be the best extraction condition, and proline:lactic acid (1:1) and choline chloride:urea (1:2) extracts showed the highest total phenolic contents (56.00 ± 0.77 mgGAE/gdw) and antioxidant activity [64.35 ± 1.74 mgTE/gdw and 72.13 ± 0.97 mgTE/gdw in 2.2-diphenyl-1- picrylhydrazyl (DPPH) and 2.20 -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods, respectively]. These extracts also exhibited enzymes inhibitory capacity particularly against Tyr and AChE. Even so, organic acid-based NADES showed to be the best extractants producing extracts with considerable ability to inhibit enzymes. Twenty-four phenolic compounds were identified by HPLC-HRMS, being rosmarinic acid, ferulic acid and salvianolic acid B the major compounds. The results confirmed that the combination of UAE and NADES provide an excellent alternative to organic solvents for sustainable and green extraction, and have huge potential for use in industrial applications involving the extraction of bioactive compounds from plants.
- Impact of temperature on Phenolic and Osmolyte contents in In Vitro cultures and micropropagated plants of two mediterranean plant species, Lavandula viridis and Thymus lotocephalusPublication . Mansinhos, Inês; Gonçalves, Sandra; Rodríguez Solana, Raquel; Ordóñez-Díaz, José Luis; Moreno-Rojas, José Manuel; Romano, AnabelaIn this study, in vitro cultures and micropropagated plants of two Mediterranean aromatic plants, Lavandula viridis L’Hér and Thymus lotocephalus López and Morales, were exposed to different temperatures (15, 20, 25, and 30 ◦C). The effect of temperature on the levels of hydrogen peroxide (H2O2 ), lipid peroxidation, and osmoprotectants (proline, soluble sugars, and soluble proteins), as well as on the phenolic profile by HPLC-HRMS and intermediates of the secondary metabolism (phenylalanine ammonia lyase (PAL) activity and shikimic acid content), was investigated. Moreover, the antioxidant activity of the plant extracts was also analyzed. Overall, considering the lipid peroxidation and H2O2 content, the extreme temperatures (15 and 30 ◦C) caused the greatest damage to both species, but the osmoprotectant response was different depending on the species and plant material. In both species, phenolic compounds and related antioxidant activity increased with the rise in temperature in the micropropagated plants, while the opposite occurred in in vitro cultures. L. viridis cultures showed the highest biosynthesis of rosmarinic acid (92.6 g/kgDW) at 15 ◦C and seem to be a good alternative to produce this valuable compound. We conclude that contrasting temperatures greatly influence both species’ primary and secondary metabolism, but the response is different depending on the plant micropropagation stage.