Browsing by Author "Vidigal, Susana S. M. P."
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- Analytical microsystem for the spectrophotometric determination of titratable acidity in winesPublication . Sandez, Natalia; Calvo-López, Antonio; Vidigal, Susana S. M. P.; Alonso-Chamarro, Julian; Rangel, António O. S. S.
- Antioxidant activity evaluation of fermentation distillation residuesPublication . Soares, Ana M. S.; Teixeira, Francisca S.; Pimentel, Lígia L.; Vidigal, Susana S. M. P.; Costa, Paula T.; Pintado, Manuela E.; Rodríguez-Alcalá, Luis M.Nature offers an unlimited variety of molecules with incredible biological activities, such as antioxidants among others, that are valuable for the maintenance of a good health by reducing the damage caused by oxidation [1,2]. This purpose allied to the richness of some wastes and by-products make distillation residues from industrial fermentation (FDRs) potential sources to obtain bioactive compounds. Accordingly the study for both its valorization and integration into a circular economy context was the aim of this work [3,4]. FDRs are known to be rich in several compounds such as phytosterols, triterpenes or fatty alcohols with potential biological activities [3,4]. Thus, two FDRs, from fermentation using sugarcane juice (FDR_SC) or very high polarity sugar (FDR_VHP) and respective extracts obtained by winterization with different solvents (ethanol (EtOH), acetone (AcO) and dichloromethane (DCM)) were used and the evaluation of its antioxidant activity were performed by DPPH, ABTS and ORAC assays. Inhibition percentage, IC 50, TEAC and ORAC Value parameters were determined. The results revealed great antioxidant potential for the studied FDRs, in particular for FDR_SC that had the best performance in most of the measured parameters. Also, the differences on solvents polarity used for the FDRs winterization had an important role in the antioxidant capacity results, which could be related to the selectivity to isolate different compounds.
- Automated analytical microsystem for the spectrophotometric monitoring of titratable acidity in white, rosé and red winesPublication . Sández, Natàlia; Calvo-López, Antonio; Vidigal, Susana S. M. P.; Rangel, António O. S. S.; Alonso-Chamarro, JuliánThe design, construction and evaluation of a low-cost cyclic olefin copolymer (COC)-based continuous flow microanalyzer with optical detection to determine the titratable acidity content of wine is here presented. The analysis method is based on the monitoring of the blue coloration decrease of a buffered bromothymol blue (BTB) solution in the presence of the acidic compounds of wine. The microanalyzer monolithically integrates the required microfluidic motifs as well as an optical flow cell where the measurements are performed by using a miniaturized and versatile photometric detection system. Fluid management is totally automated by the use of computer-controlled microvalves, permitting the automatic calibration of the system as well as the automatic sampling, including in-line dilution and analysis. The reduced size of the whole system along with its high simplicity and automation make it suitable for its application to the on-line monitoring of titratable acidity during wine-making processes. With the optimal conditions, a linear range up to 0.50 g L−1 tartaric acid, a quantification limit (LOQ) of 0.01 g L−1 and a detection limit (LOD) of 0.004 g L−1 were obtained, covering the most common acidity content of musts and wines. A sampling rate up to 26 h−1 could be achieved, consuming less than 3 mL of inexpensive reagents per analysis and requiring no pretreatment of the sample. The microsystem has been successfully applied to the quantification of the titratable acidity content of several wine samples, being the results in excellent agreement with the ones obtained by the reference method.
- Characterization of patchouli and vanillin industrial wastes as a strategy for their valorizationPublication . Pimentel, Lígia L.; Vidigal, Susana S. M. P.; Teixeira, Francisca S.; Costa, Paula T.; Pintado, Manuela E.; Rodríguez-Alcalá, Luís M.Patchouli is a cyclic terpene alcohol used as a fragrance ingredient (i.e. powerful sweet, herbaceous and spicy) [1] that has been demonstrated to exert low acute dermal toxicity [2-3]. The aromatic aldehyde Vanillin is a widely used flavoring agent and relevant antifoaming ingredient [4]. Fragrances/flavoring production from plants is accomplished by steam distillation, supercritical CO2 or microwave assisted extraction. Hence, recent investigation suggests using of genetically modified microorganism to ensure reliable and sustainable supply [5]. Thus, Vanillin can be isolated from Vanilla planifolia, from chemical synthesis or by fermentation procedures [6]. In the framework of a valorization strategy, this research work aims to characterized fermentation by-products of the production of Patchouli and Vanillin through liquid (HPLC-ELSD) and gas chromatography (GC-QqQ). The assayed materials derived from the production of Patchouli and Vanillin contained high-value molecules such as Patchouli alcohol, α-Guaiene, α-Bulnesene and Vanillin and Vanillic Acid, as well as vanillin glucosides. Future assessment of its bioactivity will provide better information on the application of these compounds to turn waste into resource.
- Characterization of Patchouli and Vanillin Industrial Wastes as a Strategy for their ValorizationPublication . Pimentel, Lígia L.; Vidigal, Susana S. M. P.; Teixeira, Francisca S.; Costa, Paula T.; Pintado, Manuela E.; Rodríguez-Alcalá, Luís M.
- Desenvolvimento de novas estratégias para ensaios bio(químicos) usando técnicas de fluxoPublication . Vidigal, Susana S. M. P.; Tóth, Ildikó V.; Rangel, António O. S. S.
- Determination of the thermodynamic binding constants of hydroxycinnamic acids with BSA using a flow-based approach with fluorimetric detectionPublication . Vidigal, Susana S. M. P.; Campos, Francisco M.; Rangel, António O. S. S.
- Determination of titratable acidity in wines in an automatic spectrophotometric analytical microsystemPublication . Sandez, Natália; Calvo-López, António; Vidigal, Susana S. M. P.; Rangel, António O. S. S.; Alonso-Chamarro, Julian
- Determination of total phenolic content in wines using Folin-Ciocalteu assay in flow injection analysis systemPublication . Wongpakdee, Thinnapong; Vidigal, Susana S. M. P.; Nacapricha, Duangjai; Rangel, António O. S. S.
- Determination of total protein content in white wines by solid phase spectrometry in a SI–LOV systemPublication . Vidigal, Susana S. M. P.; Tóth, Ildikó V.; Rangel, António O. S. S.Although present at low concentration in wine samples, proteins, have considerable technological importance, due to their capability of haze formation. The present work presents a methodology for the quantification of total protein in white wine in a sequential injection lab-on-valve system, exploiting the bead injection concept for solid phase extraction with spectrophotometric detection. The method is based on the retention of the proteins in the solid support, NTA (nitrilotriacetic acid) superflow beads, charged by Cu2+. The change in the absorbance is monitored at 500 nm at the surface of the beads after addition of the Folin–Ciocalteu’s reagent (FCr). The developed method presented a sample consumption of 400 L per assay and a consumption of FCr and Cu2+ solution of 25 L and 100 L per assay, respectively. It was possible to achieve a linear range up to 0.30 g/L with a limit of detection and quantification of 0.03 and 0.10 g/L, respectively. The proposed method was successfully applied to white wine samples.