Browsing by Author "Lima, Elisabete"
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- Angiotensin I-converting enzyme (ACE) inhibition and biological activities of green and black tea samples from Azorean Camellia sinensisPublication . Paiva, Lisete; Lima, Elisabete; Marcone, Massimo; Baptista, JoséABSTRACT: The inhibition of ACE can be targeted in order to control hypertension and much attention has recently been paid towards the search for natural products as alternatives to synthetic drugs due to their adverse side effects associated with them. Camellia sinensis tea has received considerable attention due to the beneficial effects on health, particularly as a result of its antioxidant properties. The objective of this study was to investigate the ACE inhibition of different types of Azorean C. sinensis tea samples and consequently its ability to reduce hypertension, relating it to antioxidant activity, catechin profiles, total phenolic content (TPC) and total flavonoid content (TFC) in different seasons. The results clearly highlighted differences in ACE-inhibition, FRSA, FRAP, FIC activity, TPC and epicatechin content among samples and the best results were observed in green tea collected in the summer. For TFC, higher values were observed in black tea harvested during the summer. In conclusion, the differences are related to the effect of collecting seasons, with the higher values being found in the summer with respect to the spring season.
- Angiotensin I-converting enzyme (ACE) inhibitory activity of Fucus spiralis macroalgae and influence of the extracts storage temperature : A short reportPublication . Paiva, Lisete S.; Lima, Elisabete; Neto, Ana I.; Baptista, JoséRecently, increasing attention has been paid to the marine algae as a natural source of novel angiotensin-I converting enzyme (ACE) inhibitors, such as the phlorotannins that are the predominant polyphenols in brown algae. This study reports, for the first time, the ACE inhibition of methanol extract/fractions from Azorean brown algae Fucus spiralis (Fs) determined by HPLC-UV method, their total phenolic content (TPC) quantified as phloroglucinol equivalents (PE) and the effect of the Fs dry powder methanol extracts (Fs-DME) storage temperature on ACE inhibition. The results indicate that the ACE inhibition of Fs-DME decreased by 28.8% and 78.2% when stored during 15 days at −80 ◦C and −13 ◦C, respectively, as compared with the activity of Fs-DME at a refrigerated temperature of 6 ◦C and assayed immediately after extraction that showed a value of 80.1 ± 2.1%. This Fs-DME sample was fractionated by ultrafiltration membranes into three molecular weight ranges (3 kDa), presenting the fraction >3 kDa remarkably high ACE inhibition (88.8 ± 2.4%), TPC value (156.6 ± 1.4 mg PE/g of dry weight fraction) and yield. Furthermore, chromatographic and spectrophotometric analyses corroborate that phenolic compounds were present in Fs methanol extract/fractions, and also revealed that phloroglucinol occurs in Fs. The results seem to suggest that Azorean Fs can be a source of powerful ACE-inhibitory phlorotannins with potential impact on public health, particularly on hypertensive patients.
- Angiotensin I-Converting Enzyme (ACE) Inhibitory Activity, Antioxidant Properties, Phenolic Content and Amino Acid Profiles of Fucus spiralis L. Protein Hydrolysate FractionsPublication . Paiva, Lisete S.; Lima, Elisabete; Neto, Ana I.; Baptista, JoséFood protein-derived hydrolysates with multi-bioactivities such as antihypertensive and antioxidant properties have recently received special attention since both activities can play significant roles in preventing cardiovascular diseases. This study reports, for the first time, the angiotensin I-converting enzyme (ACE)-inhibition and antioxidant properties of ultrafiltrate fractions (UF) with different molecular weight ranges (<1, 1–3 and ≥3 kDa) obtained from Fucus spiralis protein hydrolysate (FSPH) digested with cellulase–bromelain. The amino acids profile, recovery yield, protein, peptide and total phenolic contents of these FSPH-UF, and the in vitro digestibility of F. spiralis crude protein were also investigated. FSPH-UF ≥3 kDa presented remarkably higher ACE-inhibition, yield, peptide and polyphenolic (phlorotannins) contents. Antioxidant analysis showed that FSPH-UF <1 kDa and ≥3 kDa exhibited significantly higher scavenging of 2,2-diphenyl-1-picrylhydrazyl radical and ferrous ion-chelating (FIC) activity. FSPH-UF ≥3 kDa had also notably higher ferric reducing antioxidant power (FRAP). Strong correlations were observed between ACE-inhibition and antioxidant activities (FIC and FRAP). The results suggest that ACE-inhibition and antioxidant properties of FSPH-UF may be due to the bioactive peptides and polyphenols released during the enzymatic hydrolysis. In conclusion, this study shows the potential use of defined size FSPH-UF for the prevention/treatment of hypertension and/or oxidative stress-related diseases.
- Biotechnological conversion of Azorean bovine cheese whey for the production of bio-energyPublication . Rego, E.; Paiva, Lisete S.; Lima, Elisabete; Baptista, JoséThe world's economies, in most countries, are heavily dependent on fossil fuels. This reliance is becoming increasingly problematic taking into account that reserves are rapidly depleting, and no less important is the strong effect of fossil fuel emissions on the global carbon cycle. […].
- Bovine Milk Formula Based on Partial Hydrolysis of Caseins by Bromelain Enzyme : Better Digestibility and Angiotensin-Converting Enzyme-Inhibitory PropertiesPublication . Medeiros, Vera; Rainha, Nuno; Paiva, Lisete S.; Lima, Elisabete; Baptista, JoséA new methodology was developed using bromelain as a proteolytic enzyme for the production of a partially hydrolyzed bovine milk formula, without changing the milk's organoleptic and nutritional properties. This study also revealed that the in vitro angiotensin-converting enzyme inhibition increased in the modified milk as compared with the control sample, showing the highest angiotensin-converting enzyme-inhibitory activity for fractions with molecular weights between 3 and 10 kg mol⁻¹. The Lineweaver-Burk plot revealed that the produced milk formula acted as a non-competitive inhibitor, as determined by high performance liquid chromatography.
- Chemical composition and biological activities of Laurus essential oils from different Macaronesian IslandsPublication . Furtado, R.; Baptista, José; Lima, Elisabete; Paiva, Lisete S.; Barroso, J. G.; Rosa, José S.; Oliveira, LuísaEssential oils (EO) and eight pure components from the fresh leaves of Laurus novocanariensis (LN) from Madeira and of Laurus azorica (LA) from four Azorean Islands (S. Miguel-SMI, S. Maria-SMA, Pico-PIC and S. Jorge-SJO) were evaluated for fumigant and contact insecticidal effects on adult stage of Mediterranean fruit fly (medfly) and for inhibition of oviposition. The chemical composition of EO were analysed by GC/MS. Oxygen-containing mono- and sesquiterpenes (mainly 1,8-cineole) dominated in LN (50%), LA-SMA (88%) and LA-SMI (57%) and mono- and sesquiterpene hydrocarbons (mainly α-pinene) dominated in LA-PIC (61%) and LA-SJO (44%). Linalool and α-terpinyl acetate were also abundant in LA-SMA and trans-cinnamyl acetate in LA-SJO. These three components and all of the Laurus' EO showed high repulsive activity against medfly oviposition. In contact assays on medfly adults, a moderate degree of mortality was observed, being the most toxic samples, in decreasing order, trans-cinnamyl acetate > α-terpinyl acetate > LA-SMI ∼ LA-SMA > LA-SJO ∼ linalool. In fumigant assays, α-terpinyl acetate was the only compound that showed some toxicity on medfly adults. According to the obtained results, the Laurus EO seem promising to be used against medfly oviposition in integrated pest management strategy.
- Comparative Analysis of the Polyphenols, Caffeine, and Antioxidant Activities of Green Tea, White Tea, and Flowers from Azorean Camellia sinensis Varieties Affected by Different Harvested and Processing ConditionsPublication . Paiva, Lisete S.; Rego, Clara; Lima, Elisabete; Marcone, Massimo; Baptista, JoséThis study evaluates the polyphenol profiles as well as caffeine (dry weight basis), and antioxidant activities of green tea (GTs), white tea (WTs), and flowers (Fl) samples from Azorean Camellia sinensis varieties affected by different harvested and processing conditions. Epicatechins derivatives, determined by RP-HPLC/PDAD, presented higher values in GTs with respect to WTs, decreasing as follows: epigallocatechin-3-gallate > epicatechin-3-gallate epicatechin >> epigallocatechin, and higher values in summer and early autumn than in spring. This was also accompanied by an in consistent withering time pattern. Esterified catechins were higher in all samples (100.8–312.3 mg/g) with respect to non-esterified catechins (15.1–37.7 mg/g). Caffeine (6.2–27.7 mg/g) decreased as follows: WTs > GTs >> Fl, and inconsistent seasonal and withering patterns were observed among the WTs. Total phenolics (125.9–295.4 mg gallic acid equivalents/g dried extract) and total flavonoids (35.2–69.7 mg rutin equivalents/g dried extract), determined by Folin–Ciocalteu and colorimetric methodologies, were higher in GTs than in WTs and Fl. Concerning the antioxidant patterns, the free radical scavenging activity (FRSA) and ferric reducing antioxidant power (FRAP) presented EC50 values ranges from 3.6 to 17.3 µg/mL and 4.8 to 16.5 µg/mL, respectively, and ferrous ion-chelating (FIC) activity ranged from 47.1 to 82.8%, highlighting that FRSA was better than butylated hydroxytoluene (BHT). Tea leaves exhibited, in general, higher activities with respect to tea Fl, and the WT sample plucked in summer and withered for 23 h showed the highest FRAP and FIC activity. In conclusion, this study shows the characteristic variation of GTs, WTs, and Fl of two tea varieties and may support crop quality improvement and promote the valorization of tea Fl.
- Comparison of Azorean tea theanine to teas from other origins by HPLC/DAD/FD. Effect of fermentation, drying temperature, drying time and shoot maturityPublication . Baptista, José; Lima, Elisabete; Paiva, Lisete S.; Andrade, Ana L.; Alves, Maria G.The objectives of the present study were the determination of theanine (a specific amino acid of tea leaves with repercussion in human neuronal activity) by HPLC with o-phthaldialdehyde derivatisation prior analysis and comparison of its level in samples from different origins or from the same origin (Azores Islands) but with different processing conditions (fermentation, drying temperature and drying time) and shoot maturity. The results revealed a higher level of theanine in the Azorean green tea (3.10%), the only one produced in Europe, as compared with the Chinese, Japanese, Korean and Taiwan green teas that have an average theanine content of 1.52%, 1.34%, 0.89% and 2.76% of the dry weight (dw) of tea leaves, respectively. The fermentation for a longer period of time results in less theanine remaining (2.28% and 3.10% of dw for fermented and non-fermented tea, respectively). The drying temperature and time of the drying process have an inversely strong effect (4.45% and 5.65% of dw for dried at 55 °C during 8.50 h and at 40 °C during 7.10 h, respectively). The younger tea shoots have a higher theanine content than mature leaves (7.02% and 6.10% of dw, respectively). Our data suggested that a new type of Azorean theanine-rich tea may be produced by modifying the manufacturing processes of the younger tea shoots.
- O conhecimento do passado para apoiar, no futuro, a Agricultura, Zootecnia e Tecnologia de AlimentosPublication . Madruga, João; Borba, Alfredo Emílio Silveira de; Vouzela, Carlos Fernando Mimoso; Rosa, Henrique José Duarte; Rego, Oldemiro Aguiar do; Pires, Fernando Jorge da Rocha; Pinheiro, Jorge; Gomes, Anabela; Baptista, João; Batista, Edite; Depcevicius, Maria Lurdes; Silva, Célia; Lima, Elisabete; Baptista, José; Trota, Maria João; Barros, Maria João; Silva, Joaquim Fernando Moreira da; Fontes, José Carlos; Lima, Maria Teresa
- Cryptomeria japonica : inovar para (re)criar valorPublication . Arruda, Filipe Martim Pacheco; Lima, Ana; Pavão, Alexandre; Baptista, José; Rosa, José S.; Lima, Elisabete[…] Por que as florestas são importantes? Os factos falam por si: as florestas cobrem 30% da superfície terrestre; armazenam cerca de 300 gigatoneladas de carbono na biomassa; são o habitat de mais de 80% de todas as espécies terrestres; são o meio de subsistência para cerca de 1,6 biliões de pessoas; contribuem para a saúde humana e bem estar, fatores fundamentais para a qualidade de vida de um indivíduo; oferecem proteção às bacias hidrográficas; previnem a erosão do solo e possuem um papel importante na mitigação das alterações climáticas. No que respeita especificamente à Região Autónoma dos Açores (RAA), a floresta constitui um elemento determinante da paisagem do arquipélago, ocupando cerca de um terço do território insular. Desta área, mais de 12 mil hectares estão ocupados por matas de criptoméria (Cryptomeria japonica), planta originária do Japão e introduzida nos Açores em meados do século XIX. […].
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