24 results on '"Gil, Maria M."'
Search Results
2. Application of optimal experimental design concept to improve the estimation of model parameters in microbial thermal inactivation kinetics.
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Gil, Maria M., Miller, Fátima A., Silva, Cristina L.M., and Brandão, Teresa R.S.
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EXPERIMENTAL design , *MICROBIAL inactivation , *PARAMETER estimation , *ISOTHERMAL processes , *MATHEMATICAL models , *COMPARATIVE studies - Abstract
Highlights: [•] The use of D-optimal design concept considerably improved parameters precision. [•] It implies replicates of sample conditions equal to the number of model parameters. [•] This design can be applied to any kinetic model, improving parameter estimation. [•] Under non-isothermal conditions the heating rate affects parameters estimation. [ABSTRACT FROM AUTHOR]
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- 2014
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3. Sigmoidal thermal inactivation kinetics of Listeria innocua in broth: Influence of strain and growth phase
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Miller, Fátima A., Gil, Maria M., Brandão, Teresa R.S., Teixeira, Paula, and Silva, Cristina L.M.
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TEMPERATURE effect , *BIOLOGICAL decontamination , *LISTERIA , *BACTERIAL growth , *REGRESSION analysis , *FACTORIAL experiment designs , *FOOD microbiology - Abstract
Abstract: Listeria innocua inactivation was studied within the temperature range 52.5–65.0°C, comparing two different strains (10528 and 2030c) and two growth phases (exponential and stationary). Survival curves may present a sigmoidal behaviour, with an initial shoulder (L), followed by a maximum inactivation rate (k max) period and a final tailing tendency. A Gompertz-inspired model was used to fit experimental data, and kinetic parameters (L, k max and tail) were estimated by non-linear regression analysis. The influence of temperature, growth phase and strain on kinetic parameters was studied using a 23 factorial experimental design. Results showed that temperature and growth phase were the most significant variables affecting the kinetic parameters. Listeria thermal inactivation varied from a log-linear tendency till a pronounced sigmoidal behaviour, depending on the studied factors. [Copyright &y& Elsevier]
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- 2009
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4. Integrated approach on heat transfer and inactivation kinetics of microorganisms on the surface of foods during heat treatments—software development
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Gil, Maria M., Pereira, Pedro M., Brandão, Teresa R.S., Silva, Cristina L.M., Kondjoyan, Alain, Valdramidis, Vassilis P., Geeraerd, Annemie H., Van Impe, Jan F.M., and James, Steve
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FOOD microbiology , *COMPUTER software , *FOOD pasteurization , *EFFECT of heat on food , *EFFECT of heat on microorganisms - Abstract
Abstract: The objective of this work was to create a software application (Bugdeath 1.0) for the simulation of inactivation kinetics of microorganisms on the surface of foods, during dry and wet pasteurisation treatments. The program was developed under the Real Basic© 5.2 application, and it is a user-friendly tool. It integrates heat transfer phenomena and microbial inactivation under constant and time-varying temperature conditions. On the basis of the selection of a heating regime of the medium, the program predicts the food surface temperature and the change in microbial load during the process. Input data and simulated values can be visualised in graphics or data tables. Printing, exporting and saving file options are also available. Bugdeath 1.0 includes also a useful database of foods (beef and potato) and related thermal properties, microorganisms (Salmonella and Listeria monocytogenes) and corresponding inactivation kinetic parameters. This software can be coupled to an apparatus developed under the scope of the European Project BUGDEATH (QLRT-2001-01415), which was conceived to provide repeatable surface temperature-time treatments on food samples. The program has also a great potential for research and industrial applications. [Copyright &y& Elsevier]
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- 2006
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5. A modified Gompertz model to predict microbial inactivation under time-varying temperature conditions
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Gil, Maria M., Brandão, Teresa R.S., and Silva, Cristina L.M.
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FOOD microbiology , *EFFECT of heat on food , *HEATING , *FOOD safety , *FOOD pasteurization - Abstract
Abstract: Development of effective heat treatments is crucial to achieve food products’ safety, and predictive microbiology is an excellent tool to design adequate processing conditions. This work focuses on the application of a modified Gompertz model to describe the inactivation behaviour under time-varying temperature conditions at the surface of a food product. Kinetic studies were carried out assuming two different heating regimes, typically used in surface pasteurisation treatments, and compared with isothermal conditions. Parameters were estimated on the basis of generated pseudo-experimental data. It was concluded that the heating period greatly affects microbial inactivation and parameter estimation. If a slow heating treatment is used, the process time should be extended to achieve a given microbial load when compared to a fast heating process. This is explained by the fact that, in the slow heating rate process the temperature was below the lowest temperature for inactivation for a much longer time, in comparison with the fast heating regime. [Copyright &y& Elsevier]
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- 2006
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6. Linseed and xanthan gum in algae pasta: textural, sensory and antioxidant characteristics.
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Freire, Catarina D., Pinto, Filipa R., Almeida, Daniela, and Gil, Maria M.
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Summary Algae and field crops can innovate and improve pasta; however, incorporation of high‐fibre materials can weaken the protein‐starch matrix. This study's aim was to verify how ratios of xanthan gum (XG) and linseed flour (LF) would influence physical, sensory attributes and bioactivity of pasta supplemented with algae. Fucus vesiculosus and Chlorella vulgaris were incorporated into durum wheat along with LF or XG. Samples were evaluated for optimal cooking time (OCT), cooking loss, colour variation, texture profile analysis (TPA), sensory evaluation, total phenolic content and antioxidant activity. XG increased cooking time and cooking loss. The phenolic content and antioxidant activity were highest in samples with LF. TPA showed texture is influenced by incorporation of algae. Sensory analysis showed that LF‐enriched pasta had better acceptance. Observations in biochemical composition and physical parameters revealed the potential to formulate dry or fresh pasta with a better nutritional content. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Extraction of Antioxidants from Brown Macroalgae Fucus spiralis.
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Horta, André, Duarte, Ana M., Barroso, Sónia, Pinto, Filipa R., Mendes, Susana, Lima, Vasco, Saraiva, Jorge A., and Gil, Maria M.
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FUCUS , *MARINE algae , *RESPONSE surfaces (Statistics) , *GALLIC acid , *VITAMIN C , *SOLVENTS , *SUPERCRITICAL fluid extraction - Abstract
In this study, different extraction methods and conditions were used for the extraction of antioxidants from brown macroalgae Fucus spiralis. The extraction methodologies used were ultrasound-assisted extraction (ultrasonic bath and ultrasonic probe), extraction with a vortex, extraction with an Ultra-Turrax® homogenizer, and high-pressure-assisted extraction. The extracts were analyzed for their total phenolic content (TPC) and their antioxidant activity, and evaluated through the 2,2-difenil-1-picrilhidrazil (DPPH) free radical scavenging method and ferric reducing antioxidant power (FRAP) assay. Ultrasonic probe-assisted extraction yielded the highest values of TPC (94.78–474.16 mg gallic acid equivalents/g extract). Regarding the antioxidant activity, vortex-assisted extraction gave the best DPPH results (IC50 1.89–16 µg/mL), while the highest FRAP results were obtained using the Ultra-Turrax® homogenizer (502.16–1188.81 μmol ascorbic acid equivalents/g extract). For each extraction method, response surface methodology was used to analyze the influence of the experimental conditions "extraction time" (t), "biomass/solvent ratio" (R), "solvent" (S, water % in water/ethanol mixture), and "pressure" (P) on TPC, DPPH, and FRAP of the F. spiralis extracts. In general, higher TPC content and higher antioxidant capacity (lower IC50 and higher FRAP) were obtained with higher R, t, and P, and lower S (higher ethanol %). The model regarding the combined effects of independent variables t, R, and S on the FRAP response values for vortex-assisted extractions best fitted the experimental data (R2 0.957), with optimal extraction conditions of t = 300 s, R = 50 g, and S = 25%. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Use of Limestone Sludge in the Preparation of ɩ-Carrageenan/Alginate-Based Films.
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Adão, Pedro, Calado, Maria da Luz, Fernandes, Wilson, Alves, Luís G., Côrte-Real, Leonor, Guedes, Mafalda, Baptista, Ricardo, Bernardino, Raul, Gil, Maria M., Campos, Maria Jorge, and Bernardino, Susana
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LIMESTONE , *MOLDING materials , *CARRAGEENANS , *SORBITOL , *SURFACE cracks , *ALGINIC acid , *CHEMICAL structure - Abstract
The use of processed limestone sludge as a crosslinking agent for films based on Na–alginate and ɩ-carrageenan/Na-alginate blends was studied. Sorbitol was tested as a plasticizer. The produced gel formulations included alginate/sorbitol and carrageenan/alginate/sorbitol mixtures, with tested sorbitol concentrations of 0.0, 0.5 and 1.0 wt%. The limestone sludge waste obtained from the processing of quarried limestone was converted into an aqueous solution of Ca2+ by dissolution with mineral acid. This solution was then diluted in water and used to induce gel crosslinking. The necessity of using sorbitol as a component of the crosslinking solution was also assessed. The resulting films were characterized regarding their dimensional stability, microstructure, chemical structure, mechanical performance and antifungal properties. Alginate/sorbitol films displayed poor dimensional stability and were deemed not viable. Carrageenan/alginate/sorbitol films exhibited higher dimensional stability and smooth and flat surfaces, especially in compositions with 0.5 wt% sorbitol. However, an increasing amount of plasticizer appears to result in severe surface cracking, the development of a segregation phenomenon affecting carrageenan and an overall decrease in films' mechanical resistance. Although further studies regarding film composition—including plasticizer fraction, film optimal thickness and film/mold material interaction—are mandatory, the attained results show the potential of the reported ɩ-carrageenan/alginate/sorbitol films to be used towards the development of viable films derived from algal polysaccharides. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Prognostic Value of Lymph Node Ratio in Patients with Uterine Carcinosarcoma.
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Bharathan, Rasiah, Polterauer, Stephan, Lopez-Sanclemente, Martha C., Trukhan, Hanna, Pletnev, Andrei, Heredia, Angel G., Gil, Maria M., Bakinovskaya, Irina, Dalamanava, Alena, Romeo, Margarita, Rovski, Dzmitry, Baquedano, Laura, Chiva, Luis, Schwameis, Richard, and Zapardiel, Ignacio
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LYMPH nodes , *PROGNOSIS , *PROGRESSION-free survival , *LYMPHATICS , *OVERALL survival - Abstract
Uterine carcinosarcoma is a rare high-grade endometrial cancer. Controversy has surrounded a number of aspects in the diagnosis and management of this unique clinicopathological entity, including the efficacy of adjuvant therapy, which has been questioned. An unusual surgico-pathological parameter with prognostic significance in a number of tumour sites is the lymph node ratio (LNR). The availability of data in this respect has been scarce in the literature. The primary aim of this collaborative study was to evaluate the prognostic value of LNR in patients with uterine carcinosarcoma. LNR is a recognized lymph node metric used to stratify prognosis in a variety of malignancies. In this European multinational retrospective study, 93 women with uterine carcinosarcoma were included in the final analysis. We used t-tests and ANOVA for comparison between quantitative variables between the groups, and chi-square tests for qualitative variables. A multivariate analysis using Cox regression analysis was performed to determine potential prognostic factors, including the LNR. Patients were grouped with respect to LNR in terms of 0%, 20% > 0% and >20%. The analysis revealed LNR to be a significant predictor of progression-free survival (HR 1.69, CI (1.12–2.55), p = 0.012) and overall survival (HR 1.71, CI (1.07–2.7), p = 0.024). However, LNR did not remain a significant prognostic factor on multivariate analysis. Due to limitations of the retrospective study, a prospective large multinational study, which takes into effect the most recent changes to clinical practice, is warranted to elucidate the value of the pathophysiological metrics of the lymphatic system associated with prognosis. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Anti-SARS-CoV-2-specific antibodies in human breast milk following SARS-CoV-2 infection during pregnancy: a prospective cohort study.
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Fernández-Buhigas, Irene, Rayo, Nieves, Silos, Julia Cuesta, Serrano, Berta, Ocón-Hernández, Olga, Leung, Bo Wah, Delgado, Juan Luis, Fernández, David Sánchez-Nieves, Valle, Silvia, De Miguel, Laura, Silgado, Aroa, Tanoira, Ramón Perez, Rolle, Valeria, Santacruz, Belén, Gil, Maria M., and Poon, Liona C.
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REVERSE transcriptase polymerase chain reaction , *SARS-CoV-2 , *COVID-19 , *IMMUNOGLOBULINS , *BREAST milk , *COLOSTRUM , *RESEARCH funding , *DESCRIPTIVE statistics , *LOGISTIC regression analysis , *DATA analysis , *LONGITUDINAL method - Abstract
Background: While the presence of SARS-CoV-2 in human breast milk is contentious, anti-SARS-CoV-2 antibodies have been consistently detected in human breast milk. However, it is uncertain when and how long the antibodies are present. Methods: This was a prospective cohort study including all consecutive pregnant women with confirmed SARS-CoV-2 infection during pregnancy, recruited at six maternity units in Spain and Hong Kong from March 2020 to March 2021. Colostrum (day of birth until day 4 postpartum) and mature milk (day 7 postpartum until 6 weeks postpartum) were prospectively collected, and paired maternal blood samples were also collected. Colostrum samples were tested with rRT-PCR-SARS-CoV-2, and skimmed acellular milk and maternal sera were tested against SARS-CoV-2 specific immunoglobulin M, A, and G reactive to receptor binding domain of SARS-CoV-2 spike protein 1 to determine the presence of immunoglobulins. Then, we examined how each immunoglobulin type in the colostrum was related to the time of infection by logistic regression analysis, the concordance between these immunoglobulins in the colostrum, maternal serum, and mature milk by Cohen's kappa statistic, and the relationship between immunoglobulin levels in mature milk and colostrum with McNemar. Results: One hundred eighty-seven pregnant women with confirmed SARS-CoV-2 infection during pregnancy or childbirth were recruited and donated the milk and blood samples. No SARS-CoV-2 was found in the human breast milk. Immunoglobulin A, G, and M were present in 129/162 (79·6%), 5/163 (3·1%), and 15/76 (19·7%) colostrum samples and in 17/62 (27·42%), 2/62 (3·23%) and 2/62 (3·23%) mature milk samples, respectively. Immunoglobulin A was the predominant immunoglobulin found in breast milk, and its levels were significantly higher in the colostrum than in the mature milk (p-value < 0.001). We did not find that the presence of immunoglobulins in the colostrum was associated with their presence in maternal, the severity of the disease, or the time when the infection had occurred. Conclusions: Since anti-SARS-CoV-2 antibodies are found in the colostrum irrespective of the time of infection during pregnancy, but the virus itself is not detected in human breast milk, our study found no indications to withhold breastfeeding, taking contact precautions when there is active disease. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Maternal COVID-19 Serological Changes—Comparison between Seroconversion Rate in First and Third Trimesters of Pregnancy and Subsequent Obstetric Complications: A Cohort Study.
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Rayo, Maria N., Aquise, Adriana, Fernandez-Buhigas, Irene, Gonzalez-Gea, Lorena, Garcia-Gonzalez, Coral, Sanchez-Tudela, Mirian, Rodriguez-Fernandez, Miguel, Tuñon-Le Poultel, Diego, Santacruz, Belen, and Gil, Maria M.
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FIRST trimester of pregnancy , *THIRD trimester of pregnancy , *SEROCONVERSION , *PREGNANCY complications , *PREGNANCY tests , *IMMUNOGLOBULINS - Abstract
Pregnant women are especially vulnerable to respiratory diseases. We aimed to study seroconversion rates during pregnancy in a cohort of consecutive pregnancies tested in the first and third trimesters and to compare the maternal and obstetric complications in the women who seroconverted in the first trimester and those who did so in the third. This was an observational cohort study carried out at the Hospital Universitario de Torrejón, in Madrid, Spain, during the first peak of the COVID-19 pandemic. All consecutive singleton pregnancies with a viable fetus attending their 11–13-week scan between 1 January and 15 May 2020 were included and seropositive women for SARS-CoV2 were monthly follow up until delivery. Antibodies against SARS-CoV-2 (IgA and IgG) were analyzed on stored serum samples obtained from first- and third-trimester routine antenatal bloods in 470 pregnant women. Antibodies against SARS-CoV-2 were detected in 31 (6.6%) women in the first trimester and in 66 (14.0%) in the third trimester, including 48 (10.2%) that were negative in the first trimester (seroconversion during pregnancy). Although the rate of infection was significantly higher in the third versus the first trimester (p = 0.003), no significant differences in maternal or obstetric complications were observed in women testing positive in the first versus the third trimester. [ABSTRACT FROM AUTHOR]
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- 2023
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12. Fetal and maternal Doppler adaptation to maternal exercise during pregnancy: a randomized controlled trial.
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Fernández-Buhigas, Irene, Martin Arias, Aranzazu, Vargas-Terrones, Marina, Brik, Maia, Rolle, Valeria, Barakat, Rubén, Muñoz-Gonzalez, María D., Refoyo, Ignacio, Gil, Maria M., and Santacruz, Belén
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RANDOMIZED controlled trials , *UTERINE artery , *GENERALIZED estimating equations , *PREGNANCY , *FETAL ultrasonic imaging - Abstract
Regular and supervised exercise during pregnancy is worldwide recommended due to its proven benefits, but, during exercise, maternal blood flow is redirected from the viscera to the muscles and how fetal wellbeing may be affected by this redistribution is still not well known. To analyze the longitudinal effect of a supervised moderate physical exercise program during pregnancy on uteroplacental and fetal Doppler parameters. This is a planned secondary analysis of an randomized controlled trial (RCT), performed at Hospital Universitario de Torrejón, Madrid, Spain, including 124 women randomized from 12+0 to 15+6 weeks of gestation to exercise vs. control group. Fetal umbilical artery (UA), middle cerebral artery, and uterine artery pulsatility index (PI), were longitudinally collected by Doppler ultrasound assessment throughout gestation, and derived cerebroplacental ratio (normalized by z-score), and maternal mean PI in the uterine arteries (normalized by multiplies of the median). Obstetric appointments were scheduled at 12 (baseline, 12+0 to 13+5), 20 (19+0 to 24+2), 28 (26+3 to 31+3) and 35 weeks (32+6 to 38+6) of gestation. Generalized estimating equations were adjusted to assess longitudinal changes in the Doppler measurements according to the randomization group. No significant differences in the fetal or maternal Doppler measurements were found at any of the different checkup time points studied. The only variable that consistently affected the Doppler standardized values was gestational age at the time of assessment. The evolution of the UA PI z-score during the pregnancy was different in the two study groups, with a higher z-score in the exercise group at 20 weeks and a subsequent decrease until delivery while in the control group it remained stable at around zero. A regular supervised moderate exercise program during pregnancy does not deteriorate fetal or maternal ultrasound Doppler parameters along the pregnancy, suggesting that the fetal well-being is not compromised by the exercise intervention. Fetal UA PI z-score decreases during pregnancy to lower levels in the exercise group compared with the control group. [ABSTRACT FROM AUTHOR]
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- 2023
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13. Risk factors for anxiety and depression among pregnant women during the COVID‐19 pandemic: Results of a web‐based multinational cross‐sectional study.
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Kajdy, Anna, Sys, Dorota, Pokropek, Artur, Shaw, Steven W., Chang, Tung‐Yao, Calda, Pavel, Acharya, Ganesh, Ben‐Zion, Maya, Biron‐Shental, Tal, Borowski, Dariusz, Czuba, Bartosz, Etchegaray, Adolfo, Feduniw, Stepan, Garcia‐Mandujano, Rosario, Santacruz, Monica Garcia, Gil, Maria M., Hassan, Sonia, Kwiatkowski, Sebastian, Martin‐Arias, Arancha, and Martinez‐Portilla, Raigam Jafet
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PREGNANT women , *COVID-19 pandemic , *MENTAL illness , *PREGNANCY complications , *ANXIETY , *PRENATAL depression - Abstract
Objective: To assess risk factors for anxiety and depression among pregnant women during the COVID‐19 pandemic using Mind‐COVID, a prospective cross‐sectional study that compares outcomes in middle‐income economies and high‐income economies. Methods: A total of 7102 pregnant women from 12 high‐income economies and nine middle‐income economies were included. The web‐based survey used two standardized instruments, General Anxiety Disorder‐7 (GAD‐7) and Patient Health Questionnaire–9 (PHQ‐9). Result: Pregnant women in high‐income economies reported higher PHQ‐9 (0.18 standard deviation [SD], P < 0.001) and GAD‐7 (0.08 SD, P = 0.005) scores than those living in middle‐income economies. Multivariate regression analysis showed that increasing PHQ‐9 and GAD‐7 scales were associated with mental health problems during pregnancy and the need for psychiatric treatment before pregnancy. PHQ‐9 was associated with a feeling of burden related to restrictions in social distancing, and access to leisure activities. GAD‐7 scores were associated with a pregnancy‐related complication, fear of adverse outcomes in children related to COVID‐19, and feeling of burden related to finances. Conclusions: According to this study, the imposed public health measures and hospital restrictions have left pregnant women more vulnerable during these difficult times. Adequate partner and family support during pregnancy and childbirth can be one of the most important protective factors against anxiety and depression, regardless of national economic status. Synopsis: Imposed public health measures and hospital‐level restrictions have made pregnant women more vulnerable to anxiety and depression during the COVID‐19 pandemic. [ABSTRACT FROM AUTHOR]
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- 2023
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14. Development and optimization of high-protein and low-saturated fat bread formulations enriched with lupin and microalgae.
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Pereira, Tatiana, Costa, Sandrina, Barroso, Sónia, Teixeira, Paula, Mendes, Susana, and Gil, Maria M.
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BREAD , *MICROALGAE , *RESPONSE surfaces (Statistics) , *PRODUCT acceptance , *FAT - Abstract
Increased consumer awareness of healthier foods is driving the growth in the functional bread market. In view of this potential, three bread formulations were developed using various types of flour enriched with microalgae. The multigrain breads were composed of lupin and rye (F–R), lupin and spelt (F–S), and lupin, oats, and carob (F-OC) enriched with a mixture of Chlorella vulgaris (C. vulgaris White and C. vulgaris Smooth (4:1)). All breads were high in protein and low in saturated fat. Response surface methodology (RSM) following a central composite design (CCD) was used to evaluate the effect of selected technological parameters, namely water content (64.6–94.6% (w/w of flours)) and microalgae concentration (1.9–3.9% (w/w of flours)) on color, aroma, taste, texture, and overall sensory acceptance of the products. Only water content was found to affect the bread's sensory scores, especially texture, with higher water content increasing bread acceptance. This study allowed the development and optimization of three novel multigrain bread formulations enriched with microalgae that met the requirements of "rich in proteins" and "low in saturated fats" claims. [Display omitted] • Three multigrain breads enriched with Chlorella vulgaris were developed. • All breads presented high contents of protein and low levels of saturated fat. • Water content proved to impact the sensory scores of the products. • Bread from lupin-rye (F–R) showed the best overall sensory acceptance. • F–R bread was shown to be good for consumption for at least five days. [ABSTRACT FROM AUTHOR]
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- 2024
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15. Heat inactivation of Listeria innocua in broth and food products under non-isothermal conditions
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Miller, Fátima A., Ramos, Bárbara F., Gil, Maria M., Brandão, Teresa R.S., Teixeira, Paula, and Silva, Cristina L.M.
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LISTERIA , *PHYSIOLOGICAL effects of heat , *FOODBORNE diseases , *FOOD contamination , *FROZEN foods , *PARSLEY - Abstract
Abstract: The objective of this work was to study the effect of three linear temperature profiles (heating rates of 1.5, 1.8 and 2.6°C/min, from 20 to 65°C) on Listeria innocua inactivation in liquid medium. The inactivation was also analyzed in artificially contaminated parsley (heating rate of 1.8°C/min) and throughout a frying process, using a pre-cooked frozen food as case study. Inactivation showed a sigmoidal behaviour and all data was fitted with a Gompertz-inspired model. Results demonstrated that, in liquid media, Listeria inactivation is influenced by the temperature profile used. As heating rate increases, the shoulder decreases and the tail effect disappears. If Listeria was in parsley, its heat resistance increased (for identical experimental conditions in broth). Besides model adequacy was proven in all studied situations, the heating rate affected parameters’ precision. [ABSTRACT FROM AUTHOR]
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- 2011
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16. Influence of pH, type of acid and recovery media on the thermal inactivation of Listeria innocua
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Miller, Fátima A., Ramos, Bárbara, Gil, Maria M., Brandão, Teresa R.S., Teixeira, Paula, and Silva, Cristina L.M.
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EFFECT of heat on microorganisms , *GRAM-positive bacteria , *FOOD microbiology , *PH effect , *ACIDIFICATION , *ORGANIC acids , *FERMENTATION , *FOOD pathogens - Abstract
Abstract: Acidification of foods with organic acids, either by fermentation or by intentional addition, is an important and common mechanism for controlling foodborne pathogens in a diversity of food products. The objective of this work was to study thermal inactivation of Listeria innocua, an acid tolerant microorganism, at 52.5, 60.0 and 65.0 °C, at different pH values (4.5, 6.0 and 7.5), using three types of acid (lactic, acetic and hydrochloric) and three different plating media (Tryptic Soy Agar with 0.6% yeast extract—TSAYE; TSAYE plus 5% NaCl—TSAYE+5%NaCl; and Palcam Agar with selective supplement—Palcam Agar), according to a 34 factorial experimental design. Survival data experimentally obtained were fitted with a Gompertz-inspired model and kinetic parameters (shoulder, maximum inactivation rate—k max, and tail) were estimated for all conditions considered. The influence of temperature, pH, type of acid and enumeration media on kinetic parameters was assessed. Results showed that, with the exception of the type of acid, all the remaining factors and their combinations significantly affected the shoulder period and k max. In relation to tail, temperature and recovery media were the affectable factors. It was concluded that the survival of this bacteria is higher when combining low temperature with neutral pH, and when TSAYE is the enumeration medium. Bigelow-inspired models were successfully developed and describe accurately the temperature and pH effects on the kinetic parameters. [Copyright &y& Elsevier]
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- 2009
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17. CATA vs. FCP for a rapid descriptive analysis in sensory characterization of fish.
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Silva, Frederica, Duarte, Ana M., Mendes, Susana, Pinto, Filipa R., Barroso, Sónia, Ganhão, Rui, and Gil, Maria M.
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PRINCIPAL components analysis , *FISHES - Abstract
Storing non‐marketable fish aboard fishing vessels takes up valuable storage space and, consequently, it is usually discarded. Therefore, the strategy to minimize the amount of discarded fish and boost the fishing economy should entail measures to turn unexploited species into marketable fish. The use of sensory descriptive analysis is usually the first step in the characterization of foods and assess their baseline appeal to the final consumer. In this study, the sensory characterization of five unexploited fish species was conducted, using a semi‐trained panel, with the objective of establishing the appeal and marketability of these species. Check‐all‐that‐apply (CATA) and Free Choice Profiling (FCP) were used to obtain descriptive attributes. Correspondence Analysis (CA) was used to examine CATA data and to compare both sensory methods, while Principal Component Analysis (PCA) was used for FCP data analysis. The results obtained with CATA method allowed to differentiate species by appearance, odor and flavor, while appearance and odor were statistically significant descriptors in FCP. CATA method was found to be more suitable to discriminate fish species, presenting a higher discriminatory power than FCP. Practical Applications: For CATA and FCP methods, using a panel of tasters with short training may increase the quality of a descriptive profile by avoiding the use of less accurate descriptors and ensure that the most relevant descriptors are included, especially in the case of CATA. In this study, both methods were suitable for fish profiling, although they provide different sensory characterization for the different samples. The statistical methods applied allowed to statistically identify significant attributes for each fish species and to differentiate from each other. When comparing both tested sensory methods, CATA reveals a greater discriminatory character compared to FCP. This can be explained by the absence of a support list of descriptors in the FCP that limits the choice of attributes by the panelists. [ABSTRACT FROM AUTHOR]
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- 2020
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18. Stability, kinetics, and application study of phycobiliprotein pigments extracted from red algae Gracilaria gracilis.
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Pereira, Tatiana, Barroso, Sónia, Mendes, Susana, and Gil, Maria M.
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ANALYTICAL mechanics , *PHYCOBILIPROTEINS , *RED algae , *PHOSPHATES , *DIALYSIS (Chemistry) - Abstract
Phycobiliprotein (PBP) pigments were extracted from red algae Gracilaria gracilis through maceration in phosphate buffer using previously optimized conditions. The stability of PBPs in the extracts was assessed by monitoring the extracts at different pHs and temperatures for 10 days. Since phycoerythrin (PE) is the main PBP present in G. gracilis, PE content was spectroscopically determined and used as a response factor. Kinetic modeling was used to describe PE degradation under different ranges of T and pH. The pigment extracts presented higher stability at pH 6.9 and −20 °C. PE was semipurified by precipitation with ammonium sulphate 65% followed by dialysis against water until a purity index of 0.7. The pigment was successfully applied as colorant in pancakes and yogurts with a pigment concentration of 0.15%. This study highlights the potential of PE pigments extracted from G. gracilis for applications in food products. Practical Application: Phycobiliprotein pigments were extracted from red algae Gracilaria gracilis through maceration in phosphate buffer. The stability of the pigment was evaluated at different pHs and temperatures, presenting higher stability at neutral pH and low temperatures. The pigment was successfully applied as colorant in pancakes and yogurts with a low pigment concentration. This study highlights the potential of phycobiliprotein pigments extracted from G. gracilis for applications in food products. [ABSTRACT FROM AUTHOR]
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- 2020
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19. Bioaccessibility of target essential elements and contaminants from Fucus spiralis.
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Francisco, João, Cardoso, Carlos, Bandarra, Narcisa, Brito, Pedro, Horta, André, Pedrosa, Rui, Gil, Maria M., Delgado, Inês Margarida, Castanheira, Isabel, and Afonso, Cláudia
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FUCUS , *MARINE algae , *DIGESTION , *FOOD composition , *FOOD contamination - Abstract
Highlights • F. spiralis is a good dietary source of iodine. • This seaweed presented low Cd, Pb, and Hg levels. • Essential and contaminant elements displayed high bioaccessibility percentages. Abstract Fucus spiralis is an edible brown seaweed (SW) found in the Portuguese Coast that is still undervalued and not very well studied. However, SW are known to be nutritious and healthy foods, in part, for their potential to supply mineral nutrients to the body. Nevertheless, with the increasing levels of pollution in the coastal areas, SW can also accumulate some contaminants. Therefore, to expand the knowledge about this marine resource, the contents of Mg, Mn, Co, I, Cd, Pb, As and Hg in fresh and freeze-dried Fucus spiralis were determined before and after in vitro human digestion simulation. Magnesium was the major element with 11.86 mg/g dry weigh (DW), but it must be highlighted that I in this SW presented concentration values of approximately 135 μg/g DW. Concerning contaminants, F. spiralis seems to have low levels of Cd, Pb, and Hg. The elements' bioaccessibility was always high, ranging between 45.8% (I – Fresh SW) and 88.5% (Hg – FD SW). The freeze-drying process seemed to enhance element bioaccessibility. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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20. Study of the Seasonal Variations of the Fatty Acid Profiles of Selected Macroalgae.
- Author
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Pereira, Tatiana, Horta, André, Barroso, Sónia, Mendes, Susana, and Gil, Maria M.
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SEASONS , *FATTY acids , *MARINE algae , *UNSATURATED fatty acids , *SATURATED fatty acids , *FUCUS - Abstract
Due to the high consumption of fat-rich processed foods, efforts are being done to reduce their saturated fat (SFA) contents and replace it with polyunsaturated fatty acids (PUFA), creating a necessity to find alternative PUFA sources. Macroalgae, being a promising natural source of healthy food, may be such an alternative. The fatty acid (FA) profile of Fucus spiralis, Bifurcaria bifurcata, Ulva lactuca, and Saccorhiza polyschides were determined through direct transesterification and their seasonal variation was studied. F. spiralis showed the highest FA content overall, B. bifurcata presented the higher PUFA amounts, and U. lactuca and S. polyschides the higher SFA. The production of FA was shown to be influenced by the seasons. Spring and summer seemed to induce the FA production in F. spiralis and B. bifurcata while in U. lactuca the same was verified in winter. U. lactuca presented a ω6/ω3 ratio between 0.59 and 1.38 while B. bifurcata presented a ratio around 1.31. The study on the seasonal variations of the macroalgal FA profile can be helpful to understand the best season to yield FA of interest, such as ALA, EPA, and DHA. It may also provide valuable information on the best culturing conditions for the production of desired FAs. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
21. Seasonal Variation in Proximate Composition and Fatty Acid Profile of Grey Triggerfish ( Balistes capriscus) Captured Along the Coast of Portugal.
- Author
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Simões, Tiago, Carvalho, João, Sousa, Ana, Lemos, Marco F.L., Gil, Maria M., Pedrosa, Rui, and Tecelão, Carla
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DOCOSAHEXAENOIC acid , *UNSATURATED fatty acids , *FISH protein concentrate , *FAT content of fish , *PROTEIN content of fish as food - Abstract
Proximate composition (ash, moisture, total protein, and fat contents) and fatty acid profile of Balistes capriscus (grey triggerfish) were assessed over a 6-months period (April to September, 2011) in animals captured along the coast of Peniche (Portugal). High protein (18.9% to 21.4%) and low lipid (0.5% to 0.8%) contents were determined. The highest lipid level was found in June-captured animals. High proportions of n-3 polyunsaturated fatty acids (n-3 PUFA) were observed (53.87 ± 2.00%) together with substantial quantities of oleic acid (27.58 ± 1.09%) and palmitic acid (16.52 ± 0.93%). Docosahexaenoic acid accounted for 77% of the total PUFA and was 7 times more abundant than eicosapentaenoic acid, and the n-3/n-6 ratio was 7.2. Gender did not influence lipid levels and the fatty acid profile, but seasonal variations were observed for PUFA and monounsaturated fatty acid contents. Overall, the nutritional properties of this underexploited species may be comparable to those of other lean fish species with higher economic value. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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22. Seasonal Evaluation of Phlorotannin-Enriched Extracts from Brown Macroalgae Fucus spiralis.
- Author
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Almeida, Belén, Barroso, Sónia, Ferreira, Ana S. D., Adão, Pedro, Mendes, Susana, and Gil, Maria M.
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SEASONS , *POLYPHENOLS , *FUCUS , *MARINE algae , *PLANT polyphenols , *OXIDANT status , *ETHYL acetate - Abstract
Fucus spiralis that was collected in the four seasons was submitted to an extraction with ethanol:water (crude extracts Et80), followed by a liquid–liquid fractionation with organic solvents (fraction He from n-hexane; aqueous fractions AQ1, AQ2, AQ3 and AQ4; ethyl acetate fraction EA), with the aim of obtaining phlorotannin-enriched extracts. All the extracts (Et80, He, AQ1, AQ2, AQ3, AQ4 and EA) that were obtained for the F. spiralis of the four seasons were evaluated for their antioxidant capacity and total phenolic compounds. The summer extracts presented the highest contents in polyphenols (TPC), as well as the highest ferric reducing antioxidant power (FRAP), when compared to the samples from the other seasons. The reductive percentage of the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) compound was similar between the seasons. For all the seasons, the EA extract showed the highest polyphenol content (TPC), and the highest antioxidant capacity (highest ferric reducing power (FRAP) and lowest concentration needed to reduce 50% of the DPPH compound), which is in agreement with a phlorotannin-enriched fraction. This study revealed that the polyphenol content and antioxidant power of the F. spiralis extracts are influenced by the time of harvest, as well as by the solvents used for their extraction. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
23. Insulin Resistance Is Associated With Increased Serum Concentration of IGF-Binding Protein--Related Protein 1 (IGFBP-rP1/MAC25).
- Author
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López-Bermejo, Abel, Khosravi, Javad, Fernández-Real, José Manuel, Hwa, Vivian, Pratt, Katherine L., Casamitjana, Roser, Garcia-Gil, Maria M., Rosenfeld, Ron G., and Ricart, Wifredo
- Subjects
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INSULIN resistance , *INSULIN-like growth factor-binding proteins , *PEOPLE with diabetes , *GLUCOSE tolerance tests , *MULTIVARIATE analysis - Abstract
IGF-binding protein (IGFBP)-related protein 1 (IGFBP-rP1) has been shown to bind both IGFs and insulin, albeit with low affinity, and to inhibit insulin signaling. We hypothesized that IGFBP-rP1 is associated with insulin resistance and components of the IGF system in humans. To this aim, a cross-sectional study was conducted in 113 nondiabetic and 43 type 2 diabetic men. Insulin sensitivity (insulin sensitivity index [Si] from intravenous glucose tolerance tests in nondiabetic subjects, or the rate constant for disappearance of glucose [KITT] from insulin tolerance tests in type 2 diabetic subjects), circulating IGFBP-rP1 (from enzyme-linked immunosorbent assay), adiponectin (from radioimmunoassay), C-reactive protein (CRP; from immunoturbidimetry), soluble tumor necrosis factor receptor 2 (sTNFR2; from enzyme-amplified sensitivity immunoassay), and IGF system parameters (IGF-I, free IGF-I, and IGFBP-1 from immunoradiometric assay) were assessed in all subjects. Among nondiabetic men, those in the highest quartile for circulating IGFBP-rP1 exhibited decreased Si and adiponectin (both P < 0.01) as well as increased CRP and sTNFR2 (both P < 0.05). Circulating IGFBP-rP1 was also found to be increased in previously undiagnosed type 2 diabetic patients (P = 0.01) but not in known type 2 diabetic patients receiving pharmacological therapy. Although no changes in IGF system components were evident by IGFBP-rP1 quartiles in nondiabetic subjects, independent positive associations of IGFBP-rP1 with circulating fasting IGFBP-1 were evident after adjustment for insulin resistance parameters in both nondiabetic and type 2 diabetic subjects, with IGFBP-rP1 explaining 2 and 11% of IGFBP-1 variance, respectively. In additional multivariate analyses, Si, sTNFR2, and age stood as independent predictive variables of IGFBP-rP1 (together explaining 18% of its variance) in nondiabetic subjects, and BMI became the only independent predictive variable of IGFBP-rP1 (explaining 26% of its variance) in type 2 diabetic men. These findings show for the first time that circulating IGFBP-rP1 is increased with insulin resistance, and they also suggest novel interactions between IGFBP-rP1 and the IGF system in humans. Diabetes 55: 2333-2339, 2006 [ABSTRACT FROM AUTHOR]
- Published
- 2006
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24. Optimization of phycobiliprotein pigments extraction from red algae Gracilaria gracilis for substitution of synthetic food colorants.
- Author
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Pereira, Tatiana, Barroso, Sónia, Mendes, Susana, Amaral, Renata A., Dias, Juliana R., Baptista, Teresa, Saraiva, Jorge A., Alves, Nuno M., and Gil, Maria M.
- Subjects
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RED algae , *GRACILARIA , *COLORING matter in food , *ARTIFICIAL foods , *FOOD substitutes , *PLANT pigments , *SCANNING electron microscopy , *PIGMENTS - Abstract
• The extraction of PBP pigments from red algae G. gracilis was optimized using RSM. • Maceration proved to be a suitable process for PE extraction from G. gracilis. • The most impactful variable in the extraction process was extraction time. • SEM analysis revealed a more efficient cell wall rupture using maceration. The extraction of phycobiliprotein (PBP) pigments from red algae Gracilaria gracilis was optimized using maceration, ultrasound-assisted extraction (ultrasonic water bath and ultrasonic probe), high pressure-assisted extraction, and freeze-thaw. The experimental conditions, namely homogenization time (t1), buffer concentration (C), treatment time (t2), biomass: buffer ratio (R), and pressure (P), were optimized using Response Surface Methodology (RSM). The yield of phycoerythrin (PE) extracted, determined spectroscopically, was used as the response variable. Maceration was the most efficient extraction method yielding 3.6 mg PE/g biomass under the optimal conditions (t1 = t2 = 10 min; C = 0.1 M; R = 1:50). Scanning Electron Microscopy (SEM) analysis of the biomass before and after the cell disruption treatments revealed a more efficient cell wall rupture with maceration. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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