Open Access
Impact of extraction conditions on the phenolic composition and antioxidant capacity of grape stem extracts
(MDPI, 2019) Jiménez Moreno, Nerea; Volpe Sainz, Francesca; Moler Cuiral, José Antonio; Esparza Catalán, Irene; Ancín Azpilicueta, Carmen; Zientziak; Estatistika, Informatika eta Matematika; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias; Estadística, Informática y Matemáticas; Gobierno de Navarra / Nafarroako Gobernua
The use of grape stems for the extraction of bioactive compounds to be used in the pharmaceutical, food, and cosmetic industries is a promising objective. The aim of this work is to determine the influence of the different extraction conditions (temperature, ethanol concentration, and ratio of sample/solvent) on phenolic composition and antioxidant capacity of Mazuelo stem extracts. In general, the ethanol concentration of the extraction solvent was the factor that had the greatest influence on the extraction of different bioactive compounds. The greatest content of total phenolic compounds and the highest antioxidant activity of the extracts were obtained with 50% ethanol and at 40 °C. The most abundant compound found in the different extracts obtained from Mazuelo grape stem was (+)-catechin, but appreciable concentrations of gallic acid, a quercetin derivative, and stilbenes (trans-resveratrol and trans-ε-viniferin) were also extracted. Quercetin and malvidin-3-glucoside showed the highest correlation with the antioxidant capacity of the extracts, while stilbenes did not present such relation. The maximum concentration of gallic acid was extracted with water but the extraction of most of the compounds was maximum on using 50% ethanol. Consequently, the selection of the extraction method to be used will depend on the particular compound to be extracted in greatest quantity.
Open Access
Breve análisis de la presentación de la Estadística en libros de texto
(2013) Moler Cuiral, José Antonio
Open Access
Vegetable waste extracts as enhancers of baculovirus infections
(Elsevier, 2023) Martínez Inda, Blanca; Simón de Goñi, Oihane; Jiménez Moreno, Nerea; Esparza Catalán, Irene; Moler Cuiral, José Antonio; Caballero Murillo, Primitivo; Ancín Azpilicueta, Carmen; Ciencias; Zientziak; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute for Multidisciplinary Research in Applied Biology - IMAB; Institute for Advanced Materials and Mathematics - INAMAT2
Vegetable waste extracts (VWE) contain a great variety of antioxidants such as polyphenols, which have shown to potentiate baculovirus infections, making them ingredients for pest control ingredients. In the present study, the mortality enhancement of different vegetable extracts obtained from food residues when combined with baculoviruses was evaluated. Extracts from spent coffee (E2), rosehip (E17), asparagus (E28), artichoke (E29), beet stalks (E32) and banana peel (E37) were selected as they increased mortality of Spodoptera littoralis nucleopolyhedrovirus (SpliNPV) in second instar S. littoralis larvae, when comparing with the virus inoculation alone. Extracts were assayed at 1 % w/v. In S. littoralis-SpliNPV system, the selected extracts reduced the median lethal concentration (LC50) of SpliNPV against second instar larvae. The E37 extract presented the highest potentiation, as it reduced the LC50 13.61 times, while the rest of the extracts presented LC50 reductions from 3.71 to 7.72-fold. In Spodoptera exigua-SeMNPV (Spodoptera exigua multiple nucleopolyhedrovirus) system, none of the extracts decreased the LC50 of SeMNPV. In contrast, in Spodoptera frugiperda-SfMNPV (Spodoptera frugiperda multiple nucleopolyhedrovirus) system, E2 showed the greatest potentiating effect. In the heterologous systems, none of the extracts tested increased the effective host range of SfMNPV, AcMNPV (Autographa californica multiple nucleopolyhedrovirus), and MbMNPV (Mamestra brassicae multiple nucleopolyhedrovirus) in second instar S. littoralis larvae. Thus, the viral enhancing effect of VWE was host-pathogen and instar dependent. However, the potentiation effect of the extracts could not be directly related with the antioxidants content of the extracts.
Open Access
Performance measures in dose-finding experiments
(John Wiley & Sons, 2020) Flournoy, Nancy; Moler Cuiral, José Antonio; Plo, Fernando; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
In the first phase of pharmaceutical development, and assuming that the probability of positive response increases with dose, the main statistical goal is to estimate a percentile of the dose–response function for a given target Г. We compare the Maximum Likelihood and centred isotonic regression estimators of the target dose and we discuss several performance criteria to assess inferential precision, the amount of toxicity exposure and the trade-off between them for a set of some exemplary adaptive designs. We compare these designs using graphical tools. Several scenarios are considered using simulation, including the use of several start-up rules, the change of slope of the dose-toxicity function at the target dose and also different theoretical models, as logistic, normal or skew-normal distribution functions.
Open Access
Effects of reduced levels of sulfite in wine production using mixtures with lysozyme and dimethyl dicarbonate on levels of volatile and biogenic amines
(Taylor & Francis, 2016) Ancín Azpilicueta, Carmen; Jiménez Moreno, Nerea; Moler Cuiral, José Antonio; Nieto-Rojo, Rodrigo; Urmeneta Martín-Calero, Henar; Química Aplicada; Kimika Aplikatua; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa
Open Access
Efecto del contacto y la actitud en la motivación de aprendices de español L2 en un programa de estudios en el extranjero
(Taylor & Francis, 2023) López Pérez, María Victoria; Moler Cuiral, José Antonio; Ciencias Humanas y de la Educación; Giza eta Hezkuntza Zientziak; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Este artículo analiza el grado y el tipo de motivación en 97 estudiantes deespañol L2 universitarios en un programa de estudios en el extranjero(PREE). También indaga sobre el efecto del contacto conhispanohablantes previo a la movilidad, el uso de la lengua durante laestancia y las actitudes sobre el español y sus comunidades de habla.La investigación, de tipo estadístico descriptivo y correlacional, empleócomo instrumento una versión adaptada del cuestionario MAALE. Seencontraron un moderado grado de motivación y un ligero predominiode motivaciones de tipo intrínseco sobre las de tipo extrínseco.Asimismo, se hallaron asociaciones estadísticamente significativas deluso de la lengua meta durante la estancia y de las actitudes haciaEspaña, los españoles y el español con la motivación. Además decontribuir a la investigación sobre la motivación de grupos multilingüesen contextos PREE, los resultados son de utilidad a la hora de diseñarintervenciones a niveles organizativo y curricular.
Open Access
Stability of phenolic compounds in grape stem extracts
(MDPI, 2020) Esparza Catalán, Irene; Cimminelli, María José; Moler Cuiral, José Antonio; Jiménez Moreno, Nerea; Ancín Azpilicueta, Carmen; Zientziak; Estatistika, Informatika eta Matematika; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias; Estadística, Informática y Matemáticas; Gobierno de Navarra / Nafarroako Gobernua, VARASVI PI022 and PI039
Grape stem is rich in phenolic compounds, especially stilbenes. These antioxidants can be degraded during the storage of grape stem extracts for long periods of time. The aim of this work was to analyze the stability of Mazuelo stem extracts during storage at 25 and 40◦C, in two different light conditions (amber and transparent vials). The stability of the antioxidants was studied after 2, 4 and 6 months of conservation. Gallic acid and the quercetin derivative concentration were stable throughout the storage period. In contrast, catechin disappeared from all the extracts in just two months of storage. Anthocyanins were significantly affected by temperature, and light enhanced their degradation when the extracts were kept at 40◦C. Resveratrol and viniferin showed a similar behavior. Their concentration decreased from the beginning of storage, and in both cases, they were significantly affected by both temperature and light.
Open Access
Influence of the slope in percentile estimation through binary regression for dose-finding experiments
(Taylor & Francis, 2024-12-04) Flournoy, Nancy; Moler Cuiral, José Antonio; Sada Allo, Maider; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Dose-finding experiments aim to estimate the dose having a specified proportion of positive responses by collecting data in the vicinity of this unknown target dose. The importance of estimating the slope as well as a target dose has been recognized long ago in the literature. With large slopes at the target dose, a small error in the target dose estimate will be far from the target. Alternatively, with small slopes at the target, a large error conveys negligible changes on the associated response rate. Thus a reasonably reliable estimate of the slope of the response function at the target dose should accompany every reported target dose estimate. Assuming a monotone increasing dose-response relationship, we work with a sizable catalogue of binary location-scale regression models parameterized by the target dose and the slope at the target. A compound design is proposed for the joint estimation of both features.
Open Access
Reducing SO₂ doses in red wines by using grape stem extracts as antioxidants
(MDPI, 2020) Esparza Catalán, Irene; Martínez Inda, Blanca; Cimminelli, María José; Moler Cuiral, José Antonio; Jiménez Moreno, Nerea; Ancín Azpilicueta, Carmen; Zientziak; Estatistika, Informatika eta Matematika; Institute for Advanced Materials and Mathematics - INAMAT2; Ciencias; Estadística, Informática y Matemáticas; Gobierno de Navarra / Nafarroako Gobernua, VARASVI PI022 and PI038
SO₂ is a very important wine preservative. However, there are several drawbacks associated with the use of SO₂ in wine. The aim of this work is to evaluate the effect of the partial substitution of SO₂ in the Tempranillo wine by a Mazuelo grape stem extract and by a commercial vine wood extract (Vinetan®). The results were compared with a control sample (with no addition of any extract). After 12 months of storage in a bottle, total anthocyanin content, together with total polyphenol and flavonoid content were slightly higher for control wines than for those treated with extracts. These differences were of little relevance, as no differences in antioxidant activity were found between any of the wines at the end of the study. The sensory analysis revealed that the use of both extracts as partial substitutes of SO₂ could lead to wines with good organoleptic properties, similar or even better to the control ones.
Open Access
Simulation of household electricity consumption by using functional data analysis
(Taylor & Francis, 2018) Mallor Giménez, Fermín; Moler Cuiral, José Antonio; Urmeneta Martín-Calero, Henar; Estadística e Investigación Operativa; Estatistika eta Ikerketa Operatiboa