Dolores Hernanz

• Ph D at University of Seville

Antioxidant activity can be evaluated using cyclic voltammetry (CV). The aim of this work is to verify the efficacy of CV in evaluating the synergistic effect of bioactive compounds, such as phenolic and amino acid compounds, on antioxidant activity. Therefore, three types of model solutions were prepared: individual model solution (phenol and amin...

El recurso desarrollado permitirá al usuario sumergirse en un laboratorio de análisis de color real, y utilizar equipamiento de alta especialización, de gran interés, pero de difícil disponibilidad en la docencia. Un laboratorio de análisis de color cuenta con instrumentación para identificar inequívocamente y cuantificar el color de los objetos qu...

Mandarine juice is one of the richest sources of β-cryptoxanthin and flavonoids, which have been positively associated with bone mineral density. Carotenoids are lipophilic isoprenoid compounds with a complex absorption process that can be affected by different factors. In this study, we have evaluated the effect of the food matrix on the in vitro...

Our aim in this study was to outline phenolic and color characteristic that characterize the labeled unifloral resin spurge (Euphorbia resinifera) honey. With respect to phenolic composition, 17 phenolic compounds have been analyzed in the 29 honey samples. The proposed markers (syringic acid, ethyl gallate, m-coumaric acid and naringenin) might he...

Flowers have been used for centuries in decoration and traditional medicine, and as components of dishes. In this study, carotenoids and phenolics from 125 flowers were determined by liquid chromatography (RRLC and UHPLC). After comparing four different extractants, the carotenoids were extracted with acetone: methanol (2:1), which led to a recover...

In this preliminary study, the effect of regulated deficit irrigation (RDI) on the commercial quality (size, weight, soluble solids, firmness and colour), content of carotenoids, phenolics and sugars of black tomato (Solanum lycopersicum L.) ʽSunchocolaʼ was studied. Two water irrigation treatments were applied: regulated deficit irrigation (RDI) a...

Unifloral honeys are highly valued, and their botanical and geographical characterization plays an important role in quality control. This work is an essential contribution to the limited knowledge of the unique resin spurge (Euphorbia resinifera) honey. Palynological and geographical characterization was performed on 29 unifloral resin spurge hone...

Non-centrifugal cane sugar (NCS) samples obtained by traditional moulding and granulation, and also via a novel spray-drying powdering process without additives, were assessed to characterise their sugar and phenolic profiles, flavonoid content, as well as colour parameters. As expected, sucrose was the predominant sugar (91.9 – 95.5%), followed by...

Extraction solvent is a very important factor in the recovery of antioxidants from natural matrices. In this study, the effect of three solvents (ethanol, ethanol/water and water) on the phenolic composition, antioxidant and anti-cholinesterase activities and electrochemical behaviour of four winemaking byproducts (seeds, skins, stems, and pomace)...

Realidad Virtual que pone al usuario ante un laboratorio y un problema analítico que debe resolver realizando 2 valoraciones complexométricas. El recurso permite al alumno seleccionar material de laboratorio y responder a cuestiones prácticas y teóricas que le permiten ir avanzando por diferentes escenarios para poder dar respuestas al problema ana...

The emergent market for honeydew honeys in Europe prompt to increasing requirements of consumers and honey industry for the characterisation of this type of honey. The aim of this study was to characterise 59 samples of Spanish oak honeydew honeys. Physicochemical properties showed values within the limits established by the legislation and typical...

Cooperage byproducts are an important source of phenolic compounds that could be used for wine technology applications. The effects of the addition of two types of oak wood shavings (American, AOW, and Ukrainian, UOW) on the antioxidant activity and color of red wine anthocyanins, in a wine model solution, were evaluated by spectrophotometric and c...

This work analyzed the use of electrocoagulation as substitute for sugarcane clarification process using sulfitation. It was evaluated technological parameters (Icumsa color and turbidity), phenolic compounds content and CIELAB color parameters. Four kinetics of reduction color from sugarcane juice were carried out. The essays were divided accordin...

Una gran variedad de estudios sugiere que una dieta apropiada y rica en compuestos bioactivos puede contribuir a disminuir el riesgo a desarrollar ciertas enfermedades crónicas no transmisibles. En la actualidad, el uso de flores en la gastronomía va en aumento; sin embargo, poco se conoce sobre los beneficios para la salud que pueden aportar desde...

e-book CIBIA 2019

The current university environment is characterised by the implementation of an education system focused on competence-based learning. The present study has concentrated on the subject Applied Analytical Chemistry of the Pharmacy Degree and has made it possible to clearly establish the specific competences of the subject, based on levels of acquisi...

Anthocyanins are phenolic compounds with important technological applications due to its bioactive and color properties. In this study, pomaces from four red berries (blueberries, red raspberries, red currants and blackberries) have been analyzed as sources of anthocyanins. Anthocyanins were determined by high-performance liquid chromatography/mass...

An analytical method was validated for the quantitative determination of isoprenoids compounds in faecal samples, based on liquid-liquid extraction from a small aliquot (0.3-0.5 g of sample) and subsequent analysis by Rapid Resolution Liquid Chromatography (RRLC) on a C30 column. An excellent linear response was observed over the range specified fo...

De mis consideraciones, Es un placer para nuestro Comité Organizador comunicarle que su trabajo titulado: "EFECTO DEL RIEGO DEFICITARIO CONTROLADO SOBRE LOS PARÁMEROS DE CALIDAD Y CONTENIDO DE CAROTENOIDES, COMPUESTOS FENÓLICOS Y AZÚCARES DE TOMATE NEGRO (Solanum lycopersicum L.) ʽSUNCHOLAʼ" presentado por E. Coyago, M. Corell, A. Moriana, D. Herna...

The aim of this study was to assess commercial quality parameters, sugars, phenolics, carotenoids and plastid in diverse and little studied tomato varieties to gain insight into their commercial and functional quality and reveal possible noticeable differences. Five cherry tomato varieties and six common (i.e., non-cherry) tomatoes were evaluated....

The effect of in vitro gastrointestinal digestion on phenolic composition and antioxidant activity of different white winemaking byproducts extracts (grape pomace and its parts: seeds, skins and stems) was evaluated. Fourteen individual phenolic compounds were evaluated by UHPLC. The antioxidant activity was measured by DPPH and ORAC assays. Differ...

The objective of this work was verify if, based on the concentration of some key isoprenoids and the colour, olive oils from a specific mill could be differentiated from those from other mills by linear discriminant analysis. The isoprenoids studied were β-carotene, lutein, α-tocopherol, β-sitosterol, pheophytin a and squalene, which are isoprenoid...

The individual preferences of 100 consumers between 20 and 30 years old for the color of 16 milk–fruit juice beverages (MFJB) were investigated by preference mapping technique. Consumers were asked to evaluate, just by looking at the samples, how much they liked them (from “Extremely dislike” to “Extremely like”). The color of the samples was analy...

Cherry tomato varieties are widely consumed in many countries. They contain nutrients and health-promoting compounds like phenolics and carotenoids. The main purpose of this study was to determine how the fruit position on the cluster affected quality parameters of diverse nature (weight, soluble solids, firmness, colour, carotenoids, phenolic comp...

The purpose of this study was to assess the relationship between the effect of regulated deficit irrigation, cluster, developmental stages and two seasons (autumn 2015 and spring 2016) on the commercial and functional quality (carotenoids and plenolics levels) in ‘Lazarino’ and ‘Summerbrix’ tomatoes. Autumn had a positive effect on the commercial q...

The physicochemical characteristics of Euphorbia resinifera honey were studied. Considering the low water content, the majority of the honeys presented a proper maturity. The values of acidity revealed the absence of inappropriate fermentation, while the low values of hydroxymethylfurfural (0.4–16.48 mg/kg) were suitable for of unprocessed honeys....

This study aims to evaluate the effects of regulated deficit irrigation (RDI) and of cluster position (CI: first and second cluster; CII: third and fourth cluster; CIII: fifth and sixth cluster) on fruit quality parameters, carotenoids and phenolics in tomatoes. Three common (‘Tigerella’, ‘Palamós’ and ‘Byelsa’) and two cherry varieties (‘Lazarino’...

Grape pomace is composed of seeds, skins and stems that are an important source of phenolic substances, which have antioxidant properties and potential benefits to human health. Cyclic voltammetry (CV) has been used to measure the total antioxidant potential of different winemaking by-products. The electrochemical behavior of pomace, seeds, skins a...

The influence of adding seeds from grape pomace during Syrah wine fermentation in a warm climate has been studied. Seeds of Pedro Ximenez variety were rich in phenolic compounds, mainly flavonoids such as catechin and procyanidins. Changes in total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity of red wines were obs...

In this study, foam mat drying was applied to Tommy Atkins mango. Using a multifactorial design, the effect of soy lecithin (L) and carboxymethylcellulose (CMC) used as foam stabilizers (0–1.50 g/100 g), as well as temperature (T) (53–87°C), on phenolic content and antioxidant capacity of mango were evaluated. Mango pulp contains antioxidant, such...

Roselle is a plant that accumulates anthocyanins significantly, hence its importance as food coloring and as a source of antioxidant compounds for human health. This study was aimed to determine phenolic composition and antioxidant capacity of methanolic extracts, and beverages obtained from native roselle cultivars in Mexico (Negra, Sudan, Rosa an...

Background and AimsWinemaking generates a large quantity of grape marc that causes environmental and economic problems, which could be minimised by exploiting and adding value to these by-products. Marc is composed of seeds, skins and stems that are an important source of phenolic substances, which have antioxidant properties and potential benefits...

The quality of 27 Moroccan spurge (Euphorbia) honey samples was assessed. Eight physicochemical parameters and mineral composition were analysed and the CIELAB colour parameters (L∗, a∗, b∗, C∗ab and hab) were determined. Results shown no significant differences between the two Euphorbia honey types (E. officinarum subsp. echinus and E. regis-jubae...

Abstract A rapid resolution liquid chromatography (RRLC) method was developed and validated for the simultaneous determination of nine carotenoids compounds (violaxanthin, lutein, zeaxanthin, β-cryptoxanthin, α-carotene, β-carotene, lycopene, phytoene, phytofluene), four tocopherols and four chlorophylls and derivates (chlorophylls and pheophytins)...

The development and validation of a rapid method of RRLC has been carried out to determine the phenolic composition of winemaking by-products (pomaces, seeds, skins and stems). Thirty-one phenolic compounds belonging to three groups (flavanols, flavonols and phenolic acids) have been identified by use of standards and mass spectrometric detection,...

Different white winemaking by-products (pomace, skins, seeds and stems) were compared as natural sources of phenolic compounds having biological and sensory properties of oenological interest. Antioxidant and copigmentation effects of these by-products were studied in wine-like model solution. RRLC-DAD was used to establish differences on the pheno...

The effect of different cold maceration times on Syrah red wines from warm climate has been evaluated. Differential colorimetry and tristimulus colorimetry were applied to colour data at different points of the vinification stage. Virtually, all the phenolic compounds showed significantly higher content in cold macerated wines, even more when longe...

Background: This study assesses the effect of slight hue variations in orange juice (reddish to greenish) on perceived flavour intensity, sweetness, and sourness, and on expected and actual liking. A commercial orange juice (COJ) was selected as a control, and colour-modified orange juices were prepared by adding red or green food dyes (ROJ and GOJ...

This study assesses the effect of background, surrounding, thickness and dilutions on the colour specifications of orange juice (OJ) analyzed by digital image and visual evaluation. A commercial OJ was diluted with distilled water to give ten levels of concentration (100, 90, 80, 70, 60, 50, 40, 30, 20 and 10 % of juice). These samples were evaluat...

Background: This study assesses the effect of slight hue variations in orange juice (reddish to greenish) on perceived flavour intensity, sweetness, and sourness, and on expected and actual liking. A commercial orange juice (COJ) was selected as a control, and colour-modified orange juices were prepared by adding red or green food dyes (ROJ and GOJ...

This study was aimed at training a panel of assessors to evaluate specifically orange juice colour, and to establish the colour difference threshold in orange juice for a trained and untrained panel. Panellists were first preselected using Farnsworth-Munsell 100-Hue Test and then trained with a specific method for orange juice colour. This training...

This study was aimed to analyse the impact of the debittering process (DP) in the overall sensory properties of orange juice (OJ) (Citrus sinensis L. Var. Salustiana). The fresh industrial squeezed orange juice (FOJ) and the corresponding OJ after the DP (DOJ) were taken. No significant differences were found in acidity, pH and total soluble solids...

The phenolic composition of the extractable fraction of Zalema grape pomace has been analysed by HPLC-DAD-MS, and consisted of mainly flavanols and flavonols (122.75 and 23.11 mg/100 g dry pomace, respectively). The antioxidant activity has been determined by the in vitro FRAP, ABTS and ORAC assays (11.7, 34.9 and 63.6 mmols of trolox equivalents (...

The impact of orange juice pulp on the physical release of limonene to the headspace of freshly prepared orange juice was evaluated both in-vitro and in-vivo. Atmospheric pressure chemical ionization mass spectrometry was used to analyse the impact of the matrix on the dynamic release of the volatile aroma compound, limonene, in orange juice. Pulp...

Changes in quality attributes during bottled storage of white wine were studied. Different storage conditions, temperature, bottle position and exposure to light were studied over 1 year and their effects on major volatile compounds were evaluated. Ethyl lactate and diethyl succinate contents increased after 12 months of storage, whereas isoamyl ac...

The influence of different storage conditions on the volatile composition of young white wine was evaluated during 1 year of storage. The wine was bottled and stored under different conditions of temperature, position and illumination. During storage, a significant increase in total content esters (mainly due to the increase in ethyl butyrate, ethy...

The present work proposes the use of autonomous learning for students through the elaboration of standard operating procedures (SOPs). This experience is carried out within the course Analytical Methods for Quality Assurance of the majors Chemical Engineering and Technical Industrial Engineering in Chemistry at the University of Huelva in Spain. Th...

This paper presents the development of an educational innovation project done by the faculty team of the Department of Analytical Chemistry of the University of Huelva in Spain, as part of the course Instrumental Analysis of the major B.Sc. in Chemistry. This project tries to move to the laboratories a wider concept of self-learning, promoting the...

The vinification technique called pre-fermentative cold maceration is used to enhance the anthocyans diffusion from the skins to the must, increasing the pigments extraction. For using this technique the application of low temperatures is needed. In this study, two different refrigerating methods (dry ice and cooling of grapes) have been assessed r...

The Project developed by the Educational Team of the Department of Analytical Chemistry (Faculty of Pharmacy, Seville), has used the technique of Small Groups Learning (SGL) that constitutes an essential facet in the renovation of the educational methodologies for the incorporation and adaptation of the university lessons to the European Space for...

The Project developed by the Educational Team of the Department of Analytical Chemistry (Faculty of Pharmacy, Seville), has used the technique of Small Groups Learning (SGL) that constitutes an essential facet in the renovation of the educational methodologies for the incorporation and adaptation of the university lessons to the European Space for...

Different quality attributes and chemical components of wines change during storage as a function of a series of factors. Thus, in young white wines, changes in phenolics, that lead to modifications of their colour as a result of oxidation processes, are well-known. These reactions can also alter their volatile profile giving rise to the appearance...

Two ultrasound-assisted liquid-liquid extraction (LLE-I, LLE-II) methods were compared to a solid-phase extraction (SPE) protocol to assess their effectiveness for the analysis of up to 44 volatile compounds in a synthetic and several commercial white, red and "cream" wines produced in the southwest of Spain. Regardless of the extraction protocol u...

Apart from the need to assess the color of foods due to its preponderant role in their acceptability, there is currently a new trend consisting in the study of the relationships between the color and the pigments accounting for it. The color of five strawberry varieties cultivated in two different soilless systems has been studied, and an array of...

The main characteristics related to the nutritional quality were investigated in strawberry fruit cultivated in soilless systems (open and closed system) using peat, composted cork and coconut fiber like organic substrates. The values of compounds such as ash, humidity, acidity (TA) and pH, starch, reducing sugars (SS), total soluble solids (TSS),...

The influence of prefermentative maceration variables (time and temperature) on the phenolic profile of white wines elaborated at experimental and industrial scales has been evaluated. For this purpose, a total of 18 white wines were elaborated: six in a traditional way (control wines), and 12 by applying different skin contact times (2, 6, 12 and...

The phenolics from different strawberry cultivars (Aromas, Camarosa, Diamante, Medina, and Ventana) cultivated in two different soilless systems (with and without recycling nutrient solution) were quantified to assess differences in their profiles as a function of both the variety and the cultivation system. Considering groups of phenols, it was fo...

Nine different white wines were elaborated by applying different skin contact times (2, 4, 6, 8, 12, 18 and 24 h) and temperatures (5, 10 and 20 °C). The colour (tristimulus colour parameters) and the phenolic composition of the musts and wines were determined at different winemaking stages. Although extended skin contact (maceration time ⩾12 h) in...

The colour of 123 Amontillado wines from “Condado de Huelva” Designation of Origin, made from white grapes of the Zalema variety and slowly aged in different types of wood casks, has been studied. Colour differences due to different materials from which the casks were manufactured (Spanish and American oak wood) have been appreciated. Tristimulus m...

The main characteristics related to nutritional quality were investigated in strawberry fruit cultivated in soilless systems. The value of compounds such as organic acids, soluble sugars, minerals and anions was assessed. The results for all parameters were compared statistically with those from traditional cultivation. The results showed that the...

This paper will consider the influence of hydrothermal pretreatment to obtain a valuable liquid phase and suitable raw material for pulping from Arundo donax L. and the influence of the operating conditions used in the organosolv pulping of the Arundo donax L. autohydrolysis process (viz., ethanol concentration, temperature, and pulping time) on th...

The influence of different storage conditions on the colour and phenolic composition of young white wine was evaluated along 12 months of storage.The wine was bottled, and stored using three different conditions: position of bottles illumination and temperature variations. The results indicate that the time of storage has a significant effect (p <...

In the present study we have optimized the concentration of the bleaching herbicide norflurazon to obtain Dunaliella bardawil cells able to accumulate phytoene without losing viability. The highest concentration of phytoene 10.4 g/gChl was obtained for a concentration of norflurazon of 10 microg/mL. Norflurazon-treated Dunaliella bardawil cells are...

The mineral content and color characteristics of 77 honey samples were analyzed. Eighteen minerals were quantified for each honey. Multiple linear regression (MLR) was used to establish equations relating the colorimetric CIELAB coordinates to the mineral data. The results obtained shown that lightness (L) was significantly correlated with S, Ca, F...

The qualities of 25 thyme honey samples from Spain were evaluated. Eight common physicochemical parameters were analysed, namely water content, pH, acidity (free, lactonic and total), sugar content, ash, electrical conductivity and mineral composition, including potassium (K), sodium (Na), calcium (Ca), magnesium (Mg), phosphorus (P) and sulphur (S...

Twenty-four Spanish thyme honey samples were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES). Twenty-four minerals were quantified for each honey. The elements Al, As, Ba, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, P, Pb, S, Se, Si, Sr, and Zn were detected in all samples; seven elements are very abundant (Ca, K, Mg, Na, P...

Hydroxycinnamic acid content and ferulic acid dehydrodimer content were determined in 11 barley varieties after alkaline hydrolysis. Ferulic acid (FA) was the most abundant hydroxycinnamate with concentrations ranging from 359 to 624 microg/g dry weight. p-Coumaric acid (PCA) levels ranged from 79 to 260 microg/g dry weight, and caffeic acid was pr...

A simple and rapid method is described for the extraction of wine volatile compounds. The procedure was based on the ultrasonic-assisted extraction using a mixing of n-pentane-diethylether (1:2) as solvent. Factorial designs have been used to optimize the sonication process. Factors such as sample volume, extraction time and solvent volume were con...