Ana Sayago

Universidad de Huelva | UHU · Faculty of Experimental Sciences

The food industry demands novel green solvents for the extraction of bioactive compounds, particularly from residues of the agrifood industry. Herein, an ultrasound-assisted method has been developed for the environmentally friendly extraction of phenolic compounds from blueberry leaves using natural deep eutectic solvents (NADES). After the screen...

Phospholipids are essential components of membrane lipid bilayers and serve as precursors of multiple signaling molecules, so alterations in their homeostasis are associated with the pathogenesis of numerous diseases. In this context, the application of mass spectrometry-based metabolomics has demonstrated great potential to comprehensively charact...

The use of advanced chemometrics tools in food authenticity research is crucial for managing the huge amount of data that is generated by applying state-of-the-art analytical methods such as chromatographic, spectroscopic, and non-targeted fingerprinting approaches. Thus, this review article provides description, classification, and comparison of t...

Accurate, robust, and wide-coverage analytical tools are needed in polyphenol research to deal with the high physicochemical complexity of the secondary plant metabolome. In this chapter, a novel method based on reversed-phase ultrahigh-performance liquid chromatography coupled with a diode array detector and mass spectrometry is presented, which e...

Organotin compounds are widely employed as pesticides and fungicides in agriculture and as stabilizers for the industrial manufacture of polyvinyl chloride and other polymers. Accordingly, these endocrine disruptors can be found in a variety of foods and beverages. In the present study, we describe the optimization of a hollow-fiber liquid-phase mi...

The use of mass spectrometry is currently widespread in polyphenol research because of its sensitivity and selectivity, but its usual high cost, reduced robustness, and nonavailability in many analytical laboratories considerably hinder its routine implementation. Herein, we describe the optimization and validation of a high-throughput, wide-covera...

The current great concern about plastic pollution opens up opportunities for the production of more sustainable polymers. Inverse vulcanization has emerged as a novel procedure to obtain inorganic-organic hybrid polymeric materials. Sulfur is attained as a by-product of oil refining production and makes inverse vulcanization a sustainable process d...

ScienCity es una actividad que viene siendo continuada desde 2018 con el objetivo de dar a conocer los conocimientos y tecnologías emergentes siendo investigados en las universidades, informar de experiencias, servicios e iniciativas puestas ya en marcha por instituciones y empresas, llegar hasta decisores políticos que podrían crear sinergias, inc...

The purpose of this work was to investigate the physicochemical changes occurring during the thermal-based production of água-mel, a traditional Portuguese honey-related food product. The refractive index, color parameters (hue angle, H°; chroma, C*), and the content of total reducing sugars, glucose, fructose, total brown pigments, and 5-hydroxyme...

Wine lees are the major waste from wine production, containing a noticeable amount of biomass (yeast, stalks, and peels), they could be used for the stabilization of dispersed systems such as emulsions. This work is focused on the determination of techno-functional properties of whine less produced from white grapes and industrial-grade blueberries...

High-quality wine vinegars with unique organoleptic characteristics are produced in southern Spain under three Protected Designations of Origin (PDO), namely “Jerez”, “Condado de Huelva” and “Montilla-Moriles”. To guarantee their authenticity and avoid frauds, robust and low-cost analytical methodologies are needed for the quality control and trace...

The efficient analysis of polar and charged metabolites in biological samples remains a huge challenge in the field of metabolomics. Over the past years, novel mass spectrometry-based analytical tools have been developed to enable the sensitive and efficient profiling of polar ionogenic metabolites in various biological samples. This book gives the...

Context: Growing evidence suggests that prenatal exposure to methyl mercury through the maternal diet could have great influence on the neurological and physical development of neonates and young children. Objective: The aim of this review was to evaluate the clinical repercussions of maternal exposure to methyl mercury during pregnancy on the h...

Hydrophilic metabolites are closely involved in multiple primary metabolic pathways and, consequently, play an essential role in the onset and progression of multifactorial human disorders, such as Alzheimer’s disease. This review article provides a comprehensive revision of the literature published on the use of mass spectrometry-based metabolomic...

An approach of new and sustainable uses for by-products generated in the wine production industry, one of the agro-food sectors of importance, has been studied. Wine lees, a sediment obtained in different processes of decantation of wine, have been used to produce biomass of microalgae enriched in carotenoids as high added value biomolecules. Exper...

Multicompartmental metabolomics is a powerful strategy for studying organism metabolic homeostasis in a holistic manner. To this end, mass spectrometry–based platforms are very versatile tools for high-throughput metabolomics, of particular interest when dealing with large populations. This chapter details methods and tips for comprehensive analysi...

Lead and cadmium are amongst some of the most hazardous and carcinogenic heavy metals to contaminate water sources in the industrial sector. As such, there have been several research efforts to remediate this worldwide environmental concern. The main objective of this study was to determine the efficacy of using two natural agricultural waste mater...

Volatile compounds are essential for food organoleptic characteristics and of great utility for the food industry as potential markers for authenticity purposes (e.g., variety, geographical origin, adulteration). The aim of this study was to determine the characteristic volatile compounds of strawberry samples grown in a soilless system by using he...

Metabolomics can be significantly influenced by a range of pre-analytical factors, such as sample collection, pre-processing, aliquoting, transport, storage and thawing. This therefore shows the crucial need for standardizing the pre-analytical phase with the aim of minimizing the inter-sample variability driven by these technical issues, as well a...

The quality and sensory characteristics of Iberian ham are closely related to the pig feeding regime. These are mainly due to the inclusion or not of acorns into the diet, which significantly increases the content of monounsaturated fatty acids in this food product. In this work, the fatty acid profile from subcutaneous fat samples was evaluated an...

The chemical composition of foods is tightly regulated by multiple genotypic and agronomic factors, which can thus serve as potential descriptors for traceability and authentication purposes. In the present work, we performed a multi-chemical characterization of strawberry fruits from five varieties (Aromas, Camarosa, Diamante, Medina, and Ventana)...

The food industry has currently shown great interest in alternative sweeteners to sugars with the aim of producing healthier products. In light of this, steviol glycosides are natural low-caloric sweeteners present in Stevia rebaudiana, which have additionally been described as bioactive components with potential therapeutic properties. In this wor...

The adulteration of virgin olive oil with hazelnut oil is a common fraud in the food industry, which makes mandatory the development of accurate methods to guarantee the authenticity and traceability of virgin olive oil. In this work, we demonstrate the potential of a rapid luminescent method to characterize edible oils and to detect adulterations...

There is a great need for having accurate analytical methods able to guarantee the authenticity and traceability of foods, especially for those of high quality and economic value such as extra-virgin olive oil. In the present work, we assessed the potential of combining traditional analytical techniques, based on the characterization of the unsapon...

Metabolomics based on direct mass spectrometry analysis shows a great potential in biomedical research because of its high-throughput screening capability and wide metabolome coverage. This chapter contains detailed protocols to perform comprehensive metabolomic fingerprinting of multiple biological samples (serum, plasma, urine, brain, liver, sple...

Haloferax mediterranei is known to accumulate C50 carotenoids which have been proven to have strong antioxidant capacity. The knowledge on C50 carotenoids production is still very scarce at laboratory scale and has not been developed at large scale [1,2]. The main reason to explain such a low level of technical development can be found in the fact...

Haloferax mediterranei produces C50 carotenoids that have strong antioxidant properties. The response surface methodology (RSM) tool helps to accurately analyze the most suitable conditions to maximize C50 carotenoids production by haloarchaea. The effects of temperature (15–50 °C), pH (4−10), and salinity (5–28% NaCl (w/v)) on the growth and carot...

Direct mass spectrometry-based metabolomics has been widely employed in recent years to characterize the metabolic alterations underlying Alzheimer’s disease development and progression. This high-throughput approach presents great potential for fast and simultaneous fingerprinting of a vast number of metabolites, which can be applied to multiple b...

Direct mass spectrometry-based metabolomics has been widely employed in the last years to characterize metabolic alterations underlying to Alzheimer’s disease development and progression. This high-throughput approach presents a great potential for fast and simultaneous fingerprinting of a vast number of metabolites, which can be applied to multipl...

This work explores the potential of multi-element fingerprinting in combination with advanced data mining strategies to assess the geographical origin of extra virgin olive oil samples. For this purpose, the concentrations of 55 elements were determined in 125 oil samples from multiple Spanish geographic areas. Several unsupervised and supervised m...

The integration of complementary analytical platforms has emerged as a suitable strategy to perform a comprehensive metabolomic characterization of complex biological systems. In this work, we describe the most important issues to be considered for the application of a mass spectrometry multiplatform in Alzheimer’s disease research, which combines...

The analytical bias introduced by most of the commonly used techniques in metabolomics considerably hinders the simultaneous detection of all metabolites present in complex biological samples. In order to solve this limitation, the combination of complementary approaches is emerging in recent years as the most suitable strategy in order to maximize...

A simple, sensitive and rapid assay based on liquid chromatography coupled to tandem mass spectrometry was designed for simultaneous quantitation of secondary metabolites in order to investigate the influence of variety and agronomic conditions on the biosynthesis of bioactive compounds in strawberry. For this purpose, strawberries belonging to thr...

Phenolic compounds can be considered as the most important bioactive compounds in Mediterranean diet. However, many of the complex connections between phenols antioxidant reactivity and their molecular structure remain unsolved. To shine light on these issues, the antioxidant reactivity of 15 relevant phenolic compounds was studied. Two different a...

Alzheimer’s disease is a complex neurodegenerative disorder characterized by a multi-factorial etiology, not completely understood to date. In this context, the application of metabolomics is emerging in the last years because of its potential to monitor molecular alterations associated with disease pathogenesis and progression, as well as to disco...

Nowadays, the oenological market tends to the diversification through the development of new original and enriched products. Thus, the study here proposed pretends the elaboration and characterization of new "wine-type" beverages based on the use of berries, resulting in products with added value due to the increase in their content of bioactive co...

Stevia rebaudiana Bertoni is a shrub of the Asteraceae family native to South America, especially of Brazil and Paraguay. This plant accumulates a suite of diterpenoid metabolites that are natural sweeteners finding increased use as sugar. In addition, a number of healing properties have been associated to the stevia leaves intake. The objectives o...

In recent years, interest in phenolic compounds has been increased due mainly to the numerous evidences of its beneficial health effects and their impact on food quality. Numerous efforts have been made in order to increase the knowledge about phenolic compounds, with an especial focus on characterization of new food sources rich in polyphenols. Th...

Traditionally the analysis of vegetable oils has been carried out by classic procedures such as gas chromatography, which requires previous derivatization of the sample. This, involves the consumption of reagents and, sometimes, the composition of the sample could be altered with the corresponding error in the measurement. Therefore, it is desirabl...

Metabolomics based on direct mass spectrometry (MS) analysis, either by direct infusion or flow injection of crude sample extracts, shows a great potential for metabolic fingerprinting because of its high-throughput screening capability, wide metabolite coverage and reduced time of analysis. Considering that numerous metabolic pathways are signific...

In this work, we describe the isolation, identification, pigment characterization and optimization of the culture conditions for a haloarchaea strain isolated from salt evaporation ponds in the Odiel river, at Southwest of Spain. The haloarchaea belongs to the genus Halorobrum, as deduced from the analysis of its 16S rRNA encoding gene and has been...

In this article, the environmentally friendly preparation of “green nanocarriers” based on the combination of natural renewable materials is described. Cardanol (CA), obtained as the major byproduct of the cashew industry, and cholesterol (CH) have been used to encapsulate chlorogenic acids (CQAs), a class of natural phenolic compounds extracted fr...

A comparison between different extraction methods has been performed in order to assess their effectiveness for the analysis of total phenols (liquid–liquid extraction (LLE), liquid–liquid micro extraction (LLME), and ultrasound liquid–liquid extraction (USE)) and individual phenols (LLME, USE, and solid-phase extraction (SPE)) from virgin olive oi...

A characterization study of the main olive oil cultivars of southwest Spain (Picual, Arbequina, and Verdial) has been performed in order to establish logistic regression models. Several quality characteristics (free acidity, peroxide value, K232, K270, oxidative stability index) and chemical data (fatty acids, sterols, erythrodiol–uvaol composition...

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...

Natural fluorophores such as tocopherols are of great importance for the characterization and authentication of virgin olive oil. The band of the luminescent spectrum which is most accurately associated with the presence of alpha-tocopherol (380-420 nm) at lambda(exc) = 350 nm was detected and its precision was evaluated once the analytical process...

A bilogarithmic hyperbolic cosine method for the spectrophotometric evaluation of stability constants of 1 : 1 weak complexes is developed and applied to data found in the literature. The method devised does not require any approximations and the variables of the final equation proposed are well separated, being, in addition, the abscissa free from...

The fluorescence spectroscopy technique has been tested as regards its ability to differentiate between refined hazelnut and olive oils. Classification of these oils based on their excitation-emission fluorescence spectra data (spectral range 300-500 nm of the excitation spectra at lambdaem=655 and spectral range 650-900 of the emission spectra at...

An interest in vitamin E has increased in recent years due to its potent antioxidant properties and its role in preventing age-related diseases, cardiovascular diseases or Alzheimer. This work describes the biogenesis, bioavailability, nutritional requirements, activity and properties of vitamin E. Vegetable oils constitute one of the main sources...

An interest in vitamin E has increased in recent years due to its potent antioxidant properties and its role in preventing age-related diseases, cardiovascular diseases or Alzheimer. This work describes the biogenesis, bioavailability, nutritional requirements, activity and properties of vitamin E. Vegetable oils constitute one of the main sources...

A bilogarithmic hyperbolic cosine method for the spectrophotometric evaluation of stability constants of 1:1 weak complexes from continuous variation data has been devised and applied to literature data. A weighting scheme, however, is necessary in order to take into account the transformation for linearization. The method may be considered a usefu...

The absorbance changes that occur when the mole ratio of the components of ligand complex equilibria is varied while the concentration of one component is kept constant (mole ratio method) allow evaluating stability constants in favourable conditions. Values of the corresponding stability (association) constants are normally assigned on the basis o...

The use of the correlation coefficient for testing the linearity of calibration curves is performed according to the ANOVA checking of the lack-of-fit. The procedure is illustrated from a case study.

The spectral characteristics and the acid-base behavior of biacetylmonoxime-isonicotinoylhydrazone (BMIH) have been studied.

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 <...

Correlation and regression are different, but not mutually exclusive, techniques. Roughly, regression is used for prediction (which does not extrapolate beyond the data used in the analysis) whereas correlation is used to determine the degree of association. There situations in which the x variable is not fixed or readily chosen by the experimenter...

An attempt to distinguish between 1:1 and 2: 2 weak complexes from continuous variation data is given. A modification of the Heller and Schwarzenbach's method which involves the use of the absorbance ratio y=A/A(lim) (once the limiting absorbance, A(lim) is known) may be applied to 1:1 weak complexes. This allows checking if the slope obtained is c...

The purpose of the previous, this, and subsequent articles in the series is to deal with the fitting of a straight line to experimental data in those cases in which replicate observations are realized. Special attention has been paid in this occasion to the straight line model, to the determination of the variance from a number of small samples, an...