ATR-FTIR as a potential tool for controlling high quality vinegar categories

Characterization of wine vinegars qualified with a Protected Designation of Origin (PDO) is crucial to certify their quality and authenticity. Spectroscopic techniques as Fourier transform mid infrared spectroscopy (FTIR) with Attenuated Total Reflectance (ATR) has been applied to investigate its potential as a rapid, cost-effective and non-destructive tool for characterizing different categories of high-quality vinegars. Spectra from 67 wine vinegars belonging to the PDOs “Vinagre de Jerez” and “Vinagre Condado de Huelva”, including their different established categories, were analyzed in the 4000–600 cm−1 infrared region. Changes associated to categories were observed in the region 1800–900 cm−1. These changes were assigned to certain compounds that increase during aging (e.g. acetic acids, alcohols, esters) or are characteristic of Pedro Ximenez category (e.g. sugars, furfural). Principal component analysis carried out on the most relevant spectral features, revealed that aging of vinegars clearly affect the ATR-FTIR spectra obtained in each PDO.Junta de Andalucía P12-AGR-160

Método para el análisis de compuestos volátiles mediante microextracción en fase sólida en modo dinámico y dispositivo asociado

Método para el análisis de compuestos volátiles mediante microextracción en fase sólida en modo dinámico y dispositivo asociado. La presente invención se refiere a un método para el análisis de compuestos volátiles mediante microextracción en fase sólida que presenta una alta capacidad de adsorción, unos buenos factores de recuperación y además puede aplicarse a numerosos compuestos volátiles, debido a una etapa de aplicación continua de un flujo de gas portador sobre el espacio de cabeza de un vial cerrado donde se encuentra la muestra a analizar para liberar los compuestos volátiles de la muestra, así como al dispositivo asociado.Peer reviewedConsejo Superior de Investigaciones Científicas (España)B1 Patente sin examen previ

Método para el análisis de compuestos volátiles mediante microextracción en fase sólida en modo dinámico y dispositivo asociado

Método para el análisis de compuestos volátiles mediante microextracción en fase sólida en modo dinámico y dispositivo asociado. La presente invención se refiere a un método para el análisis de compuestos volátiles mediante microextracción en fase sólida que presenta una alta capacidad de adsorción, unos buenos factores de recuperación y además puede aplicarse a numerosos compuestos volátiles, debido a una etapa de aplicación continua de un flujo de gas portador sobre el espacio de cabeza de un vial cerrado donde se encuentra la muestra a analizar para liberar los compuestos volátiles de la muestra, así como al dispositivo asociado.Peer reviewedConsejo Superior de Investigaciones Científicas (España)B1 Patente sin examen previ

Analysis of Volatile Markers for Virgin Olive Oil Aroma Defects by SPME-GC/FID: Possible Sources of Incorrect Data

7 Páginas; 3 Figuras; 3 TablasThe need to explain virgin olive oil (VOO) aroma descriptors by means of volatiles has raised interest in applying analytical techniques for trapping and quantitating volatiles. Static headspace sampling with solid phase microextraction (SPME) as trapping material is one of the most applied solutions for analyzing volatiles. The use of an internal standard and the determination of the response factors of the main volatiles seem to guarantee the correct determination of volatile concentrations in VOOs by SPME-GC/FID. This paper, however, shows that the competition phenomena between volatiles in their adsorption to the SPME fiber, inherent in static headspace sampling, may affect the quantitation. These phenomena are more noticeable in the particular case of highly odorant matrices, such as rancid and vinegary VOOs with high intensity of defect. The competition phenomena can modify the measurement sensitivity, which can be observed in volatile quantitation as well as in the recording of internal standard areas in different matrices. This paper analyzes the bias of the peak areas and concentrations of those volatiles that are markers for each sensory defect of VOOs (rancid, vinegary, musty, and fusty) when the intensity and complexity of aroma are increased. Of the 17 volatile markers studied in this work, 10 presented some anomalies in the quantitation in highly odorant matrices due the competition phenomena. However, quantitation was not affected in the concentration ranges at which each volatile marker is typically found in the defective oils they were characteristic of, validating their use as markers.This work was supported by the Comisión Interministerial de Ciencia y Tecnologı́a (CICYT, Spanish government), Spanish State Secretary for Research (Ramón y Cajal Program), and FEDER (EU) within Project AGL 2011-30371-C01-01/02.Peer reviewe

Implementing Dynamic Headspace with SPME Sampling of Virgin Olive Oil Volatiles: Optimization, Quality Analytical Study, and Performance Testing

Competition and interaction phenomena among volatiles during their adsorption process by solid phase microextraction (SPME) fibers in static headspace sampling procedure (SHS) cast doubt on its ability to quantify virgin olive oil volatiles. SPME fibers being excellent traps, their use was analyzed with a new device allowing the concentration of volatiles in a dynamic headspace sampling procedure (DHS). A central composite experimental design optimized the main variables of the device (4 g sample weight, 40 °C temperature, 150 mL/min flow rate, 50 min adsorption time), while values of the analytical quality control parameters of the method (repeatability, limits of detection and quantification, working range, sensitivity, and resolution) were compared with those ones from static headspace. DHS shows better precision results for aldehydes and alcohols than SHS and allowed analyzing higher concentrations with no problem of saturation. In 19 of 28 compounds analyzed in 50 samples the chromatographic areas were higher when running DHS. The concentration values of volatile compounds in these samples after applying SHS and DHS are discussed together with the ability of the new method for distinguishing virgin olive oil by their categories (extra virgin, virgin, and lampante) by the volatiles quantified in commercial oils.This work was supported by the Comisión Interministerial de Ciencia y Tecnología (Spanish Government) through Project Nos. AGL2011-30371 and AGL2015-69320-R. Authors thank the Erasmus-Socrates bilateral exchange programme for partially funding the research stay of one of the authors (D.T.).Peer Reviewe

ATR-FTIR as a potential tool for controlling high quality vinegar categories

5 Figuras.-- 2 TablasCharacterization of wine vinegars qualified with a Protected Designation of Origin (PDO) is crucial to certify their quality and authenticity. Spectroscopic techniques as Fourier transform mid infrared spectroscopy (FTIR) with Attenuated Total Reflectance (ATR) has been applied to investigate its potential as a rapid, cost-effective and non-destructive tool for characterizing different categories of high-quality vinegars. Spectra from 67 wine vinegars belonging to the PDOs ¿Vinagre de Jerez¿ and ¿Vinagre Condado de Huelva¿, including their different established categories, were analyzed in the 4000e600 cm-1 infrared region. Changes associated to categories were observed in the region 1800e900 cm-1. These changes were assigned to certain compounds that increase during aging (e.g. acetic acids, alcohols, esters) or are characteristic of Pedro Ximenez category (e.g. sugars, furfural). Principal component analysis carried out on the most relevant spectral features, revealed that aging of vinegars clearly affect the ATRFTIR spectra obtained in each PDO.This work was supported by the “Consejería de Economía, Innovación y Ciencia, Junta de Andalucía” under the project P12-AGR-1601 and by a FPU scholarship of the Ministerio de Educación, Cultura y Deporte (FPU014/01247)

Characterization of Virgin Olive Oils with Two Kinds of >frostbitten Olives' Sensory Defect

3 Figuras.-- 2 TablasThe frost of olives on the tree due to drops of temperature can produce sensory defects in virgin olive oil (VOO). Temperature changes can be abrupt with freeze-thaw cycles or gradual, and they produce sensory and chemical variations in the oil. This study has analyzed the quality parameters (free fatty acids, peroxide value, UV absorption, and fatty acid ethyl esters) and phenols of VOOs described with the >frostbitten olives' sensory defect. The phenol profiles allowed grouping these VOOs into two types. One of them, characterized with >soapy> and >strawberry-like> aroma descriptors, had higher values of 1-acetoxypinoresinol, pinoresinol, and aldehydic form of the ligstroside aglycon. The other one, characterized with >wood> and >humidity> descriptors, had higher concentrations of luteolin and apigenin. Most VOOs (75%) from the first group, associated with abrupt drops of temperature, have concentration of phenols higher than the value established by the health claim on olive oil polyphenols approved by the European Commission.This work was supported by the Comisión Interministerial de Ciencia y Tecnologı́a (Spain) and FEDER (EU), Project AGL 2011-30371-C01-01/-02

Soft-deodorization of virgin olive oil: Study of the changes of quality and chemical composition

1 Figura.-- 5 TablasThe potential adulteration of extra virgin olive oil (EVOO) with soft-deodorized virgin olive oil (VOO) has raised the interest of researchers in investigating this fraud in recent years. The objective of this study was to determine chemical changes occurring after a soft-deodorization process in terms of volatiles, fatty acid ethyl esters (FAEEs) and pyropheophytins (PPPs) concentrations in VOOs. After testing several conditions (80, 100 and 130 ºC, for 30 and 60 min), the parameters of 100 ºC and 60 min were considered as the optima. These conditions allowed removing volatiles responsible for sensory defects with low losses of total phenols (14%¿32%), and values of PPPs (11.83%) and FAEEs (34.53 mg/kg) lower than the limits of standard regulations. The experiments show that soft-deodorized VOOs could be added up to 50% to EVOOs and current standard methods would not detect this kind of adulteration.This work was supported by the Comisión Interministerial de Ciencia y Tecnología – Spain and the European Regional Development Funds (FEDER) – European Union, Project AGL 2011-30371-C01-01/-02

Phenolic profile of virgin olive oils with and without sensory defects: Oils with non-oxidative defects exhibit a considerable concentration of phenols

3 Figuras.-- 3 TablasThe new health claim on >olive oil polyphenols> recently approved by the European Commission has produced a dramatic increase in the interest in these antioxidant compounds. Although this interest has been focused mostly on extra virgin olive oils (EVOOs), virgin olive oils (VOOs) qualified as having non-oxidative sensory defects, mostly caused by fermentation and the action of fungi on olives, may still have a considerable amount of phenols, even though their sensory quality is not flawless. This study is focused on the phenol composition of all the VOO categories: EVOOs with their ample variability in phenolic composition, VOOs with slight defects, lampante virgin olive oils (LVOO), and reference materials of defective VOOs. The average content of phenols in the analyzed EVOOs (410±16mg/kg) is higher than the recommended consumption by the health claim (250mg/kg). VOOs qualified with non-oxidative defects contain high concentrations of phenols (234±27mg/kg), but only samples characterized by the wet-wood sensory defect show concentrations of phenols close to 250mg/kg. Practical application: This study has demonstrated that VOOs with slight sensory defects still have a high concentration of phenols, providing antioxidant properties regarding health benefits and stability. The health claim should be not only applied to the extra virgin olive oil category, but also to some virgin olive oils with sensory defects.This work was supported by the Comisión Interministerial de Ciencia y Tecnología (CICYT‐EU, Spanish and European Government), Spanish State Secretary for Research (Ramón y Cajal Program) and FEDER (CE) in the projects AGL 2011‐30371‐C01‐01 and ‐02. Extra virgin olive oils were supplied by Spanish producers: Vaga de la Estrella SA, Oleoestepa SCA, Aceites 1881 y Aceites del Sur. Commercial virgin olive oils were supplied by FAECA. Standards of defects were supplied by the International Olive Council