Gradual Changes of the Protective Effect of Phenols in Virgin Olive Oils Subjected to Storage and Controlled Stress by Mesh Cell Incubation.

The oxidation reactions that take place in virgin olive oil under moderate conditions involved the combined effect of antioxidant and prooxidant compounds. Given the complexity of oxidation processes of multicomponent matrices, there is still a need to develop new methods with a dynamic approach to study the persistence of the compounds with healthy properties. This work studied the joint evolution of them, including phenols and pheophytin , modeling their tendency during a real storage.

Antioxidant Capacity of Anthocyanins and Other Vegetal Pigments: Modern Assisted Extraction Methods and Analysis.

Anthocyanins [...

An International Survey on Olive Oils Quality and Traceability: Opinions from the Involved Actors.

A survey was launched to understand the current problems and sensitivities of the olive oil market through a series of questions clustered around topics related to quality, traceability, regulation, standard methods and other issues. The questions were selected after a series of interviews with different actors to identify those aspects where some disagreement or different points of view may exist. These questions were grouped in topics such as geographical traceability, consumer perception and quality management.

Up-To-Date Analysis of the Extraction Methods for Anthocyanins: Principles of the Techniques, Optimization, Technical Progress, and Industrial Application.

Nowadays, food industries are concerned about satisfying legal requirements related to waste policy and environmental protection. In addition, they take steps to ensure food safety and quality products that have high nutritional properties. Anthocyanins are considered high added-value compounds due to their sensory qualities, colors, and nutritional properties; they are considered bioactive ingredients.

Current state of diagnostic, screening and surveillance testing methods for COVID-19 from an analytical chemistry point of view.

Since December 2019, we have been in the battlefield with a new threat to the humanity known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this review, we describe the four main methods used for diagnosis, screening and/or surveillance of SARS-CoV-2: Real-time reverse transcription polymerase chain reaction (RT-PCR); chest computed tomography (CT); and different complementary alternatives developed in order to obtain rapid results, antigen and antibody detection. All of them compare the highlighting advantages and disadvantages from an analytical point of view.

Monitoring Virgin Olive Oil Shelf-Life by Fluorescence Spectroscopy and Sensory Characteristics: A Multidimensional Study Carried Out under Simulated Market Conditions.

The control of virgin olive oil (VOO) freshness requires new tools that reflect the diverse chemical changes that take place during the market period. Fluorescence spectroscopy is one of the techniques that has been suggested for controlling virgin olive oil (VOO) freshness during its shelf-life. However, a complete interpretation of fluorescence spectra requires analyzing multiple parameters (chemical, physical-chemical, and sensory) to evaluate the pace of fluorescence spectral changes under moderate conditions with respect to other changes impacting on VOO quality.

Antioxidant Capacity of Anthocyanins and other Vegetal Pigments.

Anthocyanins are the largest group of phenolic pigments, being effective hydrogen donors [...

State of the Art of Anthocyanins: Antioxidant Activity, Sources, Bioavailability, and Therapeutic Effect in Human Health.

The antioxidant activity of anthocyanins in food is well known. Numerous antioxidant assays have been proposed to measure the capacity of anthocyanins to prevent the oxidation process that naturally occurs. Different solvents, temperatures, and pH levels are applied in each assay, and these factors should be taken into account in order to obtain useful and reproducible results.

Tracking Sensory Characteristics of Virgin Olive Oils During Storage: Interpretation of Their Changes from a Multiparametric Perspective.

Virgin olive oil is inevitably subject to an oxidation process during storage that can affect its stability and quality due to off-flavors that develop before the oil surpasses its 'best before' date. Many parameters are involved in the oxidation process at moderate conditions. Therefore, a multiparametric study is necessary to establish a link between physico-chemical changes and sensory quality degradation in a real storage experiment.

Real time monitoring of the combined effect of chlorophyll content and light filtering packaging on virgin olive oil photo-stability using mesh cell-FTIR spectroscopy.

The present work aimed at examining the combined effect of chlorophyll content and light filtering packaging material on the photo-stability of virgin olive oil (VOO) via mesh cell-FTIR spectroscopy monitoring. Four different VOOs of Koroneiki cultivar differing in total chlorophyll content (∼12-46 mg/kg) were exposed in parallel to direct visible light (6000 lx, 24 °C, 344 h) and FTIR spectra were recorded periodically with or without applying light protection by an industrial filter used for packaging. Findings suggested that the protective role of light filtering material was more evident in the VOO with the lowest total chlorophyll content.

PhotooxidationEffect in Liquid Lipid Matrices: Answers from an Innovative FTIR Spectroscopy Strategy with "Mesh Cell" Incubation.

Developing new approaches to evaluate the stability of edible oils under moderate conditions is highly demanded today to avoid accelerated experiments that are not well correlated with actual shelf life. In particular, low intensity of visible light (photooxidation) needs to be integrated in stability studies, together with mild temperature. Thus, in this work, a strategy based on a "mesh cell"-FTIR to monitor chemical changes in lipid matrices using a combination of light and mild heating was applied.

Virgin olive oil stability study by mesh cell-FTIR spectroscopy.

Mesh cell is a rapid tool designed to monitor chemical changes that occurs as a consequence of oxidation at moderate conditions. In this study this accessory has been proposed for assessing virgin olive oil (VOO) stability by Fourier transform infrared (FTIR) spectroscopy. Monocultivar VOOs have been stored in mesh cells under different temperatures (at 23, 35, 65°C) simulating the real conditions during storage and transport (<60°C).

Origin authentication of distillers' dried grains and solubles (DDGS)--application and comparison of different analytical strategies.

In the context of products from certain regions or countries being banned because of an identified or non-identified hazard, proof of geographical origin is essential with regard to feed and food safety issues. Usually, the product labeling of an affected feed lot shows origin, and the paper documentation shows traceability. Incorrect product labeling is common in embargo situations, however, and alternative analytical strategies for controlling feed authenticity are therefore needed.

In-depth assessment of analytical methods for olive oil purity, safety, and quality characterization.

This paper evaluates the performance of the current analytical methods (standard and widely used otherwise) that are used in olive oil for determining fatty acids, triacylglycerols, mono- and diacylglycerols, waxes, sterols, alkyl esters, erythrodiol and uvaol, tocopherols, pigments, volatiles, and phenols. Other indices that are commonly used, such as free acidity and peroxide value, are also discussed in relation to their actual utility in assessing quality and safety and their possible alternatives. The methods have been grouped on the basis of their applications: (i) purity and authenticity; (ii) sensory quality control; and (iii) unifying methods for different applications.

Sensor responses to fat food aroma: a comprehensive study of dry-cured ham typicality.

The physicochemical phenomena that explain the sensing mechanisms of gas sensors have been extensively investigated. Nevertheless, it is arduous to interpret the sensor signals in a practical approach when they response to complex mixtures of compounds responsible for food aroma. Thus, the concomitant interactions between the volatiles and the sensor give up a single response affected by synergic and masking effects between compounds.

Time course analysis of fractionated thermoxidized virgin olive oil by FTIR spectroscopy.

FTIR spectroscopy has been used to examine the spectral changes taking place in the polar fraction of thermoxidized virgin olive oil and compared to those changes occurring in the neat oil and the nonpolar fraction. It was demonstrated that examination of the polar fraction provides additional and substantially better information of the chemical changes taking place as oxidation proceeds because this fraction concentrates the oxygenated compounds formed. Of particular interest is the enhancement of the OH component of the spectrum (3600-3200 cm(-1)) as well as tertiary alcohol formation (~1167 cm(-1)), including the region associated with epoxides.

Quality characterization of the new virgin olive oil var. Sikitita by phenols and volatile compounds.

New cultivars with greater adaptability to modern irrigated (super-) high-density orchards and producing good sensory quality oils are highly demanded by an olive oil industry in continuous change. This work analyzes olive oil sensory quality, in terms of phenols and volatiles that are responsible for virgin olive oil flavor, for three cultivars: Picual, which is used for >15% of world olive oil production; Arbequina, which is cultivated worldwide; and the new progeny Sikitita, which is derived from the other two. The availability of data at three different levels of ripeness allowed quantifying the genetic and olive maturity effects on the oil composition by means of the analysis of variance (ANOVA) and principal component analysis (PCA).

Evaluation of virgin olive oil thermal deterioration by fluorescence spectroscopy.

The evolution of the fluorescent compounds during the thermal deterioration of virgin olive oil is not yet well-known. Samples of heated virgin olive oils collected from a fryer every 2 h up to 94 h were analyzed to study their fluorescence spectra as well as the evolution of the concentrations of alpha-tocopherol and individual phenols by high-performance liquid chromatography (HPLC). The regions of the fluorescence spectra of the heated oils, diluted in hexane at 1%, were explained by the content of these compounds with regression coefficients higher than 0.

Thermal deterioration of virgin olive oil monitored by ATR-FTIR analysis of trans content.

The monitoring of frying oils by an effective and rapid method is one of the demands of food companies and small food retailers. In this work, a method based on ATR-FTIR has been developed for monitoring the oil degradation in frying procedures. The IR bands changing during frying in sunflower, soybean, and virgin olive oils have been examined in their linear relationship with the content of total polar compounds, which is a preferred parameter for frying control.

Relationship between sensory attributes and volatile compounds qualifying dry-cured hams.

This work studies the relationship between 45 volatile compounds and 17 sensory attributes (13 flavour perceptions) of dry-cured hams. Volatile compounds were quantified by SPME-GC while the sensory assessment was carried out by 13 panellists. GC-sniffing was used to determine the odour impact zones of the chromatogram.

Volatile compounds characterizing Tunisian Chemlali and Chétoui virgin olive oils.

A total of 33 virgin olive oil samples of the two main Tunisian cultivars, Chemlali and Chétoui, were characterized by their volatile compounds. The olive oil samples were obtained from olives harvested at four stages of ripeness in costal and inland farms of different geographical places. Major volatiles, mostly C6 and C5 compounds produced from linolenic and linoleic acids through the lipoxygenase cascade, were quantified by solid-phase microextraction-gas chromatography.