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.
The methodology of sensory assessment (“panel test”) of virgin olive oil (VOO) is the sensory method included in international regulations and its application is compulsory in trading. Despite its ...application has been a success in authenticity of VOO quality, the application of panel test is not exempt of heated debates and controversies among olive oil actors that sometimes surpasses scientific arguments. Problems are consequence of some disagreements in the evaluation of the same VOOs from different testing laboratories, and today, there is a clamor for its enhancement from a considerable part of the industrial sector. The thin line that exists between the absence of sensory defects in extra‐VOOs and a very slight sensory defect that may be perceived in some VOOs by some tasters is in the origin of the controversy. Thus, this work is focuses on providing practical solutions to the current concerns of Panel Test after analyzing proposals evaluating aroma descriptors from chemistry, examining flaws of panel test and strengthening its weak points.
Practical Applications: The work describes a strategy that combines volatiles and sensory descriptors for avoiding disagreements with results provided by non‐recognized testing laboratories, and proposes a blueprint for improving the process of training tasters with reference materials.
Panel test of virgin olive oil (VOO) is the only sensory assessment included in international regulations. Although its application has been a success, some problems based on disagreements among sensory qualifications of VOOs by panel tests have been reported. The article proposes solutions and future challenges to enhance and strengthen panel test with the assistance of the volatile compounds.
Food authentication has been evolving continually to situations that were basically governed by a global market trend. Analytical techniques have been developed or modified to give plausible ...solutions to the devious adulterations at each moment. Classical tests have largely been replaced with newer technical procedures, most of which are based on gas chromatography, with some being based on high-performance liquid chromatography. Determination of
trans-fatty acid and sterolic composition, together with sterol-dehydration products, have been used most frequently used to detect contamination and adulteration. Sophisticated new adulterations, e.g., olive oil with hazelnut oil, represent a new challenge for the next millennium, although suggestive proposals for detecting these kinds of adulterations are emerging with the contribution of databases and mathematical algorithms.
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•Defective virgin olive oils were soft-deodorized under different conditions.•Soft-deodorized oils were analyzed to determine volatiles, phenols, ppps and faees.•Optimized ...soft-deodorization (100°C, 60min) produced minor chemical changes.•These results will help to detect soft-deodorized VOO in EVOO in further works.
The 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°C, for 30 and 60min), the parameters of 100°C and 60min 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 (34.53mg/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 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. The speed of the analysis, advantages and disadvantages, and multiple quality parameters are assessed. Sample pretreatment, physicochemical and data analysis, and evaluation of the results have been taken into consideration. Solutions based on new chromatographic methods or spectroscopic analysis and their analytical characteristics are also presented.
The latest regulation to protect unique virgin olive oils that have particular properties is called protected designations of origin (PDOs), and it has proven to be a successful way to protect ...quality and geographical authenticity. Nevertheless, sometimes the registration of new PDOs associated to new demarcations of geographic areas are almost based on administrative aspects rather than objective chemical data. In this study, the ability of chemical compounds of virgin olive oils with PDO is analyzed that are not labile and their concentrations do not vary over time − fatty acids, alcohols, hydrocarbons, methyl‐sterols and sterols − to differentiate them from those produced in their neighboring geographical areas. Three cases in the Andalusia region (Southern Spain) that combine pedoclimatic characteristics and variations of cultivar have been studied (9 areas with PDO and 3 non‐PDO areas). With a modified procedure of ANOVA analysis − the Brown–Forsythe test, chemical compounds that show good characteristics for the classification of samples are selected, and this ability is later checked by applying the unsupervised algorithm of Principal Component Analysis. Differences in their chemical composition are found when comparing the PDO oils with those produced in the neighboring olive tree groves despite chemical criteria are not among the most decisive factors for registering PDOs.
Practical Applications: The practical application of this study is centered in the possibilities of the chemical composition of virgin olive oil being used to differentiate the PDO authenticity. The results of this study proves that it is difficult to establish discreet limits defining the PDO areas. The current physical‐chemical information should be used by both administration and PDO councils to supplement arguments for approving or denying new PDOs.
Chemistry can assist the authenticity of virgin olive oil PDOs. The registration of new PDOs associated with new demarcations of geographic areas are almost based on administrative aspects rather than objective chemical data. In this work, chemical compounds that show good characteristics for the classification of samples are selected, and their classifying ability is later checked.
Chemistry can assist the authenticity of virgin olive oil PDOs. The registration of new PDOs associated with new demarcations of geographic areas are almost based on administrative aspects rather than objective chemical data. In this work, chemical compounds that show good characteristics for the classification of samples are selected, and their classifying ability is later checked.
Trade standards are continuously updated to give plausible solutions to situations created by fraudsters who apply the most sophisticated procedures to their objectives of olive oil adulteration. ...Clustered inside targeted and profiling approaches, methods based on spectroscopic, isotopic and chromatographic techniques are reviewed. Chromatographic methods, most of them being official methods, compete with newer methods based on spectroscopic, isotopic and trace element techniques for ensuring that the pace of research in the detection of malpractices is rapid enough.
The speed of the analyses, the need of statistical interpretation of the results, the quality parameters of the methods, limit of detection of the adulterants, and the applicability range among others are on the basis for the absolute and comparative analyses of the most known methods, which results are unpacked in the paper. The new frontiers of research in the field of olive oil authenticity are also dissected together with the challenges for the near future.
The extensive and deep analysis of the methods for quantifying the chemical compounds responsible for olive oil authenticity will contribute to a better comprehension of the complex analytical world of olive oil for the analyst working with this food product for the first time, as well as for experienced professionals.
•Critical analyses of standard methods with practical comments are provided.•Tools for olive oil analysis are divided into targeted and profiling methodologies.•Despite the high number of methods, there are still unsolved adulterations.•The geographical traceability is one of the new authenticity challenges.
The flavor of dry cured ham explains the high appreciation of this product and it determines consumer acceptance. Volatile compounds provide valuable information about the odor and sensory quality of ...dry cured hams. Since amino acids are the origin of some volatile compounds of dry cured ham, the volatile and amino acid compositions of forty-one dry cured hams from Spain and France were determined to establish associations between them. The samples included different pig breeds (non Iberian vs. Iberian), which were additionally affected by different maturation times and feeding types (acorn vs. fodder). Results showed that 20 volatile compounds were able to distinguish Iberian and non Iberian hams, and 16 of those had relevant sensory impact according to their odor activity values. 3-Methylbutanol, 2-heptanol and hexanal were among the most concentrated volatile compounds. In the case of non-volatile compounds, the concentrations of amino acids were generally higher in Iberian hams, and all the amino acids were able to distinguish Iberian from non Iberian hams with the exception of tryptophan and asparagine. A strong correlation of some amino acids with volatile compounds was found in the particular case of alcohols and aldehydes when only Iberian hams were considered. The high correlation values found in some cases proved that proteolysis plays an important role in aroma generation.
This paper provides a brief review of the most significant characteristics of olive oil. Processing, composition, authentication, sensory quality and health benefits are the examined aspects. In all ...these issues, the most recent challenges are described, most of them related to new environmental problems, emerging procedures of adulteration and new chemical features to detect them, and a deep knowledge of the relationship between olive oil consumption and the incidence of some diseases other than cardiovascular malfunction.
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