•IRs and HS-GC-IMS were for the first time compared for olive oil classification.•Pros and cons using those techniques for the analysis of olive oil were gathered.•IRs reached classification success ...for ternary and binary olive oil classification.•HS-GC-IMS showed greater olive oil classification potential than IRs.•IRs can be preliminary olive oil screening tools, and HS-GC-IMS a confirmatory one.
Virgin olive oil (OO) can be classified into three different categories: extra virgin, virgin and lampante. The official method for this classification, based on physicochemical analysis and sensory tasting, is considered useful and effective, although it is a costly and time-consuming process. The aim of this study was to assess the potential of some analytical techniques for classifying and predicting different OO categories to support official methods and to provide olive oil companies with a rapid tool to assess product quality. Thus, mid and near infrared spectroscopies (MIR and NIR) have been compared by using different instruments and with head-space gas chromatography coupled to an ion mobility spectrometer (HS-GC-IMS). High classification success rates in validation models were obtained using IR spectrometers (>70% and > 80% in average for ternary and binary classifications, respectively), although HS-GC-IMS showed greater classification potential (>85% and > 90%).
•A SPME-GC method to determine selected volatile compounds in virgin olive oils was developed and validated.•The method can support the official sensory evaluation of virgin olive oils (Panel ...test).•Two detectors can be used depending on the technical facilities of the laboratory.
During the course of the EU H2020 OLEUM project, a harmonized method was developed to quantify volatile markers of the aroma of virgin olive oil with the aim to support the work of sensory panel test to assess the quality grade. A peer validation of this method has been carried out, with good results in terms of analytical quality parameters. The method allows the quantification of volatile compounds by SPME-GC with two possible detectors, flame ionization detector and mass spectrometry, depending on the technical facilities of the labs applying this method. The method was optimized for the quantification of 18 volatile compounds that were selected as being markers responsible for positive attributes (e.g. fruity) and sensory defects (e.g. rancid and winey-vinegary). The quantification is carried out with calibration curves corrected by the internal standards. Additionally, a protocol is provided to prepare the calibration samples. This procedure enhances reproducibility between labs since one of the main sources of errors is the application of different procedures in calibration.
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In the context of supporting the panel test in the classification of virgin olive oils, the qualitative and quantitative analysis of a number of volatile compounds responsible for their aroma is of ...great importance. Herein, the data obtained from three laboratories that analyzed the same samples are presented with the view to develop an inter-laboratory validation study of a harmonized solid-phase micro-extraction coupled with gas-chromatography with flame ionized detector (SPME-GC-FID) method for determination of selected volatile compounds. In particular, quantification of the minimum number of key markers responsible for positive attributes (e.g. fruity) and sensory defects was investigated. Three quantification strategies were considered since they can have a notable impact on the effectiveness of the use of markers as well as on the robustness and simplicity of the method that is designed for control laboratories. A peer-validation study indicated repeatability with a mean relative standard deviation (RSD%) lower than 14% except for ethyl propanoate, 3-methyl-1-butanol, 1-octen-3-ol, and (E)-2-decenal. Linearity was satisfactory (R2 > 0.90) for all compounds when the calibration curves were corrected by the internal standard. Several critical issues were identified, such as high RSD% (>50%) in terms of reproducibility for ethyl propanoate, (E)-2-decenal, and possible improvements of the limits of detection (LODs) and quantitation (LOQs) of (E)-2-heptenal, (E,E)-2,4-hexadienal, and (E)-2-decenal. In particular, some compounds (ethyl propanoate, (E)-2-heptenal, 1-octen-3-ol, (E,E)-2,4-hexadienal, (E)-2-decenal and pentanoic acid) showed LOQs that were higher than the concentrations found in some samples. The discussion permitted improvement of the protocol towards the final version for an upcoming full validation process.
•SPME-GC-FID method was validated (3 labs) for analyzing 18 virgin olive oil VOCs.•R2 was >0.90 when the internal standard was used to build the calibration curves.•Mean RSD% for repeatability was <14% for 14 out 18 compounds.•Mean reproducibility RSD% was high (>50%) for ethyl propanoate and (E)-2-decenal.•LODs/LOQs were studied and the results discussed with respect to S/N ratio.
Spectroscopic techniques are presented as a reliable and economical alternative for the discrimination of olive oil quality categories. In this work, fluorescence and Raman spectroscopic techniques ...have been compared by evaluating different characteristics focused on sample preparation and analysis time, as well as classification percentages by chemometric models (PLS-DA) to classify olive oils into three categories: extra virgin (EVOO), virgin (VOO), and lampante (LOO). A statistical evaluation of the quality of the chemometric models was performed by comparing the parameters of sensitivity in terms of the true positive rate (%TPR), specificity (or true negative rate %TNR), and classification error in calibration, cross-validation and prediction. Fluorescence spectroscopy was the screening technique with the best overall accuracy in the ternary models for prediction (78.60%), with higher results than those obtained by Raman (66.03%), the latter being below the average error in the tasting panels. Regarding the classification obtained in binary models (EVOO/Non-EVOO and LOO/Non-LOO), fluorescence spectroscopy continued to present better results than Raman, with classifications of 92.5% and 88.5 % for both models, respectively (Raman obtained percentages of 70.7% and 66.6%). A comparison of the results obtained with confirmation techniques (headspace-gas chromatography-ion mobility spectrometry, HS-GC-IMS) and other spectroscopic techniques (NIR and MIR) studied in previous research was carried out, where it was observed that fluorescence spectroscopy obtained the closest classification percentage to the HS-GC-IMS technique (86.4%) in ternary models. On the other hand, the NIR technique obtained the highest classification percentage in binary models, with 92.6% for EVOO/Non-EVOO and 88.9% for LOO/Non-LOO compared to the value obtained using GC-IMS (95.4 and 86.4 %). Evaluating the rest of the parameters of interest for the olive industry, IR (both NIR and MIR) was the most interesting technique because it is a cheap, simple sensor with fast chemometric treatments and is environmentally-friendly. The results of this comparative study can be used to provide solutions and alternatives for applying new analytical strategies to support the work of tasting panels.
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•Evaluation of Spectral techniques for the discrimination of olive oil categories.•Fluorescence and Raman techniques are compared using chemometric analysis.•Fluorescence spectroscopy showed the best classification rates.•Spectroscopic techniques can be used in the industry as a rapid screening tool.
•Salinity effects on agronomic response of rice were studied in Southern Spain.•Saline irrigation negatively affects rice yield components and increases its cycle.•Rice might not be significantly ...affected by salinity below 1.67dSm−1.•Number of panicles and filled grains are the most affected parameters.•Rice is most sensitive to saline irrigation during the vegetative phase.
Losses of productivity of flooded rice in Southern Spain may occur due to the use of saline water coming from the existent tidal regime in the marshes of Guadalquivir River, and the sensibility of the plants is variable according to its stage of development. The aim of this research was to evaluate the production of rice grains and its components, spikelet sterility and the phenological development of rice at different levels of salinity and in different periods of its cycle. In the conditions of the trial, the productive potential of rice based on the electrical conductivity (EC) of the irrigation water can be estimated by using the equation “Percentage of grain yield=100−12.0 (EC – 0.92)”. It was estimated that from 1.6–1.7dSm−1 salt content affects rice grain yield. Salinity also had a negative impact on a number of yield components including panicles per surface unit, tillers and spikelets per plant; floret sterility; and even delayed heading. Individual grain size was scarcely affected by salinity increase. The vegetative and reproductive phases were significantly more sensitive to salinity than grain filling and maturation phase. Irrigation management practices should be adopted to minimize salinity during these critical growth stages.
Abstract
The organoleptic assessment (Panel test) is the only procedure within the official methods for determining the quality of virgin olive oils that involves an expert panel. There is an urgent ...need for analytical methodology that can reliably measure volatile compounds in virgin olive oils that is capable of supporting and anticipating the official Panel test. For this reason, a new method based on solid‐phase microextraction–gas chromatography with the choice of two possible detectors (FID or MS) was subjected to a large international interlaboratory validation study. The study involved a two‐stage process: first, a pretrial phase in which 7 participants were exposed to the method for the first time to identify any initial problems with the methodology; then, a formal validation stage (trial proper), which involved 20 laboratories from Europe, USA, Japan and China. The performance of the different detectors was investigated. While both methods have advantages, the method using FID provided better results for 11 compounds, in terms of reproducibility, compared to MS. This information will allow to implement the method with accurate information of the method performance depending on the detector used.
Practical applications: This study provides information from an interlaboratory validation of a method for measuring volatile compounds in virgin olive oils conducted with laboratories (from industry and academia) working in the olive oil sector. The information on the expected analytical errors in the determination of each volatile compound is necessary to apply this method for supporting the official Panel test (sensory analysis). The SPME‐GC‐MS/FID methods proposed in this work can be used for the internal quality control of a company/distributor/quality control laboratory and could also be used in cases of difficult/contradictory organoleptic assessment, or to confirm results from sensory panels in cases of disputes/disagreement (Reg. EU 2022/2105).
Wine vinegar is an increasingly appreciated product in Europe and some high-quality vinegars have been certified with “Protected Designation of Origin” (PDO) to preserve and control their production ...methods. Spain has three of the five PDO wine vinegars existing in Europe. A tentative study was carried out to assess the utility of stable isotope analysis (δ
13
C and δ
18
O) for the characterization of those Spanish wine vinegars and if the values obtained could be used as a fingerprint of their geographical origin compared with other regions. A total of 35 wine vinegar samples, belonging to the three Southern Spain PDOs and three Northern Spain non-PDO regions, were analyzed for their isotopic composition. Our analysis revealed that most of the Spanish vinegars presented δ
13
C values that were in agreement with some other isotopic studies about Mediterranean vinegars, since all the samples were under − 20‰ and the vast majority of them were below − 24‰. On the other hand, the δ
18
O analysis confirmed its utility for discriminating all the Spanish vinegars according to the three geographical coordinates (latitude, longitude and altitude). Positive mean values were associated to Southern vinegars (2.16 ± 1.59‰) and negative δ
18
O values were related with Northern vinegars (− 2.93 ± 2.82‰). We also found a highly significant (
p
< 0.001) correlation of δ
18
O with altitude (
R
2
= − 0.48) and longitude (
R
2
= 0.36), which allowed us to conclude that δ
18
O analysis could be used as a fingerprint of the geographical origin in Spanish wine vinegars.
An appropriate characterization of agronomic and quality traits is a fundamental tool for selecting stable genotypes suitable to be registered as new varieties. The objective of this work was to ...evaluate agronomic and quality traits of rice germplasm tested in two consecutive years for 23 advanced lines of Portuguese Rice Breeding Program and 3 commercial varieties. The influence of genotype, year and their interaction on grain yield and milling yield, grain uniformity and selected quality indicators for rice was assessed as well as the correlations between the agronomic, biometric and quality parameters. Results showed a generally dominant influence of the genotype, but with some quality parameters significantly affected by year conditions, and with some genotypes more stable than others. Some accessions have also shown better grain biometric uniformity within a year and between years. Significant correlations between quality and agronomic parameters that were observed may mark a plant pattern that can be used as predictor of the milling yield. These analyses provide objective tools for selecting most promising genotypes in rice breeding programs.
Objective
To evaluate the effectiveness of a high calorie and protein, β-hydroxy-β-methylbutyrate containing oral nutritional supplement (HP-HMB-ONS), on nutritional status, activities of daily ...living and quality of life (QoL) in old malnourished subjects.
Methods
We conducted an observational, prospective, open label, multicenter study. Participants were > 65 years, undernourished or at nutritional risk Nutrition Risk Score (NRS) ≥ 3 and had been included on an ONS (HP-HMB-ONS twice daily for 12 weeks) per standard of care. Visits at baseline (V1), 6 weeks (V2) and 12 weeks (V3) were performed. The primary endpoints were gain of body weight, change in body mass index (BMI) and NRS 2002 index. Data from QoL (EQ-5D-3L) and activities of daily living (Katz index) were also collected.
Results
A total of 235 participants were included in the study. Of these 148 took at least a 75% of the HP-HMB-ONS and were included in the analysis (per protocol); median age was 80.0 (SD:8.3) years, 65.5% (
n
= 97) were female, 67.6% (
n
= 100) had 2 or more diseases. At V3, a statistically significant increase in weight (2.1 kg; SD: 3.8) (
p
< 0.001) and BMI (0.8 kg/m
2
; SD: 1.45) were found compared to V1, whereas NRS 2002 values decreased by 0.9 (SD: 1.2). A significant (
p
< 0.001) improvement in Katz index (mean change = 0.3; SD:1.4) and EQ-5D scoring (mean change = 0.5; SD:1.9) compared to V1, were also reported.
Conclusions
The results suggest that administration of a HP-HMB-ONS improve the nutritional status and may led to a significant improvement in patients’ activities of daily living and QoL, independent of baseline BMI.
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