Changes in saffron volatile profile according to its storage time

Seventy-three saffron samples belonging to three different storage time (<1 year, 3\u20134 and 8\u20139 years) were analysed using ultrasound assisted extraction-gas chromatography\u2013mass spectrometry and ultrasound assisted extraction-gas chromatography\u2013olfactometry. Nineteen volatile compounds were identified and their aromatic notes were assigned. In addition to safranal, the main compound found, (30.14\u201343.94% in mass of total volatiles), other major compounds were 4-hydroxy-2,6,6-trimethyl-1-cyclohexen- 1-carboxaldehyde and 3,5,5-trimethyl-2-cyclohexene-1-one. These compounds were significantly different for less than 1 year storage when compared with the 3\u20134 and 8\u20139 years of storage, although the minor constituents 2-hydroxy-3,5,5-trimethylcyclohex-2-en-1,4-dione and isomer of 4-hydroxy-3,5,5- trimethyl-2-cyclohex-1-one varied significantly for all three harvests. Positive and negative aroma descriptors were related with the overall saffron chemical volatile composition. Saffron with less than 1 year storage contained a higher proportion of saffron, flower and spicy descriptors, while the oldest saffrons (3\u20134 and 8\u20139 years of storage) contained volatiles with vegetal, caramel and citrus notes. The aromatic notes that contributed most to saffron storage differentiation are spicy, freshly cut grass and vegetable

Quantification of crocetin esters in saffron (Crocus sativus L.) using Raman spectroscopy and chemometrics.

The feasibility of Raman spectroscopy for predicting the content of crocetin esters (crocins), and coloring strength was assessed. 114 samples from Greece, Iran, Italy and Spain were divided into two sets: a calibration set with 49 samples and a validation one with 65 samples. Calibration models for crocetin esters (r 0.97, RMSEC 0.92, RMSEP 0.97, RPD 3.46) and coloring strength (r 0.95, RMSEC 12.2, RMSEP 11.3, RPD 2.59) were built in the spectral region 1700-955 cm-1 using partial least-squares (PLS) regression. The calibration models were validated using cross-validation, leaving one sample out (r 0.97, RMSECV 1.09 for crocetin esters and r 0.93, RMSECV 14.5 for coloring strength). The crocetin esters content as determined by liquid chromatography fluctuated between 18.8 and 31.7 mg/100 g saffron. The corresponding values, as calculated using the Raman method, fluctuated between 19.2 and 32.0 mg/100 g saffron. The coloring strength determined by the reference method ranged from 177.0 to 296.7 units, while with the Raman method the values were between 186.8 and 297.6 units. The results, as compared to the reference methods (liquid chromatography and UV-vis spectrophotometry), show that the proposed methodology gives data with acceptable accuracy. The proposed models can be used as a tool for rapid screening of quality in saffron samples

Quantitative Determination of the Main Phenolic Compounds, Antioxidant Activity, and Toxicity of Aqueous Extracts of Olive Leaves of Greek and Spanish Genotypes

Olive leaves are rich in phenolic compounds, which give them antioxidant properties that are associated with a lower incidence of disease. Therefore, the aim of this work was to determine the phenolic content, antioxidant activity, and toxicity of the aqueous extracts of olive leaves of the main Spanish and Greek cultivated and wild genotypes. For these purposes, ‘Picual’ and ‘Arbequina’ leaves from Spain and ‘Koronoeiki’ and ‘Kalamon’ leaves from Greece were collected, as were wild olive leaves from both countries. The aqueous extracts of these genotypes were analyzed by HPLC-DAD, and the DPPH·, ABTS·+ Folin–Ciocalteu, and Microtox® methods were also used. ‘Picual’ had the highest oleuropein values, followed by wild olive leaves from both countries and ‘Arbequina’. The latter was reflected in the antioxidant activity measured by DPPH· and ABTS·+, which positioned the leaves of ‘Arbequina’, ‘Picual’, and the wild genotypes as having the most antioxidant activity. As expected, these leaves also had the highest total phenol content, as measured by Folin–Ciocalteu. Regarding the inhibition of the bioluminescence of Aliivibrio fischeri of the aqueous leaf extracts measured by Microtox®, the EC5015 ranged between 11.82 and 82.50 mg/mL, demonstrating similar behavior to other herbal infusions

Differentiation of saffron from four countries by multivariate analysis of Mid-infrared spectroscopy

Mid-infrared spectroscopy combined with multivariate analysis has been applied for the discrimination of 250 saffron samples from Greece (40 samples), Iran (87 samples), Italy (60 samples) and Spain (63 samples). The infrared spectra of saffron filament samples and their organic extracts were recorded. Principal component analysis was applied to different spectral regions. Then the principal components were used as variables in discriminant analysis. The best discriminatory approach was achieved in the spectral region 2000–700 cm-1. The spectral region responsible for the differentiation of Italian samples is in the region of carbonyl group around 1746 cm-1. The spectral region at around 1600 cm-1 and the band at 1670 cm-1 are responsible for the differentiation of samples from the remaining countries. From the original grouped cases, 93.6% were correctly classified. The correct classification rates for saffron samples from Greece, Iran, Italy and Spain were 90.0, 89.5, 96.7 and 98.4%, respectively. The combination of infrared spectroscopic technique with multivariate analysis is a rapid and ambient method to discriminate saffron samples in terms of geographical origin

Rapid determination of safranal in the quality control of saffron spice (Crocus sativus L.)

A method to determine safranal content based on non-polar solvent extraction followed by UV\u2013Vis analysis available in the industry for quality control of saffron spice has been studied. Ultrasound-assisted extraction of safranal was carried out and optimised with respect to the solvent: diethyl ether, hexane and chloroform; the time of extraction; and the concentration of saffron in each organic solvent. Best extraction conditions were obtained when 20 g L-1 of saffron was extracted with chloroform for 15 min. Intra-laboratory validation of the optimised conditions and analysis by UV\u2013Vis spectrophotometry showed satisfactory results in linearity, repeatability, intermediate precision and recovery. The limit of detection was 1 mg safranal kg-1 saffron and the limit of quantification was 3 mg safranal kg-1 saffron

Effects of mild temperature conditions during dehydration procedures on saffron quality parameters

BACKGROUND: The dehydration procedure is responsible for saffron sensorial properties: colour, taste and aroma. Changes in the compounds responsible for these characteristics have been studied when dehydration processes at high and low temperature are employed. However, the evolution of these changes at mild temperatures is not available in the current bibliography. In this paper the effect of different mild conditions (18\u201320 \ubaC for 24 h, 40\u201350 \ubaC for 75 min and 55 \ubaC for 75min) applied to 45 saffron samples with the same origin was investigated. RESULTS: Crocetin esters, the compounds responsible for saffron colour, increased their content with no significant differences from other processes when high temperatures (55 \ubaC) were used, thus producing a noticeable increment in saffron colouring capability. Similar behaviour was obtained for picrocrocin, the compound responsible for saffron taste, with higher average content at the highest temperature (55 \ubaC) butwithout significant differences with the inferior conditions (40\u201350 \ubaC). However, more volatile compounds were generated, especially safranal,at higher temperatures, e.g. 55 \ubaC, during the dehydration procedure. CONCLUSIONS: The results found support the idea for employingmild to high temperatures during the dehydration process of saffron

Picrocrocin content and quality categories in different (345) worldwide samples of saffron (Crocus sativus L.)

In this paper, 345 saffron samples were analyzed from different countries to study their picrocrocin content using different analytical techniques. The E1cm1% of 257 nm results from all samples are inflated in comparison by the high-performance liquid chromatography (HPLC) data, because of the interferences with the crocetin ester pool and especially with those with a lower trans/cis relation. A picrocrocin range update is proposed for International Organization for Standardization (ISO) 3632 normative because category III should be incremented up to 50 units, while category II should be incremented up to 60 units. More accurate data are achieved when the \u394Epic measurement is carried out. Consequently, improvements to the ISO method are suggested. Fourier transform (FT)-near-infrared spectrometry analysis has also been carried out, showing excellent results from the calibration with HPLC data. This spectrophotometric technique could be used by saffron enterprises to obtain quick and more accurate data for picrocrocin determination

Effect of Dough-Related Parameters on the Antimold Activity of <i>Wickerhamomyces anomalus</i> Strains and Mold-Free Shelf Life of Bread

The aim of the present study was to assess the antimold capacity of three Wickerhamomyces anomalus strains, both in vitro and in situ, and to identify the responsible volatile organic compounds. For that purpose, two substrates were applied; the former included brain heart infusion broth, adjusted to six initial pH values (3.5, 4.0, 4.5, 5.0, 5.5, 6.0) and supplemented with six different NaCl concentrations (0.0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%), while the latter was a liquid dough, fortified with the six aforementioned NaCl concentrations. After a 24 h incubation at 30 °C, the maximum antimold activity was quantified for all strains at 5120 AU/mL, obtained under different combinations of initial pH value and NaCl concentration. A total of twelve volatile compounds were detected; ethanol, ethyl acetate, isoamyl alcohol and isoamyl acetate were produced by all strains. On the contrary, butanoic acid-ethyl ester, acetic acid-butyl ester, ethyl caprylate, 3-methyl-butanoic acid, 2,4-di-tert-butyl-phenol, benzaldehyde, nonanal and octanal were occasionally produced. All compounds exhibited antimold activity; the lower MIC was observed for 2,4-di-tert-butyl-phenol and benzaldehyde (0.04 and 0.06 μL/mL of headspace, respectively), while the higher MIC was observed for butanoic acid-ethyl ester and ethyl caprylate (5.14 and 6.24 μL/mL of headspace, respectively). The experimental breads made with W. anomalus strains LQC 10353, 10346 and 10360 gained an additional period of 9, 10 and 30 days of mold-free shelf life, compared to the control made by commercially available baker’s yeast. Co-culture of the W. anomalus strains with baker’s yeast did not alter the shelf-life extension, indicating the suitability of these strains as adjunct cultures