Classification of vine-shoots for use as enological additives.

BACKGROUND: Toasted vine shoots have recently been proposed as enological additives with the aim of improving the sensorial profile of wines. However, so far, there is no simple method for classifying vine shoots for this innovative enological practice. In this study, therefore, an enological aptitude classification for toasted vine shoots has been proposed for the first time. Moreover, given the need for quick techniques to be used in wineries to determine the main phenolic compounds of vine shoots, near-infrared (NIR) spectroscopy has been calibrated and validated. RESULTS: By means of a detailed statistical analysis, an enological classification of toasted vine shoots has been proposed based on their total polyphenol index and (+)-catechin, (-)-epicatechin, ellagic acid, and trans-resveratrol. Moreover, the NIR methodology that was developed showed good validation statistics and acceptable accuracy. CONCLUSIONS: This work proposes the first enological toasted vine-shoot classification and it provides a tool for rapid screening, mainly of phenolic compounds, in toasted vine shoots. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Development and validation of an HPLC-DAD method for determination of oleuropein and other bioactive compounds in olive leaf by-products.

BACKGROUND: Oil mills could benefit by preparing their own aqueous extracts from olive leaves. Accordingly, the present study aimed to measure the bioactive compounds richness of such extracts, especially oleuropein. A water-based microwave extraction procedure was developed and a selective and precise high-performance liquid chromatography with diode array detection (HPLC-DAD) method was validated for the determination of oleuropein and others bioactive compounds from olive leaves. RESULTS: The water solubility of oleuropein was determined to be 9.5 g L-1 . The extraction procedure was optimized in terms of power, olive leaf weight/water volume ratio and time of extraction, and the results revealed that 2 mg mL-1 and a microwave irradiation at 800 W for 30 s resulted in the greatest efficiency. Oleuropein was determined by the new validation method, which showed good linearity (r2 = 0.996), precision (% relative standard deviation < 10%), recovery (118.6%), and limits of detection (17.48 mg L-1 ) and quantification (21.54 mg L-1 ). Good correlation (r2 = 0.979) was obtained between oleuropein of the olive leaf extracts determined by HPLC-DAD and by UV-visible spectrophotometry. CONCLUSION: A simple extraction method was developed and validated to obtain aqueous extract from olive leaves by microwave extraction, determining for the first time oleuropein water solubility. Validation of the method showed that oleuropein in olive leaves could be quantified when it is at least 1% of dry weight by means of HPLC-DAD. UV-visible spectrophotometry can be useful in oil mills because it enables the content of oleuropein and other bioactive compounds content to be determined in situ in such leaf aqueous extracts. © 2020 Society of Chemical Industry.

Bioactivity and Bioavailability of the Major Metabolites of Crocus sativus L. Flower.

Crocus sativus L. has been cultivated throughout history to obtain its flowers, whose dried stigmas give rise to the spice known as saffron. Crocetin esters, picrocrocin, and safranal are the main metabolites of this spice, which possess a great bioactivity, although the mechanisms of action and its bioavailability are still to be solved. The rest of the flower is composed by style, tepals, and stamens that have other compounds, such as kaempferol and delphinidin, which have an important antioxidant capacity, and these can be applied in foods, phytopharmaceuticals, and cosmetics. The aim of this work was to provide an updated and critical review of the research on the main compounds of Crocus sativus L. flower, including the adequate analytical methods for their identification and quantification, with a focus on their bioactivity and bioavailability.

The effects of geographical origin and virus infection on the saffron (Crocus sativus L.) quality.

Saffron is appreciated by its colour, taste, and aroma. To examine the effect of abiotic and biotic stress on these main properties, in the span of 2014-2016, saffron stigmas were collected from major different saffron cultivation areas of Iran and saffron quality was estimated. The quality of saffron was assessed by ultraviolet-visible spectroscopy following the ISO3632:2011 standard. However, the composition and concentration of crocetin esters, picrocrocin, safranal, and kaempferols, the most critical compounds determining the properties and quality of saffron can vary with the geographical origin and virus effects, being more accurate High-Performance Liquid Chromatography and Diode Array Detection (HPLC-DAD) methods were used to analyze saffron quality. Using HPLC-DAD we analyzed saffron plants grown at various conditions (considering altitude, temperature, and precipitation/rainfall) and in presence/absence of virus infections; we found that edaphoclimatic and cultivation conditions significantly determine the quality of the spice and the presence of virus modifies the content of its metabolites.

The Microvine, a plant model to study the effect of vine-shoot extract on the accumulation of glycosylated aroma precursors in grapes.

BACKGROUND: The Microvine plant model displays unique reproductive organ behavior and is suitable for grapevine fruit physiological studies, allowing one to undertake studies up to five times more rapidly than the current situation with grapevines. Recently, vine-shoot aqueous extracts, which have an interesting phenolic and aroma composition, have been proposed as viticultural biostimulants, since their post-veraison foliar application to grapevines impacts the wine aroma profile. Using Microvines, the aim of this study was to determine the effect of vine-shoot extract foliar application on 21 stages of grape development. The application was carried out from BBCH 53 (inflorescences clearly visible) to BBCH 85 (softening of berries) to reveal stage-specific responses of the accumulation of glycosylated aroma precursors at BBCH 89 (berries ripe for harvest), the phenological stage selected to study the treatment effect. RESULTS: Microvine use made it possible to carry out 15 sampling time points during 86 days of the experiment, which were established by the cumulative degree days (CDD) parameter. The results confirmed that vine-shoot extract treatment had a positive impact on total glycosylated compounds, especially aglycones such as alcohols, terpenes and C13 -norisoprenoids, with a higher effect when the treatment was applied during ripening. CONCLUSION: Extrapolation of the results to grapevines suggests that vine-shoot extract treatment could modulate the synthesis of grape glycosylated aroma precursors. © 2017 Society of Chemical Industry.

Influence of Diet in Multiple Sclerosis: A Systematic Review.

Nutrition is considered to be a possible factor in the pathogenesis of the neurological disease multiple sclerosis (MS). Nutrition intervention studies suggest that diet may be considered as a complementary treatment to control the progression of the disease; a systematic review of the literature on the influence of diet on MS was therefore conducted. The literature search was conducted by using Medlars Online International Literature (MEDLINE) via PubMed and Scopus. Forty-seven articles met the inclusion criteria. The reviewed articles assessed the relations between macro- and micronutrient intakes and MS incidence. The patients involved used alternative therapies (homeopathy), protocolized diets that included particular foods (herbal products such as grape seed extract, ginseng, blueberries, green tea, etc.), or dietary supplements such as vitamin D, carnitine, melatonin, or coenzyme Q10. Current studies suggest that high serum concentrations of vitamin D, a potent immunomodulator, may decrease the risk of MS and the risk of relapse and new lesions, while improving brain lesions and timed tandem walking. Experimental evidence suggests that serum vitamin D concentration is lower during MS relapses than in remission and is associated with a greater degree of disability [Expanded Disability Status Scale (EDSS) score >3]. The findings suggest that circulating vitamin D concentrations can be considered a biomarker of MS and supplemental vitamin D can be used therapeutically. Other studies point to a negative correlation between serum vitamin B-12 concentrations and EDSS score. Vitamin B-12 has fundamental roles in central nervous system function, especially in the methionine synthase-mediated conversion of homocysteine to methionine, which is essential for DNA and RNA synthesis. Therefore, vitamin B-12 deficiency may lead to an increase in the concentration of homocysteine. Further research is clearly necessary to determine whether treatment with vitamin B-12 supplements delays MS progression.

Accumulation of guaiacol glycoconjugates in fruit, leaves and shoots of Vitis vinifera cv. Monastrell following foliar applications of guaiacol or oak extract to grapevines.

Previous studies have shown that volatile compounds present within a vineyard during the growing season can be absorbed by grapevines, assimilated within grapes, and then released during fermentation to influence the final aroma of wine. For example, the accumulation of volatile phenols in glycoconjugate forms following grapevine exposure to bushfire smoke, and their subsequent release during winemaking. This study investigated the accumulation of guaiacol glycoconjugates in the fruit, shoots and leaves of Monastrell grapevines following foliar applications (at veraison) of either an aqueous solution of guaiacol or an aqueous oak extract. Fruit, shoot and leaf samples were then collected at 3 time points between veraison and maturity, and analysed by gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry, to quantify guaiacol and its glycoconjugates, respectively. Guaiacol glycoconjugates were observed in fruit and leaves in particular, demonstrating glycosylation occurred after grapevine treatment; however, different glycoconjugate profiles were apparent.

Comparative evaluation of an ISO 3632 method and an HPLC-DAD method for safranal quantity determination in saffron.

The aim of this work was a comparison of the ISO 3632 (2011) method and an HPLC-DAD method for safranal quantity determination in saffron. Samples from different origins were analysed by UV-vis according to ISO 3632 (2011) and by HPLC-DAD. Both methods were compared, and there was no correlation between the safranal content obtained by UV-vis and HPLC-DAD. An over-estimation in the UV-vis experiment was observed, which was related to the cis-crocetin esters content, as well as other compounds. The results demonstrated that there was no relationship between ISO quality categories and safranal content using HPLC-DAD. Therefore, HPLC-DAD might be preferable to UV-vis for determining the safranal content and the classification of saffron for commercial purposes. In addition, HPLC-DAD was adequate for determining the three foremost parameters that define the quality of saffron (crocetin esters, picrocrocin and safranal); therefore, this approach could be included in the ISO 3632 method (2011).

Saffron: An Old Medicinal Plant and a Potential Novel Functional Food.

The spice saffron is made from the dried stigmas of the plant Crocus sativus L. The main use of saffron is in cooking, due to its ability to impart colour, flavour and aroma to foods and beverages. However, from time immemorial it has also been considered a medicinal plant because it possesses therapeutic properties, as illustrated in paintings found on the island of Santorini, dated 1627 BC. It is included in Catalogues of Medicinal Plants and in the European Pharmacopoeias, being part of a great number of compounded formulas from the 16th to the 20th centuries. The medicinal and pharmaceutical uses of this plant largely disappeared with the advent of synthetic chemistry-produced drugs. However, in recent years there has been growing interest in demonstrating saffron's already known bioactivity, which is attributed to the main components-crocetin and its glycosidic esters, called crocins, and safranal-and to the synergy between the compounds present in the spice. The objective of this work was to provide an updated and critical review of the research on the therapeutic properties of saffron, including activity on the nervous and cardiovascular systems, in the liver, its antidepressant, anxiolytic and antineoplastic properties, as well as its potential use as a functional food or nutraceutical.

Accumulation of Glycoconjugates of 3-Methyl-4-hydroxyoctanoic Acid in Fruits, Leaves, and Shoots of Vitis vinifera cv. Monastrell following Foliar Applications of Oak Extract or Oak Lactone.

Grapevines are capable of absorbing volatile compounds present in the vineyard during the growing season, and in some cases, volatiles have been found to accumulate in fruits or leaves in glycoconjugate forms, that is, with one or more sugar moieties attached. The presence of oak lactone in wine is usually attributable to oak maturation, but oak lactone has been detected in wines made with fruit from grapevines treated with oak extract or oak lactone. This study investigated the accumulation of glycoconjugates of 3-methyl-4-hydroxyoctanoic acid (i.e., the ring-opened form of oak lactone) in the fruits, leaves, and shoots of Monastrell grapevines following foliar application of either oak extract or oak lactone at approximately 7 days postveraison. Fruits, leaves, and shoots were collected at three different time points, including at maturity. The oak lactone content of fruit was determined by gas chromatography-mass spectrometry, with declining concentrations observed in fruit from grapevines treated with oak lactone with ripening. The concentrations of a ß-d-glucopyranoside of 3-methyl-4-hydroxyoctanoic acid in fruits, leaves, and shoots was determined by liquid chromatography-tandem mass spectrometry, with the highest oak lactone glucoside levels observed in leaves of grapevines treated with oak lactone. A glucose-glucose disaccharide was also tentatively identified. These results demonstrate both ring-opening and glycosylation of oak lactone occurred after experimental treatments were imposed.

Vine-shoot waste aqueous extracts for re-use in agriculture obtained by different extraction techniques: phenolic, volatile, and mineral compounds.

Vine-shoots are an important waste in all viticulture areas that should be re-used with innovative applications. The aim of this work was to produce Airén waste vine-shoot aqueous extracts by four solid-liquid extraction techniques such as conventional solid-liquid extraction (CSLE), solid-liquid dynamic extraction (SLDE-Naviglio), microwave extraction (ME), and pressurized solvent extraction (PSE). Their chemical composition was studied in terms of phenolic, volatile, and mineral compounds. The highest concentrated extracts corresponded to CSLE and SLDE-Naviglio, independent of the conditions tested. The CSLE extracts had the highest flavanols, phenolic acids, and stilbenes contents. The volatile composition, quantified for first time in this work, shows that furanic compounds were the most abundant. All extracts showed an interesting mineral content, which may be assimilated by plants. These results show the agricultural potential of Airén vine-shoot waste aqueous extracts to be used as grape biostimulants and/or foliar fertilizer.

Determination of saffron quality by high-performance liquid chromatography.

The aim of this work was to propose a high-performance liquid chromatography with diode array detection (HPLC-DAD) method for determining the three main compounds responsible for determining the quality of saffron (crocetin esters, picrocrocin, and safranal) by preparing an aqueous extract according to the ISO 3632 standard to solve the difficulty that this standard has for aroma and taste determination by ultraviolet-visible spectroscopy. Toward this aim, laboratory-isolated picrocrocin, a safranal standard with a purity of ≥ 88%, trans-crocetin di(ß-D-gentiobiosyl) ester (trans-4-GG) and trans-crocetin (ß-D-glucosyl)-(ß-D-gentiobiosyl) ester (trans-3-Gg) standards, both with a purity of ≥ 99%, and 50 different saffron spice samples from Italy, Iran, Greece, and Spain were used in the intralaboratory validation of the HPLC method. The analytical method proposed was adequate in terms of linearity, selectivity, sensitivity, and accuracy for determining the three foremost parameters that define the quality of saffron using only a saffron solution prepared according to the ISO 3632 standard.

Antitumor effects of saffron-derived carotenoids in prostate cancer cell models.

Crocus sativus L. extracts (saffron) are rich in carotenoids. Preclinical studies have shown that dietary intake of carotenoids has antitumor effects suggesting their potential preventive and/or therapeutic roles. We have recently reported that saffron (SE) and crocin (CR) exhibit anticancer activity by promoting cell cycle arrest in prostate cancer (PCa) cells. It has also been demonstrated that crocetin esters are produced after SE gastrointestinal digestion by CR hydrolysis. The aim of the present report was to investigate if SE, crocetin (CCT), and CR affected in vivo tumor growth of two aggressive PCa cell lines (PC3 and 22rv1) which were xenografted in male nude mice treated by oral gavage with SE, CR, and CCT. We demonstrated that the antitumor effects of CCT were higher when compared to CR and SE and treatments reverted the epithelial-mesenchymal transdifferentiation (EMT) as attested by the significant reduction of N-cadherin and beta-catenin expression and the increased expression of E-cadherin. Additionally, SE, CR, and CCT inhibited PCa cell invasion and migration through the downmodulation of metalloproteinase and urokinase expression/activity suggesting that these agents may affect metastatic processes. Our findings suggest that CR and CCT may be dietary phytochemicals with potential antitumor effects in biologically aggressive PCa cells.

Cytotoxic effect against 3T3 fibroblasts cells of saffron floral bio-residues extracts.

For every kilogram of saffron spice produced, about 63 kg of floral bio-residues (FB) (tepals, stamens and styles) are thrown away. Extracts of these bio-residues in water (W1), water:HCl (100:1, v/v) (W2), ethanol (E3), ethanol:HCl (100:1, v/v) (E4), dichloromethane (D5) and hexane (H6) were prepared. Their composition in flavonols and anthocyanins, and their effect on cell viability were determined. W1 was the richest in kaempferol 3-sophoroside (30.34 mg/g dry FB) and delphinidin 3,5-diglucoside (15.98 mg/g dry FB). The highest tested concentration (900 µg/ml) of W1, W2, E4, D5 and H6 did not significantly decrease the cell viability. Only E3 at that concentration caused a significant decrease of 38% in the cell viability. Therefore, all extracts studied are not cytotoxic at concentrations lower than 900 µg/ml, and W1 is proposed as the optimal for food applications due to its greater contribution of phenolic compounds.

Preservation of saffron floral bio-residues by hot air convection.

Large amounts of floral bio-residues are wasted in saffron spice production, which need to be stabilized because of how quickly they deteriorate. These bio-residues are rich in phenolic compounds, and the aim of this study was to evaluate the effect of drying temperatures and air flows on their color and phenolic composition. Anthocyanins and flavonols were degraded at 110 and 125°C. The best drying temperatures were 70 and 90°C for maintaining their physicochemical quality. The duration at 70°C was double than that of 90°C. Anthocyanins and flavonols were stable at 70 and 90°C with 2, 4, 6 and 8ms(-1). Dehydrations at 90°C with 2, 4 and 6ms(-1) were the most appropriate, due to a better color and greater similarity to control samples for their flavonols and anthocyanins.

Glycosidic aroma precursors of Syrah and Chardonnay grapes after an oak extract application to the grapevines.

Syrah and Chardonnay grapevines were treated with an oak extract in order to determine the effect on glycosidic aroma precursors. Grapevines were treated at three different timings of the veraison (treatment 1, 2 and 3). Aglycons were obtained by enzymatic hydrolysis, and these were identified and quantified by means of gas chromatography-mass spectrometry (GC-MS). Results suggest that after the applications the majority of compounds from the oak extract were assimilated and stored as glycosidic forms in both cultivars. Also, other compounds not present in the extract were affected, with a different behaviour observed depending on the timing of application and the variety. In general, C6 compounds, alcohols, terpenes, phenols and C13-norisoprenoids in Syrah showed a decrease and in Chardonnay an increase. Thus, this study proved a change in the glycosidic aroma profile in grapes after the oak application, so these treated grapes could produce wines with different aromatic quality.

Increasing the applications of Crocus sativus flowers as natural antioxidants.

UNLABELLED: Large amounts of floral bio-residues (92.6 g per 100 g of flowers) are generated and wasted in the production of saffron (Crocus sativus) spice. Progress in mechanization of saffron crop offer the opportunity to expand the uses of C. sativus flowers, beyond the spice (dried stigmas). The antioxidant potential of flowers of saffron, their separate parts (tepals, stamens, styles, and stigmas) and floral bio-residues were evaluated by 4 in vitro assays: lipid peroxidation, deoxyribose assay, Rancimat test, and Trolox equivalent antioxidant capacity. Phenolic content and crocetin ester composition were also determined. All the samples studied showed to be potential antioxidants. The highest phenolic, flavonoid, and anthocyanin contents were observed in tepals. Stamens showed lower phenolic, flavonoid, and anthocyanin contents than those of whole flowers, tepals, and floral bio-residues. Crocetin esters were not found in tepals or stamens. Stamens exhibited the most potent LOO(•) and OH(•) radicals scavenging activity, being higher than those of food antioxidant propyl gallate. Flowers of saffron, tepals, stamens, styles, and floral bio-residues showed LOO(•), OH(•), and ABTS(•-) radicals scavenging activity, while stigmas showed LOO(•) and ABTS(•-) radicals scavenging activity. All samples studied improved the oxidative stability of sunflower oil in Rancimat test. These antioxidant properties could suggest the application of this floral material as functional ingredients with the subsequent added value. PRACTICAL APPLICATION: Saffron spice, the most valuable spice worldwide, is the dried stigma that only represents 7.4% of Crocus sativus flowers. Other parts of the flowers different to stigmas are discarded. Flower harvest and all the postharvest steps to produce saffron spice are performed manually. Mechanization of flower collection, stigma separation, and dehydration process is a revolution in saffron spice production, which increases the productive capacity making it possible to extend the uses of C. sativus flowers, beyond the production of saffron spice. Flowers possessed high-phenolic content and excellent antioxidant properties that could contribute to their application as functional ingredients.

Effect of oak extract application to Verdejo grapevines on grape and wine aroma.

Volatile compounds from a commercial aqueous oak extract application to white Verdejo grapevines at veraison have been studied. Treated grapes under two types of formulation (25% and 100%) have been analyzed at the optimum maturation time, and winemaking was then subsequently carried out. The volatile compounds were analyzed by stir bar sorptive extraction-gas chromatography-mass spectrometry. The results suggest that after the grapevine treatments, grapes store the volatiles in the form of nonvolatile precursors, and some of the volatiles are released during the winemaking process, especially six months after the alcoholic fermentation. The sensory analysis shows that wines maintain the typical aroma properties of Verdejo wines at the end of fermentation; but after six months, the wine color is greener and more astringent, and, in terms of aroma, it has wooden notes as if the wine has been aged in oak barrels.

Picrocrocin kinetics in aqueous saffron spice extracts (Crocus sativus L.) upon thermal treatment.

The kinetics of picrocrocin degradation in aqueous extracts of saffron upon thermal treatment from 5 to 70 °C have been studied, together with the degradation of purified picrocrocin in water at 100 °C. The best fits to experimental data were found for a second-order kinetics model. Picrocrocin showed high stability with half-life periods (t(1/2)) ranging from >3400 h at 5 °C in saffron extracts to 9 h in the experiments with purified picrocrocin at 100 °C. In saffron extracts, the evolution of the rate constant (k) with temperature showed maximum values at 35 °C, and filtration of the extracts contributed to picrocrocin stability. In the case of purified picrocrocin, the generation of safranal in the first 5 h (yield up to 7.4%) was confirmed. Spectrometric parameters used in saffron quality control (E(1cm)(1%) 257 nm and ΔΕ(pic)) were not appropriate for documenting the evolution of picrocrocin.

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 E1cm 1% 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 deltaEpic 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.