Olive oil aromatization with saffron by liquid-liquid extraction.

A new aromatization method for olive oils with saffron aqueous extracts rich in safranal has been developed using liquid-liquid extraction. Four flavoured olive oils were obtained (SO1-SO4). SO1 showed the highest safranal concentration (145.89 mg L-1), followed by SO2 (79.33 mg L-1), SO3 (0.30 mg L-1) and SO4 (0.01 mg L-1). Although flavouring originated a decrease in the quality parameters and the oxidative stability of the oils, even after 7 months of storage, at room and refrigeration temperatures, the oil parameters evaluated were still comparable to those of extra virgin olive oil. Flavored olive oils with less safranal (SO3, SO4) are preferred by consumers.

Effects of Crocetin Esters and Crocetin from Crocus sativus L. on Aortic Contractility in Rat Genetic Hypertension.

BACKGROUND: Endothelial dysfunction, characterized by an enhancement in vasoconstriction, is clearly associated with hypertension. Saffron (Crocus sativus L.) bioactive compounds have been recognized to have hypotensive properties. Recently, we have reported that crocetin exhibits potent vasodilator effects on isolated aortic rings from hypertensive rats. In this work, we have aimed to analyze the anticontractile ability of crocetin or crocetin esters pool (crocins) isolated from saffron. Thus, we have studied the effects of saffron carotenoids on endothelium-dependent and -independent regulation of smooth muscle contractility in genetic hypertension. METHODS: We have measured the isometric responses of aortic segments with or without endothelium obtained from spontaneously hypertensive rats. The effects of carotenoids were studied by assessing the endothelial modulation of phenylephrine-induced contractions (10(-9)-10(-5) M) in the presence or absence of crocetin or crocins. The role of nitric oxide and prostanoids was analyzed by performing the experiments with L-NAME (NG-nitro-l-arginine methyl ester) or indomethacin (both 10(-5) M), respectively. RESULTS: Crocetin, and to a minor extent crocins, diminished the maximum contractility of phenylephrine in intact rings, while crocins, but not crocetin, increased this contractility in de-endothelizated vessels. In the intact vessels, the effect of crocetin on contractility was unaffected by indomethacin but was abolished by L-NAME. However, crocetin but not crocins, lowered the already increased contractility caused by L-NAME. CONCLUSIONS: Saffron compounds, but especially crocetin have endothelium-dependent prorelaxing actions. Crocins have procontractile actions that take place via smooth muscle cell mechanisms. These results suggest that crocetin and crocins activate different mechanisms involved in the vasoconstriction pathway in hypertension.

Crocetin, a carotenoid derived from saffron (Crocus sativus L.), improves acetylcholine-induced vascular relaxation in hypertension.

BACKGROUND: Hypertension is associated with endothelial dysfunction characterized by decreased vasorelaxation. Crocetin, a bioactive compound of saffron, exhibits favorable cardiovascular properties. We analyze the vasomodulatory effects of crocetin in hypertension. METHODS: Myographical experiments were performed to compare the relaxation induced by acetylcholine (ACH) on aortic rings from normotensive (Wistar) and hypertensive (SHR) rats, incubated with or without crocetin or saffron extract and L-NAME or indomethacin. Extracts were also assayed in deendothelialized rings. UV-vis spectrophotometry and HPLC-DAD were used to characterize and quantify the saffron used. RESULTS: Crocetin enhanced the ACH relaxations in aorta from hypertensive (strongly) and normotensive rats (weakly). Saffron extract did not modify this. Crocetin plus L-NAME abolished the relaxant response in SHR but not in Wistar aorta. Crocetin plus indomethacin did not modify the indomethacin response in either SHR or Wistar aorta. Crocetin in rubbed segments did not modify the ACH responses. In contrast, saffron increased this response in rubbed segments from SHR but not Wistar rats. CONCLUSION: Crocetin exerts healthy vasomodulatory effects in hypertension, strongly improving endothelium-dependent ACH relaxations via endothelial nitric oxide but not the cyclooxygenase pathway. This work proposes that crocetin supplements are a possible complement in the therapy of hypertension.

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.

Fast methodology of analysing major steviol glycosides from Stevia rebaudiana leaves.

The aim of this work is to propose an HPLC method for analysing major steviol glycosides as well as to optimise the extraction and clarification conditions for obtaining these compounds. Toward this aim, standards of stevioside and rebaudioside A with purities ⩾99.0%, commercial samples from different companies and Stevia rebaudiana Bertoni leaves from Paraguay supplied by Insobol, S.L., were used. The analytical method proposed is adequate in terms of selectivity, sensitivity and accuracy. Optimum extraction conditions and adequate clarification conditions have been set. Moreover, this methodology is safe and eco-friendly, as we use only water for extraction and do not use solid-phase extraction, which requires solvents that are banned in the food industry to condition the cartridge and elute the steviol glycosides. In addition, this methodology consumes little time as leaves are not ground and the filtration is faster, and the peak resolution is better as we used an HPLC method with gradient elution.

Flavonoid Determination in the Quality Control of Floral Bioresidues from Crocus sativus L.

A high-performance liquid chromatography with photodiode array detection method (HPLC-DAD) was validated for the analysis of floral bioresidues obtained in saffron spice production by using three different solvent mixtures [water/hydrochloric acid (HCl) (100:1, v/v), water/acetonitrile/trifluoroacetic acid (47:50:3, v/v/v), and water/acetonitrile/HCl (50:50:1, v/v/v)]. Fifteen phenolic compounds were tentatively identified, kaempferol 3-O-sophoroside and delphinidin 3,5-di-O-glucoside being the main ones. The extracts showed very different phenolic profiles obtained by HPLC-DAD coupled with electrospray ionization mass spectrometry (ESI-MSn), and several experiments were carried out to explain this. The use of acetonitrile as solvent causes the chromatographic splitting of the peak of the delphinidin 3,5-di-O-glucoside into two peaks. Results obtained in this paper show that the extract prepared with water/HCl (100:1, v/v) would be the best suited for determining phenolic compounds in the quality control of the floral bioresidues from Crocus sativus L.

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.

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.