An update procedure for an effective and simultaneous extraction of sesquiterpene lactones and phenolics from chicory

A new method for recovering and purifying sesquiterpene lactones (SLs) and optimise the solvent system for their extraction from freeze-dried chicory leaves was studied. Catalogna (leafy chicory) and Head Radicchio types were used as test samples. Solid phase extraction (SPE) employing silica-based cartridges allowed a fast and straightforward purification of SL from interfering phenolics, before HPLC determination. Under these conditions, SL were eluted during loading and washing steps whereas polar phenolic compounds were retained on silica stationary phase. Hydrophilic mixtures methanol/water acidified by small percentages of formic acid led to consistently higher SL recoveries in comparison to organic solvents and enabled the simultaneous extraction of phenolics. Phenolic recovery in crude extracts was assessed at levels higher than 95% for both Catalogna and Head Radicchio. Total, free and bound SL amounts detected in extract obtained by 2% (v/v) formic acid in methanol/water 4/1 (v/v) were 2223.4, 778.5 and 1444.9 mg/kg of dried product in Catalogna, and 401.2, 105.1 and 296.0 in Head Radicchio. In both cases, recoveries were consistently higher than those obtained with methanol alone

Evaluation of glucosinolates and phenolics in rocket salad (Eruca sativa and Diplotaxis tenuifolia) germplasm

Salad crops of the Brassicaceae family, such as Diplotaxis tenuifolia and Eruca vesicaria, commonly referred to as \u201crocket salads\u201d, attracted considerable interest as culinary vegetables, for their strong flavour and the content of putative health-promoting compounds. Among these, glucosinolates and phenolics are well-known phytochemicals with an important role also in determining the characteristic flavour of these species. These two classes of components are therefore interesting for the evaluation of qualitative characters of germplasm of these two genera Within a program aimed at evaluating genetic resources of leafy vegetables, thirty-two Eruca and five Diplotaxis accessions, supplied from the IPK Genebank, Gatersleben, were studied by RP-HPLC-ESI-MS, in order to analyse their different polyphenols and glucosinolates profile. Glucosinolate profiles of the thirty-seven accessions were very similar, irrespective of the species, and ten desulpho(DS)-glucosinolates were detected in all extracts. Total GLS content ranged from 756 to 3031.1 mg/kg d.w. and the more abundant components were DS-glucoraphanin, DS-glucoerucin and the dimeric form of DS-glucosativin. Ample variability of phenolic profiles of D. tenuifolia and E. sativa was detected, corresponding to a prevalence of quercetin and kaempferol derivatives, respectively. The Eruca accessions exhibited very ample range of total flavonoid content, from 9.99 to 31.39 g/kg d.w., whereas Diplotaxis accessions ranged between 4.68 and 19.81 g/kg d.w. Differently to Diplotaxis, all the Eruca samples had kaempferol-3,4-diglucoside as the main flavonoid and it should be possible to identify this compound as a marker for the Eruca species. A principal component analysis highlighted the clear separation of the two genera on the basis of flavonoid profile, also revealing further, within-genus variability due to the association of specific components

\u201cRelating rocket salad (Diplotaxis and Eruca spp.) glucosinolate and sensory attributes\u201d

Glucosinolates are an important group of sulfur-containing metabolites, typical of the Brassicaceae family, presently highly valued for putative anti-carcinogenic properties (1). Glucosinolates and their breakdown products (isothiocyanates, thiocyanates and nitriles) are responsible of the sensory properties of the Brassica vegetables, with also potential adverse effects on acceptance, at high concentrations. By consequence, breeding of vegetable crops was often addressed at lowering their content (2), with potential contrast between health promoting and sensory properties. Eruca sativa L. (cultivated rocket) and Diplotaxis tenuifolia L. (wild rocket) are highly. Previous investigation on several Diplotaxis and Eruca species, with ample range of glucosinolate appreciated vegetables, characterised by peculiar spicy flavour and pungency, in relation to their glucosinolate content and composition, indicated a negative relation between glucosinolate content and acceptance (3). The aim of this study was to examine typical cultivated material for sensory and analytical characters. Preliminarily, a vocabulary and a simple sensory profile for rocket salad evaluation were developed. Nine assessors were trained for sensory evaluation of fresh samples, in order to develop descriptive terms for the aroma and flavor attributes, and design an appropriate record sheet. After that, the sensory attributes of thirty-seven Eruca and Diplotaxis accessions of different geographic origin were evaluated. All samples were analyzed for total and individual glucosinolate content by high performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS). Within the relatively limited range of glucosinolate content and composition of this cultivated material, no adverse effect of glucosinolates on acceptance was detected. On the contrary, there was some evidence of a positive relation between glucosinolate content and pungency, also related to typical rocket salad flavour. Therefore, no possible adverse effect of high glucosinolates on intake and health promoting properties was brought out. Potential high value types for breeding were also individuated

The agronomic techniques as determinants of the phenolic content and the biological antioxidant effect of palm-tree kale

The content of phytochemicals in vegetables is strongly affected by genetic, agronomic, and environmental factors, and by transportation and storage conditions, potentially affecting the sensory and putative health-promoting properties. In this study the impact of different agricultural techniques on the phenolics content and antioxidant activity of extracts from a traditional Italian kale landrace, called palm-tree kale (Brassica oleracea L., ssp. acephala DC, var. sabellica L.) was evaluated. Furthermore, the antioxidant effects of the different extracts were assessed in a biological system using primary cultures of neonatal rat cardiomyocytes. The final aim was to evidence whether and how the agronomic practices can affect the antioxidant properties of kale not only in vitro but also in cells. Results herein reported underline the influence of the crop production strategies in establishing the potential health benefits of a vegetable. This research approach could be useful for the selection of production techniques that are able to provide edible vegetables with higher functional activity, and evidences the need to study the food domain as a whole with the nutrition domain, and to integrate all results in order to have an overall \u201cfoodomics\u201d vision allowing the improvement of health and well-being

Black Sea area traditional foods as a new, valuable source of antioxidant polyphenols.

Rationale and objectives. The antioxidant capacity of many commonly consumed fruits and vegetables is well-documented. Many traditional foods from the Black Sea area (BSA) have plant components as main ingredients; nevertheless their antioxidant properties are not yet well characterized. In the BaSeFood project, we have tested the antioxidant capacity, and evaluated the polyphenol content of more than 30 traditional foods ofthe BSA, generally not yet known by western European consumers. Materials and methods. Traditional dishes were prepared in different Countries of the BSA (Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine) by local Partners, according to the typical recipes and according to the seasonal availability of plant ingredients. After preparation, foods were sent to the University of Bologna for further analysis. The samples were prepared using a water/ethanol extraction procedure. The extracts were examined for antioxidant capacity and polyphenol content. Results. Overall, the antioxidant capacity and polyphenol content of analyzed BSA traditional foods are very relevant with respect to other vegetable foods and beverages commonly considered rich in bioactive compounds. Some foods, in particular, deserve attention in the light of their very high antioxidant potential. Conclusions. For the first time, the antioxidant properties and the phenolic compounds of traditional foods of the BSA were studied. Although these foods are largely consumed with the daily diet in individuai Black Sea area countries, less is known about their potential health benefits. Our data, evidencing foods with the highest antioxidant capacity, represent the first step for further researches on their health effects. The nutritional revaluation of traditional foods will be interesting for both consumers, that can discover or rediscover typical dishes, and food processors, that can exploit these scientific data to implement and optimise production scheme

Salvia officinalis L. essential oil and carnosic acid analysis by means of NIR spectroscopy

This paper reports the results of a research aimed at investigating the applicability of the NIRS technique to the quantitative determination of sage quality traits, such as the content of carnosic acid, essential oil content and composition. 143 samples were analysed by means of two NIR spectrometers (a FOSS dispersive spectrometer and a mobile ZEISS spectrometer equipped with a photo diode detector), in comparison with a reference method, based on solvent extraction followed by gas-chromatography (essential oil), or liquid chromatography (carnosic acid). Reference essential oil content ranged form 8.6 to 31.3 ml kg-1 d.m., with α- and β-thujone, camphor and 1,8-cineole as main components, while carnosic acid content was 8.6-39.9 g kg-1 d.m. After spectra correction and wavelength selection, the application of modified partial least square regression (MPLS) allowed good NIR calibration for the analysis of carnosic acid and essential oil content and composition

Determination of flavonoids in Eruca and Diplotaxis rocket salad species: MEKC-DAD method establishment and comparison with HPLC-DAD-MS

The phenolic compounds in ten rocket salad samples were determined in this study using micellar electrokinetic chromatography (MEKC). A detailed method optimisation plan was performed to separate the phenols in rocket salad with the following four separation parameters: buffer concentration, buffer pH, applied voltage and temperature. The best results in terms of peak resolution and reproducibility among separations were obtained with a MEKC running buffer (pH 9.0) composed of 40 mM sodium tetraborate and 15 mM SDS. Using this new MEKC method, it was possible to separate the flavonoids in less than 5 min. The results obtained by MEKC analysis were compared with the data obtained by high-performance liquid chromatography (HPLC) coupled with DAD and MS detectors. The polyphenol study by HPLC-DAD-MS allowed the identification of two different classes of compounds. Quercetin and kaempferol derivatives were determined in the Diplotaxis and Eruca species, respectively. A positive correlation of phenolic compounds identified by MEKC and HPLC was found

Cold-storage effects on strawberry fruit quality traits and bioactive compounds

The results of a three-year trial designed to determine cold-storage effects on the stability of quality traits and bioactive compounds of ripe strawberry fruit indicate that soluble solids, sugars, acids and skin colour scored higher at harvest than after storage. Of the health-promoting compounds, storage affected only total polyphenols, leaving vitamin C, TAC and total anthocyanins without significant alterations