11The antiradical activity, polyphenols, flavonoids and total condensed tannins contents have been determined in the case of seven local 12 edible Brassicaceae, i.e. Italian kale, broccoli, Savoy and white cabbage, cauliflower, green cauliflower and Brussels sprouts. Rapid spec-13 trophotometric methods were applied. The results achieved were compared with the quali-quantitative information obtained by HPLC/ 14 DAD and HPLC/MS. The polyphenolic compounds detected were: kaempferol and quercetin glycosides and hydroxycinnamic esters. 15 The EC 50 values ranged from 81.45 to 917.81 mg sample/mg DPPH Å and the total phenolic content from 4.30 to 13.80 gallic acid equiv-16 alents (mg gallic acid/g sample). The peculiar characteristics of these vegetables can be evaluated and can increase their value as func-17 tional food. 18

Flavonoids and hydroxycinnamic derivatives of turnip tops (Brassica rapa L. subsp. sylvestris L.) were characterized for the first time in four samples from different origins. Turnip tops exhibit a high polyphenols content (ranging from 107 to 191 mg/100 g, fresh weight) and a good antiradical activity, determined with the DPPH • test. After a liquid-liquid extraction and fractionation procedures, most flavonoids (isorhamnetin, kaempferol, and quercetin glycosides) and hydroxycinnamic derivatives were identified by means of HPLC-DAD/MS techniques. Isorhamnetin glycosides were the main flavonoid derivatives, differing from that found in the vegetables belonging to the Brassica oleracea group.

The antiradical activity of dry beans was evaluated in order to assess the validity of this test and to correlate the results with those achieved with the Folin-Ciocalteu method and with a rapid spectrophotometric method for the analysis of total flavonoids. Four landraces (12 samples) of common beans (Phaseolus vulgaris L.), collected in two regions of Italy (Tuscany and Basilicata) in three different years, were analyzed. The EC50 values ranged from 39 to 2810 mg sample/mg 1,1-diphenyl-2-picrylhydrazil radical. The phenolic content of each sample was expressed as gallic acid equivalents; it changed from 1.17 to 4.40 mg/g. The flavonoid content, expressed as mg of (+)-catechin per g of dry seeds, ranged from 0.24 to 1.43 mg/g. The qualiquantitative composition of polyphenols has been also elucidated by means of high-performance liquid chromatography (HPLC)-diode array detection and HPLC/MS. These investigations showed that rapid tests can contribute to assessing the quality of functional food.

Lactuca sativa L. plants (cv. Audran) developed in greenhouse or in open air, were analysed for their polyphenol compounds (caffeic acid derivatives, quercetin and kaempferol glycosides) to verify whether these two different growing environments affected both the qualitative and quantitative phenol patterns. The lettuce extracts from greenhouse and open-air samples were compared and directly analysed by HPLC/DAD, HPLC/MS and HPTLC. All open-air samples had higher flavonol contents than the greenhouse ones. The applied rapid and sensitive HPTLC method could be routinely employed to determine the leaf flavonol content of a large number of lettuce samples. #

Ten genotypes belonging to Lactuca sativa, Cicorium intybus, Plantago coronopus, Eruca sativa, and Diplotaxis tenuifolia and used in fresh mixed salads were investigated for their polyphenol contents. Flavonoids and hydroxycinnamic acids were characterized by high-performance liquid chromatography (HPLC)/diode array detection/mass spectrometry. Quercetin, kaempferol, luteolin, apigenin, and crysoeriol derivatives were identified; hydroxycinnamic acids were all caffeoyl derivatives. The total polyphenol content was obtained through the Folin-Ciocalteu test and from the HPLC data. The amounts ranged between 0.9 and 4.7 mg/g fresh weight. The antiradical activity was determined by the reaction with the stable DPPH* radical. The Fe2+ chelating activity was determined with a spectrophotometric test. From the complex of data, a quite complete picture of the characteristics of the vegetables emerges. A cultivated C. intybus cultivar exhibited the highest polyphenol content, while a wild C. intybus genotype exhibited the highest antiradical activity. In every case, the characteristics of the different salads as functional foods have been pointed out.

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relevance of scientific studies on this subject. Taking into account the reviews published since 2008, a general overlook on the research topics can emphasize the main current fields in which the research is presently developed. The different subjects which may be inferred are: problems in the analytical assays of polyphenols [1][2][3][4][5], polyphenols composition of fruits and vegetables [6][7][8][9][10], the fate of polyphenols in postharvest technology [11, 12], chemistry and biochemistry [13][14][15][16], polyphenols and food [17][18][19][20][21], polyphenols and health [22][23][24][25][26][27][28]. From this short survey which takes into account only partly the last years, the great number and variety of researches on these plants metabolites can be pointed out. There is a lack of reviews on the relations between polyphenols content, fertilization and agriculture practice, with the exception of a recent review on the possibility of differentiating organic practice by means of secondary plant metabolites in carrots [29], and the review of Stefanelli et al. [18] focused on horticulture quality under minimal nitrogen and water supply.The aim of this review is concerned with the relationships between polyphenols content, fertilization and agricultural practice correlated to soil management. Effect of nitrogen and/or potassium fertilizationAs summed up by Nguyen and Niemeyer [30], the carbon/nitrogen balance (CNB) pathways can be taken into account when studying the effect of nitrogen fertilization on phenolic content. Phenylalanine is the rate-limiting precursor for phenylpropanoid synthesis (e.g., lignin, flavonoids and condensed tannins), and at the same time, it is an essential amino acid for protein synthesis. Plant growth is heavily dependent on protein synthesis for the manufacture of photosynthetic, biosynthetic and regulatory enzymes, as well as for structural protein, and phenolic synthesis Abstract The review deals with polyphenol content of vegetables and fruits under different experimental conditions. The effect of fertilizers, mainly nitrogen containing fertilizers, on qualitative and especially quantitative content of the polyphenols mixture, was reviewed. Soil nitrogen affects both anthocyanins and flavonoids content, and generally, a higher polyphenolic content is observed when less nitrogen fertilizer is added to the soil. Also the effect of different agricultural management (conventional, organic, biodynamic, integrate) is reviewed with respect to polyphenols. In this case, a major effect has pointed out in the case of vegetables, while agricultural practice affects in a minimal way fruits polyphenols content. The effect of different management is, however, hardly pointed out, since many environmental factors are involved and affect polyphenols biosynthetic pathway.