The phenolic composition in walnut husks of the Slovenian cultivar Elit, which is a basic material for the traditional making of walnut liqueur, was investigated by HPLC with a PDA detector. Four ...different samplings of green husks were performed on different dates in order to compare the contents of phenolic compounds. The 2nd sampling coincided with the picking time of walnut fruits intended for the making of liqueur. Phenolic composition of walnut liqueur was investigated as well. Thirteen phenolic compounds were identified in walnut husks: chlorogenic acid, caffeic acid, ferulic acid, sinapic acid, gallic acid, ellagic acid, protocatechuic acid, syringic acid, vanillic acid, catechin, epicatechin, myricetin, and juglone. In walnut liqueur, 1,4-naphthoquinone was also identified. The major phenolic in the husks was juglone with the highest content in the 2nd sampling; its content in walnut liqueur was low. The concentrations of individual phenolics in the liqueur were quite low compared with the contents in the green husks, due to the traditional way of making the liqueur.
► Color changes of rose flowers due to prohexadione-Ca application. ► Decrease in individual and total anthocyanin content levels. ► Phase-dependant effect of prohexadione-Ca foliar application. ► ...Temporal effect on color and phenolic composition.
The effect of foliar application of prohexadione-calcium (ProCa) on the expression of color and the content of secondary metabolites was observed in two rose cultivars: an orange-red cultivar ‘KORcrisett’ and a dark red cultivar ‘KORikis’. The study aims to describe the induced accumulation of specific flavanones in rose by ProCa sprayings and the effects on the content levels of major flavonoids and anthocyanins in rose petals important for their ornamental value. Plants were sprayed once with 300ppm Regalis® solution in bi-distilled water and the control plants with bi-distilled water only. Color parameters were colorimetrically evaluated, and individual phenolic compounds were identified with the use of HPLC–MS. A significant visual change in red petal coloration was observed and recorded as a decline of the color parameter a* after the application of Regalis® on day 9 and particularly on day 15. Similarly, lightness (L*) increased and chroma (C) decreased in both analyzed cultivars as expected in paler petals. The content of major anthocyanins in rose petals, cyanidin-3,5-di-glucoside, pelargonidin-3,5-di-glucoside, cyanidin-3-glucoside, pelargonidin-3-glucoside and peonidin-3-glucoside, was drastically reduced after Regalis® application in both analyzed roses. Also, the content of quercetin and kaempferol compounds generally decreased to the point of detection; however, newly formed eriodictyol was identified in the petals of the treated ‘KORikis’ flowers 15 days after application and in the petals of ‘KORcrisett’ flowers 9 and 15 days after application. Foliar application of ProCa thus altered visual properties of red rose flowers, which has been directly correlated to the content of anthocyanins, and also induced the formation of 3-deoxyflavonoids, normally not present in roses under natural conditions. Different shades of red and light pink flowers were present on a single rose plant which can potentially present an interesting marketable product for the consumers.
The phenolic profile of healthy and infected raspberry canes was investigated in three raspberry cultivars: Autumn Bliss, Himbo Top and Polka. The content of total phenols and tannins was determined ...using spectrophotometric methods, whilst individual phenolic acids, flavan‐3‐ols, ellagic acid derivatives and glycosides of quercetin were analysed using HPLC/MS analysis. The content of secondary metabolites varied considerably among the analysed raspberry cultivars. Moreover, Didymella applanata and Leptosphaeria coniothyrium infection significantly altered the metabolism of phenolic compounds. Flavanols represented the greatest share of all identified phenolics in raspberry canes (90%), followed by glycosides of quercetin (6%), derivatives of ellagic acid (3%) and traces of hydroxycinnamic acid derivatives. Spur and cane blight diseases caused an increase of flavan‐3‐ols and tannins but the levels of hydroxycinnamic acid derivatives, conjugates of ellagic acid and quercetin glycosides were significantly reduced. Cultivars Himbo Top and Polka contained higher levels of hydroxycinnamic acid and ellagic acid derivatives in healthy and infected canes compared to cv. Autumn Bliss. Cultivar Polka also contained the highest level of flavanols and tannins. However, despite high levels of flavanols and total phenols measured in cv. Polka, the canes were highly diseased following infection with D. applanata and L. coniothyrium. The results of the study provide evidence that the level of phenolic compounds in the canes could be causally linked to the differences in disease susceptibility.
The research was performed on healthy green walnut fruits and on fruits infected with
Xanthomonas arboricola pv.
juglandis (
Xaj). Fruits of cultivars ‘Cisco’, ‘Sampion’, ‘Fernette’, ‘Seiferdorfer’ ...and genotypes ‘Zdole’ and ‘Erjavec’ were sampled at phenophases Gf, Gf + 30 and Gf + 45. In the green husk tissue the content level of gallic acid, three hydroxycinnamic acids, catechin and five quercetin glycosides was determined with the high-performance liquid chromatograph coupled with mass spectrometer (HPLC-MS). During the growing season, the content of phenolic compounds decreased and was related to the physiological stage of the fruits and cultivar analyzed. The cumulative content of ten determined polyphenols in healthy walnuts was cultivar dependent, and weakly correlated to the blight susceptibility observed in the orchard. In comparison to healthy husk tissue, the infected husks contained up to 5 fold more hydroxycinnamic acids, up to 3 fold more gallic acid, up to 4.3 fold more quercetins and up to 23 fold more catechin. The cultivars ‘Cisco’ and ‘Zdole’ showed the strongest post-infectional accumulation of the phenolic compounds. An essential influence of quercetin-3-
O-rhamnoside, as well as 4-
O-
p-coumaroylquinic, 3-
O-caffeoylquinic and 3-
O-
p-coumaroylquinic acid on the walnut blight severity was confirmed and points out to the role of these phenolic compounds in the walnut resistance against bacterial blight.
► Defense mechanisms and reactions of walnut fruits against bacterial attack. ► Polyphenolic patterns in healthy and
Xaj infected young fruit tissue. ► Relationships between the levels of phenolics in green walnuts and
Xaj resistance. ► Researching the plant–pathogen interactions. ► Identifying walnut cultivars with potential built in resistance on molecular level.
The correlation between the anthocyanin concentrations of seven
Acer palmatum Thunb. cultivars and the chromaticity values
a*,
b*,
a*/
b* ratio,
h° and
L* was investigated. According to the position ...of leaves on the branch terminal, middle and base sample leaves were analyzed and the positional effect on the level of the major anthocyanin was estimated. Leaf color was measured with a portable colorimeter and individual anthocyanins were detected with the use of HPLC–MS. Cyanidin-3-glucoside was present in all senescing leaves of
Acer cultivars and its content decreased from terminal to base position. Cyanidin-3-rutinoside was identified in lower concentrations in the leaves of all cultivars. Multiple variable analysis was calculated for each of the tristimulus values and two major anthocyanins (cyanidin-3-glucoside, cyanidin-3-rutinoside) in senescing leaves of ornamental
Acer cultivars. Correlations were detected between the major anthocyanin (cyanidin-3-glucoside) in analyzed
Acer cultivars and all chromaticity parameters. The highest correlation coefficient (0.94) was observed between cyanidin-3-glucoside and
a*/
b* ratio in cultivar ‘Bloodgood’ and lowest (0.54) between cyanidin-3-glucoside and
a* in
Acer palmatum Thunb. The correlation between cyanidin-3-rutinoside and chromaticity parameters was not detected in all
Acer cultivars, additionally correlation coefficients and statistical significance were much lower. The expression of red color in both senescing leaves and in all-year-red cultivars can be tightly linked with the content level of cyanidin-3-glucoside; the second major anthocyanin does not contribute much to the red leaf color.
Phenolic compounds were measured in leaf tissues of apple cvs Jonagold and Golden Delicious, healthy and infected by Venturia inaequalis. Leaves were sampled from May to September 2005 and analyzed ...by high performance liquid chromatography. Hydroxycinnamic acids detected were chlorogenic, caffeic, ferulic and p-coumaric. In addition, the presence was ascertained of the dihydrochalcone phloridzin and the flavonoids epicatechin, catechin, rutin and quercitrin. Total phenolics were determined with the Folin-Ciocalteu method. Infection by V. inequalis caused an accumulation of phenolic compounds in infected leaves with a 1.4 to 6.2-fold increase of flavonols, a 2 to 6-fold increase of chlorogenic acid and a 1.4 to 2.4-fold increase of the Folin-Ciocalteu values.
Phenolic compounds in apple leaves after infection with apple scab Mikulic Petkovsek, M., University of Ljubljana (Slovenia). Agronomy Dept; Slatnar, A., University of Ljubljana (Slovenia). Agronomy Dept; Stampar, F., University of Ljubljana (Slovenia). Agronomy Dept ...
Biologia plantarum,
12/2011, Letnik:
55, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Leaves of the scab-susceptible apple cultivar Golden Delicious were harvested from May to August 2008 and 2009. Some leaves were healthy and some infected with Venturia inaequalis. The phenolic ...compounds were analysed in healthy leaves, infected leaves and in the scab spot tissue. In comparison with healthy leaves, the infected leaves showed higher concentrations of hydroxycinnamic acid, flavanols and phloridzin, and lower concentrations of procyanidins, quercetins and phloretin. The total amount of phenolic compounds in the infected tissue was 10 to 20 % higher than in the healthy leaves. Accumulation of phenolic compounds is a post-infection response.
Sugars and organic acids in the fruit of two cultivars and three selections of black elderberry (
Sambucus nigra L.): ‘Haschberg’, ‘Rubini’, ‘Selection 13’, ‘Selection 14’ and ‘Selection 25’ were ...quantified. The anthocyanin as well as quercetin profiles of this plant material were also established by the use of HPLC/MS. Significant differences in the concentration of sugars and organic acids were detected between the widely spread cultivar ‘Haschberg’ and all other cultivars/selections; ‘Haschberg’ was the richest in organic acids (6.38
g
kg
−1
FW), and it contained the least sugar (68.5
g
kg
−1
FW). The following major cyanidin based anthocyanins were identified in the fruit of black elderberry: cyanidin 3-sambubioside-5-glucoside, cyanidin 3,5-diglucoside, cyanidin 3-sambubioside, cyanidin 3-glucoside and cyanidin 3-rutinoside. The most abundant anthocyanin in elderberry fruit was cyanidin 3-sambubioside, which accounted for more than half of all anthocyanins identified in the berries. The ‘Rubini’ cultivar had the highest amount of the anthocyanins identified (1265
mg/100
g
FW) and the lowest amount was measured in berries of the ‘Selection 14’ (603
mg/100
g
FW). The ‘Haschberg’ cultivar contained a relatively low amount of anthocyanins in ripe berries (737
mg/100
g
FW). From the quercetin group, quercetin, quercetin 3-rutinoside and quercetin 3-glucoside were identified; the latter prevailing in black elderberry fruit. The cultivar with the highest amount of total quercetins was ‘Selection 25’ (73.4
mg/100
g
FW), while the ‘Haschberg’ cultivar contained average amounts of quercetins (61.3
mg/100
g
FW). The chemical composition of the ‘Haschberg’ cultivar, the most commonly planted, conforms to the standards for sugars, anthocyanins and quercetins and exceeds them in the content levels of organic acids, the most important parameter in fruit processing.
The study was performed on apple trees, 'Golden Delicious' cv., which is a scab-susceptible cultivar. The phenolic content of apple fruit was determined in different parts of the peel. The phenolic ...compounds were analysed in the scab spot, in the tissue around the spot and in the healthy tissue. We determined the concentration of various phenolic compounds and related enzyme activities. Infection with the Venturia inaequalis fungus enhanced the metabolism of phenolic compounds at the scab spot, around the spot and in healthy peel. Compared with the healthy tissue and the tissue around the spot, the scab spot showed higher enzyme activity for all tested enzymes, except for dihydrochalcone 2′-O-glucosyltransferase, which had lower activity in the scab spot. In comparison to the healthy peel, the scab spot showed up to 3.4 times more hydroxycinnamic acids, up to 1.1 times more dihydrochalcones and up to 1.4 times more flavan-3-ols. In contrast, the healthy peel showed up to 1.6 times more flavonols than the scab spot.
Phenolics are an important constituent of fruit quality because of their contribution to the taste, colour and nutritional properties of fruit. We have tried to evaluate the phenolic profile of fig ...fruit, since only limited information on that topic is available in the literature. With the HPLC-PDA system, we have identified the following phenolics: gallic acid, chlorogenic acid, syringic acid, (+)-catechin, (−)-epicatechin and rutin. Phenolics were extracted from three different fig cultivars that are commonly grown in Slovenia’s coastal region. These cultivars were ‘Škofjotka’ (‘Zuccherina’) a white type fruit, ‘Črna petrovka’ and ‘Miljska figa’, both dark type fruit. The fruit from the first and the second crop were collected and compared. In general, fruit from the second crop contained higher values of phenolics than fruit from the first crop. The analysed phenolics present at the highest content were rutin (up to 28.7
mg per 100
g FW), followed by (+)-catechin (up to 4.03
mg per 100
g FW), chlorogenic acid (up to 1.71
mg per 100
g FW), (−)-epicatechin (up to 0.97
mg per 100
g FW), gallic acid (up to 0.38
mg per 100
g FW) and, finally, syringic acid (up to 0.10
mg per 100
g FW). Both cultivars with dark fruit exhibited a higher total level of analysed phenolics, in comparison to the white fruit cultivar ‘Škofjotka’. The amounts measured are comparable to those of other fruits grown in this region. The amounts of rutin in particular are quite high and comparable to apples, for example. As a typical, seasonal fresh fruit, figs can be an important constituent of the regional diet.
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