Copigmentation Effect Research Articles

Anthocyanins and chlorogenic acid copigmentation - influence on the colour of strawberry and chokeberry juices

The effect of copigmentation of chlorogenic acid with anthocyanins in strawberry and chokeberry juices was investigated. It was found that chlorogenic acid, at concentrations greater than that of anthocyanins, enhanced the colour intensity of these juices. The maximum copigmentation effect in both juices was observed at pH 3.4. In the investigated range of the copigment/pigment ratio, i.e. 1∶1 to 50∶1, absorbance increased (ΔA) linearly with copigment content, ΔA/g chlorogenic acid was greater in chokeberry than in strawberry juices. In solutions of purified pigments of these fruits, smaller copigmentation effects were observed than in juices under the same conditions, which indicates the participation of natural copigments present in fruits in the copigmentation process.

Formation of anthocyanin ion-pairs. A co-pigmentation effect

Download options Please wait... Article information DOI https://doi.org/10.1039/P29940000775 Article type Paper Download Citation J. Chem. Soc., Perkin Trans. 2, 1994, 775-778 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Formation of anthocyanin ion-pairs. A co-pigmentation effect P. Figueiredo and F. Pina, J. Chem. Soc., Perkin Trans. 2, 1994, 775 DOI: 10.1039/P29940000775 To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Search articles by author Paulo Figueiredo Fernando Pina

Isolation of a new flavonol glycoside and its effects on the blue color of seed coats ofOphiopogon jaburan

From the blue seed coats ofOphiopogon jaburan, a new flavonol glycoside was isolated as needles and determined to be kaempferol 3-O-β-d-galactoside-4′-O-β-d-glucoside (OK-2) by UV and NMR spectral analyses. OK-2 and kaempfrol 3, 4′-di-O-β-d-glucoside (OK-1), which was detected previously, in the blue seed coat were present in a molar ratio of about 13:7. OK-2 was newly found as a factor causing the blueing effects on ophionin which is a main anthocyanin in the blue seed coats. The mixture of 4.8×10−3 M OK-2 and 2.5×10−3 M ophionin in Mcllvaine's buffer solution (pH 5.6) showed stable blue color, and the absorption spectrum of the mixture showed two absorption peaks and a shoulder in visible reasion, coinciding with that of the fresh blue seed coat. The effect of ophionin and OK-2 co-pigmentation on the blue color of seed coat ofO. jaburan was discussed.

Effect of Anthocyanin, Flavonol Co-Pigmentation and pH on the Color of the Berries of Ampelopsis brevipedunculata

Summary Four anthocyanins and two flavonol glycosides were identified using chromatographic and spectrophotometric techniques in the epicarp of the berries of Ampelopsis brevipedunculata . The anthocyanins were malvidin 3- O -rhamnoside-5- O -glucoside, petunidin 3- O -rhamnoside-5- O -glucoside, delphinidin 3- O -rhamnoside-5- O -glucoside and malvidin 3- O -glucoside-5- O -glucoside, in the ratio of approximately 5.6:1:2:1.5. Quercetin 3- O -rhamnoside (quercitrin) and myricetin 3- O -rhamnoside (myricitrin) were the major flavonols present, and their ratio was approximately 1:0.8. The color of berries changed from green via reddish-purple to bluish-purple to blue as maturation proceeded, and then finally the the color faded. Concurrently with the color changes, the pH of the berries increased from 4.8 (green) to 6.5 (blue). The bluish-purple berries had the highest content of anthocyanin (0.26 mg · g −1 fr.wt.). At the same stage, the quercitrin and myricitrin contents were 0.62 and 0.55 mg · g −1 fr.wt. respectively, and the pH of berries was 5.8. A visible absorption spectrum of the intact epicarp of the bluish-purple berries was simulated with a solution of anthocyanin and flavonols at the same molarity and pH as those of the berries. When the pH (5.8) of the solution, which gave a fairly stable bluish-purple color, was increased to 6.5, the color changed to blue. This indicated that the change of berry color from reddish-purple to blue was related to the pH of the tissue and that the berry color was due to the occurrence of anthocyanin flavonol co-pigmentation.

Changes of Petal Colors during Senescence in Hibiscus syriacus

The blueing effect of purplish petals during senescence in Hibiscus syriacus L. was investigated. Absorption spectra of old petals of purple flowers always produced small shoulders at 640 nm. Anthocyanin content was decreased in old petals, while flavone content was not changed. Resulting increased flavone/anthocyanin ratio enhanced the copigmentation effect. This effect was further accelerated by the increase of cell sap pH.

Phlox の花色に関する研究 (第2報)

The F2 plants of Phlox drummondii raised from the cross 38(violet)×26(white) and 38×39(oriental red) were classified in 10 visible colors and in 7 chromatogram types.As to anthocyanidin, in F2 plants from 38×39, cyanidin- malvidin- delphinidin production was incompletely dominant to pelargonidin production. And in 38×26, the white type was recessive to the colored.For glycosylation, 3:5-glycoside type was dominant to 3-glycoside type.As for the plants of which the chromatogram type was C, D, E and F, the same composition of anthocyanins exhibited the various colors and this phenomenon was assumed to be mainly due to co-pigmentation, because the deepening in blueness was in proportion to the increasing in the F/A ratio.In order to evaluate the effect of co-pigmentation of malvidin 3:5-diglucoside with luteolin 5:7-xyloside-glucoside in vitro, both pigments were mixed in various proportions. And it was confirmed with the absorption spectra of the mixtures that the absorption maxima of the mixtures shifted to longer wave-length in the visible region, as increasing of the concentration of luteolin glycoside, but in the ultraviolet region the absorption of the mixtures decreased as compared with that of luteolin glycoside.

Co-pigmentation effect of quercetin glycosides on absorption characteristics of cyanidin glycosides and color of Red Wing azalea

A quercetin 5-methyl ether and five quercetin glycosides were isolated from flowers of Red Wing azalea 1 but were found only in trace amounts in an orange sport of this cultivar. The anthocyanins (cyanidin glycosides) extracted from the orange and red flowers were identical, even though the absorption spectra of the intact cells differed. The absorption spectrum of the orange sport was simulated with a 10 −3 M aqueous solution of cyanidin 3,5-diglucoside at the pH of the tissue, 2·8. The absorption spectrum of Red Wing was matched with cyanidin 3,5-diglucoside at the same concentration and pH, co-pigmented with the 3-rhamnoside or galactoside of quercetin.

Flower color in Fuchsia cultivars

The color of the petals of two cultivars of Fuchsia which exhibit a color change with age was studied with respect to the pigments present and the pH of the cell sap at various stages of development. In both varieties, malvidin 3,5-diglucoside appeared to be the dominant pigment, with peonidin 3,5-diglucoside as a minor component. There appeared to be no change in the pigments themselves with age, although the color ranged from a blue in young flowers to a magenta in old flowers. This color change was correlated with a drop in pH from about 5.5 in young blue flowers to about 4.0 in old flowers, a drop which seemed to occur abruptly about the time of pollen release. The operation of a copigmentation effect was confirmed, and the presence of a copigment in addition to quercitin glucosides is suggested.

Flower Pigment Composition of Natural Bud-Variants Among Hybrid Chinese Azaleas,Rhododendron Simsii(Planch.)

SummaryThe different flower-colour cultivars which arise by bud mutation from hybrids of Rhododendron simsii (Chinese azalea) present the same qualitative pattern of anthocyanin and flavonol pigments. Therefore, the quantities of anthocyanins and flavonols have been compared. For cultivars with colours that are based on cyanidin and peonidin as the only anthocyanidins the difference between bluish-red and magenta petal colours (Horticultural Colour Chart number >52) and their scarlet or salmon-orange sports (H.C.C. number <52) lies in the latter possessing a very much lower total flavonol content (or its absence) and a correspondingly higher cyanidin content. With cultivars that are low in flavonols a rise in the ratio of cyanidin 3, 5-diglycoside to cyanidin 3-glycoside has a reddening effect. With cultivars that are high in flavonols this ratio is relatively unimportant. Variations in the pH of the petal juice (3.35 → 3.85) are the same within groups of both orange and magenta cultivars.It seems probable that a metal ion is required in addition to anthocyanin and flavonol in order to produce a co-pigmentation effect.