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Red beet betalains, grape anthocyanins, and their mixtures were used as colorants in white currant juice. Storage stability of the compounds was evaluated using liquid chromatography and the degradation kinetic order and parameters were calculated. Degradation of betalains followed first-order kinetics, while the degradation of anthocyanins did not have any trend toward any order kinetics. The coexisting anthocyanins and their concentration affected the rate constant of betalains. Betalains degraded faster than anthocyanins, their mixtures promoted respective degradation. Pyruvate derivatives of anthocyanins showed better stability. During storage, all samples became more yellowish with CIELab method and lighter in color. In the projective mapping sensory test, samples were distinguished by the colorant type as the main criteria and the storage time as the second criteria. Anthocyanin (described as 'dark' and 'natural') was preferred by sensory panelists over betalain (described as 'pink' and 'unnatural'), as were the fresh samples over stored samples., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Consumers and regulations encourage the use of naturally derived food colorants. Anthocyanins (ACN), plant pigments, are unstable in foods. In aged red wines, ACN with a free hydroxyl group at C-5 condenses to form pyranoanthocyanins (PACN), which are more stable but form inefficiently. This study attempted to produce PACN efficiently using high cofactor concentration and heat. Elderberry anthocyanins were semi-purified and caffeic acid (CA) was dissolved in 15% ethanol and diluted with a buffer to achieve ACN:CA molar ratios of 1:50, 1:100, 1:150, and 1:200, then incubated at 65 °C for 5 days. The effect of temperature was tested using ACN samples incubated with or without CA at 25 °C, 50 °C, and 75 °C for 7 days. Compositional changes were monitored using uHPLC-PDA-MS/MS. Higher CA levels seemed to protect pigment integrity, with ACN:CA 1:150 ratio showing the highest tinctorial strength after 48 h. PACN content growth was fastest between 24 and 48 h for all ACN:CA ratios and after 120 h, all ACN had degraded or converted to PACN. PACN formed faster at higher temperatures, reaching ~90% PACN in 24 h and ~100% PACN in 48 h at 75 °C. These results suggest that PACN can form efficiently from elderberry ACN and CA if heated to produce more stable pigments.

Colour is the first organoleptic property that consumers appreciate of a foodstuff. In blueberry (Vaccinium spp.) fruits, the anthocyanins are the principal pigments determining the colour as well as many of the beneficial effects attributed to this functional food. Commercial blueberry-derived products represent important sources of these healthy molecules all year round. In this study, blueberries were produced into purees comparing two homogenization methods and further heated following different thermal treatments. All the supernatants of the homogenates were monitored for pH. Then, the hydroalcoholic extracts of the same samples were characterized by CIELAB and HPLC-DAD analyses. These analytical techniques provide complementary information on fruit pigments content as a whole and on quali-quantitative profile of the single bioactive colorants. These data could be very interesting to know the best manufacturing procedure to prepare blueberry-derived products, well accepted by the consumers, while maintaining their healthy properties unaltered., (Copyright © 2017. Published by Elsevier Ltd.)

Jambolão fruits are promising sources of anthocyanins, and in this study, the jambolão fruit from the Brazilian Amazonian region was characterized and the efficiency of six ethanol-based solutions to extract anthocyanins was determined. Moreover, the color changes of anthocyanin extracts, as influenced by different pH conditions (pH from 1.0 to 8.0), were evaluated. The fruits exhibited high contents of total anthocyanins (296 mg/100 g) and the CIELAB parameters characterized jambolão as a purple-red colored fruit (a* = 20.30, b* = -4.17, and hab∘= 348.39). Among the six different ethanol-based solutions, ethanol 95% with 1% of HCl (v/v) was the most efficient solution to extract anthocyanins from jambolão fruits. Furthermore, the CIELAB parameters were characterized as useful tool to monitor the color changes of anthocyanins of jambolão over the tested pH range. Therefore, jambolão fruits from Amazonian region have technological potential for the application by food, pharmaceutical, and cosmetic industries., Practical Application: Jambolão fruits are great source of anthocyanins and the incorporation of these natural pigments as food colorants is not only valuable to improve overall appearance, but it is also beneficial to human health. The production of natural extracts with high levels of anthocyanins from jambolão can be considered a very useful approach to the food, pharmaceutical and cosmetic industries., (© 2017 Institute of Food Technologists®.)

The effect of adding an enzymatic hydrolysate of grape seeds (EH-GS) during Syrah wine fermentation in a warm climate has been evaluated. We focused on the polyphenolic composition as well as the application of differential and tristimulus colorimetry to colour data. This is the first attempt at using this oenological alternative to avoid common colour losses of red wines elaborated in a warm climate. The addition of 250g (simple dose, SW) of EH-GS to 120kg of fermentation material promoted a significant (p<0.05) increase in the polyphenolic content of stored wines, especially in benzoic acid, hydroxycinnamic acid derivative, flavonol and anthocyanin levels. This increase could promote a higher copigmentation percentage and maximum colour stabilization (C(∗)ab) without significantly changing the wine tonality. Unexpectedly, the use of a double quantity (DW) of EH-GS resulted in significantly less chroma than for control wines (CW), demonstrating visually perceptible colour changes (ΔE(∗)ab>3 CIELAB units)., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

This study investigates the potential of Australian Traditional foods as novel sources of natural colourants for food applications, employing untargeted metabolomics and chemometrics. Two native species were analysed: Davidson plum and native currant. The species were quantitatively assessed for colour properties using the CIELAB colour system in conjunction with Ultra Performance Liquid Chromatography-Quadrupole Time of Flight Tandem Mass Spectrometry (UPLC-Q-ToF-MS/MS). The results highlight diverse phenolic, flavonoid, and significant anthocyanin levels in Davidson plum and native currant, contributing to their robust red hues, comparable to commercial blueberry standards. Davidson plum and native currant exhibited high phenolic, flavonoid, and anthocyanin levels, contributing to vibrant red hues and significant bioactivity. Compared to blueberry, these species showed greater redness (a*) and chroma. Native currant demonstrated the highest phenolic content (146.73 mg g−1), anthocyanin content (14.48 mg g−1), and antioxidant activity (95.48 μmol Trolox equivalents/g). The chemometric analysis identified 46 key pigment metabolites, including anthocyanins and flavonoids, directly correlating to observed colour properties. UPLC-Q-ToF-MS/MS combined with CIELAB colourimetry facilitated pigment identification and colour analysis. These findings position Davidson plum and native currant as promising natural food colourants and functional ingredients. Additionally, the study underscores the efficacy of integrating chemometric analysis with CIELAB and UPLC-Q-ToF-MS/MS methodologies for pinpointing specific metabolites that influence the colour properties of these Traditional foods. This approach facilitates a deeper understanding of how indigenous Australian bushfoods can be innovatively incorporated into the food industry, aligning with consumer demand for natural and sustainable food options.

Societal Impact Statement In blueberry, fruit color is one of the most important quality traits affecting consumers' choices. Both pigments and waxes impact fruit color; however, their roles have not been clearly elucidated. Here, the contributions of waxes and anthocyanins to fruit color are characterized. A higher content of β‐diketones—the second largest wax group in blueberries—determines a lighter fruit color; hence revealing that, at harvest, waxes contribute more than anthocyanins in determining variations in fruit color among blueberry varieties. Summary Fruit color is one of the major quality traits determining the marketability of fruits by affecting consumers' choices. In blueberries, although fruit surface color is mainly determined by pigments (e.g., anthocyanins), cuticular waxes also play a role in modulating the surface color, and a lighter color given by a dense wax bloom is normally preferred by consumers. This study investigated the content and composition of cuticular waxes and their roles in modulating fruit surface color in 12 (seven northern highbush, three southern highbush, and two hybrids) blueberry genotypes at harvest (H1, representing the first commercial pick, and H2, representing the second commercial pick). The ultrastructural morphology of cuticular waxes was analyzed in four selected genotypes by scanning electron microscopy. The level and profile of anthocyanins and their contributions to the color were also assessed. Total cuticular wax content ranged from 27.7 to 95.8 μg cm−2 among genotypes at H1 and decreased by an average of 23.9% from H1 to H2. Triterpenoids (62.5% of the total cuticular waxes on average) and β‐diketones (22.9% on average) were the first and second largest wax groups in all genotypes, respectively. β‐Diketones were previously proven to affect leaf surface color in wheat; in this study, their content strongly correlated with the lightness of the blueberry surface. Scanning electron microscopy revealed distinct wax morphologies among genotypes. No significant relationships were found between total or individual anthocyanin concentrations and fruit surface color. Our results suggest that, at harvest, variation in the fruit surface color among blueberry genotypes is more closely related to the content and composition of cuticular waxes than the level and profile of anthocyanins, with β‐diketones being particularly important. This study provides new insights for blueberry breeding programs aiming to improve the surface color in order to meet the market demand.

Societal Impact Statement: In blueberry, fruit color is one of the most important quality traits affecting consumers' choices. Both pigments and waxes impact fruit color; however, their roles have not been clearly elucidated. Here, the contributions of waxes and anthocyanins to fruit color are characterized. A higher content of β‐diketones—the second largest wax group in blueberries—determines a lighter fruit color; hence revealing that, at harvest, waxes contribute more than anthocyanins in determining variations in fruit color among blueberry varieties. Summary: Fruit color is one of the major quality traits determining the marketability of fruits by affecting consumers' choices. In blueberries, although fruit surface color is mainly determined by pigments (e.g., anthocyanins), cuticular waxes also play a role in modulating the surface color, and a lighter color given by a dense wax bloom is normally preferred by consumers.This study investigated the content and composition of cuticular waxes and their roles in modulating fruit surface color in 12 (seven northern highbush, three southern highbush, and two hybrids) blueberry genotypes at harvest (H1, representing the first commercial pick, and H2, representing the second commercial pick). The ultrastructural morphology of cuticular waxes was analyzed in four selected genotypes by scanning electron microscopy. The level and profile of anthocyanins and their contributions to the color were also assessed.Total cuticular wax content ranged from 27.7 to 95.8 μg cm−2 among genotypes at H1 and decreased by an average of 23.9% from H1 to H2. Triterpenoids (62.5% of the total cuticular waxes on average) and β‐diketones (22.9% on average) were the first and second largest wax groups in all genotypes, respectively. β‐Diketones were previously proven to affect leaf surface color in wheat; in this study, their content strongly correlated with the lightness of the blueberry surface. Scanning electron microscopy revealed distinct wax morphologies among genotypes. No significant relationships were found between total or individual anthocyanin concentrations and fruit surface color.Our results suggest that, at harvest, variation in the fruit surface color among blueberry genotypes is more closely related to the content and composition of cuticular waxes than the level and profile of anthocyanins, with β‐diketones being particularly important. This study provides new insights for blueberry breeding programs aiming to improve the surface color in order to meet the market demand. [ABSTRACT FROM AUTHOR]

Background: Ananas comosus var. bracteatus is a colorful plant used as a cut flower or landscape ornamental. The unique foliage color of this plant includes both green and red leaves and, as a trait of interest, deserves investigation. In order to explore the pigments behind the red section of the chimeric leaves, the green and red parts of chimeric leaves of Ananas comosus var. bracteatus were sampled and analyzed at phenotypic, cellular and molecular levels in this study. Results: The CIELAB results indicated that the a* values and L* values samples had significant differences between two parts. Freehand sections showed that anthocyanin presented limited accumulation in the green leaf tissues but obviously accumulation in the epidermal cells of red tissues. Transcriptomic and metabolomic analyses were performed by RNA-seq and LC-ESI-MS/MS. Among the 508 identified metabolites, 10 kinds of anthocyanins were detected, with 6 significantly different between the two samples. The cyanidin-3,5-O-diglucoside content that accounts for nearly 95.6% in red samples was significantly higher than green samples. RNA-Seq analyses showed that 11 out of 40 anthocyanin-related genes were differentially expressed between the green and red samples. Transcriptome and metabolome correlations were determined by nine quadrant analyses, and 9 anthocyanin-related genes, including MYB5 and MYB82, were correlated with 7 anthocyanin-related metabolites in the third quadrant in which genes and metabolites showing consistent change. Particularly, the PCCs between these two MYB genes and cyanidin-3,5-O-diglucoside were above 0.95. Conclusion: Phenotypic colors are closely related to the tissue structures of different leaf parts of Ananas comosus var. bracteatus, and two MYB transcription factors might contribute to differences of anthocyanin accumulation in two parts of Ananas comosus var. bracteatus chimeric leaves. This study lay a foundation for further researches on functions of MYBs in Ananas comosus var. bracteatus and provides new insights to anthocyanin accumulation in different parts of chimeric leaves. [ABSTRACT FROM AUTHOR]

The aim of the present study was characterisation of selected varieties of still wines produced in Slovak Republic in vintage year 2013 and one 2012. There were tested ten samples of nine varieties of wines originated from Malokarpatská "Lesser Carpathian" and Južnoslovenská "Southern Slovakia" wine regions of Slovak Republic, Dornfelder, Frankovka modrá, Svätovarinecké, Zweigeltrebe, Müller Thurgau, Veltlínské zelené, Rizling rýnsky, Rizling vlašský and Sauvignon wines. There were studied selected physico-chemical properties of tested wines as a total contents of anthocyanins and polyphenols by means of spectrophotometry, titratable acidity, density and chromatic characteristics. The highest content of anthocyanins (TAC) was found in red wine Frankovka modrá, 183 mg.L-1 and the lowest for sample rose wine St. Laurent 19 mg.L-1. The content of total phenolic compounds as a gallic acid was in range 2833 to 1961 mg.L-1 for red wines, 1016 and 1013 mg.L-1 for rose wines, 1085 to 549 mg.L-1for white wines. Total acidy was average 6.3 ±0.3 g.L-1 only for Ryzling rýnský, 8.2 g.L-1 and Sauvignon rose 8.0 g.L-1 and was expressed as the amount of tartaric acid. Quality of wines can be expressed by colour intensity too. Was evaluated and compared intensity of colour in wines by CIE Lab method and the total differences between red, rose and white wine DE* was calculated. The most differences was found for Svätovarinecké a Frankovka modrá (2.5) - red wines ("clearly perceptible") and 4.9 for Veltlýnské zelené and Müller Thurgau - white wine ("moderating effect").

Jambolão fruits are promising sources of anthocyanins, and in this study, the jambolão fruit from the Brazilian Amazonian region was characterized and the efficiency of six ethanol-based solutions to extract anthocyanins was determined. Moreover, the color changes of anthocyanin extracts, as influenced by different pH conditions (pH from 1.0 to 8.0), were evaluated. The fruits exhibited high contents of total anthocyanins (296 mg/100 g) and the CIELAB parameters characterized jambolão as a purple-red colored fruit ( a* = 20.30, b* = −4.17, and [ABSTRACT FROM AUTHOR]

Aims: The aim of this work was to study the color of the wine grapes using the CIELAB parameters and to develop colorimetric indexes which can be used as a rapid method to assess the anthocyanin content of the wine grapes in the vineyard. Methods and results: L*, a*, b* parameters were measured by a reflectance spectrophotometer on eighteen red winegrapes at harvest. Two indexes were calculated: CIRG2, used as colorimetric index for table grapes and CIRWG (Color Index for Red Wine Grapes). These indexes showed effective potentialities for descriptive, taxonomic and ampelografic studies. Particularly the CIRWG index is more correlated to the total anthocyanin amount, while the CIRG2 is more correlated to the different forms of the anthocyanins. Conclusion: The colorimetric indexes applied directly in the vineyard permit to assess the total anthocyanin content and to give further quickly information on grape quality and maturity. Significance and impact of study: The development of analytical methods for the evaluation of anthocyanin immediates, easily applicable, at low cost in the field by grape-growers and winemakers, can be very useful in deciding the harvest date.

The aim of the present study was characterisation of selected varieties of still wines produced in Slovak Republic in vintage year 2013 and one 2012. There were tested ten samples of nine varieties of wines originated from Malokarpatská “Lesser Carpathian” and Južnoslovenská “Southern Slovakia” wine regions of Slovak Republic, Dornfelder, Frankovka modrá, Svätovarinecké, Zweigeltrebe, Müller Thurgau, Veltlínské zelené, Rizling rýnsky, Rizling vlašský and Sauvignon wines. There were studied selected physico-chemical properties of tested wines as a total contents of anthocyanins and polyphenols by means of spectrophotometry, titratable acidity, density and chromatic characteristics. The highest content of anthocyanins (TAC) was found in red wine Frankovka modrá, 183 mg.L-1 and the lowest for sample rose wine St. Laurent 19 mg.L-1 . The content of total phenolic compounds as a gallic acid was in range 2833 to 1961 mg.L-1 for red wines, 1016 and 1013 mg.L-1 for rose wines, 1085 to 549 mg.L-1 for white wines. Total acidy was average 6.3 △0.3 g.L-1 only for Ryzling rýnský, 8.2 g.L-1 and Sauvignon rose 8.0 g.L-1 and was expressed as the amount of tartaric acid. Quality of wines can be expressed by colour intensity too. Was evaluated and compared intensity of colour in wines by CIE Lab method and the total differences between red, rose and white wine △E* was calculated. The most differences was found for Svätovarinecké a Frankovka modrá (2.5) – red wines (“clearly perceptible”) and 4.9 for Veltlýnské zelené and Müller Thurgau – white wine (“moderating effect”). [ABSTRACT FROM AUTHOR]

To date, innovative, rapid and non-invasive techniques have been used to assess variations in morphological and technological characteristics between grape cultivars. In order to improve knowledge of the qualitative expression of the genetic traits of cv. Cannonau (syn. Grenache), fluorescence, texture and colorimetric analyses were performed on 85 biotypes attributable to this variety. Eighty-five Cannonau biotypes cultivated in the same vineyard were analysed in order to evaluate their morphological and agronomical characteristics. As regards the morphological traits, of the six descriptors observed, five were able to discriminate the Cannonau population according to different expression levels. Must composition, berry colour (using the Minolta tristimulus colorimeter), texture (assessed using the TaxT2i plus texturimeter) and fluorescence (using the Multiplex III detector) were determined on clusters harvested at the same time. Cluster analysis was able to separate the Cannonau population into five groups, characterised by differences in the following criteria: L*, a* and b*, berry skin thickness, FERARI, TSS, pH and titratable acidity, total polyphenols and total anthocyanins. The FERARI index was highly and positively correlated with total anthocyanins and negatively correlated with grape colour, while berry weight and berry skin thickness were not correlated with any variable assessed. The remarkable intra-variability encountered for the qualitative and quantitative characters in the Cannonau variety suggests that new biotypes could be selected for different oenological purposes, using techniques such as the measure of fluorescence and colorimetry. This is the first study carried out within the cv. Cannonau using innovative and classical techniques suitable to investigate intra-varietal variability. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to observe the thermal and colour stabilities of coating films consisting of natural dye anthocyanin colourant with acid and nitrate salt as additives. Design/methodology/approach – The natural dye was extracted from Hibiscus sabdariffa L. (Roselle) by using distilled water as solvent. The extracted dye was mixed with 1 weight per cent hydrochloric acid and 5 weight per cent calcium nitrate to conduct the comparison study. The dye samples were than mixed with poly (vinyl alcohol) (PVA). The mixtures were applied on glass panels to form coating films. The coating films were left to dry for 24 hours. The thermal stability of coating films was investigated by using thermogravimetric analysis (TGA). The amorphousness coating films molecular structures were observed by using x-ray diffraction (XRD). CIE L*a*b* colour coordinate space technique was used to investigate the coating films colour stability against ultraviolet (UV). Findings – The results show that addition of hydrochloric acid (HCl acid) enhanced thermal stability of PVA-anthocyanin coating and shifted the degradation temperature to higher temperature at 300°C. HCl acid also improved UV stability of the coating system significantly with the reduced ΔE from 26.67 to 16.89. Addition of calcium nitrate (Ca(NO3)2) salt promotes good interaction with PVA-anthocyanin system that caused structural changes, improved thermal stability and increased Tg from 61.5 to 83.1°C. Research limitations/implications – The potential of using natural dye extracted from plant as renewable material. Practical implications – The coating films developed in this works are suitable for glass substrate application. Originality/value – Development of water-based coating from PVA binder with anthocyanin colourant is introduced in this study. [ABSTRACT FROM AUTHOR]

Highlights: [•] Addition of oenological tannin may solve deficiencies in flavanol and pigment contents. [•] Use of overripe grapes might contribute to the stabilization of the colouring matter. [•] Synthesis of vinylphenol-type pyranoanthocyanins is promoted in overripe wine. [•] Synthesis of Vitisin A is promoted in Tannin wine. [•] Both oenological treatments lead to darker wines (lower L* values). [Copyright &y& Elsevier]

Abstract: Organic compounds present in plants have been used in various experimental conditions for dyeing tests aimed to develop safe and environmentally friendly temporary and semipermanent hair dyes. Yak hairs were used as a model for the colorimetric evaluation of red, yellow, blue, and brown shades conferred to hair by selected natural compounds. Two different sources for red, yellow, blue and brown shades were tested. Anthocyanins from mulberry fruits and alizarin emerged as promising candidates for red shades, anthocyanin-blue and curcumin for blue and yellow, respectively, and p-benzoquinone and juglone for browns. The influence of pH, dye concentration, soaking time, and medium in which the dyes have been dissolved or dispersed has been studied. [Copyright &y& Elsevier]

Purpose – The purpose of this paper is to develop a new water-based coating system composed of poly(vinyl alcohol) and anthocyanin colourant extracted from Hibiscus sabdariffa L. and to characterise the system. Design/methodology/approach – Anthocyanin from Hibiscus sabdariffa L. (roselle) calyxes was extracted by using distilled water and filtered to remove insoluble particle. Salts introduced into the extract were 5wt percent calcium nitrate, 5wt percent magnesium nitrate, and 5wt percent zinc nitrate. The solution was mixed with poly(vinyl alcohol) in ratio of 3:1. The mixtures were coated on glass substrate and allowed to cure for approximately one day. Colour of the extract systems was determined by CIELab colourimetry. FTIR spectroscopy was conducted on the samples to identify their functional groups and changes upon addition of salt. Thermal stability was assessed by thermogravimetric analysis (TGA). Differential scanning calorimetry (DSC) was employed to measure the glass transition temperature Tg of the samples. XRD was employed to determine the amorphous properties of the coating samples. Findings – From FTIR spectroscopy, shifting in the OH stretching and CH2 bending bands was attributed to hydrogen bonds formation between PVA and nitrate salt. Shifting in the main decomposition step in samples with addition of nitrate salts in TGA was due to interaction of PVA and nitrate. Increase in glass transition temperature of samples with salts was attributed to the formation of hydrogen bonding. From XRD study, increase in the amorphous properties was due to the incorporation of nitrate salts into PVA coating. Research limitations/implications – Limitation of implementating poly(vinyl alcohol) as coating is caused by its weak water resistance and hydrophilic properties. This study could bring about research towards incorporation of different natural colourant with different binder materials to form coatings which are environmental-friendly and low cost. Practical implications – Mixture of PVA and anthocyanin colourant from roselle for use as coating has been developed. The coating can find usage in various applications such as coloured coating for furniture and wooden materials for decorative purposes, biodegradable design materials for interior purposes. It can be practically applied on a variety of substrates such as glass and wood. Originality/value – Development of water-based coating from PVA binder with anthocyanin colourant is introduced in this study. [ABSTRACT FROM AUTHOR]

Abstract: The aim of the present work was to determine whether there is any relationship between measurement by transmission and reflection (in the latter case, with and without contact with the sample). We also evaluated which methodology used would offer a better interpretation of the results in visual terms. For this purpose, different colorimetric techniques such as transmission spectrophotometry, diffuse reflectance spectrophotometry and spectroradiometry were applied. The samples consisted of increasing dilutions (0, 20, 40, 60, 80 and 100%) of the phenolic fractions obtained from 4 wines: Tempranillo (T) and Graciano (G) monovarietal wines, and two 80:20 mixtures: M (wine elaborated by blending grapes) and W (a blend of the T and G wines) (9 fractions per wine). Fractionation was performed using gel permeation chromatography with a Toyopearl HW-40S column, and the dilutions of the fractions were performed with synthetic wine (pH=3.6). The spectroradiometric measurements permitted the differences due to the dilution effect on the fractions to be established more clearly than with the results obtained using diffuse reflectance and spectrophotometry. Thus, this technology is very suitable for use in comparative interpretations by the human eye. In turn, we assessed the changes in colour due to the effect of dilution on the fractions, observing that the effect of dilution led to an increase in the values of lightness (L*), while the chroma values (C*ab) followed the opposite trend, in agreement with its role as a variable related to chromatic intensity or vividness of the sample. In contrast, hue (hab) did not seem to be affected by dilution of the fractions, in consonance with the qualitative nature of this parameter. [Copyright &y& Elsevier]

Pigment accumulation, anthocyanin structure and the expression of floral anthocyanin genes were evaluated in anthocyaninbased colored florets of a pale-mauve Vanda hybrid (V. teres x V. hookeriana) and compared to those of a white Vanda hybrid (V. teres var. alba x V. Cooperi var. White Wing). In the pale-mauve Vanda hybrid, anthocyanins gradually accumulated during all of the three developmental stages of the florets, whereas no anthocyanins detected in the florets of the white Vanda hybrid at any of the stages. The chlorophyll a content accumulated to higher levels in the white Vanda hybrid florets and slightly decreased from the unopened-floret stage (B) to the full-bloom floret stage (FB) in both hybrids. In the pale-mauve Vanda hybrid, the anthocyanin contents in each of the floral parts revealed a direct correlation to the a* values (R2=0.7276) and an inverse relation to the L* values (R2=0.9023). Based on HPLC-PDA and LC-ESI-MSn analyses, the anthocyanins in the pale-mauve hybrid were only derived from cyanidin molecules, which were diversely conjugated with some hexose sugars and organic acids, such as ferrulic acid, sinapic acid and malonic acid. In addition, the semiquantitative expression of four genes involved in the anthocyanin biosynthetic pathway, including phenylalanine ammonia-lyase (Va-PAL1), chalcone synthase (Va-CHS1), flavanone 3-hydroxylase (Va-F3H1) and dihydroflavonol 4-reductase (Va-DFR1), of the pale-mauve Vanda hybrid showed that all of the genes, except Va-CHS1, were highly expressed in all of the three stages of the florets, whereas Va-F3H1 was rarely expressed in the vegetative organs. When Va-PAL1 was expressed at high levels in the florets at all of the floral stages, Va-F3H1 expression was very low only in the developing florets of the white hybrid. Therefore, Va-F3H1 could play an important role in controlling the biosynthesis of anthocyanin in the Vanda hybrids. [ABSTRACT FROM AUTHOR]

nthocyanins play a crucial role in wine color. Thus, their analysis results essential for evaluating their contribution to perceived color in wines, attribute directly linked to quality judgements. In this context, this study was aimed at: (1) defining the color space of a relative large number of commercial oaked Spanish red wines and (2) establishing a linkage between wine coloring, anthocyanic composition, and quality perception of this set of wines. Therefore, CIELab parameters ( a*, b*, L*), monomeric anthocyanin contents analyzed by HPLC with ultraviolet and mass detection, and polymeric pigment content estimated by a protein precipitation assay combined with bisulfite bleaching were evaluated in a total of 58 wine samples. Principal component analysis was performed on color variables, and their correlations were discussed. The results have evidenced the important role played by the pyranoanthocyanic compounds since they seem to be the main contributors to the red color of these aged wines, and they have been demonstrated not to increase their yellow nuances. On the other hand, results highlight that, regardless of the time of aging, wines presenting more red (higher values for a* and for low molecular weighted anthocyanins) and lower yellow nuances (lower values for b* and T) as well as a darker color (lower in L* and higher in CI) are in general evaluated with higher quality scores by wine experts. [ABSTRACT FROM AUTHOR]

Berry skin color OIV index, anthocyanin composition, and content of 78 grape cultivars were surveyed using a CIELAB system and high-performance liquid chromatography (HPLC)-mass spectrometry (MS) coupled with photodiode array detection. There were high correlations between L*, b*, and color, while a* was not a representative parameter. L* and b* values declined as berry skin color OIV became darker, and a* increased as berry skin color OIV became darker in pink and red grape cultivars only. The composition and content of anthocyanins varied widely among the cultivars. Total anthocyanins and types of anthocyanins were significantly correlated with color OIV parameters. Through multiple linear regression analysis, cyanidin derivatives had a positive effect on values of L* and b*. Delphinidin derivatives had positive effects on the value of a*. The CIELAB system gave good results for differentiation of grape berry skin color OIV. [ABSTRACT FROM AUTHOR]

Abstract: With the aim of evaluating the importance of the copigmentation process between anthocyanins and flavanols on the colour expression of red wine, assays were carried out in wine model systems with mixtures of compounds obtained from two Vitis vinifera grape varieties (Graciano and Tempranillo). Spectrophotometric and chromatic analyses were performed to evaluate the magnitude of the copigmentation and the modifications induced in the colour of the solutions. Measurement of the changes in the anthocyanin hydration constant (K h) was also used to determine the strength of the copigmentation process. All the flavanols assayed induced significant changes in the colour, perceptible to the human eye, of the wine-like anthocyanin solutions at concentrations similar to those that can exist in red wines. The percentage contribution of the copigmentation with flavanols to the colour of the anthocyanin solutions was found to range from 2% to 20%. The extent of this effect was related not only to the concentration of flavanols but also to the qualitative composition of the flavanol preparations, as influenced by the part of the grape (either skin or seed) and the variety considered. Divergences were found between the evaluation of the copigmentation based on chromatic parameters in the CIELAB colour space and that based on the measurement at visible λ max, as the latter does not consider the integral colour changes produced in the visible spectrum. The results obtained confirmed the importance of the qualitative phenolic composition, determined in the wine by the type of grape and winemaking practices, to the production of an effective copigmentation process. [Copyright &y& Elsevier]

Abstract: Blanching and one year freezer storage were performed on one purple, two white and two green varieties of cauliflower (Brassica oleracea L. ssp. botrytis) to assess the effects on several health-related phytochemicals. Blanching, prior to freezing, reduced total aliphatic and indole glucosinolates (GLS) by 31% and 37%, respectively. l-ascorbic acid (L-AA), total phenols (TP), anthocyanins, FRAP and ORAC were on average reduced by 19, 15, 38, 16 and 28%, respectively. The colour measured as CIELAB parameters was partly affected by blanching: lightness was significantly reduced in the white cultivars and in a romanesco type cultivar. Chromaticity was reduced in the coloured cultivars with a twice-as-large reduction in the purple cultivars. Hue increased for all samples, except for the purple cultivar where a decrease was found. Long-term freezer storage did not affect total aliphatic and indole GLS in cauliflower in a major way. Freezer storage did result in an average L-AA decrease of 24% for all but the purple cultivar. Some reductions in the TP levels were also found but not to the extent found for L-AA. When an effect was found in the FRAP and ORAC values, the reductions occurred towards the end of the storage period and were 15% and 37%, on average, respectively. Long-term freezer storage did not affect the anthocyanin content and only minor effects were found for the colour parameters. [Copyright &y& Elsevier]

Abstract: The roselle extract, using acidified water–95% ethanol (1:1) as a solvent, was subjected to freeze-drying. Maltodextrin and trehalose, 2 and 3g/100ml extract, were used as stabilisers. Addition of the stabiliser retarded anthocyanin degradation. Colour changes of the freeze-dried roselle powder during storage were monitored using the CIELAB system. It was found that pigment concentration markedly changed with a minor change in lightness and hue. However, the changes in chroma mainly came from anthocyanin degradation. The freeze-dried roselle powder with maltodextrin (3g/100ml) proved to have superior colour stability. A model system of a drink adding this powder was carried out and the colour evaluation was compared to drinks containing commercial colorants: SAN RED RC® and carmoesin. During a 12-week storage period at 30°C, the change in hue of all three groups was within the same shade suggesting any change in pigment concentration had insignificant effect on hue shift. By contrast, the degradation of pigments highly correlated to changes in lightness and chroma. Even though a drink with roselle anthocyanin powder was the least stable in colour, the overall appearance of the drink was rated close to ‘like slightly’ throughout 56 days. [Copyright &y& Elsevier]

Abstract: During winemaking and ageing, the colour of red wine evolves from the initial purple-red hues of young red wines towards more red-orange ones. Simultaneously, a modification in the pigment profile takes place. The stability of pigments isolated from red wine has been usually studied in model solutions. However, studies carried out on wines are scarce. The objective of this work was to analyse the changes in composition, colour and stability in relation to pH and SO2 that take place in a red wine during winemaking and maturation. For this purpose, samples of red wine from Tempranillo grapes were collected periodically during 18 months and submitted to chromatic analysis using the CIELAB and CIELUV colour spaces and high performance liquid chromatography–diode array detection coupled to a mass spectrometer analysis (HPLC–DAD–MS). The results obtained showed the existence of processes capable of causing quantitative and qualitative changes in the colouring material of the wine. These changes, in spite of the relatively short time considered, are sufficient to cause changes of colour that can be perceived by the human eye and lead to the formation of pigments that are more stable against pH and against bleaching by SO2 than the original anthocyanins. [Copyright &y& Elsevier]

Abstract: This paper was aimed at optimizing the extraction conditions for the maximum yield of anthocyanins from Jaboticaba (Myricia Jaboticaba Berg.) skins. Tristimulus colorimetry was applied to evaluate quantitatively and qualitatively the process. A mixed 2 and 3 full factorial design was used (21 ·33). The factors and levels studied were type of solvent: ethanol or methanol; solvent/water mixture: 100% v/v, 90% v/v, 80% v/v; type of acid: clorhidric acid, citric acid or acetic acid and pH: 2, 3 or 4. The estimated effect and ANOVA parameters were calculated. The yield of anthocyanins, quantified following an spectrophotometric method based on the absorbance at 535nm was 92.92±mg/kg of skin. The yield of anthocyanins showed a high and significant correlation with chroma () (p &#60;0.05; r =0.84) and lightness (L*) (p &#60;0.05; r =−0.85) and it was significantly (p &#60;0.001) affected by the type of acid used and the solvent/water% (p &#60;0.05). [Copyright &y& Elsevier]

This study focuses on the impact of anthocyanin structures such as 5-glucosidic substitution and aromatic acylation on anthocyanin, colour and stability at various pH values. Two concentrations (0.05 and 0.15 mM) of cyanidin 3-glucoside (1), cyanidin 3-(2″-glucosylglucoside)-5-glucoside (2), and cyanidin 3-(2″-(2′′′-sinapoylglucosyl)-6″-sinapoylglucoside)-5-glucoside (3) in aqueous solutions were studied at fourteen pH levels between 1.1 and 10.5 during a 98 day period at 10 °C. The three pigments represent the structural variation of many anthocyanins isolated from fruits and vegetables. Colours were expressed by the CIELAB coordinates hab, (hue angle), C* (chroma=saturation), and L* (lightness), as well as by visible absorption maxima (λmax) and molar absorption coefficients (#x03B5;). Limitations of using only spectral parameters, such as λmax and #x03B5;, to express colour variations, were revealed. Pigment 2 was more unstable than 1 at most pH values, showing lower C* and higher L* values after storage for only hours in neutral and weakly acid solutions. Pigment 3 showed higher colour stability than the nonacylated forms at all pH values but pH 1.1, where all pigments retained their colours in the storage period, and in the most alkaline solutions, where all pigments experienced dramatic colour changes. Of potential importance for some food products, in solutions with pH 4.1 and 5.1, 3 maintained nearly the same hab, C*, and L* values during the whole measuring period (98 days), in contrast to pigments 1 and 2. The hue angle shift towards bluish tones in freshly made samples of anthocyanins with 5-glucosidic substitution, were amplified with aromatic acylation (3) throughout the entire pH range except pH 10.5. The variations in the results emphasizes the importance of structure for anthocyanin properties in fresh and processed fruits and vegetables. [Copyright &y& Elsevier]

An anthocyanin, 1, with the novel 4-substituted aglycone, 5-carboxypyranopelargonidin, was isolated in small amounts from the acidified, methanolic extract of strawberries, Fragaria ananassa Duch., by preparative HPLC after purification by partition against ethyl acetate, Amberlite XAD-7 and Sephadex LH-20 column chromatography. It was identified mainly by 2D NMR spectroscopy and electrospray LC-MS as the 3-O-β-glucopyranoside of 5-carboxy-2-(4-hydroxyphenyl)-3,8-dihydroxy-pyrano[4,3,2-de]-1-benzopyrylium, an anthocyanidin which is homologous to 5-carboxypyranomalvidin (vitisidin A) reported in red wines and 5-carboxypyranocyanidin recently isolated from red onions. By comparison of UV–Vis absorption spectra, 1 showed in contrast to 2, pelargonidin 3-O-β-glucopyranoside, a local absorption peak around 360 nm, a hypsochromic shift (8 nm) of the visible absorption maximum, and lack of a distinct UV absorption peak around 280 nm. The similarities between the absorption spectra of 1 in various acidic and neutral buffer solutions implied restricted formation of the instable colourless equilibrium forms, which are typical for most anthocyanins in weakly acidic solutions. The molar absorptivity (∊) of 1 varied little with pH contrary to similar values of for instance the major anthocyanin in strawberry, 2. However, 2 revealed higher ∊-values than 1 at all pH values except 5.1. At pH 5.1, the ∊-value of 1 (6250) was nearly four times the corresponding value of 2 (1720), which showed the potential of 5-carboxypyranopelargonidin derivatives as colorants in solutions with pH around 5. The colours of 1 and 2 in buffered solutions with pH 1.1 and pH 6.9 have been described by the CIELAB coordinates hab (hue angle), C* (chroma), and L* (lightness). [Copyright &y& Elsevier]

Anthocyanins, isolated from natural sources by countercurrent chromatography, were reacted with cinnamic acids bearing at least one electron-donating substituent at the para-position. The resulting pyranoanthocyanins obtained by this simple one-step reaction were much less susceptible to pH shifts and retained their original colour over a wide pH-range. Through reaction with p-dimethylamino cinnamic acid, synthetic malvidin- and cyanidin-based anthocyanins with a unique violet hue were prepared. [Copyright &y& Elsevier]

One of the main consequences of the advancement of harvest date associated to global climate change is that the phenolic maturity of grapes can be delayed in relation to their technological maturity. As a consequence, wines made from these grapes can be poor in phenolic compounds or possess an unbalanced phenolic composition, affecting their global quality. The combined post-fermentative addition of seeds and an astringency-modulator mannoprotein (MP) might be a potential strategy to solve this problem, since seeds might supply flavanols and improve wine chemical stability and the mannoprotein might modulate the changes induced in astringency by the addition of seeds and improve wine colloidal stability. The present study aimed at monitoring at different moments of winemaking and ageing the effects and side-effects of this combined strategy on the detailed flavanol, flavonol and anthocyanin compositions and on colour of wines made from Syrah grapes. Seeds were obtained from Pedro Ximénez overripe grapes. Flavanol composition and flavonol and anthocyanin compositions were determined by HPLC-MSn-MRM and HPLC-DAD-MSn analyses, respectively. Colour changes caused by these additions were studied from CIELAB parameters as well as the ability of these techniques to protect colour from bleaching agents, such as SO 2. In general, the addition of seeds initially increased the levels of flavanols and anthocyanins. However, during bottle ageing a reduction in the levels of flavanols, flavonols and anthocyanins could be observed in seed treated wines, which might be related to the greater formation of flavanol aggregates associated with greater levels of flavanols. This effect was partially solved for most of the flavonoids studied with the additional MP treatment. Treated and control wines showed colour differences that were visible to human eye, although they were reduced over time. At the end of the study, treated wines showed colour parameters corresponding to younger wines than those observed in control wines. A greater resistance against SO 2 bleaching was also observed in treated wines, which can be mainly associated to the greater percentages of polymeric pigments caused by seed treatment and to the improvement of the colloidal stability of SO 2 -resistant pigments caused by the addition of the MP. Unlabelled Image • The addition of seeds from overripe grapes caused changes in wine flavanol profile. • The extra supply of flavanols caused higher decreases in their levels during ageing. • Flavonols and anthocyanins were also affected by the greater flavanol levels. • Mannoproteins can partly revert these flavonoid decreases related to seed addition. • Colour of treated (seed+MP) wines was more stable and associated to younger wines. [ABSTRACT FROM AUTHOR]