Principal component regression analysis of the relation between CIELAB color and monomeric anthocyanins in young Cabernet Sauvignon wines.

Center for Viticulture and Enology, College of Food Science & Nutritional Engineering, China Agricultural University, Haidian District, Beijing, PR China.
Molecules (Impact Factor: 2.42). 02/2008; 13(11):2859-70. DOI: 10.3390/molecules13112859
Source: PubMed

ABSTRACT Color is one of the key characteristics used to evaluate the sensory quality of red wine, and anthocyanins are the main contributors to color. Monomeric anthocyanins and CIELAB color values were investigated by HPLC-MS and spectrophotometry during fermentation of Cabernet Sauvignon red wine, and principal component regression (PCR), a statistical tool, was used to establish a linkage between the detected anthocyanins and wine coloring. The results showed that 14 monomeric anthocyanins could be identified in wine samples, and all of these anthocyanins were negatively correlated with the L*, b* and H*ab values, but positively correlated with a* and C*ab values. On an equal concentration basis for each detected anthocyanin, cyanidin-3-O-glucoside (Cy3-glu) had the most influence on CIELAB color value, while malvidin 3-O-glucoside (Mv3-glu) had the least. The color values of various monomeric anthocyanins were influenced by their structures, substituents on the B-ring, acyl groups on the glucoside and the molecular steric structure. This work develops a statistical method for evaluating correlation between wine color and monomeric anthocyanins, and also provides a basis for elucidating the effect of intramolecular copigmentation on wine coloring.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: PurposeThe quantification of phytopigments in riverbed sediments deserves further attention because it provides information about eutrophic levels, and therefore about sediment and water quality. Due to the current interest in the study of eutrophication processes, there is a need for the development of a rapid, simple, cost-effective, and nondestructive method of quantifying phytopigment content. We describe one method based on color measurements and without the need for extraction and chemical assay. Materials and methodsSediment cores were collected along the watercourse of the Anllóns River (northwest Spain). The reflectance color measurements were analyzed with the CIELAB color parameters, using Cartesian (L*a*b*) and cylindrical (L*C*abhab) coordinates. Phytopigments (chlorophyll a, chlorophyll b, phaeopigments and total carotenoids) were extracted with dimethylsulphoxide and were determined spectrophotometrically. Results and discussionThe CIELAB color parameters were significantly correlated with phytopigment content (involving logarithmic, inverse, and simple data). The linear regression equations were used to predict chlorophyll a, chlorophyll b, and carotenoid contents, as well as the total pigment contents from parameter a* (redness–greenness of the color) and parameter C*ab (chroma of the color), and values of adjusted R 2 were close to 0.9. The closest relation between phytopigments and color parameters corresponded to chlorophyll a, which may be estimated by means of Chla = 46.4–70.6 log10 (a*) and Chla = −15.7 + 238.1 (1/C*ab) as predictive equations. The phaeophytinization quotient is somewhat questionable due to the low adjusted R 2 values obtained. ConclusionsThis work demonstrates that it is possible to determine phytopigment contents in riverbed sediments by means of a nondestructive colorimetric method employing the CIELAB color parameters. In addition, the abundance of phytopigments in the sediment core showed no clear trend either along the longitudinal axis of the river or in relation to sediment depth. KeywordsBenthic algae–Chlorophyll–CIELAB color measurements–River sediments–Settled phytoplankton
    Journal of Soils and Sediments 07/2011; 11(5):841-851. DOI:10.1007/s11368-011-0358-z · 2.11 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Phenolic compound profiles were investigated by HPLC-MS in two consecutive years to assess genotypic variation in berry skins of nine red Vitis vinifera cultivars. The results showed that the types and levels of phenolic compounds greatly varied with cultivar. Common wine grape cultivars such as Syrah, Cabernet Sauvignon, Cabernet Gernischt and Merlot contained more types of anthocyanins, flavonols, flavan-3-ols, stilbenes and phenolic acids than Gamay, Yan73, Pinot Noir, Zinfandel and Muskat Rosovyi. Yan 73 and Pinot Noir had abundant anthocyanins, but only a few nonanthocyanin phenolic compounds. Gamay, Zinfandel and Muskat Rosovyi contained only a few anthocyanins and flavonols. For a grape cultivar, the ratio of one anthocyanin content to total anthocyanin content did not change greatly from one year to the next, unlike for non-anthocyanins. Cluster analysis showed that except for Syrah and Yan 73, the phenolic profiles in the tested grape cultivars had no significant year-to-year variations.
    Molecules 12/2009; 14(12):4922-35. DOI:10.3390/molecules14124922 · 2.42 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To obtain maximum non-anthocyanin phenolics from grape skins, various extraction conditions were evaluated according to the amounts of 8 non-anthocyanin phenolics. The result showed that the optimal extraction was performed in ethyl acetate solution at 25°C, with liquid/solid ratio of 10:1 (ml/g) and for 30 min. On this basis, the non-anthocyanin extracts from two red and two white grape cultivars were analyzed using high performance liquid chromatography coupled with tandem mass spectrometry (HPLC- MS/MS), and twenty-four compounds were qualified and simultaneously quantified, which indicated that the present extraction method was suitable for the study of non-anthocyanin in grape skins.
    Analytical Letters 02/2010; 43(5):776-785. DOI:10.1080/00032710903486351 · 0.98 Impact Factor


Available from