Polyphenols colored

The polyphenolic colored substances of cane juice, largely tannins and anthocyanins,34 form even more intensely colored iron complexes. Some of these compounds survive defecation and darken further with prolonged exposure to air and ferric ion at elevated temperatures. 

Upon maturation of both softwoods and hardwoods, the parenchyma cells at the core die. This portion of the wood is called heartwood and often contains polyphenols, davones, and other colored compounds that do not occur in the contrasting sapwood. A clear, visual distinction usually exists between heartwood and sapwood, depending on the species. Heartwood compounds, eg, dihydro quercetin (taxifofin,... 

Fruifs and vegetables also contain ofher bioactive substances such as polyphenols (including well-known pigments anthocyanins, flavonols) and non-provitamin A carotenoids (mainly lycopene, lutein, and zeaxanthin) that may have protective effects on chronic diseases. Polyphenols and carotenoids are known to display antioxidant activities, counteracting oxidative alterations in cells. Besides these antioxidant properties, these colored bioactive substances may exert other actions on cell signaling and gene expression. 

The effects of catechin, epicatechin, procyanidin B2, caffeic acid, / -coumaric acid, myricetrin, and quercetrin on the color intensity and stability of malvidin 3-glucoside at a molar ratio of 1 1 under conditions similar to red wine were evaluated. " Flavan 3-ols appeared to have the lowest protective effects and flavonols the highest strong color changes were visually perceptible. " In the complexation of malvin chloride and natural polyphenols, flavonol glycosides by far exerted the best protector effect. ... 

Zakharova and co-workers studied a red variety in 1997 to gain a closer insight into its polyphenol oxidase activity. More recently, a study addressing the antioxidant properties of a red colored Swiss chard was published. However, the pigments were erroneously addressed as anthocyanins. 

Thousands of polyphenols from fruits (grapes, apples, etc.), vegetables (horse beans), and teas have been identified, many having good coloring properties, especially anthocyanins and some flavonoids. Well-documented reviews discuss the coloring capacities of some polyphenols including procyanidins. - Detailed presentations of anthocyanin and flavonoid properties and analysis are included in Sections 2.3, 4.3, and 6.3. The soluble proanthocyanidins of the colored horse bean Viciafaba L. seed coats were isolated and separated by solvent partition. 

Francis, F.J., Polyphenols as natural food colorants, in Polyphenolic Phenomena, Scalbert A., Ed., INRA, Paris, 1993, 209. 

Francis, F.J., Caramel, brown polyphenols and iridoids, in Colorants, Eagan Press, St. Paul, MN, 83,1999. 

French researchers provided an alternative to the tartrazine synthetic colorant (E 102), valorizing a phloridzine oxidation product (POP) generated as a by-product of the cider industry. Phloridzine is a polyphenol specific to apples and shows good antioxidant capacity. When apples are pressed to yield juice, phloridzine, oxygen, and polyphenoloxidase enzyme combine to form POP. This brilliant yellow natural colorant with nuances dependent on pH level can be incorporated easily into water-based foods such as beverages (juices, syrups) and confectionery creams because it is stable during production processes. Details about the specific formulations of these colorants are presented in Section 5.1. 

Lea AGH. 1992. Flavor, color and stability in fruit products the effect of polyphenols. In Hemingway RW and Leaks PE, editors. Plant Polyphenols. New York Plenum Press, pp. 827-847. 

Wine and beer industry Polyphenols can alter color and flavor of products such as wines. There are many aggressive ways of removing polyphenolic compounds, such as using polyvinylpolypyrrolidone (PVPP) or sulfur dioxide. However, polyphenol removal should be selective to avoid the undesirable alteration of the wine s organoleptic characteristics. For this reason, one option is to use laccases that polymerize the polyphenolic compounds during the wine-making process and then to remove these polymers by clarification (Morozova and others 2007). Several papers have reported that laccase is able to remove undesirable polyphenols and produce stable wines with a good flavor. 

Sanchez-Morcno (2002) considered that this assay is an easy and accurate method for determining antioxidant capacity in fruit and vegetable samples. The DPPH assay has been used to determine the antioxidant activity of polyphenols (Sanchez-Moreno and others 1998 Bao and others 2004) flavonols (Jimenez and others 1998 1999 Choi and others 2002) anthocyanin-based natural colorants from berries (Espin and others... 

There are two important sources of brown polyphenols, cocoa and tea, used as colorants for foods. Both are very old and date back to antiquity. 

The tea plant, Thea sinensis, has provided a desirable beverage for centuries but it is also used as a colorant. Extracts of tea contain a very complex mixture of glycosides of myricetin, quercitin and kaempferol, epicatechin, epigallocatechins, acyl acids and many other polyphenol compounds.33 In black tea, the above compounds may act as precursors to the poorly defined compounds thearubin and theaflavin. 

FRANCIS, F. J. Caramel, Brown Polyphenols, and Iridoids. Chap. 10 in Colorants, Eagen Press, St. Paul, MN, 1999, pp. 83-8. 

Graham HD (1992) Stabilization of the Prussian blue color in the determination of polyphenols. J Agric Food Chem 40 801-805... 

Removing Interfering Polyphenols. The most troublesome problem encountered was high polyphenol content. If not removed, this dark-colored wood extractive decreased resolution during chromatographic separations, quickly render expensive chromatographic media (e.g., HPLC columns) nearly useless, and often precipitated enzymes during subsequent purification steps (14,15), We found it best to remove the bulk of this material prior to the first concentration step. 

Curcumin (16) is a polyphenolic compound derived naturally from the plant Curcuma longa also known as turmeric (Haldi). It is the primary source of the distinctive bright yellow color of the spice commonly used in the preparation of curries. Originating in India, turmeric was probably cultivated initially as a dye, and later used in cosmetics and foods. It has... 

PVPP is commonly used to remove undesirable brown or pink pigments from wine (Jackson, 1994). However, because much of the color of red wine is due to polyphenolic compounds, treatment with PVPP or other polyamides can diminish the red color and so must be carefully controlled. Additions of gelatin or egg white (egg albumin has about... 

Nakayama, T. et al., Aureusidin synthase a polyphenol oxidase homolog responsible for flower coloration. Science, 290, 1163, 2000. 

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