Grape skin

Typically, grape skin extract has a specific gravity of 1.13 g/mL at 20°C, a solids content of 28—32° Brix (=t3°), a pH of 3.0, and a color strength as anthocyanin of about 1.25% (as measured at 520 nm ia pH 3.0 citrate buffet). Grape skin extract is also available as spray-dried powders with color values three to four times those of the liquid. The properties and uses of grape skin extract ate similar to those of grape color extract. 

Spices Rosemary (1000 ppm of extract with 0.92 mmol/g total phenols) Rosemary (200 ppm of extract with 0.92 mmol/g total phenol) Dried chicken meat for soup powder (up to 1000 ppm is acceptable sensorically) Potato flakes for mashed potatoes (up to 200 ppm is acceptable sensorically) Rosemary extract gave better protection than extracts of tea, grape skin or coffee Rosemary extract gave better protection than extracts of green tea, grape skin or coffee Nissen et al., 2000 Nissen et al., 2002... 

A number of handbooks and monographs are available with detailed descriptions of a variety of plant products and their use (Shahidi and Naczk, 1995). From a more practical point of view, an interlaboratory comparison between six university and industry laboratories of 17 extracts of spices, teas, coffees, and grape skin and of tomato peel slurry established within the framework of an EU sponsored programme, would be of interest (Schwarz et al, 2001). In this collaboration, detailed chemical analysis of the content of different phenolic compounds is compared with six antioxidant assays for the 17 extracts including different extraction procedures. 

Revilla, 1. et al.. Identification of anthocyanin derivatives in grape skin extracts and red wines by liquid chromatography with diode array and mass spectrometric detection, J. Chromatogr. A, 847, 83, 1999. 

Yong Ju, Z. and Howar, L.R., Effects of solvent and temperature on pressurized liquid extraction of anthocyans and total phenolics from dried red grape skin, J. Agric. Food Chem., 51, 5207, 2003. 

Ju and Howard (2003) studied pressurized hquid extraction of anthocyanins from dried red grape skins with six solvents at temperatures ranging from 20 to 140°C using 10.1 MPa. They found that the type of solvent and the temperature used affected the types and levels of anthocyanins in the PLE extracts. 

Anthocyanins, grape color extract, grape skin extract E 163 Yes... 

Kobayashi S, Goto-Yamamoto N and Hirochika H. 2004. Retrotransposon-induced mutations in grape skin color. Science 304 982. 

Figure 19 presents results of PCL examination of wines, grape skins, and grape pips. The very low antioxidant capacity of white wine is obviously related to the technology of its manufacturing it is prepared from pure juce without grape skins and pips, in contrast to red wine. The dependency of ACW on the storage time of red wine is depicted in Figure 20. White wine is stable in this sense.

Anthocyanins are extracted commercially using either acidified water or alcohol. The extract is then vacuum evaporated to produce a commercial colour concentrate. The raw materials can be blackcurrants, hibiscus, elderberry, red cabbage or black grape skins. The most commonly used commercially are black grape skins, which can be obtained as a by-product. 

The mash that ferments to form wine sometimes includes grape skins which are rich in enzymes. 

Grape skin extract (Enocianina) GMP for beverages E163 0-2.5... 

The optimum conditions for the MS detection of anthocyanin derivatives have also been intensively studied. Grape skin extract was prepared by macerating skins with methanol-formic acid (95 5) for three days changing the extracting agent each day. The combined extracts were evaporated and diluted with water. RP-HPLC measurements were carried out in an ODS column (150 X 4.6 mm i.d. particle size 5 /an) at 30°C. The solvents were water-formic acid (90 10, v/v, A) and methanol-water-formic acid (45 45 10, v/v, B). The gradient was from 35 to 95 per cent B in 20 min to 100 per cent B in 5 min final hold... 

Kennedy JA, Hayasaka Y, Vidal S et al (2001) Composition of grape skin proanthocyanidins at different stages of berry development. J Agile Food Chem 49 5348-5355... 

Fragments of plant raw materials (e.g., grape skins or fruit pulp) can in some cases pass through a process and enter the final product. If this occurs due to a processing problem, it is generally transitory and can be addressed by refiltering the product. 

Vidal, S. et al.. Mass spectrometric evidence for the existence of oligomeric anthocyanins in grape skins, J. Agric. Food Chem., 52, 7144, 2004. 

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