Extraction of anthocyanins

ReviUa, E. et al.. Comparison of several procedures used for the extraction of anthocyanins from red grapes, J. Agric. Food Chem., 46, 4592, 1998. 

The extraction of anthocyanins is the first step in the determination of both total and individual anthocyanins in any type of plant tissue. The choice of an extraction method is of great importance in the analysis of anthocyanins and largely depends on the purpose of the extraction, the nature of the anthocyanins, and the source material. A good extraction procedure should maximize anthocyanin recovery with... 

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. 

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

Mantell, C., Martinez de la Ossa, E., and Rodriguez, M., Supercritical fluid extraction of anthocyanins from grape pomace, in Solvent Extraction for the 21st Century, Cox, M., Hidalgo, M., and Valiente, M., Eds., Barcelona, Spain, 1999. 

Corrales M, Toepfl S, Butz P, Knorr D and Tauscher B. 2008. Extraction of anthocyanins from grape byproducts assisted by ultrasonics, high hydrostatic pressure or pulsed electric fields a comparison. Innov Food Sci Emerg Technol 9(1) 85-91. 

The sugars attached to the anthocyanin molecule are in order of relative abundance glucose, rhamnose, galactose, xylose, arabinose, and glucuronic acid. The molecule may also contain one or more of the acyl acids p-coumaric, caffeic, and ferulic or the aliphatic acids malonic and acetic esterified to the sugar molecules. Extracts of anthocyanins invariably contain flavonoids, phenolic acids, catechins and polyphenols. The net result is that it is impossible to express the chemical composition accurately. Specifications usually present tinctorial power, acidity, per cent solids, per cent ash and other physical properties. 

Extraction of flavonoids from grapes is classically carried out with organic solvents, starting from fresh, frozen, or freeze-dried material. The most commonly used solvents are methanol, ethanol, and acetone, which can be used pure or mixed with water. Extraction of anthocyanins is commonly achieved at low temperatures with acidified methanol. The use of acid maintains the anthocyanins in the most stable flavylium forms but may cause degradation of... 

Basic Protocol 1 Acetone Extraction and Chloroform Partition of Anthocyanins FI.1.1 Alternate Protocol Methanol Extraction of Anthocyanins FI.1.3... 

Metivier, R.P., Francis, F.J., and Clydesdale, F.M. 1980. Solvent extraction of anthocyanins from wine pomace. J. Food Sci. 45 1099-1100. 

Manhita, A.C. Teixeira, D.M. da Costa, C.T. 2006. Application of sample disruption methods in the extraction of anthocyanins from solid or semi-solid vegetable samples. J. Chromatogr. A 1129 14-20. 

Seabra, I.J. Braga, M.E.M. Batista, M.T. de Sousa, H.C. 2010. Effect of solvent (CO2/ ethanol/Fl20) on the fractionated enhanced solvent extraction of anthocyanins from elderberry pomace. J. Supercrit. Fluids 54 145-152. 

Sun, Y. Liao, X. Wang, Z. Hu, X. Chen, F. 2007. Optimization of microwave-assisted extraction of anthocyanins in red raspberries and identification of anthocyanin of extracts using high-performance liquid chromatography mass spectrometry. Eur. Food Res. Tech. 225 511-523. 

Yang, Z. Zhai, W. 2010. Optimization of microwave-assisted extraction of anthocyanins from purple com (Zea mays, L.) cob and identification with HPLC-MS. Innov. Food Sci. Emerg. Tech. 11 470 76. 

Measurement of absorptivity of a solution of a crude extract of anthocyanins from a food or botanical extract at a single wavelength has been used for the measurement of total anthocyanins. This is possible because anthocyanins have a typical absorption band in the 490 to 550 nm region of the visible spectra. This simple method may be inappropriate in some cases because of interferences from antho-cyanin degradation products. In an attempt to overcome this deficiency, a subtractive or differential method has been used to quantify anthocyanins separate from their degradation products (Jackman et ah, 1996). The differential method measures the absorbance at two different pH values, and relies on the structural transformations of the anthocyanin chromophore as a function of pH (Figure 5.3). This concept was first introduced by Sonheimer and Kertesz in 1948, who... 

FIGURE 11.17 Extraction of anthocyanins from grape pomace at room temperature with ethanol containing 1% HC1. (From Metivier et al., 1980)... 

C. One gram of the sample is ground with mortar and pestle and extracted twice with 5 mL of a formic acid/methanol 1 9 (v/v) solution for 1 h under shaking at room temperature in the dark. The extracts are combined and centrifuged at 18.000 g for 10 min. In an alternative, 50% (v/v) acetic acid in water was proposed as solvent in the extraction of anthocyanins from skins (Yamane et al., 2006). 

Mantell, C., Rodriguez, M., and de la Ossa, E. M. (2003). A screening analysis of the high-pressure extraction of anthocyanins from red grape pomace with carbon dioxide and cosolvent. Eng. Life Sci. 3, 38M2. 

Extraction of anthocyanins in Cabernet Sauvignon grape skins. 

---