ANTHOCYANIN

Anthocyanin Extraction

Ketaren (1986) explains that the extraction is a way to get the substance of the material suspected to contain the substance. Extraction can be done in various ways. Using solvent extraction based on the solubility of the component to other components in the mixture (Suyitno, 1989). Shriner et al. (1980) stated that polar solvents will dissolve polar solutes and non-polar solvents will dissolve the non-polar solute or so-called "like dissolve like".

In the fruit or vegetable, anthocyanin pigments are generally located in the cells near the surface (Markakis, 1982). Extraction of anthocyanin pigments from plant materials commonly used solvent extractors HCl in ethanol (Gao and Mazza, 1996). HCl in ethanol plants will denaturation of the cell membrane and then dissolving the pigment anthocyanin out of the cell. Anthocyanin pigments soluble in ethanol because both polar (Broillard, 1982).
In the study Saati (2002) for the extraction of anthocyanins from flowers girlfriend water, the best solvent used is ethanol 95%. So also with the research Wijaya (2001) on the extraction of the pigment from the skin of the fruit rambutan. This is due to the level of anthocyanin polarity similar to the 95% ethanol that can dissolve well in ethanol 95%. In addition to the solvent, according Pifferi and Vaccari (1998), factors that can affect the outcome of anthocyanin extraction is the extraction time, pH and temperature extraction.

The basic structure of anthocyanin is anthocyanidins. Anthocyanidins or aglycone consists of aromatic rings (A) that binds to the heterocyclic ring (C) that contains oxygen and bound by carbon-carbon bonds in the third aromatic ring (B). When anthocyanidins found in the form of glycosides, it is called anthocyanin. Anthocyanin is very unstable and susceptible to damage. Stability is affected by several factors such as pH, temperature, chemical structure, light, solvents, enzymes, flavonoids, protein and metal ions (Castañeda-Ovando et al. 2009).

Anthocyanins are synthesized in the shikimic biosynthetic pathway and use phenylalanine as a precursor. Enzymes that work is PAL

(phenylalanineammonialyase), CHS (Chalcone synthase), CHI (Chalcone isomerase), F3H (flavonone 3-hydroxylase), F3'H (flavonoid 30-hydroxylase), DFR (dihydroflavonol reductase), LDOX (anthocyanidin synthase), GST (glutathione-S-transferase) (Guo et al.2001).

Anthocyanins in plants serves as a veil to ultraviolet B light and protect chloroplasts against high light intensity. Anthocyanins may also act as a means of transport for the monosaccharides and as an osmotic regulator during periods of drought and low temperature. In general, anthocyanin antioxidants are believed to increase the response of plants to survival in biotic or abiotic stress. In addition, anthocyanins also plays an important role in the reproduction of plants that attract pollinators that can help in the pollination of flowers (Mori et al. 2007).

Anthocyanins are considered as an important component in human nutrition as a higher antioxidant than vitamins C and E. These compounds can capture free radicals by donating a hydrogen atom phenolic. Anthocyanins can be transported in the human body and show the antitumor activity, anticancer, antiviral, anti-inflammatory, inhibiting platelet aggregation, lowering blood capillary wall permeability and boost immunity (Stintzing and Carle 2004).

Materials for Extraction Process

Ethanol

Ethanol is a clear solution, colorless, volatile, and with a distinctive odor. In high concentrations, will cause a burning sensation when in contact with skin. Ethanol is an alcohol group, where the molecule contains a hydroxyl group (-OH) bonded to carbon atoms. Ethanol made since ancient times by the fermentation of sugar. This process is widely used in the industry with raw materials such as sugar. Ethanol is soluble in water and many organic solvents (Anonymous, 2004b)).

Ethanol is toxic, but the body will set immediately. More than 90% ethanol will be processed by the liver. In the liver, the enzyme alcohol dehydrogenase converts ethanol into acetaldehyde which is still toxic.

Ethanol Acetaldehyde

But acetaldehyde will be destroyed by the enzyme aldehyde dehydrogenase that megkonversinya into acetate ions.

Ethanol acetate ions

Meanwhile, according to the FDA, the residue levels of ethanol as a solvent in the extraction

is 50 ppm.

Hydrochloric acid (HCl)

Hydrochloric acid is a solution of hydrogen chloride (HCl) in water. The color varies from colorless to light yellow. The difference in color depending on its purity. At concentrations above 10%, hydrochloric acid produces a very pungent odor. Hydrochloric acid is highly corrosive and can damage metals such as iron and steel (Wikipedia, 2002).

Steam highly concentrated acid solutions can cause irritation to the eyes, while the direct contact can cause injury to the eyes and can cause blindness. If contact with the skin will cause burns. HCl is hygroscopic, these substances are generally present in the form of aerosols in the atmosphere (NRC, 2000). According to Revilla (1998), HCl can cause partial hydrolysis of the anthocyanins of red wine.

According to Maga and Tu (1994) allowed a marinade HCl food by FAO in 1974. HCl is also used to process that requires hydrolysis on materials such as proteins and starch. HCl can also be used for the production of "corn syrup" (Maga and Tu, 1994).

Citric Acid

Citric acid is an organic acid found in many fruits and vegetables. The highest concentration found in lemon and lime which is about 8% of the dry weight of the fruit. The acidity of citric acid by its three carboxyl groups COOH which can release protons into the solution. If this happens, the resulting ion called citrate ion (Wikipedia, 2004).
At room temperature, citric acid is a white crystalline powder form. Citric acid can be found in the form of "substance" (water-free) or monohydrate that contains one molecule of water per molecule of citric acid. Citric acid is used in food safe even in large amounts. It is based on national and international food regulations. Citric acid can be metabolized and excreted from the body (Wikipedia, 2004).

Food and beverage industry are using citric acid. Selection of type of acid is due to provide the typical incorporation of desirable properties and the market are available in large quantities. Citric acid is a food additive that has varied functions. Industrial food and beverage consumed mostly to reinforce the flavor and color. Another function is to control acidity. Control of the proper pH will prevent the growth of microorganisms and act as a preservative and helps prevent browning reaction (Hui, 1992).