Chlorogenic acid BIOACTIVE COMPOUNDS

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D. BIOACTIVE COMPOUNDS

Bioactive compounds are compounds usually produced by plant which has pharmacological or toxicological effects in man and animals Bernhoft, 2010. Typically, bioactive compounds are produced as secondary metabolites. Secondary metabolites are produced by plants or animals in addition to the primary metabolic routes of compounds as plant growth and development, such as carbohydrates, amino acids, proteins and lipids. Every plant contained different bioactive compounds and several compounds have specific function in plant metabolisms. Coffee fruit has several bioactive compounds such as phenolic compounds, alkaloid, flavonoids and etc. Phenolic compound is the largest class of bioactive compounds in plants. It has the highest amount than the other bioactive compounds in plants. Phenolics are chemical compounds consisting of a hydroxyl group —OH bonded directly to an aromatic hydrocarbon group Rispail, 2005. Phenolic compounds like chlorogenic acid and caffeine are the mainly found in coffee and other phenolic compounds such as tannin, lignin, and anthocyanin are present in minor amounts Farah et al., 2006. Phenolic composition of green Arabica coffee bean was shown Figure 3. Table 1 Phenolic composition of green Arabica coffee bean Wang, 2012 No. Phenolic compounds Amount g100g 1 Aliphatic acid 1.1 2 Quinic acid 0.4 3 Chlorogenic acid 6.5 4 Caffeine 1.2 5 Trigonelline 1.0 6 Other compounds 0.2

1. Chlorogenic acid

Chlorgenic acids are esters of trans-cinnamic acids and quinic acids. Coffee beans are part of coffees which have the highest amounts of chlorogenic acid approximately 14 Esquivel et al., 2011. Chlorogenic acid has been reported that could be influence in determining coffee quality and play an important role in the formation of coffee flavor Carelli et al., 1974. Esters of chlorogenic acid which usually found in the coffee beans are caffeic acid, ferulic acid, and p- coumaric acid Cliford, 2003. Furthermore, these compounds have potential as antioxidant activity. Chlorogenic acid in coffee by products such as silver skin and spent waste contributed to antioxidant activity and contained antioxidant dietary fiber Murthy et al., 2010. Chlorogenic acid, trigonelline, and caffeic acid from coffee exert inhibitory activity against the growth of Streptococcus mutans Anonio et al., 2010. 2. Caffeine Caffeine is an alkaloid which belongs to xanthenes family. Approximately, coffee beans contained 1-4 dry basis of caffeine Belitz et al., 2009. Caffeine has slightly bitter flavor. Therefore, caffeine strongly related to the quality of coffee beverages. Caffeine has strong stimulant effects. Caffeine could increase alertness through stimulation of the central nervous system, rise blood circulation and respiration Belitz et al., 2009. The antioxidant capacity of coffee brew was contributed by caffeine and caffeolyquinic acid Ludwig et al., 2011. Coffee bean 125 µgmL conc. also could inhibit the growth of some bacteria such as Staphylococcus aureus, Escherichia coli and Bacillus cereus. 3. Anthocyanin Anthocyanins are one of flavonoid compounds, which are widely distributed plant. Anthocyanins just differ in oxidation state from the other flavonoids such as flavonols, flavan-3- ols, flavones, flavanones, and flavanonols Einbond et al., 2002. Fresh coffee husk outer skin and pulp was investigated as potential source of anthocyanins. Cyanidin 3-rutinoside was characterized as the dominant anthocyanin in fresh coffee husks and its recommended fresh coffee husks to be a good candidate as pigment source Emille et al., 2007. 6

4. Lignin