Phytochemical screening Determination of Lignin Content

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IV. RESULTS AND DISCUSSIONS

A. PHYTOCHEMICAL SCREENING AND LIGNIN CONTENT OF CGR

SAMPLES Coffee ground residue Coffea arabica that were collected from 10 coffee shops in Chiang Rai Province, Thailand were labeled as A, B, C, D, E, F, G, H, I and J as shown in Appendix 1. The coffee shops were chose by several criterias such as scale of production, location and coffee bean distributor. The preliminary research included the phytochemical screening and determination of lignin content in dried-coffee ground residue less than 13 of moisture content Figure 5 Figure 5 Dried-CGR

1. Phytochemical screening

Phytochemical screening normally is used as preliminary research to know the chemical constituent contained in plant material. This screening could investigate qualitatively presence of some phythochemicals Kantamreddi et al., 2010. The presence of phytochemicals was shown by changing of color, turbidity, pH or other physical properties when small portions of extract was dissolved with tested chemical or reagents. Phytochemical screening in CGR revealed the presence of phenolic compounds, gallic acid, and chlorogenic acid in all samples and negative for the presence of anthocyanin, leucoanthocyanidin, flavonoids, tannin, and catechin Table 2. This result showed that CGR still had a large amount of those compounds. The other compounds that showed negative results in the test might be contained at the small amount in the dried-CGR. Therefore, the amount of phenolic compounds and chlorogenic acid were determined in the CGR extracts in the next part of this work. The amount of caffeine and anthocyanin were also determined.

2. Determination of Lignin Content

Lignin is complex non-soluble phenolic polymers and integral part of secondary cell walls of plants Poeteau et al., 2003. Lignin acts naturally as antioxidant against chemical, biological and mechanical stress in plants Kosikova, 2009. Total lignin in dried-CGR samples were shown in Figure 6. The result showed that total lignin content of dried-CGR ranged between 395 – 444 mgg. The result also showed that sample B had the highest lignin content 444.25 mgg. This result was slightly higher than that those reported by Caetano et al. 2012, which was 336 mgg. Lignin contained in a minor amount in coffee seeds than the other parts of coffee berry Murthy, 2011. 16 Table 2 Results of phytochemical screening of coffee ground residue CGR No. Bioactive Compounds Name Positive Appearances Coffee Ground Residue From Picture A B C D E F G H I J 1 Phenolic Compounds a Dark blue precipitate + + + + + + + + + + 2 Gallic Acid a Dark blue precipitate + + + + + + + + + + 3 Chlorogenic Acids a Dark blue solution + + + + + + + + + + 4 Flavonoids and its derivaties i.e: flavanonol, flavonone, and flavonol- 3-glycoside b ; flavonol, xanthone, chalcone, and ourone c Dark red or light color solution b ; yellow, orange, red-purple, and orange-brown solution c - - - - - - - - - - 5 Anthocyanin d Red color solution when added HCl and changing into blue when added ammonia - - - - - - - - - - 6 Catechin e Yellow color solution - - - - - - - - - - 7 Leucoanthocyanidin e red color solution - - - - - - - - - - 8 Tannin compounds f precipitates - - - - - - - - - - a determined by ferric chloride test b determined by pew test c determined by base reaction d determined by pH test e determined by leucoanthocyanidin test f determined by gelatin test 17 The values with different letters a-h in each column show a significant differencep0.05 Figure 6 Total lignin of dried-coffee ground residue

B. Extraction of CGR