Extraction of Pectin RESULTS AND DISCUSSIONS

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IV. RESULTS AND DISCUSSIONS

A. Extraction of Pectin

In this pectin extraction, two factors were used, which were microwave power and heating time. Microwave power used was 600 W and 800 W. Trial and error were done prior to the determination of these two values of microwave power. At trial and error, the use of microwave power above 800 W which was 1000 W resulted in overheating and very aqueous solution, so the solution could not be filtered using a cheesecloth. Therefore, this research was only used two power alone which was 600 W and 800 W. While another factor, heating time used was 3 minutes, 5 minutes, and 7 minutes. Various studies on the extraction of pectin by microwave heating was using the average time between 2-10 minutes. Therefore, this study used 3, 5, and 7 minutes for the range which was not too narrow and fairly evenly. In the first step of extraction, sugar palm seed was weighed and crushed using blender for 2 min by adding 600 mL of distilled water Figure 8a. Adjustment of pH was done by adding hydrochloride acid 0.25 N until pH reaches 1.5 Figure 8b. Extraction was performed on microwave oven with microwave power and time varies as treatments Figure 8c. After heating in the microwave, solution then filtrated using cheesecloth. The waste of this solution was separated and was not used for further step Figure 8d. The filtrate then concentrated using a rotary evaporator. Concentration process was done until the volume of solution became half of the initial volume Figure 8e. This was necessary because the ethanol would be able to precipitate the polysaccharide inside solution when the solution had a concentration over 80. Ethanol used also must have a concentration above 85. Therefore, this study used 95 ethanol solution, and the ratio between solution and ethanol was 1:2. The addition of ethanol could precipitate the polysaccharide inside solution because the ethanol would bind water so that the stability of the water- polysaccharide binding could be disrupted and polysaccharids eventually settled. After addition of ethanol, all types of polysaccharides inside solution would precipitate into fibrous-like clumps Figure 8f. The precipitate was then filtered, dried, and blended to produce a powdered polysaccharide Figure 8g. This powder contained various polysaccharide components such as pectin, starch, cellulose, and others. Extraction of pectin was conducted according to the flowchart on previous section. These are the documentation of pectin extraction. a Sugar palm seed blend with water b After adjustment pH into 1.5 c After microwave treatment d After filtration using cheesecloth 14 e Waste of filtration f After concentration using rotary evaporator g After ethanol addition h Dried pectin after drying in hot air oven Figure 8. Extraction of pectin from sugar palm seed Pectin is a complex substance belongs to heteropolysaccharides. Like other plant polysaccharides, pectin has varied composition and molecular size so that the chemical structure and molecular weight also has so many varieties. The composition depends on the type of extracted materials, the extraction conditions, the origin location of materials and another environmental factor Chang et al. 1994. Pectin is obtained from plant tissue by extraction using a solvent, in this case was using water acidified with hydrochloric acid. Yield of pectin produced depends on the type and plant parts that extracted. Before extraction of pectin, it is important to made materials preparations so the contact material with a solution which will be easier. The yield of pectin from young sugar palm seed of Arenga westerhoutii Griff. ranged between 20.50- 39.31. The highest yield obtained from extraction with microwave power of 800 Watt for 7 minutes and the lowest yield obtained in the extraction with microwave power of 600 Watt for 3 minutes. The graph showing the relationship between microwave power and time of extraction to the pectin yield produced can be seen in Figure 9. The longer the time and the higher the microwave power, extraction of pectin produced larger yield. 15 Figure 9. The relationship between microwave power and extraction time to pectin yield Results of analysis of variance showed that the microwave power and extraction time significantly affect the yield produced, but interaction between microwave power and extraction time was not significantly affect the yield produced Appendix 1b. On the pectin extraction with treatment microwave power of 600 watt for 3 minutes, the yield is 20.50 and would become higher as the microwave power and extraction time were increased. The improvement in yield was proportional to the power and duration of microwave heating. The longer the contact between the material and solvent, would provide greater opportunities to hydrolyze protopectin contained in the material so it could increase the yield of pectin. The higher the microwave power would effect on increasing extraction temperature, the kinetics of protopectin hydrolysis reaction increased so the resulted pectin yield also increased. In addition, the quantities in Figure 9 confirm that there was an inverse correlation between the microwave power and required time to achieve the highest yields. In case of weaker microwave powers, longer heating time was needed. For instance the pectin yield in microwave radiation of 600 W and 7 min 32.05 was close to the one in power of 800 W and 5 min 31.21. Bagherian et al. 2011 found that in the conventional method, it took 90 minutes to get a high yield, while using microwave heating, time can be reduced to 2 minutes to extract the same amount of pectin. Theoretically, microwave radiation loosens the cell wall matrix and lead to severing the parenchymal cells Kratchanova, Pavlova, and Panchev, 2004, thereby the skin tissues are rapidly and extensively opened up by the microwave. This will lead to increased interaction between extracting agent and source material in extraction process. As a result, permeation of the extracting agent will be increased. It leads to effective increase in the yield of pectin extraction. Pectin yields produced from sugar palm seed Arenga westerhoutii Griff. were quite high. When compared to sugar palm seed from species Arenga pinnata, the resulting yield was still higher. Pectin yield of Arenga pinnata seed that extracted using the microwave ranged between 10.80-23.50 Rungrodnimitchai, 2011. While other sources of pectin which is often used for the extraction like grapefruit produced yield around 28.71 Bagherian et al., 2011. Based on data reported by Yoeh et al. 2008, the amount of extracted pectin increased with the extraction period, but the increase was gradual. Also, the experimental data obtained by Kratchanova, Pavlova, and Panchev 2004 showed similar trends. Meanwhile, Goycoolea and Adriana 2003 explains that the use of HCl with a concentration of 0.1 N on the extraction of pectin provides the best yield of pectin.

B. Pectin Characterization