Paper presented at the 52nd CFCS Annual Meeting, Guadeloupe, July 10-16, 2016
THE EXTRACTION OF PECTIN FROM GRAPEFRUIT CITRUS PARASIDI AND PASSION FRUIT PASSIFLORA EDULIS FLAVICARPA PEELS USING THE DIRECT BOILING EXTRACTION METHOD A.Cederboom1 and R.Sahtoe2 1
Student and 2 lecturer of Agricultural Production, Faculty of Technology, Anton de Kom University of Suriname, Paramaribo, Suriname Keywords: grapefruit, passion fruit, peels, pectin extraction, pectin yield fresh weight base, direct boiling method Abstract Pectin is a commercially interesting polysaccharide frequently used as gelling agent in food. Common sources of pectin are the peels of fruit, a waste product of for instance the juice industry. The objective of this present study was to extract pectin from grapefruit and passion fruit peels that are cultivated in Suriname under different extraction conditions with variation of two acids. The different solvents for extraction were 35% HCl and HNO3 68%. The purpose was to see which of the selected fruits had a higher yield percentage on fresh weight basis. The solvents were diluted to a pH of 2, the extraction temperature was ± 98 ̊ C and the time periods consisted of ½h; 1h; 1½h; 2h; 2½h and 3h. The experiment was performed in duplicate. The yield of pectin on fresh weight basis extracted using diluted HCl on grapefruit was 3.17% and HCl on passion fruit was 1.22%. The extraction of pectin using diluted HNO3 acid on grapefruit yielded 2.63% and for passion fruit it resulted in 1.08%. The optimum extraction times for grapefruit extracted with HCl and HNO3 were both 2 hours and for passion fruit extracted with HCl was 1½ hours and the extraction with HNO3 was 2 hours. The use of HCl for the pectin extraction resulted in a higher yield for both fruits. The pectin extraction for grapefruit resulted in a higher yield percentage on fresh weight basis. This study resulted in the extraction of pectin from grapefruit and passion fruit peels, providing essential information for potential industrial extraction of pectin. Introduction Pectin is a commercially interesting polysaccharide frequently used as gelling agent in food. Common sources of pectin are the peels of fruit, a waste product of for instance the juice industry. Pectin is found in fruits, vegetables and nuts (Baker, 1997). Fruit pectin is primarily found in the cell wall of plant cells and it gives structure to the non-woody parts of the plant (Srivastava and Malviya, 2011.) Popular sources of commercial pectin are citrus fruit peels and seeds and apple pomace (May, 1989). Fruit pectin is an essential ingredient in the food industry but also in the pharmaceutical and cosmetical industry. Its main uses are as a gelling agent, thickening agent and stabilizer in foods (Srivastava and Maliviya, 2011; GENU pectin book, 2004). The first commercial pectin production of liquid pectin extract took place in Germany in 1908. Soon the process expanded in the US where it was patented by Douglas (IPPA, 2001). In recent years the biggest pectin producers are in Europe and other countries are Mexico, China and Brasil (IPPA, 2001). Popular pectin brands are CPKelco, Danisco, Cargill, H&F and Yantai (Helal, 2014). From a recent trade site online the trade prices of pectin can differ from US$1 up to US$ 300,- per kilogram pectin (alibaba.com, 2016). Currently in Suriname there is no pectin production known to be executed. The food processing industry in Suriname mainly uses imported pectin in their processing production even though there are a lot of fruits known to be cultivated here that may potentially serve as a source of pectin. The objective of this study was to extract pectin from an exotic fruit, passion fruit, and a citrus fruit, grapefruit and to gain its pectin yield by comparing it to the literature values for the selected fruits. Materials and methods The raw material was purchased in a local fruit stand for the grapefruits and market for the passion fruits nearby the university complex. The pectin extraction was performed by gathering the fruits and cleansing them with clean tap water and a brush. The pulp of the fruits are removed from the peels and the peels are collected. The peels are minimized and cut into smaller portions of approximately 2 by 2 mm. After weighing the peels, they are placed in an acid solution of either 68% HNO3 or 35% HCl of pH ≈ 2 or 0.01M. The peels are heated to the boiling point, 100˚ C, and left to cool down when the extraction time is reached. The alcohol precipitation is carried out using 95% ethanol. The obtained pectin is separated from the solute and dried at 50˚ C for 24 h and weighed for calculating the pectin yield. Results and discussions The experiment resulted in a pectin yield for grapefruit extracted with HCl of 3,17% and extracted with HNO3 was 2,63% with peak extraction times of 2 hours and 2½ hours. The pectin yield of passion fruit extracted with HCl is 1,22% and extracted with HNO3 was 1,08% with a peak extraction time of 2 hours and 1½ hours.
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