During orange juice
production, a half of fresh oranges weight is considered as production waste
(peels, pulp, seeds, orange leaves and damaged orange fruits). An alternative
for the management of these wastes is their treatment by addition of lime and a
latter pressing, obtaining a press cake and a press liquor rich in sugars (10° Brix)
and citric acid, protein, pectin and ethanol. For non-thermal concentration of
press liquor to obtain citruss molasses (65°-70° Brix), the removal of pectin
is necessary. Traditionally, depectinization of juices has been done by using
pectinmethylesterase (PME) enzymes from external sources. In this work it performed
the extraction of PME enzymes from orange peels to obtain the optimum
extraction conditions. Two different methods of solventextraction were compared (conventional andultrasound-assisted
methods). For the conventional extraction experiments, a central composite design
with three variables ([NaCl], pH and time) and five replicates of the center
point was used. For ultrasound-assisted extraction, experiments were done at pH
= 5.5 and [NaCl] = 1.25M), varying
extraction time (1-30 min). Response variables were PME activity,
protein content and a ratio between them, named PME effectiveness (ηPME). At the same experimental
conditions (pH =5.5, [NaCl] = 1.25 M, t = 15 min) it was found that conventional extractions led to slightly better results in terms of ηPME than ultrasound-assisted extraction method.
Cite this paper
D. Rodriguez-Lopez, A. , Mayor, L. , M. Galfarsoro, M. , Martinez-Otalo, J. and M. Garcia-Castello, E. (2013) Pectinmethylesterase extraction from orange solid wastes: Optimization and comparison between conventional and ultrasound-assisted treatments. Agricultural Sciences
, 45-50. doi: 10.4236/as.2013.49B008
 Braddock, R.J. (1999) Handbook of citrus by-products and processing technology, John Wiley & Sons, Inc., Hoboken.
 García, E., Gozálvez, J.M. and Lora, J. (2002) Use of reverse osmosis as a preconcentration system of waste leaching liquid from the citric juice production industry. Desalination, 148, 137-142.
 United States Department of Agriculture, USDA (2010) http://usda.mannlib.cornell.edu/MannUsda/viewStaticPage.do?.url=http://usda.mannlib.cornell.edu/usda/ers/./89022/2006/index.html.
 Martín, M.A., Siles, J.A., Chica, A.F. and Martín, A. (2010) Biomethanization of orange peel waste. Bioresource Technology, 101, 8993-8999.
 Bampidis, V.A. and Robinson, P.H. (2006). Citrus by- prod-ucts as ruminant feeds: A review. Animal Feed Science and Technology, 128, 175-217.
 Wing, J.M., Van Horn, H.H., Sklare, S.D. and Harris Jr., B. (1988) Effects of citrus molasses distillers solubles and molasses on rumen parameters and lactation. Journal of Dairy Science, 71, 414-420.
 Garcia-Castello, E., Lora-Garcia, J., Garcia-Garrido, J. and Rodriguez-Lopez, A.D. (2006). Energetic comparison for leaching waste liquid from citric juice production using both reverse osmosis and multiple-effect evaporation. Desalination, 191, 178-185.
 Garcia-Castello, E.M., Mayor, L., Chorques, S., Argüelles, A., Vidal-Brotóns, D. and Gras, M.L. (2011) Reverse osmosis concentration of press liquid from orange juice solid wastes: Flux decline mechanisms. Journal of Food Engineering, 106, 199-205.
 Garcia-Castello, E.M. and McCutcheon, J.R. (2011) Dewatering press liquor derived from orange production by forward osmosis. Journal of Membrane Science, 372, 97- 101. http://dx.doi.org/10.1016/j.memsci.2011.01.048
 Pagan, J., Ibarz, A., Llorca, M., Pagan, A. and Barbosa-Canovas, G.V. (2001) Extraction and characterization of pectin from stored peach pomace. Food Research International, 34, 605-612.
 Cassano, A., Conidi, C. and Drioli, E. (2010) Physicochemical parameters of cactus pear (Opuntia ficus-indica) juice clarified by microfiltration and ultrafiltration processes. Desalination, 250, 1101-1104.
 Liu, Y.Z., Dong, T., Lei, Y., Deng, X.-X. and Gu, Q.-Q. (2011) Isolation of polygalacturonase gene from Citrus si-nensis fruit and its expression relative to fruit mastication trait, fruit development, and calcium and boron treatments. Plant Molecular Biology Reporter, 29, 51-59.
 Arbaisah, S.M., Asbi, B.A., Junainah, A.H. and Jamilah, B. (1996) Determination of optimum conditions for pectinesterase extraction from soursop fruit (Anona muricata) using response surface methodology. Food Chemistry, 55, 289-292.
 Contreras-Esquivel, J.C., Correa-Robles, C., Aguilar, C.N., Rodríguez, J., Romero, J. and Hours, R. (1999) Pectinesterase extraction from Mexican lime (Citrus aurantifolia Swingle) and prickly pear (Opuntia ficus indica L.) peels. Food Chemistry, 65, 153-156.
 Hou, W.N., Jeong, Y., Walker, B.L., Wei, C.I. and Marshall, M.R. (1997) Isolation and characterization of pectinesterase from Valencia orange. Journal of Food Bio-chemistry, 21, 309-333.
 Vivar-Vera, M.A., Salazar-Montoya, J.A., Calva-Calva, G. and Ramos-Ramirez, E.G. (2007). Extraction, termal stability and kinetc behavior of pectinmethylesterase from hawthorn (Crataegus pubescens) fruit. LWT-Food Science and Technology, 40, 278-284.
 Zhou, H.-W., Ben-Arie, R. and Lurie, S. (2000) Pectin esterase, polygalacturonase and gel formation in peach pectin fractions. Phytochemistry, 55, 191-195.
 Kertesz, Z.I. (1955) Pectic enzymes. Methods in Enzimology, 1, 158-166.
 Bradford, M.M. (1976) A rapid and sensitive method for quantitation of microgram quantities of protein utilizing the principle of pro-tein-dye binding. Analytical Biochemistry, 72, 248-254.