In this work, the hydrolysis of fresh and dried turmeric (Curcuma longa L.) and ginger (Zingiber officinale R.) in the presence of subcritical water + CO2 was studied. The hydrolysis of ginger and turmeric bagasses from supercritical fluid extraction was also studied. The reactions were done using subcritical water and CO2 at 150 bar, 200°C and reaction time of 11 minutes; the degree of reaction was monitored through the amount of starch hydrolyzed. Process yields were calculated using the amount of reducing and total sugars formed. The effects of supercritical fluid extraction in the starchy structures were observed by scanning electron microscopy. Higher degree of hydrolysis (97- 98 %) were obtained for fresh materials and the highest total sugar yield (74%) was established for ginger bagasse. The supercritical fluid extraction did not significantly modify the degree of hydrolysis in the tested conditions.232235242AOAC, Association of Official Analytical Chemists, Cuniff, P., AOAC International, Gaithersburg, Maryland (1997)Bemiller, J.N., Acid hydrolysis and other lytic reactions of starch (1984) Chemistry and Technology, 1. , Whistler, R.L., BeMiller, J.N. and Paschall, E.F. Starch, Academic Press, London, New YorkBraga, M.E.M., Leal, P.F., Carvalho, J.E., Meireles, M.A.A., Comparison of the yield, composition, and antioxidant activity of turmeric (Curcuma longa L.) extracts obtained using various techniques (2003) J. Agric. Food Chem., 51, p. 6604Freud, R.J., Littell, R.C., SAS system for regression (1995) SAS Series in Statistical Applications, 2nd Ed., p. 211. , SAS Institute: Cary, NCJacobs, M.B., (1981) The Chemical Analysis of Foods and Food Products, , Robert Krieger Publishing Co, New York, NYKrammer, P., Vogel, H., Hydrolysis of esters in subcritical and supercritical water (2000) J. Supercrit. Fluids, 16, p. 189Miller, G.L., Use of dinitrosalicylic acid reagent for determination of reducing sugar (1958) Analyt. Chem., 31, p. 426Moreschi, S.R.M., Petenate, A.J., Meireles, M.A.A., Hydrolysis of ginger bagasse starch in subcritical water and carbon dioxide (2004) J. Agric. Food Chem., 52, p. 1753Nelson, N.A., A photometric adaptation for Somogyi method for determination of glucose (1944) J. Biol. Chem, 153, p. 375Pasquel, A., Meireles, M.A.A., Marques, M.O.M., Petenate, A.J., Extraction of stevia glycosides with CO2 + ethanol and water and ethanol (2000) Braz. J. Chem. Eng., p. 271Rosa, P.T.V., Meireles, M.A.A., Rapid estimation of the manufacturing cost of extracts obtained by supercritical fluid extraction (2004) J. Food Eng, , www.sciencedirect.comSiskin, M., Hydrolysis of esters in subcritical and supercritical water (2000) J. Supercrit. Fluids, 16, p. 189. , cited by Krammer,P and Vogel, HTheander, O., Nelson, D.A., Aqueous, high-temperature transformation of carbohydrate relative to utilization of biomass (1988) Adv Carbohyd Chem. Bi., 46, p. 273Zancan, K.C., Marques, M.O.M., Petenate, A.J., Meireles, M.A.A., Extraction of ginger (Zingiber officinale Roscoe) oleoresin with CO 2 and co-solvents: A study of the antioxidant action of the extracts (2002) J. Supercrit. Fluids, 24, p. 57Zheng, Y., Lin, H.M., Wen, J., Cao, N., Yu, X., Tsao, G.T., Supercritical carbon dioxide explosion as a pretreatment for cellulose hydrolysis (1995) Biotech. Letters, 17, p. 84
