Calendula Officinalis L. Desorption Isotherms: Experimental Determination And Mathematical Modeling [isotermas De Dessorção De Calendula Officinalis L.: Determinação Experimental E Modelagem Matemática]

Calendula officinalis L. desorption isotherms were determined by gravimetric at three differents temperatures (30,45 and 60°C) to verify the temperature influence on the water activity. Experimental data was adjusted to the following sorption models: BET, GAB, HALSEY, OSWIN, PELEG, HENDERSON and CHUNG & PFOST. The average relative errors between calculated to select best fit model. The best model was Peleg with the following relative errors: 9.40% for the temperature of 30°C, 5.71 % for the temperature of 45°C and 3.36% for the temperature of 60°C.912128AGUERRE, R.J.SUAREZ, C.VIOLLAZ, P.E. New BET type multi-layer sorption isotherms - Part II: Modelling water sorption in foods. Lebensmittel-Wissenschaft & Technologie, v.22, n.4, p.192-5, 1989ENCICLOPAEDIA Britannica, Chicago (1970) Encyclopaedia Britannica, 10, p. 422AMERICAN SOCIETY OF AGRICULTURAL ENGINEERS - ASAE. Moisture Measurement-Forages. St. Joseph, 1991a. p.401. (ASAE Standards, S532.2)AMERICAN SOCIETY OF AGRICULTURAL ENGINEERS - ASAE. Moisture Relationship of Grains. St. Joseph, 1991b. p.363-7. (ASAE Data, D245.4)CHINNAN, M.S., BEAUCHAT, L.R., Sorption isotherms of whole cowpeas and flours (1985) Lebensmittel-Wissenschaft & Technologie, 18, pp. 83-88CHUNG, D.S., PFOST, H.B., Adsorption and desorption of water vapour by cereal grains and their products (1967) Transactions of the ASAE, 10 (4), pp. 149-157GÁL, S., Recent advances in techniques for determination of sorption isotherms (1975) Water relations of Foods, pp. 139-154. , DUCKWORTH, R.B, ed, London: Academic Press IncHALSEY, G., Physical adsorption on uniform surfaces (1985) Journal of Chemical Physics, 16 (10), pp. 931-937LOMAURO, C.J., BAKSHI, A.S., LABUZA, T.P., Evaluation of food moisture sorption isotherm equations. Part I: Fruit, vegetable and meat products (1985) Lebensmittel-Wissenschaft & Technologie, 18 (2), pp. 111-117MARTINS, E.R., et al. Plantas medicinais. Viçosa, MG:UFV, 1994. 220pMOHSENIN, N.N., (1986) Physical properties of plants and animals materials, , 2.ed. Amsterdam: Gordon and Breach Publishers, 841pPARK, K.J., NOGUEIRA, R.I., Modelos de ajuste de isotermas de sorgao de alimentos (1992) Engenharia Rural, 3 (1), pp. 81-86PELEG, M., Assessment of a semi-empirical four parameter general model for sigmoid moisture sorptionisotherms (1993) Journal of Food Processing Engineering, 16 (1), pp. 21-37STATISTICA for Windows 5.0. Computer program manual. Tulsa, OK: StatSoft Inc., 1995TEXEIRA NETO, R.O.QUAST, D.G. Isotermas de adsorção de umidade em alimentos. In: ITAL. Coletâneas do ITAL. Campinas, 1977. v.8, p.141-97TREYBALL, R.B., Drying (1968) Mass Tranfer Operations, pp. 569-575. , New York: McGraw-HillTESKE, M., TRENTINI, A.M., (2001) Herbarium : Compêndio de fitoterapia, , 4. ed. Curitiba: Herbarium Laboratório Botânico, 317pVan der, B.C., Description of water activity of foods for engineering purposes by means of the GAB model of sorption (1984) Engineering and Food, 1, pp. 311-321. , MCKENNA, B.M, Ed, London: Elsevier Applied ScienceWANG, N., BRENNAN, J.G., Moisture sorption isotherm characteristics of potatoes at four temperatures (1991) Journal of Food Engineering, 14, pp. 269-28