Resumo

BROUSSE, Maria M; LINARES, Ramon A; VERGARA, Maria L  e  NIETO, Andrea B. Adsorption isotherm of dehydrated mashed cassava from different varieties. Rev. cienc. tecnol. [online]. 2017, n.28, pp.29-37. ISSN 1851-7587.

Water sorption isotherms of two varieties of dehydrated mashed cassava, Conception and Pomberi, were determined for a temperature range between 25° C and 45° C. The dehydrated mashed cassava exhibited Type II behavior. Sorption isotherms showed that for aw values below 0.85, the sorption capacity decreased when temperature increased; opposite behavior was observed at aw above 0.85. The inversion point (aw = 0.85) was attributed to the fact that more active sites were exposed to the adsorption processes, due to the enhanced molecular mobility promoted in the amorphous regions by starch crystallization. The experimental data were fit to different sorption models. Model constants and correlation coefficients were obtained. BET, GAB and PELEG equations showed highest correlation coefficients for all range of aw. Total heat of sorption increased when moisture content decreased.

Palavras-chave : BET equations; Storage stability; Net isosteric heat; Nonlineal regression; Mathematical models.

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