Soy protein isolate/carboxymethyl chitosan （SPI/CMCH） blended films incorporated with glycerol were prepared using solution casting to investigate the effects of the SPI and CMCH ratios （100：0, 88：12, 67：33, 50...Soy protein isolate/carboxymethyl chitosan （SPI/CMCH） blended films incorporated with glycerol were prepared using solution casting to investigate the effects of the SPI and CMCH ratios （100：0, 88：12, 67：33, 50：50, 33：67, 12：88, 0：100） on the water sorption isotherm. The moisture sorption isotherm of the SPI/CMCH blended films was determined using various relative humidity＇s （16%, 35%, 55% and 76% RH） at 25 ± 1℃. The isotherms showed that the equilibrium moisture content （EMC） of the films increased with increasing CMCH content and the EMC value sharply increased above aw = 0.55. Understanding of sorption isotherms is important for prediction of moisture sorption properties of films via moisture sorption empirical models. The Guggenheim-Oswin, Brunauer-Emmett-Teller （BET）, and Anderson-de Boer （GAB） sorption model predictions were tested against the experimental data. The root mean square （RMS） values from the Oswin, BET, and GAB models respectively ranged from 698.54 to 1,557.54, 38.85 to 58.30, and 52.52 to 95.95. Therefore, the BET model was found to be the best-fit model for SPI/CMCH blended films at 25 ± 1 ℃.展开更多
文摘Soy protein isolate/carboxymethyl chitosan （SPI/CMCH） blended films incorporated with glycerol were prepared using solution casting to investigate the effects of the SPI and CMCH ratios （100：0, 88：12, 67：33, 50：50, 33：67, 12：88, 0：100） on the water sorption isotherm. The moisture sorption isotherm of the SPI/CMCH blended films was determined using various relative humidity＇s （16%, 35%, 55% and 76% RH） at 25 ± 1℃. The isotherms showed that the equilibrium moisture content （EMC） of the films increased with increasing CMCH content and the EMC value sharply increased above aw = 0.55. Understanding of sorption isotherms is important for prediction of moisture sorption properties of films via moisture sorption empirical models. The Guggenheim-Oswin, Brunauer-Emmett-Teller （BET）, and Anderson-de Boer （GAB） sorption model predictions were tested against the experimental data. The root mean square （RMS） values from the Oswin, BET, and GAB models respectively ranged from 698.54 to 1,557.54, 38.85 to 58.30, and 52.52 to 95.95. Therefore, the BET model was found to be the best-fit model for SPI/CMCH blended films at 25 ± 1 ℃.
