Author(s): Alp Akn, Necdet zbalta, Ali Gngr
In this paper, we report on the water activity and moisture contents of Capsicum annuum in different saturated salt solutions. The sorption isotherms of Capsicum annuum were determined within the range of 10-98% relative air humidity at three different temperatures (30 oC, 45 oC and 60 o C), using static gravimetric method. The moisture content of the product was used as in the marketing standard, assuming that no microbial spoilage would occur below a certain moisture level. The best equation was predicted for the experimental data at each temperature using non-linear regression technique. Hence, this correlation between equilibrium moisture content (EMC) and equilibrium relative humidity (ERH) can be given as a new model. Consequently, the experimental data were fitted in several models such as Oswin, GAB, Modified Henderson, Halsey and Modified Halsey. In order to compare these models, three statistical error parameters were used and the best fitted models between sorption isotherms were studied. GAB was the best model to describe the sorption isotherm adequately, over entire temperature range among the others. Besides, a new model which can be considered as better than GAB model, taking into account the experimental results for three temperatures, was proposed.