Farklı ön işlem uygulanan Ahlatın kuruma ve büzülme davranışının modellenmesi

Abstract

Highlights:Graphical/ Tabular Abstract  The effect of pretreatment and temperature on Ahlat drying  Modeling of drying and shrinkage behavior for non-researched Ahlat before  Calculation of the Diffusion Coefficient for the case where the diameter change is taken into account and not taken Model Adı Model Model Adı Model Newton MR=exp(-k.t) Rahman D/Do=1-a.(M-Mo) Page MR=exp(-k.tn) Ratti D/Do=a+b.(M/Mo) Henderson ve Pabis MR=a.exp(-k.t) Mayor ve Sereno D/Do= a.exp(b.M/Mo) Logaritmik MR=a.exp(-k.t)+c Correa ve ark. D/Do=1/(a+b.ln(M/Mo)) Midilli MR=a.exp(-k.t)n+c.t Hatamipour ve Mowla D/Do=a.ln(M)+b Kilpatrick, Lowe, and Van Ardsel D/Do=(M+a)/(Mo+a) Table A. Selected drying and shrinkage models Purpose: In this study, Ahlat (pyrus eleagrifolia) known as wild pear, was dried for four various drying temperatures (45-75 o C) in laboratory type dryer with and without pre-treatment. Theory and Methods: The pre-treatment solutions such as %65 maltose, sucrose, glucose, maltodekstrin, sorbitol and %55 sucrose-%10 salt %5 Na2SO5, %2 EO %5 Na2SO5, %5 K2SO5 and %2 EO %5K2SO5 was used in experiments. Dimensionless moisture content vs. drying time and drying rate vs. moisture content were investigated during drying Ahlat. Exchange of dimensionless moisture content vs time of ahlat was modelled by five model commonly used in literature. Shrinkage during drying Ahlat was investigated six models in literature. Models coefficients were tested in significance level p<0,05. The convenience between models and measured values was investigated by determination coefficient (R 2 ) and reduced chi square ( 2 ).Drying and shrinkage Models given in Table A were used for Ahlat drying. Results:Diffusion coefficients, characteristic transport coefficient for falling drying rate period, were determined with and without considering shrinkage for the whole drying temperatures and pre-treatments. There were obtained lower diffusion coefficients and lower activation energy by considering shrinkage. Conclusion:It was seen that the logarithmic model for non-pre-treatment, maltose, glucose, sucrose, sucrose-salt, %5 Na2S2O5, %2 EO %5 Na2S2O5 and %5 K2S2O5 pre-treatment and Newton model for sorbitol, maltodekstrin ve %2 EO %5K2S2O5 pre-treatment were convenient for drying Ahlat. It was seen that linear and exponential models were convenient the other models for explaining shrinkage.