Response surface modeling of mass transfer and water rehydration phenomena of apple fruit slices during osmotic drying

In this study response surface modeling was performed by using experimental datachr(chr('39')39chr('39'))s obtained from the amount of samples weigh, moisture content and the Brix of produced samples after different condition of osmotic dehydration process including: different concentration (0-60 %w/w) of sucrose solution with different temperature (45-55 0C) and different processing time (60-180 minutes). Results showed that osmotic solution concentration and temperature and duration of osmotic process had significant effect on the amount of moisture content, Brix, the weight of sample after osmotic process and sensory attributes of final product. The highest amount of Brix (39.69%) was observed in the dried samples in osmotic solution with 60% concentration for 180 minutes, while the lowest amount of brix was related to osmotic processing time of 60 minutes and solution temperature of 45 ° C, which shows the significant effect of osmotic solution concentration and osmotic processing temperature and time on the brix changes of samples. Results of the sensory evaluation showed that, the highest amount of texture (8.85) and color (8.46) desirability score were observed in the osmotic processing time and temperature range from 45-52.5 ° C for 160-85 minutes. The amount of texture and color desirability score of the samples decreased by increasing osmotic processing time and temperature. The higher osmotic solution concentration and the lower osmotic processing time and temperature lead to the better color and texture of the samples. Osmotic dehydration improved different quality attributes (color, taste and texture) of final product compared with blank samples. Increase of samples Brix during osmotic dehydration process, indicates an increase in the transfer of sugar molecules into the samples tissue. Therefore, in sensory evaluation, the amount of taste sensory score increased with increasing osmotic processing time and temperature and osmotic solution concentration.