Optimizing quality characteristicsof semiwet kumquat with osmotic-ultrasonic methods

In this study, response surface methodology was used to optimize the osmotic-ultrasonic drying condition to achieve maximum water loss, phenolic compounds and minimum solid gain and %EC50. Temperature (40, 50 and 60), processing time (4, 7 and 10h), sucrose syrup concentration (40, 50 and 60% v/w) and frequency (0, 35 and 130 KHz) were the investigated factors influencing kumquat properties during the osmotic-ultrasonic drying. The liquid medium to fruit ratio was 10:1 (weight basis). Experiments were designed according to the central composite rotatable design. Results showed that the linear effects of temperature, processing time, sucrose syrup concentration and frequency on water loss, solid gain, phenolic compound and EC50 were statistically significant (p<0.05). For each response, second-order polynomial models were developed using multiple linear regression analysis. Analysis of variance was performed to check the adequacy and accuracy of the fitted models.