Abstract:

The aim of this study was to investigate the effects of hot air (60, 70°C), vacuum (60, 70°C at 150, 250 mbar absolute pressures) and microwave (90, 180 W) drying on drying characteristics, degradation kinetics of colour, mineral content and textural properties of vegetable pestil prepared with carrot and red pepper. Page and Modified Page were determined as the best appropriate models to determine drying characteristics of pestil samples. Effective moisture diffusivity coefficient (Deff) values were changed between 2.45×10-8 to 9.93×10-8 m2/s. Zero and first order kinetic models were applied to describe colour degradation kinetics of samples. While L* colour value fitted both of the models, zero order kinetic model described the degradation kinetics of a* value. The best fitted model for the b* value was changed with drying conditions. Mineral content (Na: 987.84 - 1121.65, K: 3427.95 - 4959.38, Ca: 569.52 - 4302.94, Mg: 270.20 - 353.80, P: 511.15 - 681.17, Mn: 2.08 - 2.65, Fe: 3.68 - 12.37, Zn: 3.53 - 6.13, Cu: 1.80 - 2.60) of pestils showed higher values than non-dried mixture. Significant differences were determined between textural properties (hardness, adhesiveness, springiness, gumminess and chewiness) of pestil samples.

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