Kinetics of ascorbic acid degradation during air-drying of whole rosehip has been investigated. Changes of vitamin C content
during drying have been affected by drying time, drying air temperature and as well as moisture content. Vitamin C degradation
rates for whole fruits during drying have been satisfactorily described by first-order kinetics. Temperature dependency of the model
has been described also by Arrhenius relationship. Activation energy and reaction rate constant have been determined as a function
of moisture content and described as Ea = 38600 + 100M and k0 = exp(6.32 + 0.75M). In addition, rosehip has been pre-treated by
cutting into pieces and drying experiments were conducted with air and with the atmospheres prepared with various ratios of air–
CO2 mixtures. Cutting of the rosehips before drying accelerated the drying process and increased the retention of vitamin C. The loss
of vitamin C was increased depending on the rate of the oxygen in the air–CO2 mixtures used as a drying medium.