Effects of dehydrofreezing conditions on carrot β-carotene and kinetics of β -carotene change in dehydrofrozen carrots during storage

Abstract

Dehydrofreezing is a food freezing method in which the foods are partially dehydrated before freezing. In this study, carrots were frozen with convective (-30, -35, -40 o C and 2 m/s airflow) and cryogenic methods after dehydrating them by different methods (osmotic dehydration, convective and vacuum drying). The effects of dehydration method, freezing conditions and storage time on β-carotene amounts of dehydrofrozen carrots and the changes in β-carotene content of dehydrofrozen carrots during storage for six months at -20 o C were investigated. The findings obtained in this study showed that the reaction representing the carotene change in the storage process took place in accordance with the first-degree kinetic model. The reaction rate constants (k) were affected by freezing conditions, and the k value decreased as the freezing temperature decreased. The β-carotene losses were less in the storage process in the cryogenically frozen carrots compared to those frozen by the convective method. As the freezing temperature decreased, the half-life period increased.

Osmotik ve Konvektif Kurutma Sonrası Dondurma İşleminin Enerji Verimliliğine ve Kırmızıbiberin Bazı Fizikokimyasal Özellikleri Üzerine Etkisi

“…The researchers explained these differences in skin puncture force can be related to the increasing turgor pressure in the cell. In another study, it was reported that since the water content before freezing in the dehydrofreezing process decreases, the texture of the product will be less damaged by the less amount and small size of ice crystals [36]. Additionally, during the storage, skin puncture values were significantly different (p<0.05) in the control and convective dehydrofrozen samples.…”

The Optimization of Hybrid (Microwave–Conventional) Drying of Sweet Potato Using Response Surface Methodology (RSM)

“…The HPLC system was previously described in [61]. The mobile phase flow rate was set at 0.25 mL/min, and the proportions of acetonitrile, methanol, dichloromethane, and hexane in the mobile phase were in a volumetric ratio of 40:20:20:20.…”