Changes of Physical and Chemical Traits of Roots of Different Carrot Cultivars Under Cold Store Conditions

The objective of this three-year study, performed in 2006-2008, was to determine the influence of long-term cold storage on some physical and chemical parameters influencing nutritive and biological value of carrots of different storage root colours and shapes. Eight carrot cultivars were chosen for the experiment: Perfekcja, Interceptor F₁, Vita Longa, Nebula F₁, Purple Haze F₁, Deep Purple F₁, Mello Yello F₁ and White Satin F₁. Quality parameters of the carrots, including CIE L^*a^*b^* colour parameters of the whole roots and juice, root firmness (with HPE firmness tester), dry matter, soluble solids, sugars, total phenolics, total carotenoid, antioxidant activity of the whole roots and juice (with DPPH method), were determined directly after harvest and after 6-month storage of the roots at 0-1°C and 97% RH. The results showed significant influence of the storage on most of the quality traits of the roots, particularly colour, firmness, soluble solids and phenolics content. These changes were also related to the cultivars. Storage of the carrot roots caused a decrease in their firmness. Soluble solids and sugars content showed a tendency to increase during the storage period. Storage of the carrots resulted in decreasing nitrates content and increasing phenolics and carotenoid compounds content in the roots. Antioxidant activity of carrot juice showed small increasing tendency resulting from the storage of the roots, but antioxidant activity of the roots decreased.