Quality Deterioration and Physiological Biochemical Changes in Different Parts of Brassica campesttris L. ssp. Chinesiss (L.) Makino var. rosularis Tsen et Lee during Storage at 20℃

The changes of quality and physiology biochemical indexes in different parts of yellow heart cabbage (outer leaf, inner leaf and petiole) were investigated in order to discuss the mechanism of quality deterioration during storage at 20℃. The results showed that yellow heart cabbage there was quality mainly limited by water loss, yellowing, decay and tissues age. The whole yellow heart cabbage usually lost edible value after 4 days of storage at 20℃. There was a negative correlation between the chlorophyll content and etiolation index (outer leaf, r=-0.9614^**, inner leaf, r=-0.9347^**, p<0.05), which was proved that etiolation in outer and inner leaves of yellow heart cabbage was probably ascribed to the degradation of the chlorophyll. Yellow heart cabbage was abundant in essential nutrients, the nutrients in leaf (especial inner leaf) ranked the first, followed by petiole. The remaining nutrients in inner leaf was more than the one in outer leaf during storage time, however, the reduction in petiole was the lowest. (CAT) activity decreased, the peroxidase (POD) and superoxide dismutase (SOD) greatly increased during storage. Furthermore, the superoxide anion radical (O₂^-·) production rate and malondialdehyde (MDA) content rose continually. And, etiolation index, decomposition index, membrane lipid peroxidation degree and antioxidant enzyme activity in outer leaf was higher than that of inner leaf and petiole, which indicated that it was the first tissue to be senescence in three parts of yellow heart cabbage, followed by inner leaf. The quality deterioration in yellow heart cabbage may be accelerated by water losses, free radical accumulation and oxidative damage.