Antioxidants and chlorophyll content of blanched vegetables stored at the temperature of -10OC ± 2OC

Abstract

The fresh leaves of ‘Tete’ (Amaranthus hybridus) and ‘Soko’ (Celosia argentea) were blanched and stored in the freezer at the temperature of -10oC±2oC where there was 8hours (day) and 5hours (night) electric power supply to the freezer. The antioxidant (Vitamin C, total phenol and reducing power) and chlorophyll a and b contents were subsequently determined. The results of the analysis shows that the unblanched vegetables had 160.0mg/100g vitamin C, 4.24% total phenol, 0.26700nm reducing power, 0.35ìg/ml chlorophyll a and 0.40ìg/ml chlorophyll b for ‘Tete’ (Amaranthus hybridus) and 75.26mg/100g vitamin C, 4.89% total phenol, 0.31700nm reducing power, 0.25ìg/ml chlorophyll a and 0.30ìg/ml chlorophyll b for ‘Soko’
(Celosia argentea). However, blanching causes a significant decrease (P< 0.05) in the antioxidants and the chlorophyll contents of the vegetables. During storage, despite the inactivation of the enzymes, there was a significant (P<0.05) decrease in the antioxidants of the vegetables but the decrease in the chlorophyll content was not significant (P<0.05). The decrease during storage was caused by the
intermittent electric power supply which affected the storagetemperature.