RELATIONSHIP BETWEEN RESPIRATION AND VITAMIN C CONTENT IN VEGETABLES

Respiration rate and ascorbic acid content of cut-cabbage, spinach leaves and broccoli florets were determined throughout storage at 10°C. Accumulated CO₂ production (AR_CO2) over a 10 d observation period increased linearly with an average daily CO2 production rate of 449, 1772 and 2268 mg kg^-1 d^-1 for cut-cabbage, spinach leaves and broccoli florets, respectively. Throughout storage, relative ascorbic acid (AsA_rel) content declined for each type of vegetable but the highest rate decrease was found in broccoli florets. At the end of storage, AsA_rel in cut-cabbage, spinach leaves and broccoli florets was about 78, 42 and 26% of original values, respectively. To predict AsA_rel, the relationship between AsA_rel and AR_CO2 during storage was investigated. All samples showed the same pattern and AsA_rel decreased exponentially as a function of AR_CO2, with a rate decline of 5.25×10^-5. The more AR_CO2, the more AsA_rel was lost over the same time period. Vitamin C content of cut-cabbage, spinach leaves and broccoli florets could be described as a function of respiration rate.