EFFECT OF HIGH CO2 AND CONTROLLED-ATMOSPHERE (CA) ON THE ASCORBIC ANDDEHYDROASCORBIC ACID CONTENT OF SOME BERRY FRUITS

High CO2 concentrations as well as controlled atmosphere storage are w idely used to extend the storage and shelf-life of many fruits. To inv estigate the effect of these storage procedures on several berry fruit s, strawberries, raspberries, currants and blackberries were stored at three different elevated CO2 concentrations, with or without a parall el reduction in O-2. Vitamin C content (ascorbic acid plus dehydroasco rbic acid) was reduced by high CO2 concentrations (10-30% CO2), partic ularly in strawberries. This reduction in vitamin C was moderate in bl ack currants and blackberries and almost absent in raspberries and red currants when compared with strawberries. Reducing the O-2 concentrat ion in the storage atmosphere in the presence of high CO2 had little e ffect on the vitamin C content. Ascorbic acid was more diminished al h igh CO2 than dehydroascorbic acid. This suggests a stimulating effect of high CO2 concentrations on the oxidation of ascorbic acid and/or an inhibition of mono- or dehydroascorbic acid reduction to ascorbic aci d. (C) 1997 Elsevier Science B.V.