The purpose of this study is to analyze the changes of pH values, vitamin C, acidity, density, water activity of fruit juices during storage. The manufacture of pulp and clear juice must ensure that the vitamin and mineral content of fruits and vegetables used is found in the finished product. Of citrus juices, orange juice is the most appreciated and used because of its flavor and high content of vitamin C. Evaluation of the quality and determination of life (shelf life) it is based mainly on the progress of vitamin C during storage. Fruit juices were prepared using a robot type fruit squeezer. Were prepared orange juice, kiwi, apple, the flesh and clear and mixed fruit in different proportions. Physico-chemical characteristics were determined from fresh juice as well as from juice kept in refrigerator, at certain time intervals (one day, two days, five and seven days). The storage of these juices under refrigeration conditions has determined percentage reductions of vitamin C content of these ones. Kiwi fruit and oranges are high in vitamin C, the results confirm that mixtures containing two fruits have a higher ascorbic acid than the other.