EN
Technology should make possible production of safe product, with retain of raw material nutritive value and with good sensory quality. Producer should take the technological possibilities and costs under the account. Quality of juices or nectars depends in a large degree on the method of their preparation, whether is it clear, naturally turbid or pulpy. The less solid parts content, more parts of fruits and of vegetables became removed in processing, and the composition of juice differs more from the raw material. In the last years there is a great attention on the fruits and vegetables as the sources of biologically active compounds, e.g. with an antioxidant activity. The creation of desirable sensory qualities may be the reason of an unintentional lowering of juice nutritional values. During the juice clarification the fibre is removed. In an effort to decrease the haze-forming tendency of packaged juices, processes are employed to minimise or eliminate polyphenols. Polyphenols, ascorbic acid and carotenoides are the main compounds responsible for antioxidant activity' of fruits and vegetables. Changes of technology can be the reason of an introduction of new health risk, for example E. coli 0157: H7 infections after consumption of not pasteurised apple juices. The short-term storage of the juice may enhance the lethality of these microorganisms. Influence of technological process on nutritive value was presented as examples of juice antioxidant capacity changes during processing. It is connected with loss of naturally occurring antioxidants, as well with formation of novel antioxidant compounds. Modifications of each process can have different, both positive and negative effect on quality of juice. It was presented on example of extraction processes and of clarifying.