Blackcurrant juice, vitamin

The important commercial feature of these juices, especially significant with blackcurrant and tomato juices, is their ascorbic acid (or vitamin C) content, of which loss by oxidation is known to be accelerated both by heat and by metal (particularly copper) contamination. The effect of copper has been carefully investigated for pure ascorbic acid", and more recently ascorbic acid in blackcurrant juice and model systems. There are, however, oxidation inhibitors of different kinds (which may themselves be heat-sensitive) present in various fruits, which give differing results. The presence of metals will also affect flavours", may cause discoloration, and may give rise to clouding effects, as in apple juice. ... 

Ascorbic acid. Many juices contain ascorbic acid or vitamin C, which is quantitatively the most important vitamin in soft fruits, ranging from a negligible level in some whortleberries to around 200 mg/100 g in blackcurrants. Ascorbic acid performs a valuable function as an antioxidant in minimising degradation of certain flavour principles, and it is often important for it to be included in the processed juice or in a soft drink formulation. Levels in the range 200-400 mg/kg are typical. It should be noted that ascorbic acid can be added to natural strength juice only if it is... 

Arthur s Fresh Company POMtastic (arthursjuice.com)—contains pomegranate juice, apple juice, banana puree, and blackcurrant puree fortified with dietary fiber, vitamins C, D, and E, five B vitamins, and three dietary minerals... 

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