Anthocyanins from black grapes

Anthocyanins are widespread in food plants, with an estimated worldwide consumption of 10000 tonnes from black grapes alone [53]. The anthocyanin content of many fruits and vegetables has been estimated by various methods (Table 16) [56-58]. The main sources of these plant pigments are fresh fruits such as cherries, plums, strawberries, raspberries, blackberries, grapes, red currants and black currants. 

Centrifugal partition chromatography (CPC), a type of CCC that uses discrete partition cells inside a rotor, was used by Renault et al. (1997) to separate anthocyanins from black currant and grape skins. They used two instmments from Sanki Engineering Ltd (Kyoto, Japan) a laboratory model LLB-M and a pilot-scale model LLI-7, both fitted with a stacked disks type rotor. 

The anthocyanin stabilities of grape-marc, elderberry, and black currant extracts were lower in all sucrose (100 g/L)-added systems as compared to the controls at pH values of 3, 4, and 5, whereas the brown index did not change with the addition of sugar. On the contrary, a protective effect of 20% sucrose added to frozen crowberries and strawberries was reported and the stabilities of anthocyanin juices from aronia were higher in syrups than in diluted extracts. Roselles pre-... 

The anthocyanins are extracted commercially using either acidified water or alcohol. The extract is vacuum evaporated in order to produce a commercial colour concentrate. The raw materials can be blackcurrants, hibiscus, elderberry, red cabbage or black grape skins, the most commonly used commercially being black grape skins which can be obtained as a by-product from grape-juice or wine making. 

In other laboratory studies, anthocyanins, tannins, or other polyphenols from red grapes, black or red raspberries, blackberries, strawberries, cranberries, blueberries, goji berries (wolfberries), a ai berries, or pomegranates were shown to inhibit promotion and growth of premalignant cancer cells by the following specific mechanisms ... 

Most of the anthocyanins acylated with caffeic acid have this cinnamyl moiety linked to a glucosyl position 6, as in gooseberries, some grape cultivars, ° " ° black carrots, red cabbage,red radishes," and sweet potatoes. Some anthocyanins isolated from species of potatoes have a caffeyl group located at position 4 of the rhamnosyl unit of the rutinose disaccharide. " ... 

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