The consumption of fruits and vegetables in the diet is associated with a lower incidence of disease, particularly of degenerative diseases associated with aging (e.g cancer and heart disease), and improved well-being.
One of the mechanisms of their protective action is thought to be their antioxidant activity, providing protection against the harmful effects of free radicals and other reactive oxidants.
Vitamin C has been regarded as a major nutritional antioxidant for many years. More recently, other constituents of fruits and vegetables, including other phenolics such as the flavanoids present in red wines have been shown to have significant antioxidant activity.
Spectrophotometric analysis of the colours of various fruit juices under standard conditions (see fig 1) show Blackcurrants to have a colour intensity twice as strong as the next, which is Boysenberry, and this colour intensity reflects the very high Anthocyanin levels. This means that as well as the potential health benefits; there is also a rich and strong colour.
Comparative Colour Intensity Blackcurrant v other berryfruits
Measurements on freshly pressed fruit juices at standard dilution. The strong natural colour of Blackcurrant reflects its very high anthocyanin content; a major contributor to the high antioxidant activity.
It therefore comes as no surprise that in tests carried out by the respected New Zealand government owned research laboratories, Crop and Food Research, Blackcurrants were found "to have exceptionally high antioxidant activity". The January 2000 report on their findings stated "Of all the fruit and vegetables we have tested so far blackcurrant juices gave the highest antioxidant activity as measured by the ABTS assay.
(* Assay method Miller, Rice-Evans, Redox Reports 2 161-171)
The average results obtained in comparative tests on extracts 3 samples of New Zealand Blackcurrants compared with those on extracts from Blueberry were as follows:-
|Antioxidant activity* mmol TEAC/g fruit weight||189||78|
|Anthocyanin HPLC mg/g fruit weight (Based on peak area relative to cyanidin-3-glucoside
|Total Phenolics mg gallic acid equivalent/g fruit weight
Calculated using Folin Ciocalteu reagent
TEAC = Trolox Equivalent Antioxidant Activity measured by ABTS test method (Ref Miller, Rice-Evans).
The comparative findings are supported by the earlier findings published by Luca Constantino et al., Planta Med 58 (1992) in which Blackcurrant anthocyanin and polyphenol contents were compared with a range of other berryfruits, including Blueberry and their activity towards chemically generated superoxide radicals and inhibitory activity towards xanthine oxidase were compared. They concluded that "Ribes nigrum (Blackcurrants) extracts exhibit the highest activity, being the richest in anthocyanins and polyphenols."
Millet J et al. have reported improvement in blood filterability in monkeys on high fat diet when treated with the purified extract of Blackcurrant anthocyanosides . (J Pharmacol 1984 Oct-Dec 15 (4) 439-45). Blackcurrant may thus have positive effect on factors associated with cardiovascular disease.
Practical research conducted by the South Australian Network for Research on Ageing claimed Blackcurrant juice alleviated urinary tract infection and associated problems. (Ref Sanra Research Proj 0026 completed 1996).
Blackcurrant has reportedly been used as a natural remedy for the treatment of a wide range of ailments and improved well being. Continuing research may now provide a better understanding of the beneficial effects.
|Total Vit A Equiv.||39µg|
|Beta Carotene Equiv.||232µg|
|Thiamin (Vit B1)||0.01mg|
|Riboflavin (Vit B2)||0.01mg|
|Total Niacin Equiv.||0.4mg|
|Avail. Carbohydrate||7.4g||Total avail. Sugars.||7.3g|
Blackcurrant from New Zealand
It has been suggested that the clear and unpolluted air of New Zealand and the intense natural light levels combined with the breeding and selection of blackcurrant fruit varieties may further enhance the anthocyanin content and antioxidant activity of the blackcurrants grown in New Zealand.