Antioxidants in Blackcurrants                            

In addition to anthocyanins, blackcurrants are very high in antioxidants such as flavonoids and polyphenolics. Recent test results shown below, show blackcurrants have more antioxidants than all the other 24 fruits tested by the same method.  The high antioxidant levels in blackcurrants are what makes blackcurrants such a healthy fruit choice.

Antioxidants are thought to protect the body against the action of free radicals, which are produced by the body’s own metabolic processes and also enter the body from our environment from many sources such as pollution. Free radicals can cause tissue damage. The body has it’s own defence mechanisms against free radical damage but antioxidants absorbed from the diet may aid the body’s natural defence systems.

Antioxidant Testing

1. ORAC hydro levels in New Zealand blackcurrant fruit

Antioxidant levels in fruit and vegetables can be measured a number of ways. The oxygen radical absorbance capacity (ORAC) assay is considered the most accurate, providing a measure of the scavenging capacity of antioxidants against the peroxyl radical, which is one of the most common reactive oxygen species (ROS) found in the body. ORAC hydro reflects water-soluble antioxidant capacity.

Recently the New Zealand Blackcurrant Cooperative sent fruit to Brunswick Laboratories, the premier ORAC testing lab in North America, for analysis. The results, presented below, show NZ blackcurrants had ORAC levels higher than 24 other common fruits tested by the same method.

Figure 1. ORAChydro levels in New Zealand blackcurrants compared with other fruits
(unit: µmol TE/g)

 

1 Source: Xianli Wu et al. 2004. Lipophilic and hydrophilic antioxidant capacities of common foods in the United States. Journal Agricultural and Food Chemistry 52: 4026-4037

Note: When comparing ORAC data, care must be taken to ensure that the units and food being compared are similar. Some evaluations will compare ORAC units per grams dry weight, others will evaluate ORAC units wet weight and still others will look at ORAC units/serving. Under each evaluation, different foods can appear to have higher ORAC values.


2. ORAChydro levels in New Zealand blackcurrant juice concentrate

The ORAC level of New Zealand Blackcurrant Co-operative concentrate has also been determined by Brunswick Laboratories, and was shown to be a staggering 416,476 and 477,479 µmol TE per litre (2 samples tested). Blackcurrant concentrate was compared to a range of USA fruit-based health drinks, based on label claims. 

The level found in blackcurrant concentrate surpasses that of leading US health drink concentrate products, which have levels typically of 100,000 – 200,000 µmol TE per litre.

While not the highest on the list, in terms of units per serving, New Zealand blackcurrant concentrate is exceeded only by mangosteen and goji berry based products, see Figure 2. This result shows that blackcurrant drinks also rate very well as an antioxidant fruit beverage, even though they have not traditionally been marketed for this benefit.

Figure 2. ORAC levels per typical serving of some common US
and international antioxidant fruit based drinks and syrups1
(unit: µmol TE)


1 To allow comparison, each product was diluted to its correct concentration, (according to each product’s own label dilution instructions) to give ORAC levels per serving.