Aronia (black chokeberry) - Food and Nutraceutical Uses
Raw black chokeberry fruits are stringent, so the fruits are generally eaten in processed form. Knudson notes that fruits can be canned whole, the juice can be used in fruit drinks and jelly, and extracts can be used as natural colorants in the food industry. As a juice product, black chokeberry is usually blended with other juices such as apple, black currant, cranberry and grape (Brand). It has been grown commercially in Russia since the 1940s, where it is used in juice products (mixed with apple juice), wine, compote and pickles (Kask). And, it has been commercially grown in Europe where its fruits are used in juice, alcoholic beverages, energizing beverages, and as a food colorant (Bussières et al.).
In response to current worldwide human dietary concerns, new functional foods and healthy food products are being developed at a rapid pace. For example, Georgiev and Ludneva explored processing the fruits into nectars and purees, and found that the ascorbic acid and anthocyanin levels dropped considerably during processing and also during subsequent storage, but that the new products still retained a high level of the biologically active substances found in fresh fruit. González-Molina et al. assessed the feasibility of producing aronia-enriched lemon juice as a new beverage with antioxidant properties.
Generally, black chokeberry fruits are high in sugar (12 – 20% soluble solids), anthocyanins (560 – 1050 milligrams/100 grams fresh weight), have a pH of 3.3 – 3.7, and titratable acidity of 0.7 – 1.2% (Jeppsson and Johansson; Oszmianski and Sapis).
Anthocyanins: The pigments that cause black chokeberry fruits to appear black are phenolics, primarily anthocyanins. These pigments are produced to protect the fruit pulp and seeds from exposure to ultraviolet radiation by filtering intense sunlight. Total anthocyanin levels in black chokeberry have been reported to be as high as 1480 mg/100 g fresh fruit (Wu et al. 2006). This level is among the highest measured in plants. In addition to shielding the fruits from sunlight, anthocyanins contribute to the fruits’ astringent taste. And, anthocyanins are antioxidants, which combat stress in the fruit during metabolic processes.
Fruit quality can vary from one year to the next, with anthocyanin content differing as much as 110% from a poor production year to a good year, and anthocyanin content increasing by 50% under a low fertilizer regime compared to a medium high fertilizer regime (Jeppsson and Johansson).
ORAC (oxygen radical absorbance capacity) is a widely used test that measures antioxidant strength of foods. Black chokeberry produces one of the highest values recorded, 16,062 micromoles of Trolox Eq. per 100 g fresh fruit, compared to values of 7960 for black currant, 3387 for red currant, 3277 for gooseberry and 14,697 for elderberry (Wu et al., 2004).
The antioxidant properties of black chokeberry fruits have led to research into their use as functional foods to contribute to prevention of diseases caused by oxidative stress, such as certain cancers, cardiovascular diseases and chronic inflammations.