Fruit of the Week – Blackberry

May 16, 2011 at 12:01 PM | Posted in diabetes, diabetes friendly, Food, fruits | Leave a comment

Blackberry

The blackberry is an edible fruit produced by any of several species in the Rubus genus of the Rosaceae family. The fruit is not a true berry; botanically it is termed an aggregate fruit, composed of small drupelets. The plants typically have biennial canes and perennial roots. Blackberries and raspberries are also called caneberries or brambles. It is a widespread, and well known group of over 375 species, many of which are closely related apomictic microspecies native throughout the temperate northern hemisphere and South America.

The distinction between blackberries and raspberries revolves around fruit characteristics. All bramble fruits are aggregate fruits, which means they are formed by the aggregation of several smaller fruits, called drupelets. The drupelets are all attached to a structure called the receptacle, which is the fibrous central core of the fruit. In raspberries, the receptacle remains with the plant when fruit are picked, creating the hollow appearance of the harvested fruit. In blackberry, the drupelets remain attached to the receptacle, which comes off with the fruit when picked. A second distinction – raspberry drupelets are hairy and adhere to one-another, whereas blackberry drupelets are hairless and smooth.

Some of the most important commercially grown brambles are actually blackberry – red raspberry hybrids. Examples include ‘Boysenberry’, ‘Loganberry’, and ‘Youngberry‘. The fruit flavor is unique, but culture and management is more like blackberry than raspberry.

Blackberries are native to Asia, Europe, North and South America. However, blackberries grown in specific regions are largely derived from species indigenous to that region. Blackberries have been used in Europe for over 2000 years, for eating, medicinal purposes, and as hedges to keep out marauders. In the US, R. allegheniensis, R. argutus, R. cuneifolius, and R. canadensis have been important in developing “northern” blackberry cultivars, including thornless types (cultivars popular in the western US also). In the southeastern US, R. trivialis has been used to confer low-chilling and disease resistance into cultivars, such as ‘Brazos’. In Europe, R. lacinatus (“cut leaf” or “evergreen”) was the first domesticated species; it was imported into the Pacific Northwest in 1860, where it produced one of the main cultivars for that region, ‘Thornless  Evergreen’. R. ursinus is native to the Pacific Northwest and has been important in the development of trailing cultivars grown in that region.

Almost all brambles are processed; perhaps 10% of the crop is sold fresh. Among the products using bramble fruit (in order of importance): preserves, jam, jelly; bakery products; frozen fruit; juices, extracts; ice cream, yogurt ; canned. Per capita consumption is 0.08 lb/yr for blackberry, and 0.22 lb/yr for raspberries.