|Authors: ||S.A. Raccuia, C. Patanè, M. Melilli|
|Keywords: ||Cynara cardunculus var. sylvestris, wild cardoon, germplasm evaluation, root yield, root carbohydrate characterisation, inulin yield.|
Inulin is a polymeric carbohydrate consisting of β-(2→1) linked fructofuranosyl moieties with a terminal glucose, which make it widely suitable for food and non food utilisation.
Since inulin is not digested by acid hydrolysis or by enzymes in the human stomach or small intestine, it passes undigested to the colon, thus reaches the large intestine unaltered, to be utilised by bifidobacteria of the intestinal microflora.
In this respect, it behaves as a dietary fibre.
The small amount of glucose in the molecule makes it an alternative source of carbon for diabetics.
In all species of Cynara, including Cynara cardunculus L. var. sylvestris Lam. (wild cardoon), inulin is present both in heads and roots.
In an experimental field located in the plain of Catania - Sicily (37°27' N, 15°4' E, 10 m a.s.l.), thirteen wild cardoons and one globe artichoke (C. scolymus L.) cv. ‘Violetto di Sicilia’ (‘VS’), were evaluated for total biomass, root, total sugar, and inulin yield from roots.
At harvest, total dry biomass (DM) ranged from 7.8 to 16.8 t ha-1 of DM in wild cardoon, and was 17.2 t ha-1 of DM in globe artichoke.
In wild cardoon, DM cumulated in roots ranged from 39.2 to 74.3% of total DM, whereas in globe artichoke it was 62.7% of total DM. Root yield ranged from 3.5 to 11.6 t ha-1 of DM in wild cardoon, whereas in globe artichoke it was 10.8 t ha-1 of DM.
The total sugar content, on average of all wild cardoons, was 370 g kg-1 of DM, with a CV of 14.8%. Globe artichoke showed a total sugar content of 348 g kg-1 of DM.
The total sugar yield ranged from 1.14 to 4.64 t ha-1 of DM in wild cardoon and was 3.69 t ha-1 of DM in globe artichoke.
Inulin represented, on average of all genotypes of wild cardoon, 90.1% of total sugars extracted from roots.
The experimental results showed the potential of wild cardoon to produce inulin from roots.
The collection of the Sicilian genotypes exhibited a range of variability which may be important in the development of new cultivars for this specific use.
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