Oligofructans content and yield of yacon ( Smallanthus sonchifolius ) cultivated in Mississippi

Inulin and oligofructans-rich crops have great industrial versatility because these sugars can replace sucrose, fat and flour with low caloric index, while providing many health benefits to consumers. Recent clinical studies reveal that supplementation of oligofructans promotes weight loss by suppressing ghrelin and increasing peptide YY in overweight and obese adults. Thus, greater consumption of vegetables and fruits rich in oligofructans may improve health conditions, which is particularly important for Mississippi as it has one of the highest rates of obesity and diabetes in the United States. Species belonging to the Asteraceae family including yacon, Smallanthus sonchifolius, are particularly rich sources of stored inulin and oligofructans in their storage roots and rhizophores (the underground storage organs). Thus, we cultivated yacon in North Mississippi as a specialty crop: expecting that in the near future fresh yacon could be introduced as a functional food to supplement the diet of Mississippians treating diet related chronic diseases. We evaluated the quality of leaves harvested in mid-November based on the content of chlorogenic and 3,5-dicaffeoylquinic acids and the fructan yields in roots and rhizophores. After the leaves were damaged by frost, the content of oligofructans was reduced affecting the quality of the tuberous roots and rhizophores. Estimated yield based on the relative fresh weight of plants harvested on November 17, before the frost, was 73.1 t/ha of underground parts from which 25.6 t/ha produced roots and 47.5 t/ha rhizophores. (c) 2012 Elsevier B.V. All rights reserved.