Assessment of Jerusalem artichoke as a source for the production of gluten-free flour and fructan concentrate by ultrafiltration.

Jerusalem artichoke (JA) is a tuber considered a functional food. The tubers accumulate a high amount of fructans (inulin and fructo-oligosaccharides) although tubers also have a high content of minerals and proteins of high biological value. In this study Jerusalem artichoke flour (JAF) was obtained by means of two drying methodologies: convective air oven drying and freeze-drying. Physico-chemical characteristics were analyzed in both samples, as well as a colorimetric analysis and microstructure. As a by-product of the production of JAF, a residual liquid is obtained from which fructans can be extracted, this process included separation steps in aqueous medium without the addition of organic solvents. The optimal extraction conditions were: solid/solvent ratio of 1:2 (Kg JA/L distilled water) during 40min at 90 ± 5°C. The flours obtained presented a high protein and fiber content, 9.73-9.94% and 1.21-1.47% respectively, while the morphology of the matrix of protein and inulin could be...