Extraction, quantification and degree of polymerization the fructans the yacon (smallanthus sonchifolia)

Extraction, quantification and degree of polymerization the fructans the yacon (Smallanthus sonchifolia)

Yacon tubers have been a distinguished alternative to the obtaining of fructans. To those tubers are ascribed many effects beneficial to man, for fructans are no digested by the upper gastrointestinal tract, stimulating the growth of intestinal bifidobacteria, preventing the elevation of the glucose level in the blood and/or stimulating insulin secretion. So, the yacon tubers appear as an option of great importance, given the functional properties of fructans, minerals and fibers, calling the researchers attention and of the food industries. Before an excellent functional food, there is the need for studies as to cultivation, extraction and quantification of their fructans. This wok was designed to evaluate 3 extractors of fructans: water 95ºC, water 75ºC, ethanol 90ºC; in 3 sizes of yacon tubers: large, medium, small; in two days’ storage: 1 and 20 days; at room temperature as well as to compare two quantification techniques. The best technique employed utilizing the three fructans extractors was High Performance Liquid Chromatography (HPLC). For spectrometry -quantification, the best extractor is ethanol at 90°C. Medium and small -sized roots presented the highest contents of fructans. Storage influence negatively fructan contents. The HPLC technique was more efficient than colorimetry. As regards the degree of polymerization (GP), all the treatments showed GP in the range of 3-7. That work showed that yacon is an excellent option in fructan-obtaining.

Resumo

Tubérculos do yacon são uma alternativa diferenciada para a obtenção de frutanos. A esses tubérculos são atribuídos muitos efeitos benéficos para o Homem, pois os frutanos não são digeridos pelo trato gastrintestinal superior, estimulando o crescimento de bifidobactérias intestinais, evitando a elevação do nível de glicose no sangue e ou estimulando a secreção de insulina. Assim, os