Study of total fructan and fructooligosaccharide content in different onion tissues

✍ Scribed by Laura Jaime; Francisco Martínez; Maria A Martín-Cabrejas; Esperanza Mollá; Francisco J López-Andréu; Keith W Waldron; Rosa M Esteban

• Book ID: 101325461
• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 100 KB
• Volume: 81
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/1097-0010(20010115)81:2<177::aid-jsfa796>3.0.co;2-9

✦ Synopsis

The objective of this work was to determine the fructan and fructooligosaccharide (FOS) content of different onion tissues in order to evaluate the potential use of onion by-products from the food industry as a source of FOS and fructans. Assays with two methods were carried out to optimise the extraction procedure. The main FOS, namely kestose (GF 2 ), nystose (GF 3 ) and fructofuranosylnystose (GF 4 ), were measured directly using standard sugars. The method for total fructans was based on enzymatic treatment (Novozym 230) of ethanolic/aqueous extract followed by determination of released fructose and glucose by HPLC. Data showed a clear predominance of GF 2 in every onion tissue and no occurrence of highly polymerised fructans. The tissues richest in fructans were the ¯eshy layers, so that the outer two ¯eshy layers turn out to be the best onion by-product as a possible fructan source.