title: Transfructosylation reaction in cured tobacco leaf (Nicotiana tabacum).
abstract: Tobacco plant was known to be a non-fructan-storing plant. However, we demonstrated that fructo-oligosaccharides (FOSs) were formed in cured tobacco leaf on adding sucrose to the leaf in our previous report (Nagai et al., J. Agric. Food Chem., 60, 6606-6612, 2012). Also, it was expected from the results obtained in previous study that FOSs were generated by enzymatic reaction in cured tobacco leaf. The purpose of this study is to confirm and understand the mechanisms of above-mentioned FOSs formation. Thus, we tried to purify the enzymes related to the production of FOSs. The enzymes were extracted from pulverized cured tobacco leaf (burley type leaf), and were purified by charcoal treatment, ultrafiltration, and several chromatography techniques. As a result, one of the enzymes was purified up to 414-fold. It was revealed that this enzyme was acid invertase exhibiting maximum transfructosylation activity at pH 6.0, 60 °C. In addition, general properties of this enzyme were also investigated. The enzyme purified in this study enhanced the ratio of FOSs formation under the condition of high concentrated sucrose. From these results, it was suggested that this enzyme participated in the formation of FOSs in tobacco leaf after curing.
authors.affiliation: Tobacco Science Research Center, Japan Tobacco Inc., 6-2 Umegaoka, Aoba-ku, Yokohama, Kanagawa 227-8512, Japan; Department of Innovative Science and Bioenvironmental Sciences, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan. Electronic address: ultimate2ol@hotmail.com.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nagai
authors.forename: Toshiki
authors.initials: T
authors.lastname: Mine
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Wariishi
mesh_terms: D002850:Chromatography, Gel; D005630:Fructans / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D006358:Hot Temperature; D008970:Molecular Weight; D009844:Oligosaccharides / Q000378:metabolism; D010936:Plant Extracts / Q000378:metabolism; D018515:Plant Leaves / Q000201:enzymology*; D013395:Sucrose / Q000378:metabolism; D014026:Nicotiana / Q000201:enzymology*; D043324:beta-Fructofuranosidase / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D005630:Fructans; D009844:Oligosaccharides; D010936:Plant Extracts; D013395:Sucrose; D043324:beta-Fructofuranosidase; D005947:Glucose
keywords: Cured tobacco; Heat stability; Invertase; Remaining activity; Transfructosylation