title: Preparation of slowly digestible sweet potato Daeyumi starch by dual enzyme modification.
abstract: Sweet potato Daeyumi starch was dually modified using glycogen branching enzyme (BE) from Streptococcus mutans and amylosucrase (AS) from Neisseria polysaccharea to prepare slowly digestible starch (SDS). Dually modified starches had higher SDS and resistant starch (RS) contents than control starch. The branched chain length distributions of the BE-modified starches indicated an increase in short side-chains [degree of polymerization (DP)≤12] compared with native starch. AS treatment of the BE-modified starches decreased the proportion of short side-chains and increased the proportion of long side-chains (DP≥25) and molecular mass. It also resulted in a B-type X-ray diffraction pattern and an increased relative crystallinity. Regarding thermal properties, the BE-modified starches showed no endothermic peak, whereas the BEAS-modified starches had a broader melting temperature range and lower melting enthalpy compared to native starch. The combined enzymatic treatment resulted in novel glucan polymers with slow digestion properties.
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: A Ra
authors.initials: AR
authors.lastname: Jo
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Ha Ram
authors.initials: HR
authors.lastname: Kim
authors.affiliation: Department of Food Science and Technology, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea.
authors.forename: Seung Jun
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Bioenergy Crop Research Institute, National Institute of Crop Science, Rural Development Administration, Muan-gun, Jeollanam-do 58545, Republic of Korea.
authors.forename: Joon Seol
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Bioenergy Crop Research Institute, National Institute of Crop Science, Rural Development Administration, Muan-gun, Jeollanam-do 58545, Republic of Korea.
authors.forename: Mi Nam
authors.initials: MN
authors.lastname: Chung
authors.affiliation: Bioenergy Crop Research Institute, National Institute of Crop Science, Rural Development Administration, Muan-gun, Jeollanam-do 58545, Republic of Korea.
authors.forename: Seon Kyeong
authors.initials: SK
authors.lastname: Han
authors.affiliation: Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Republic of Korea.
authors.forename: Cheon-Seok
authors.initials: CS
authors.lastname: Park
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Republic of Korea; Center for Food and Bioconvergence and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea. Electronic address: twmoon@snu.ac.kr.
authors.forename: Tae Wha
authors.initials: TW
authors.lastname: Moon
mesh_terms: D015061:1,4-alpha-Glucan Branching Enzyme / Q000378:metabolism*; D000687:Amylopectin / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D004063:Digestion; D005964:Glucosyltransferases / Q000378:metabolism*; D027723:Ipomoea batatas / Q000737:chemistry*; D009343:Neisseria; D010194:Pancreatin / Q000378:metabolism; D013295:Streptococcus mutans; D013552:Swine; D013696:Temperature; D013816:Thermodynamics
chemical_list: D010194:Pancreatin; D000687:Amylopectin; D005964:Glucosyltransferases; D015061:1,4-alpha-Glucan Branching Enzyme; C019700:amylosucrase
keywords: Amylosucrase; Branching enzyme; Enzymatic modification; Slowly digestible starch; Sweet potato starch