Branch chain elongation by amylosucrase: production of waxy corn starch with a slow digestion property.
Starches with high slowly digestible starch (SDS) contents were prepared by treating completely gelatinized waxy corn starch with amylosucrase. The structural properties of the prepared starches were then investigated. The content of SDS increased by up to 38.7% after amylosucrase modification, and the portion of chains with degree of polymerisation (DP) 25-36 increased, while the portion of chains with DP⩽12 decreased. Amylosucrase-modified starches showed a weak B-type crystalline structure. A slight increase in the degree of relative crystallinity was observed with increased reaction time. The thermal properties, including melting temperature and enthalpy, of the amylosucrase-modified starches were higher than for the control starch. Although the amylosucrase-modified starches showed varying structural properties according to reaction time (1-45 h), their digestibilities did not change much after 6 h. By controlling the reaction time of the amylosucrase treatment, a tailored starchy food containing the desired amount of SDS can be produced.
Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea.
Bo Kyung
BK
Kim
Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea.
Hye In
HI
Kim
Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea; Center for Food and Bioconvergence, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea.
Tae Wha
TW
Moon
Department of Food Science and Technology, Seoul National University of Science and Technology, Seoul 139-743, Republic of Korea. Electronic address: choisj@seoultech.ac.kr.
Seung Jun
SJ
Choi
D001426:Bacterial Proteins / Q000737:chemistry*; D055162:Biocatalysis; D004063:Digestion; D005964:Glucosyltransferases / Q000737:chemistry*; D015394:Molecular Structure; D009343:Neisseria / Q000201:enzymology*; D010936:Plant Extracts / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry*
D001426:Bacterial Proteins; D010936:Plant Extracts; D013213:Starch; D005964:Glucosyltransferases; C019700:amylosucrase
Amylosucrase; Branched chain length distribution; Digestion; Slowly digestible starch; Waxy corn starch