Structural Properties of Branched Α-Limit Dextrins Produced by Different Sources of Α-Amylase on Various Botanical Sources of Starches

Session: 
PS2 Poster session 2 Even numbers
Code: 
P208
Location (hall): 
Foyer
Start/end time: 
Tuesday, July 2, 2019 - 15:45 to 17:15
Ye-eun
Shim

Ye-eun Shim1, Moon-Gi Hong1, Byung-Hoo Lee1

1Department of Food Science and Biotechnology, Gachon University, Seongnam, South Korea

Starch was hydrolyzed to linear maltooligosaccharides (mainly maltose and maltotriose) and branched α-limit dextrins (αLDx) by α-amylase reaction. αLDx were slowly hydrolyzed to glucose by small intestinal α-glucosidases compared to linear α-glucans, thus those can be applied to a functional food material to attenuate the post-prandial blood glucose level. In this study, ten different types of botanical starches were hydrolyzed by individual α-amylases from porcine pancreas, Aspergillus oryzae, Bacillus amyloliquefaciens, and Bacillus licheniformis to produce different structures of branched αLDx. The result clearly showed that each α-amylase produced different ranges of molecular weights (ca. 614 - 8855 Da) and amounts (16.8 - 66.2%) of branched αLDx, and the α-amylolysis on waxy corn starch showed the highest production yield (24.6±0.5%) among different starches. While α-amylase from Bacillus species produced more than 50% of αLD from starch molecules, those were further hydrolyzed by human pancreatic α-amylase (HPA). However, αLDx produced by α-amylase from Aspergillus oryzae were not much hydrolyzed by HPA, which implies those structure will not be more digested by salivary and pancreatic α-amylases in gastrointestinal tract. Furthermore, the chromatographically-purified branched αLDx had higher α-1,6 linkage ratios which will be slowly digested by mammalian α-glucosidases compared α-amylolyzed-starch molecules. Thus, this study clearly suggested that αLDx production by Aspergillus oryzae α-amylase has a potential to apply in food industry as a slowly-digestible ingredient to decrease the glucose spike with an extending energy delivery.

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