Slowly digestible starch in fully gelatinized material is structurally driven by molecular size and A and B1 chain lengths

Mario M Martinez; Cheng Li; Monika Okoniewska; Indraneil Mukherjee; Dominic Vellucci; Bruce Hamaker

doi:10.1016/j.carbpol.2018.06.021

Slowly digestible starch in fully gelatinized material is structurally driven by molecular size and A and B1 chain lengths

Carbohydr Polym. 2018 Oct 1:197:531-539. doi: 10.1016/j.carbpol.2018.06.021. Epub 2018 Jun 13.

Authors

Mario M Martinez¹, Cheng Li², Monika Okoniewska³, Indraneil Mukherjee³, Dominic Vellucci³, Bruce Hamaker⁴

Affiliations

¹ Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, 745 Agriculture Mall Drive, West Lafayette, IN, 47907, USA. Electronic address: mario.martinez@uoguelph.ca.
² Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, 745 Agriculture Mall Drive, West Lafayette, IN, 47907, USA.
³ Mondelez International, 100 Deforest Avenue, East Hanover, NJ, 07936, USA.
⁴ Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, 745 Agriculture Mall Drive, West Lafayette, IN, 47907, USA. Electronic address: hamakerb@purdue.edu.

PMID: 30007644
DOI: 10.1016/j.carbpol.2018.06.021

Abstract

The objective of this study was to obtain structure-digestion relationships of fully gelatinized starch. Twelve starch samples with marked fine structural differences (HPLC-SEC) were studied for their retrogradation behavior (thermal and rheological properties of starch gels) and in vitro digestibility. A reduction in the digestion rate during storage for 7 days was observed in all samples and, interestingly, this reduction was particularly evident in sago (64.7%), potato (57.3%), pea (55.1%) and acid-converted maize (ACM, 51.6-51.8 %) starches. Results indicated two potential interactions that may result in slowly digestible supramolecular structures: 1) double helices between external A and B1 chains of DP at peak maximum ≥ 15.5 Glucose Units (perhaps involving internal long chains) that also are prone to forming intermolecular associations [high relative drop in the storage modulus (G') during heating of 7 days-stored gels] and; 2) interactions of small molecular size acid-hydrolyzed starch molecules that may be more mobile and easily aligned.

Keywords: Acid-converted maize; Chain length distribution; Digestion; Retrogradation; Sago; Starch.