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Effect of molecular weight profile of sorghum proanthocyanidins on resistant starch formation
Author(s) -
Barros Frederico,
Awika Joseph,
Rooney Lloyd W
Publication year - 2014
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.6400
Subject(s) - amylose , starch , proanthocyanidin , chemistry , sorghum , food science , catechin , resistant starch , monomer , degree of polymerization , biochemistry , polymerization , polyphenol , organic chemistry , agronomy , biology , polymer , antioxidant
Abstract BACKGROUND There is a growing interest to increase resistant starch (RS) in foods through natural modification of starch. Sorghum tannins (proanthocyanidins, PAs) were recently reported to interact with starch, increasing RS. However, there is no information about how the molecular weight profile of PAs affects RS formation. This study investigated how different‐molecular‐weight PAs from sorghum affected RS formation in different starch models . RESULTS The levels of RS were higher (331–437 mg g −1 ) when high‐amylose starch was cooked with phenolic extracts containing mostly high‐molecular‐weight PAs compared with extracts containing lower‐molecular‐weight PAs or monomeric catechin (249–285 mg g −1 ). In general, binding capacity of PAs with amylose increased proportionally with molecular weight. For example, the percentage of PAs bound to amylose increased from 45% (PAs with degree of polymerization (DP) = 6) to 94% (polymeric PAs, DP > 10). The results demonstrate that molecular weight of the PAs directly affects their interaction with starch: the higher the molecular weight, the stronger the binding to amylose and the higher the RS formation . CONCLUSION Polymeric PAs from sorghum can naturally modify starch by interacting strongly with amylose and are thus most suitable to produce foods with higher RS. © 2013 Society of Chemical Industry