title: Biophysical features of cereal endosperm that decrease starch digestibility.
abstract: The influence of the physical structure of cereal endosperm on the natural structural integrity (intact cells) and starch bioaccessibility of the resultant flours was studied using maize as example. Endosperm hardness, defined by its intracellular (protein matrix) and extracellular (cell walls) constituents, affected the granular and molecular damage of the starch of the resultant flours leading to higher digestibility of raw hard than soft endosperm flours, but comparatively lower digestibility after cooking. After milling, hard endosperm possessed more damaged starch (radial splitting of amylopectin clusters) in the periphery of the resultant particles that increased in vitro starch digestibility of raw flours. Conversely, the hard endosperm plant tissue matrix significantly limited water availability and heat transfer on starch gelatinisation, thereby decreasing the digestion rate after hydrothermal processing (in particle size flours >80μm). This study provides a unique mechanistic understanding to obtain cereal flours with slow digestion property for commercial utilisation.
authors.affiliation: Food Technology Area, College of Agricultural Engineering, University of Valladolid, 34004 Palencia, Spain; Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University,745 Agriculture Mall Drive, West Lafayette, IN 47907, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Roman
authors.affiliation: Food Technology Area, College of Agricultural Engineering, University of Valladolid, 34004 Palencia, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Gomez
authors.affiliation: Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University,745 Agriculture Mall Drive, West Lafayette, IN 47907, USA.
authors.forename: Cheng
authors.initials: C
authors.lastname: Li
authors.affiliation: Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University,745 Agriculture Mall Drive, West Lafayette, IN 47907, USA.
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Hamaker
authors.affiliation: Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University,745 Agriculture Mall Drive, West Lafayette, IN 47907, USA. Electronic address: mart1269@purdue.edu.
authors.forename: Mario M
authors.initials: MM
authors.lastname: Martinez
mesh_terms: D004063:Digestion; D002523:Edible Grain / Q000648:ultrastructure*; D056625:Endosperm / Q000648:ultrastructure*; D005433:Flour / Q000032:analysis; D013213:Starch / Q000737:chemistry*; D003313:Zea mays
chemical_list: D013213:Starch
keywords: Cell walls; Digestion; Endosperm; Flour; Maize; Plant tissue; Starch