title: Combined techniques for characterising pasta structure reveals how the gluten network slows enzymic digestion rate.
abstract: The aim of the present study is to characterise the influence of gluten structure on the kinetics of starch hydrolysis in pasta. Spaghetti and powdered pasta were prepared from three different cultivars of durum semolina, and starch was also purified from each cultivar. Digestion kinetic parameters were obtained through logarithm-of-slope analysis, allowing identification of sequential digestion steps. Purified starch and semolina were digested following a single first-order rate constant, while pasta and powdered pasta followed two sequential first-order rate constants. Rate coefficients were altered by pepsin hydrolysis. Confocal microscopy revealed that, following cooking, starch granules were completely swollen for starch, semolina and pasta powder samples. In pasta, they were completely swollen in the external regions, partially swollen in the intermediate region and almost intact in the pasta strand centre. Gluten entrapment accounts for sequential kinetic steps in starch digestion of pasta; the compact microstructure of pasta also reduces digestion rates.
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
authors.forename: Wei
authors.initials: W
authors.lastname: Zou
authors.affiliation: NSW Department of Primary Industries, Tamworth Agricultural Institute, 4 Marsden Park Road, Calala, NSW 2340, Australia.
authors.forename: Mike
authors.initials: M
authors.lastname: Sissons
authors.affiliation: The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Gidley
authors.affiliation: Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Gilbert
authors.affiliation: The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia. Electronic address: f.warren1@uq.edu.au.
authors.forename: Frederick J
authors.initials: FJ
authors.lastname: Warren
mesh_terms: D003296:Cooking; D004063:Digestion; D005502:Food; D005983:Glutens / Q000737:chemistry*; D006868:Hydrolysis; D013213:Starch / Q000737:chemistry*; D014908:Triticum / Q000737:chemistry*
chemical_list: D005983:Glutens; D013213:Starch
keywords: Gluten entrapment; Pasta structure; Starch digestion rate