Combined techniques for characterising pasta structure reveals how the gluten network slows enzymic digestion rate. (1st December 2015)

• Record Type: Journal Article
• Authors: Zou, Wei; Sissons, Mike; Gidley, Michael J.; Gilbert, Robert G.; Warren, Frederick J.
• Is Part Of: Food chemistry. Volume 188(2015)
• Page Start: 559
• Page End: 568
• Publication Date: 2015-12-01
• Subjects: Pasta structure -- Gluten entrapment -- Starch digestion rate; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2015.05.032
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: Sequential steps in pasta hydrolysis are quantified. The observed hydrolysis rates are related to structural features. The compact structure of pasta protects the gluten from proteolysis. The intact gluten network reduces the rate of starch hydrolysis. Evidence is presented for interactions between α-amylase and gluten. 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.