Combined techniques for characterising pasta structure reveals how the gluten network slows enzymic digestion rate

Abstract

Please cite this article as: Zou, W., Sissons, M., Gidley, M.J., Gilbert, R.G., Warren, F.J., Combined techniques for characterising pasta structure reveals how the gluten network slows enzymic digestion rate, Food Chemistry (2015), doi: http://dx.doi.org/10.1016/j.foodchem. 2015.05.032 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractThe 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.

Compact structure and proteins of pasta retard in vitro digestive evolution of branched starch molecular structure

“…Two commercial durum wheat varieties (Caparoi and Yawa) were chosen, for which information regarding their production and chemical composition is described in a previous publication (Zou et al, 2015). Semolina was prepared from the two varieties according to procedures described elsewhere (Sissons, Gianibelli & Batey, 2002).…”

“…Semolina was prepared from the two varieties according to procedures described elsewhere (Sissons, Gianibelli & Batey, 2002). Semolina composition, and the methods for processing purified starch, whole pasta (spaghetti) and pasta powder are described elsewhere (Zou et al, 2015). The following combinations are studied for each of the two Durum wheat varieties used here.…”

“…The first is the compact structure of pasta, which reduces the reaction area where starch granules can be accessed by digestive enzymes (Jenkins et al, 1983;Zou, Sissons, Gidley, Gilbert & Warren, 2015), prevents the starch granules from being thermally swollen (Heneen & Brismar, 2003;Sissons, Aravind & Fellows, 2010;Zou et al, 2015) and inhibits pepsin from hydrolyzing the gluten network, thus reducing the digestion rates of entrapped starch (Zou et al, 2015). As a result, the starch digestion of pasta proceeds with sequential kinetic steps, at a slower rate than purified starch or deconstructed pasta (Zou et al, 2015). The second is the presence of a continuous gluten network that entraps the starch granules, as suggested by many workers.…”

“…This reduces the accessibility of α-amylase to the starch (Colonna et al, 1990;Cunin, Handschin, Walther & Escher, 1995;Dexter, Dronzek & Matsuo, 1978;Favier, Samson, Aubled, Morel & Abecassis, 1996;Singh & MacRitchie, 2004;Sissons et al, 2010), because the tortuosity of the gluten network may increase the length of the pathway the enzyme has to take to access the starch substrate (Fardet et al, 1998). It has also recently been shown that α-amylase may form weak binding interactions with the gluten network, which retards the penetration of the enzyme into the gluten network (Zou et al, 2015).…”

Understanding the texture of cooked rice from the molecular, instrumental and sensory levels

“…Total starch content of leached materials was measured using a Megazyme total starch (AA/AMG) assay kit following a method described elsewhere (Zou, Sissons, Gidley, Gilbert & Warren, 2015). The protein content of leached materials was determined using a BCA Protein Assay Kit (Pierce).…”