The Effects of Ovine Whey Powders on Durum Wheat-Based Doughs

Nicola Secchi,Pasquale Catzeddu,Simonetta Fois,Ivo Pinna,Antonio Piga,Massimo Piccinini,Costantino Fadda

doi:10.1155/2018/1789892

Abstract

Two types of ovine whey powder, with different protein content, were added at increasing substitution rates to two types of semolina, one with strong and tenacious gluten and the other with weak and sticky gluten. For each dough the optimum mixing time and hydration level were calculated using the consistograph. The whey powder negatively affected the leavening volume of all doughs, at all percentages except the lowest one (5%), mainly because of its effects on the elastic component of gluten as measured with a stress relaxation test. Differences of the secondary structure of gluten proteins among samples were investigated by analyzing the amide I band in the Fourier transform infrared spectra of the dough. Weak and strong semolina showed a different relative percentage of α-helix, random coil, and β-sheet structures. The longer mixing times for dough formation when using semolina with strong gluten led to an increase in α-helices and random coils, which caused a worse leavening performance than the weak-gluten semolina.

Highlights

Semolina from durum wheat is used to make different types of local breads in the Mediterranean area, in Southern Italy [1]
Differences of the secondary structure of gluten proteins among samples were investigated by analyzing the amide I band in the Fourier transform infrared spectra of the dough
The data show the differences between the two semolina samples with regard to protein content, gluten index, and the alveograph parameters configuration ratio (P/L) and deformation energy (W). 48T had a higher protein content, gluten tenacity, and extensibility than 4T; the latter was obtained from a wheat cultivar that is well known for its poor gluten quality, due to the pattern of the high molecular weight glutenin subunit 20 (HMW-GS 20), which is the predominant pattern in durum wheat landraces and old genotypes [19]; in new cultivars, as those of 48T, it has been almost completely replaced by the 6 + 8 and 7 + 8 HMW patterns, which exhibit stronger dough properties and superior baking quality than HMW-GS 20 cultivars

Summary

Introduction

Semolina from durum wheat is used to make different types of local breads in the Mediterranean area, in Southern Italy [1]. The chemical and rheological characteristics of semolina greatly affect the handling properties of the dough, its leavening capacity, and the final quality of the bread. Semolina characterized by a strong gluten network, resulting in high gluten index and P to L values, is suitable for producing soft bread with low specific weight [2] due to the high leavening and gas retention capacity. Semolina with a weak-gluten network results in dough that is not able to expand well, producing bread that is heavy and hard with an inhomogeneous structure [3]. An increasing consumer desire for high food quality has led to renewed interest in ancient raw materials and traditional food production [4] The importance of this topic was stated at the Universal Exhibition hosted in Milan in 2015 [5] where “the best of the agri-food and gastronomic traditions of each of the exhibitor countries”

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Conclusion