Effect of By-Products from Selected Fruits and Vegetables on Gluten-Free Dough Rheology and Bread Properties

Fairouz Djeghim,Wojciech Tanaś,Hayat Bourekoua,Mohammed Nesreddine Zidoune,Renata Różyło,Agata Bieńczak

doi:10.3390/app11104605

Abstract

The aim of the study was to investigate the effect of using various by-products (orange and apple pomace, tomato peel, pepper peel, prickly pear peel, and prickly pear seed peel) on the dough rheology and properties of gluten-free bread. The by-products were incorporated into a gluten-free bread formulation based on corn and chickpea flours (2/1 w/w). Different levels of each by-product (0, 2.5, 5, and 7.5% in the basic replacement) were tested. Wheat bread and gluten-free bread without the addition of by-products were used as controls. The results indicated that the by-products increased the maximum dough height, the total CO2 production, and CO2 retention coefficient compared to unenriched gluten-free dough. The highest K-value consistency coefficient was observed for the dough enriched with the prickly pear peel. The addition of by-products significantly improved (p < 0.0001) the specific volume of gluten-free bread, with values increasing from 1.48 to 2.50 cm3/g. The hierarchical cluster analysis and the constellation plot showed four groups: the wheat bread group, the second group containing the gluten-free control bread, the group with bread enriched by pomace, and the group with bread enriched with peels, exhibit the same effect on gluten-free bread and the peels exhibit the same effect on gluten-free bread.

Highlights

Global market data have shown 10.4% compound annual growth rate in gluten-free sales between 2015 and 2020 because of the incidence of celiac disease and other glutenassociated allergies [1,2]
The highest moisture content was found for dried apple pomace (DAP) and the highest values of ash and protein content were noted for dried prickly pear peel (DPPP)
dried tomato peel (DTP), dried prickly pear seed peel (DPPSP), and dried pepper peel (DPP) presented high fiber contents compared to other by-products

Summary

Introduction

Global market data have shown 10.4% compound annual growth rate in gluten-free sales between 2015 and 2020 because of the incidence of celiac disease and other glutenassociated allergies [1,2]. The gluten-free market today provides a variety of foods that can be eaten safely by patients suffering from celiac disease [3]. Breads formulated with gluten-free raw materials have low nutritional properties, poor taste, and are of inferior quality. In the absence of gluten, dough presents poor rheological properties (viscoelasticity) and is unable to develop a protein network, affecting the final quality of gluten-free bread [6,7]. The use of alternative ingredients including starch, hydrocolloids, protein, enzymes, emulsifiers, and fibers in the preparation of gluten-free bread can improve the texture, mouthfeel, acceptability, shelf life, and nutritional properties of the products. Similar effects can be expected when adding fruit and vegetable by-products to bread [13]

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Conclusion