The anti-staling effect of pre-gelatinized flour and emulsifier in gluten-free bread

Abstract

The use of gluten-free products is increasing since an increasing number of people (1-2 %) are suffering from Celiac disease and thereby need a gluten-free diet. Gluten-free bread tends to have shorter shelf life and quality compared with white wheat bread. In this study, 3 % (flour basis) of pre-gelatinized oat and barley flour as well as an emulsifier were added to a gluten-free mix to increase the water content by 1.5-2 %, affect the starch retrogradation and the formation of amylose lipid complex. The staling was followed measuring the firmness (texture analyzer), water content and distribution (nuclear magnetic resonance), amylopectin retrogradation and the formation of amylose-lipid complex (differential scanning calorimetry) in order to see the impact of both macroscopic and molecular changes on firmness. Both gluten-free bread and a white wheat bread were used as control loaves. Largest specific volume was found in the gluten-free control. The firmness varied with both the specific volume and the point of measurement. The amount of retrograded amylopectin increased the firmness, although this effect was dependent on the type of bread, in terms of distribution and availability of the water within the system. The proton relaxation time, which was representing movable water, decreased during storage and revealed that both the amylopectin retrogradation and the lipid complex formation were affecting the rigidity of the amorphous domain and not only the crystalline regions. In contrast to the other recipes, the use of emulsifier caused limited retrogradation and a low correlation between the texture properties and time-dependent events.

Texture Development in Gluten‐Free Breads: Effect of Different Enzymes and Extruded Flour

“…Purhagen et al . () showed that the addition of emulsifiers could decrease bread hardening over the first 3 d. That finding coincides with the observations of Nunes et al . () after the addition of sodium stearoyl lactylate (SSL) and monoglycerides, but not with other emulsifiers, such as lecithin or diacetyl tartaric acid ester of mono‐ and diglycerides.…”

Effect of hydrocolloids and emulsifiers on the shelf‐life of composite cassava‐maize‐wheat bread after storage

“…; Purhagen et al. ). According to Gray and Bemiller (), amylopectin is the major factor in the retrogradation process but is not solely responsible for the observed change in texture.…”

Comparison of the effects of different heat treatment processes on rheological properties of cake and bread wheat flours

“…Thermal treatment has numerous applications, it is a valuable tool for extending shelf-life of the flours by reducing the enzyme activity and moisture content of the lipid-rich fractions (Lehtinen et al, 2003;Purhagen, Sjöö, & Eliasson, 2011, 2012. Beside the biological effects, dry heat process has a significant impact on the techno-functional properties of flours.…”