Impact of different protein sources in gluten-free bread making on crumb structure formation

status: publishe

Current and forward looking experimental approaches in gluten-free bread making research

Research efforts on gluten-free bread making have rapidly increased during the last decade. A lot of different approaches are being used to improve the quality of these products. The techniques used in gluten-free bread making research vary widely. This review focuses on the methodological aspects of gluten-free bread making research and extracts relevant data from all Web of Science peer reviewed research articles on gluten-free bread published from 2010 to date. Recipes and methodologies are grouped by (main) starch source and list other ingredients, additives and treatments used. The focus lies on the experimental setups typically used to analyze batter/dough and end product. Small deformation rheological measurements are typically performed on gluten-free batter/dough, along with several other batter/dough properties, but there is no clear link between these characteristics and the bread quality which typically is determined by volume and texture analysis or sensory evaluation. Some more recent techniques that have already been used on wheat bread or other bakery products are discussed as well. Their application in gluten-free bread making research may help extend the current knowledge.status: publishe

Native and enzymatically modified wheat (Triticum aestivum L.) endogenous lipids in bread making: a focus on gas cell stabilization mechanisms

Lipopan F and Lecitase Ultra lipases were used in straight dough bread making to study how wheat lipids affect bread loaf volume (LV) and crumb structure setting. Lipase effects on LV were dose and dough piece weight dependent. The bread quality improving mechanisms exerted by endogenous lipids were studied in terms of gluten network strengthening, which indirectly stabilizes gas cells, and in terms of direct interfacial gas cell stabilization. Unlike diacetyl tartaric esters of mono- and diacylglycerols (DATEM, used as control), lipase use did not impact dough extensibility. The effect on dough extensibility was therefore related to its lipid composition at the start of mixing. Both lipases and DATEM strongly increase the levels of polar lipids in dough liquor and their availability for and potential accumulation at gas cell interfaces. Lipases form lysolipids that emulsify other lipids. We speculate that DATEM competes with (endogenous) polar lipids for interacting with gluten proteins.status: publishe

Impact of egg white and soy protein on crumb firming in gluten-free breads based on rice flour or a mixture of cassava and potato starch

Oral Presentation.status: publishe

A lipase based approach to understand the role of wheat endogenous lipids in bread crumb firmness evolution during storage

When forming amylose-lipid (AM-L) inclusion complexes, surfactants retard bread crumb firming. Some wheat endogenous lipids have structures similar to those of surfactants. Lipase use in bread making increases the level of free fatty acids and ‘lyso’ lipids which can form AM-L complexes. We here used three lipases (Lipopan F, Lecitase Ultra, and Lipolase) with different specificities and the surfactant sodium stearoyl lactylate (SSL) for studying the role of lipids in bread crumb firmness and storage induced crumb firming. The lipases and SSL similarly impacted bread crumb texture. Their use induced less pronounced crumb firmness and stiffness increases as well as a less pronounced decrease in resilience than in control bread loaves. Amylopectin (AP) retrogradation was slower but in the end proceeded to a similar extent, as noted with low-field nuclear magnetic resonance. Differences in AP retrogradation after 7 days of storage (as observed with Lipolase) were attributed to the location and type of lipids hydrolysed by the respective lipase enzymes. Lipase hydrolysis products originating from lipids in the free lipid fraction probably had more impact on AP retrogradation than the free fatty acids and ‘lyso’ lipids obtained by hydrolysis of lipids ‘bound’ to the gluten network.status: publishe

Electrical resistance oven baking as a tool to study crumb structure formation in gluten-free bread

Gradientless baking by means of ohmic heating was used for the first time in gluten-free (GF) bread making. Combination thereof with in-line measurements of batter height, viscosity and carbon dioxide (CO2) release proved to be powerful for studying structure formation in GF breads. GF breads studied here were based on (i) a mixture of potato and cassava starches and egg white powder (C/P-S+EW), (ii) rice flour (RF) or (iii) a mixture of RF and egg white powder (RF+EW). The work revealed that bread volume and crumb structure rely heavily on the balance between the moment of CO2 release from batter during baking and that of crumb setting. At the moment of CO2 release, C/P-S+EW bread crumb had already (partly) set, while this was not the case for RF bread crumb, resulting in a collapse and thus low volume of the latter. When a part of RF was replaced by egg white powder, the moment of CO2 release was postponed and the batter collapse was less pronounced, leading to a higher volume and a finer crumb. The presence of egg white proteins in C/P-S+EW or RF+EW batters improved gas cell stabilization. Thus, increasing batter stability or altering the moment of crumb setting results in GF breads with higher volume and a finer crumb structure.status: publishe