The study – published in Food Hydrocolloids – aimed to optimise the composition of a blend of inulin, pectin and guar gum to enrich the fibre content of partially baked frozen bread without impairing its technological quality.
Led by Duška Ćurić from the University of Zagreb, Croatia, the research team explained that in addition to being a convenient food, bread is expected to be nutritious. As a result the team proposed to create a fibre rich product in the form of partially baked frozen (PBF) bread.
“In this study we investigated the effects of inulin, pectin and guar alone and in combination on the quality and stability of partially baked frozen breads using response surface methodology,” explained the researchers.
“In PBF breads stored frozen for one day and rebaked, we found that a blend of all three components can improve the specific volume, crumb hardness and chewiness.”
Ćurić and his team said their study provides insights into the complexity of interactions between fibres and hydrocolloids “and their combined influence on bread characteristics, thereby serving as a guide for future research in this area,”
“The conclusions of this and similar work may help increase the marketing of breads that provide consumers with a convenient source of fibre for a range of health benefits,” said the researchers.
“In addition, fibre blends with compositions similar to the one examined here may be especially beneficial in the production of gluten-free bread, which is known to be of particularly low nutritional value.”
Partial baking
The team noted that the baking industry “is constantly trying to offer benefits to consumers, including freshly baked breads. As a result, partially baked frozen technology is a growing industrial practice.”
They noted that the PBF process involves controlled partial baking, before freezing and storing of bread. This is followed by rebaking at the point of sale or by the end-user.
Study details
“We prepared 20 formulations following a central composite design, together with 4 control breads,” explained the researchers.
They revealed that bread enriched with inulin had higher crumb hardness, lower specific volume, shape, moisture content, and crumb cohesiveness than control bread, but improved flavour.
Pectin and guar improved moisture content and crumb cohesiveness.
“There was no interaction between inulin and pectin for any of the bread attributes investigated, while interactions between inulin and guar were small,” revealed Ćurić and his colleagues.
“In contrast, guar and pectin significantly interacted to decrease volume and increase crumb hardness and chewiness.”
The team revealed that the final optimised blend contained 3% inulin, 0.9 to 1% pectin and 0.3 to 0.4% guar.
Source: Food Hydrocolloids
Volume 30, Issue 1, January 2013, Pages 428–436, 10.1016/j.foodhyd.2012.06.005
“Combined effects of inulin, pectin and guar gum on the quality and stability of partially baked frozen bread”
Authors: Nikica Škara, Dubravka Novotni, Nikolina Čukelj, Bojana Smerdel, Duška Ćurić