Assessment of Kefir and Sourdough on the Flavor Profile, Quality of White Bread and Rheology of Wheat Dough

Abstract

Kefir sourdough bread is a new development on product design strategy and is alternative starter for sourdough bread. Na reduction is desirable due to health effects associated with excess sodium consumption. The objective of the study was to investigate the effect of kefir, sourdough (SD) and NaCl on the flavor characteristics, rheological property and shelf life of white bread. Breads were prepared with NaCl (0.1, 0.4, 0.8, 1.2% flour based), kefir (30, 40, 50, 60% flour based) and sourdough (20, 40, 70% flour based) in a factorial design. Crumb firmness and color were measured over 7 days of storage. Elastic recovery index of dough was evaluated using a compression-recovery test (Gluten CORE). Sensory evaluation was done with a consumer acceptance test with 64 untrained panelists in three independent replicates. NaCl did not affect texture and color of white bread while high sourdough and kefir made softer breads. Increase in crumb firmness from the combination of treatments ranged from 32 to 62% at day 4 and 45 to 78% at day 7 while bread with 0.8% NaCl without kefir and sourdough showed highest increase by 116% at day 7 compared to day 1. Dough with kefir at 50% had significantly higher recovery than 30% kefir. Significantly higher height of bread was obtained at 70% sourdough than 40%. In the breads without kefir or sourdough, 1.2% NaCl had higher scores of all sensory attributes compared to 0.8%. Sourdough had more influence on the sensory perception of breads than kefir. In the presence of fermented products, difference in NaCl levels were not identified by the panelists and reduction of NaCl up to 47% could be achieved without affecting sensory quality and shelf life of the bread.This study suggested that sourdough and kefir are potential ingredients for the improvement of dough rheology, texture, and flavor attributes of white bread.