The effect of different compositions of starter cultures developed from phytic acid-degrading lactic acid bacteria on the sensory quality of bread

Abstract

Sourdough is an initial product used in cereal fermentation, usually prepared by adding lactic acid bacteria (LAB) strains to a mixture of wheat and water. Phytic acid present in wheat flours negatively affects the bioavailability of bread. LAB is found to have phytase activity. The present work thus aimed to determine the effect of starter culture combinations developed from phytic acid-degrading LAB (PAD-LAB) strains isolated from sourdough samples on bread sensory quality. De Man, Rogosa, and Sharpe (MRS) agar, MRS Broth, M17 agar, M17 broth, sodium phytate, and mass spectrometry were used to isolate and identify PAD-LAB from sourdough samples. The extracellular phytase activity of PAD-LAB strains was determined by spectrophotometry. Sourdough samples were prepared using different strains having high phytase activity, and breads produced from these samples were evaluated using sensory attributes. Extracellular phytase activities of 30 strains were determined by the spectrophotometric method, showing the highest value at 1109.7 U/mL, and lowest at 386.9 U/mL, with a mean of 685.1 U/mL. Sourdough samples were prepared using five different strains with high phytase activity as starting cultures; and of the four sourdough samples selected, the count of LAB increased (7.80 - 9.87 log CFU/g), pH decreased (3.53 - 4.57), and TTA (total titratable acidity) values increased (10.17 - 14.29 mL) during the fermentation period. In the sensory evaluation, bread produced with starter culture combination CS30 was preferred. In conclusion, it was determined that the bread produced with PAD-LAB strains has an advantage in terms of sensory quality as compared to the control samples.

Isolation and screening of lactic acid bacteria and yeast starters from ersho (traditional Ethiopian sourdoughs) and evaluation of their role in bread production

“…The pH of breads was closely similar to the finding of Dogan (2021), who reported that the pH of breads was 5.19. The titratable acidity (TA) of the breads was higher than the finding of Dashen et al .…”

“…In the current study, at 0 day storage, the overall mean scores of colour was 7.4, texture 7.6, taste 7.3, odour 7.8, and overall acceptability 7.5 (Table 4). This outcome was better than that of Dogan (2021), who reported that breads' average scores for colour, texture, odour, taste, and overall acceptability were 4.0, 3.7, 3.8, 3.7, and 3.9, respectively. In contrast, Stavros et al .…”

“…The reasons might be variation in bread's protein content (Azza et al, 2020), difference in bread's moisture and fat contents (Shereen & Hafez, 2020), and strain diversity of the starters used (Nadia et al, 2017;Xu et al, 2019). The pH of breads was closely similar to the finding of Dogan (2021), who reported that the pH of breads was 5.19. The titratable acidity (TA) of the breads was higher than the finding of Dashen et al (2021), who reported that the TA of bread was 0.5%.…”

Metabolic characterization of selected probiotic consortia during gluten and wheat bread simulated digestion

“…Endogenous phytase is missing in humans and, therefore, exogenous enzymatic supplementation can be considered as an efficient alternative to overcome this lack [52] . Considering that LAB [53] and non-LAB [54] have shown the ability to decrease phytic acid levels in sourdough, both cereals and pseudo-cereals can be fermented by microbes to achieve the same outcome [55] or, as in our case, the supplementation can be provided by gut colonizing probiotics selected by high phytase activity.…”