Effects of Lactic Acid Bacteria on Reducing the Formation of Biogenic Amines and Improving the Formation of Antioxidant Compounds in Traditional African Sourdough Flatbread Fermentation.

ABSTRACT

This study investigated the safety and functionality of traditional African sourdough flatbread (kisra), based on the content of biogenic amines (BAs) and antioxidant compounds and their improvement using lactic acid bacteria (LAB) species. The primary BAs detected in naturally fermented kisra were tyramine, histamine, putrescine, and cadaverine, with putrescine being the most abundant after baking. In vitro BA production of microorganisms isolated from kisra sourdough revealed that the Enterococcus genus contributed to tyramine accumulation, whereas presumptive yeasts may contribute to putrescine and cadaverine accumulation. The use of LAB species, including Lactiplantibacillus plantarum, Limosilactobacillus fermentum, Levilactobacillus brevis, and Weissella cibaria, significantly reduced putrescine content to less than about 23% of that of naturally fermented kisra, and eliminated tyramine, histamine, and cadaverine formation. Meanwhile, DPPH scavenging activity, total polyphenolic content, and tannin content in naturally fermented kisra were 85.16%, 1386.50 µg/g, and 33.16 µg/g, respectively. The use of LAB species did not affect the DPPH scavenging activity or tannin content but significantly increased the total phenolic content by up to 20% compared to naturally fermented kisra. Therefore, fermentation with LAB starter cultures might be a promising approach to improve the safety related to BAs as well as the functionality of kisra bread.