Effect of Green Tea Extract Concentrations on Sourdough Bread with Lactiplantibacillus plantarum

Abstract

In this study, sourdough breads were made using Lactiplantibacillus plantarum starter isolated from traditional sourdoughs. The main objective of this study was the effect of green tea powder extracts (0.25%, 0.50%, 0.75% and 1.0%) on Lactiplantibacillus plantarum added sourdough bread. The dynamic rheological properties of the doughs were determined. Bread production was carried out and then texture analysis, specific volume, color analysis, DPPH and total phenolic analysis were performed. Frequency scanning test was used to determine viscoelastic properties. G' ˃ G'' was found in all doughs prepared using Lb. plantarum strain. The fact that G' ˃ G'' indicated that all sourdoughs exhibited elastic properties. It was observed that the hardness values of sourdough breads containing green tea powder extracts were lower compared to the control bread. The hardness of the other breads varied between 161.9-267.6 g. Bread containing green tea powder extract at 0.75% concentration had the lowest hardness value. It was observed that the specific volumes of the breads increased as the green tea powder extract concentration increased. The specific volumes values for the concentrations (0.25,0.50.0.75,1.0 and control) were 3.39,3.80,3.95,5.21 and 4.45 (mL g-1), respectively. In the color analysis of the breads, it was noted that as the ratio of green tea powder extract increased, the density increased. Another important parameter in our study is DPPH and total phenolic analysis. DPPH values of breads changed from 0.54 mmol g-1 to 1.46 mmol g-1. The antioxidant value increased as the concentration of green tea powder extract increased in sourdough breads. Sourdough bread containing 1.0% green tea powder extract had the highest antioxidant value, while control bread (0.54) had the lowest value. The total phenolic content (TPC) of sourdough breads made with green tea powder extract varied from 10.67 to 104.65 ug g-1. In the results, as the concentration of green tea powder extracts increased, the total phenolic content increased. A linear relationship between DPPH and total phenolic content was found. As a result, it can be said that green tea powder extracts improve the quality of sourdough breads.