Process Optimization and Storage Characteristics Analysis of Lactic Acid Bacteria Lyophilized Powder Fermented Whole Wheat Sourdough Bread

Objective: In order to make whole wheat sourdough bread (WWSB) using Lactobacillus plantarum lyophilized powder fermentation, and to analyze its processing and storage characteristics. Method: Based on the previous single-factor experiments, the whole wheat sourdough (WWSD) addition and the fermentation time of whole wheat sourdough were selected as the influencing factors, and the final pH, total acidity (TTA), specific volume, hardness and sensory score of the bread were used as the response values to optimize the process formulation of whole wheat sourdough using the Central composite design method. On this basis, wheat bread (WB) and whole wheat bread (WWB) were used as the blank group and the control group, both were stored at 4 ℃ for one week, and samples were taken at day 0, 1, 3, 5 and 7 to analyze the whole texture characteristics and water migration of the three breads. Results: The best process recipe for whole wheat sourdough bread was 18% whole wheat sourdough addition and 16 h whole wheat sourdough fermentation time, at which time the whole wheat sourdough bread had pH4.82, TTA 5.62 mL, specific volume 3.47 mL/g, hardness 5.59 N, and sensory score 83. The storage characteristics of the three breads under this processing condition were as follows: The hardness growth rate of WWSB (35.75% and 21.57%) throughout the storage period was less than that of WWB (39.98% and 25.36%) and WB (43.81% and 28.22%) in the early and late stages, the relaxation time T₂₁, T₂₂, and T₂₃ of WWSB decreased at a rate less than that of WWB and WB, especially the decrease rate of semi-bound water T₂₂. Conclusion: The optimized recipe of whole wheat sourdough bread had reasonable conditions and could better inhibit moisture loss and extend the shelf life of the bread during storage.