Experimental study reveals that 30% sourdough co-fermentation prevents volume loss and hardening in frozen dough, suggesting enhanced gluten and cryoprotective metabolic retention.
Key Points
To evaluate how different proportions of sourdough in a sourdough–yeast co-fermentation system affect dough microstructure, microbial survival, and product quality in frozen raw steamed buns.
Formulated bun dough with 0%, 30%, 50%, 70%, and 100% sourdough replacement within a sourdough–yeast co-fermentation system.
Stored dough samples at −18 °C for 30 days to monitor changes in dough height, specific volume, texture hardness, and sensory qualities.
Quantified viable yeast and lactic acid bacteria (LAB) counts, proline accumulation, and free sulfhydryl content to assess cryoprotection and gluten structural integrity.
A 30% sourdough addition achieved the highest dough height (47.7 mm) and preserved the highest specific volume after 30 days at −18 °C, exceeding the control by approximately 21% alongside reduced hardness.
Yeast and lactic acid bacteria counts reached 6.21 and 7.50 lg CFU/g, respectively, at 30% sourdough addition, with elevated proline levels correlating positively with freeze tolerance.
Free sulfhydryl content rose by only 6.25% in the 30% sourdough group compared with a 73.02% increase in the control group, indicating substantial preservation of gluten disulfide bonds during freezing.