Immobilization of baker's yeast in the alginate-based hydrogels to impart sensorial characteristics to frozen dough bread

The objective of this study was to improve the sensorial characteristics of frozen dough bread by replacing free yeast cells with calcium alginate-yeast cells (CAY) or calcium alginate-starch yeast cells (CASY) hydrogels. Alginate-starch increased encapsulation efficiency by 18.7% compared with alginate-based encapsulation. Frozen storage affected the viability of all yeast cells, particularly free yeast cells, followed by yeasts encapsulated in CAY and CASY. The sensory evaluation of bread baked from both fresh and frozen doughs revealed that the highest scores for crust color and firmness, taste, smell, and overall acceptability were awarded to bread baked using dough containing CAY-encapsulated yeast that was subjected to 3-months storage. The scores obtained for crumb texture and specific volume (3.61 and 4.5, respectively) for frozen dough bread containing CAY-encapsulated yeast were similar to the highest scores, which were awarded to bread made from fresh dough with free yeast cells (3.63 and 4.84, respectively). These results indicated that the immobilization of baker's yeast in an alginate-based hydrogel could represent a viable solution for overcoming yeast cryosensitivity, allowing for the production of frozen dough bread with improved sensorial characteristics, which would be highly acceptable by consumers and opening new avenues for the economic sector of frozen baked good products.