Primary and secondary shelf-life of bread as a function of formulation and MAP conditions: Focus on physical-chemical and sensory markers

Bread is one of the most widely consumed foods worldwide, and extending its shelf-life is a key concern for reducing waste, especially in light of the expected increase in the world population. This study aimed to assess how the bread formulation (flour, leavening agent) or storage conditions (modified atmosphere packaging (Air or Ar)) could influence its primary shelf-life (PSL) and secondary shelf-life (SSL), also determining possible physical, chemical and sensory markers. The results revealed that the choice of leavening agent had a significant effect on the PSL of bread, especially when combined with the gas used in the packaging. Compared to Air, Ar combined with sourdough slowed down weight loss and the staling process and allows bread to have a longer shelf-life, preserving its initial characteristics. The same synergistic effect was not observed for bread made with baker's yeast, suggesting the potential need of employing a different storage gas in the packaging. Indeed, for the SSL, the only effects detected are related to the leavening agents, where the sourdough exhibits a longer shelf-life compared to the baker’s yeast. These findings lead us to conclude that easily and quickly measurable parameters such as weight loss and water activity decrease, together with sensory analysis, can be used as markers to assess the PSL and SSL of bread.