Aim
The aim of this study is to investigate the effect of a broad spectrum of culture conditions on the acidification activity and viability of Carnobacterium maltaromaticum CNCM I‐3298, the main technological properties that determine the shelf‐life of biological time‐temperature integrator (TTI) labels.
Methods and Results
Cells were cultivated at different temperatures (20–37°C) and pH (6–9·5) according to a modified central composite design and harvested at increasing times up to 10 h of stationary phase. Acidification activity and viability of freeze‐thawed concentrates were assessed in medium mimicking the biological label. Acidification activity was influenced by all three culture conditions, but pH and harvest time were the most influential. Viability was not significantly affected by the tested range of culture conditions.
Conclusions
Carnobacterium maltaromaticum CNCM I‐3298 must be cultivated at 20°C, pH 6 and harvested at the beginning of stationary phase to exhibit fastest acidification activities. However, if slower acidification activities are pursued, the recommended culture conditions are 30°C, pH 9·5 and a harvest time between 4–6 h of stationary phase.
Significance and Impact of the Study
Quantifying the impact of fermentation temperature, pH and harvest time has led to a predictive model for the production of biological TTI covering a broad range of shelf‐lives.
Freeze-drying or lyophilization has become a reference process for preserving lactic acid bacteria. The development of stable freeze-dried lactic acid bacteria (LAB) requires maintaining the biological activity of the cells and the macroscopic porous structure while increasing the efficiency of the manufacturing process. Physical properties of protective solutions such as glass transition and collapse temperature, are key elements not only for process optimization but also for the stability of freeze-dried LAB. This chapter provides a stepwise approach for developing a protective formulation for long term preservation of LAB and an efficient freeze-drying process. Methods for determining glass transition and collapse temperatures of protective solutions and cell suspensions, as well as water activity and water content of freeze-dried products are described.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.