Developing Stable Freeze-Dried Functional Ingredients Containing Wild-Type Presumptive Probiotic Strains for Food Systems

Featured Application The present study contributes to the design and development of ready-to-use dry food ingredients containing high numbers of functional microbes to be directly incorporated into food systems. Designing stable dried functional food ingredients and foods containing live probiotic cultures maintaining high viable cell loads at the time of consumption is a challenge for the industry. The aim of the present study was the development of stable freeze-dried functional food ingredients with enhanced shelf-life during long storage. Zea flakes, pistachios, and raisins were used as immobilization supports for the wild-type presumptive probiotic strains Pediococcus acidilactici SK and Lactiplantibacillus plantarum F4, while L. plantarum B282 was used as a reference strain. Cell survival was monitored during storage at room and refrigerated temperatures for up to 6 months. Levels of freeze-dried cultures were maintained up to 7.2 logcfu/g after 6 months storage at room temperature and up to 8.5 logcfu/g at refrigerator temperature, in contrast to free cell levels that ranged <7 logcfu/mL, suggesting the positive effects of immobilization and freeze-drying on cell viability. Of note, levels of freeze-dried immobilized P. acidilactici SK cells on zea flakes and pistachios remained stable after 6 months of storage at 4 degrees C, ranging 8.1-8.5 logcfu/g (survival rates 98.2 and 99.7%, respectively). The technology developed presents important advantages for the maintenance of cell viability during storage, assuring stability of ready-to-use functional food ingredients that could be directly incorporated in food systems.

Automated summary

This study focuses on the design and development of ready-to-use dry food ingredients that contain a high number of functional microbes, which can be directly added to food systems. The aim is to create stable freeze-dried functional food ingredients with enhanced shelf-life during long storage. The technology developed in this study has important advantages for maintaining cell viability during storage and ensuring stability of ready-to-use functional food ingredients.