Researchers in Brazil have investigated whether proso millet can improve the stability of probiotic dry-fermented sausages. The study explored the grain’s potential as a natural carrier for Lactiplantibacillus plantarum, a beneficial bacterium used in fermented foods.

The researchers prepared sausages containing free probiotic cells, free cells combined with millet, and probiotic cells immobilised on proso millet at two inclusion levels. After ripening, the products were monitored during storage for up to 121 days.

Results showed that millet helped protect the probiotic bacteria throughout the storage period. Sausages containing millet-immobilised cells maintained bacterial populations above 8 log CFU per gram at the end of the experiment. This indicates that proso millet could provide a supportive environment for probiotic survival in fermented meat products.

Millet also demonstrated an antioxidant role. Lipid oxidation, which can cause rancidity and reduce product quality, developed more slowly in the millet-containing sausages. The untreated formulation crossed the study’s rancidity threshold after approximately 61 days, while millet formulations reached that level much later—around 100 or 121 days, depending on the treatment.

Analysis identified 41 volatile compounds associated with the products’ aroma. Adding millet did not substantially disrupt the characteristic volatile profile of fermented sausage, with storage duration having a greater effect than the millet treatment. Researchers also reported no meaningful negative effect on factors such as pH, water activity or protein oxidation.

The findings suggest that proso millet may serve two functions in fermented food manufacturing: carrying probiotic microorganisms and helping protect products against oxidative deterioration. This could create a new value-added market for millet beyond conventional food and feed applications.

However, the research was conducted under experimental conditions and did not include a consumer sensory panel. Further work is required to evaluate taste, texture, consumer acceptance, industrial-scale production and regulatory requirements before the technology can be widely commercialised.