Oven-dried microbial culture for improved backslopping fermentation

Backslopping fermentation, which uses a portion of previously fermented products as a starter, offers several advantages over spontaneous fermentation. This study utilized well characterized microbial cultures to produce a dried fermented dough, designed as an improved and stabilized starter—hereafter referred to as ‘’backslop starter’’—for backslopping fermentation. Optimal oven-drying conditions (temperature and duration) were established using a composite central design associated with response surface methodology. The fresh backslop starter displayed a microbial load [Log10 (CFU/g)] of 9.18 ± 0.08 for lactic acid bacteria (LAB) and 7.93 ± 0.25 for yeast, with a pH of 5.05 ± 0.47 and titratable acidity of 0.07 ± 0.00% lactic acid. Drying at the established optimum conditions (39.5 °C for 20.5 h) resulted in a dried matter content of 93.72 ± 0.06% with water activity of 0.26 ± 0.003 and a log reduction of 0.64 for yeast and 0.44 for LAB. The oven-dried backslop culture was stable after one year of preservation at 4 °C and showed high performance during cereal fermentation. The results demonstrated that oven-drying could be promoted as an affordable drying technique offering facilities and comparable utilities to the freeze-drying technique for starter culture production, stabilization, distribution, and utilization in West African conditions.