Economical assessment of pilot level calcium propionate production from unutilized food

Abstract

Food waste biorefinery approach is an effective route for waste management and the generated food waste can be exploited to produce high-cost products like propionic acid. The current study aims at food waste valorization for calcium propionate synthesis. Among the microorganisms screened, Propionibacterium shermanni was selected based on clear zone formation in the presence of calcium carbonate. Subsequently, the unserved food waste was pre-treated with enzymes- amylase and protease, and used for fermentative production. The process parameters were statistically optimized using Box Behnken design. By applying the optimized parameters, pH 6.5 ± 0.1, temperature 35 ± 2 °C and time 15 ± 0.5 days, a maximum of ∼86 % yield was obtained. To validate the optimized data, fed batch fermentation was set up resulting in the production of 7.9 g/100 mL calcium propionate under the optimized conditions. Finally, cost analysis was performed, showing that the utilization of food waste resulted in 1.6–fold lesser cost than other carbon sources.