Evaluation of acetoin production and recovery from under-utilized sugar streams

A number of existing low-value sugar streams are generated when table sugar is produced from sugar beet and sugarcane. In addition, sweet sorghum is a promising crop for sugar syrup production. These materials were evaluated as sugar sources for acetoin production by Bacillus subtilis in shaker flasks and stirred fermenters. The recovery of acetoin from fermentation broth via salting- or sugaring-out extraction was also studied. Based on experimental data and published studies, we performed an economic study on a process to produce acetoin via fermentation and its recovery via extraction followed by distillation.

The process was evaluated on three scales that resulted in production costs ranging from USD 17 to 175 kg^-1 of acetoin. This demonstrated the feasibility of the process, as the estimated sales price is USD 40 kg^-1. Thus, the process appears economically feasible if the scale is appropriate. For the base case studied, the production cost was approximately USD 30 kg^-1 of acetoin for a facility producing 1.33 × 10⁶ kg y^-1 from sugar beet extract. This represents about 27% of the global acetoin market.

This work demonstrates a potential new revenue stream for the sugarcane and sugar beet processing industry. This is achieved through effective valorization of low-value molasses streams via fermentation for acetoin production. The production of acetoin, or other platform chemicals, shows promise for future development in support of improving economic sustainability of sugar crop agriculture industries. Published 2026. This article is a U.S. Government work and is in the public domain in the USA.