Biomass-based production of food preservatives

Sorbate and benzoate are the two most important preservatives in the food and beverage industry. Currently, they are manufactured from fossil-derived ketene and toluene, respectively. To reduce dependence on non-renewable energy, we herein exploit alternative routes to access preservatives using biomass-based malonate, crotonaldehyde, and acrolein as the starting materials. With organoamine DABCO as a catalyst, preservative sorbate is selectively produced in 75% yield via one-step condensation of malonate and crotonaldehyde. The success of this reaction relies on tuning the distribution between thermodynamic and kinetic products. Acrolein can participate in this process as well, followed by the Diels-Alder reaction with acrolein and Pd/C-catalyzed domino decarbonylation/dehydrogenation to produce preservative benzoate in a 73% overall yield. In addition, life-cycle assessment indicates that our biobased production of preservatives release less greenhouse gases compared with their traditional synthesis.