Farzaneh Rezaei and Jean S. VanderGheynst. Biological and Ag Engineering, University of California, Davis, One Shields Ave. 3022 Bainer Hall, Davis, CA 95616
Food processing residues are suitable feedstock for bioenergy generation because they are abundant; being wasted or used for lower value products, do not compete with food, and are low in lignin content. However, these materials are produced seasonally and their outer pectin layer needs to be loosened to improve access of cellulose to hydrolyzing enzymes. These necessitate appropriate and low cost storage and pretreatment methods. Ensilage is an ancient biomass preservation method that has been proposed to be a low cost method for the storage of biomass. In this research the effectiveness of ensilage of food waste residues for simultaneous storage and pretreatment was evaluated. Production of carbohydrate active enzymes that might facilitate the preservation /pretreatment processes was monitored during ensilage of two food processing residues. Results showed that during 2 months of ensilage of Sugar Beet Pulp and Tomato Pomace, secreted xylanase and Endo-β-1,4-Glucanase activity increased gradually with the peak activity occurring at day 14 followed by a decline in activity. Pectinase activity had its highest peak at day 7 and then it started to decrease. The results indicate that the enzymes are produced during ensilage that can facilitate both successful storage and pretreatment. To the best of our knowledge, this is the first time that enzyme production during ensilage has been reported. More analysis is required to further monitor the different factors affecting the storage/pretreatment.
