Developing Confectionery Industry Biorefineries

摘要

Food wastes are generated worldwide at significant quantities and could be regarded as a valuable renewable resource for biorefinery development aiming at the production of fuels, chemicals and materials. This study presents novel bioprocessing and biorefinery concepts based on the utilisation of waste streams from confectionery industries that are generated in significant quantities and are enriched in carbohydrates (starch, sucrose, glucose, fructose and lactose), protein and various micro-nutrients. Such waste streams can be utilised as fermentation media for the production of microbial oil using oleaginous microorganisms. Confectionery industry flour-rich waste streams were enzymatically hydrolyzed to produce fermentation media with high glucose and Free Amino Nitrogen (FAN) concentrations. The produced hydrolysates were evaluated as fermentation feedstocks for the production of microbial oil using oleaginous yeasts and their efficiency was compared with synthetic media. Shake flask fermentation carried out with Rhodosporidium toruloides produced up to 24.4 g/L dry cell weight with a microbial lipid content of 50 % (w/w). Preliminary bioreactor fermentations with R. toruloides carried out in fed-batch mode enhanced significantly yeast growth and microbial oil accumulation. The results obtained indicate that integration of microbial oil production in existing confectionery industries may lead to the production of an important feedstock for the chemical industry.