2009 Annual Report
Value-added Processing of Sugarcane-Ethanol Vinasse: Production of Protein-rich fungal Biomass as a Fish Feed Ingredient: Rapidly increasing production of biofuel generates significant amounts of low-value residues/wastes which pose significant burden on emerging biofuel industries. Value-added processing of such residues/wastes is extremely important for economic viability of biofuel industries. For sugarcane producing states, including Hawaii, there are considerable efforts toward developing cane sugar ethanol biorefinery. Sugar-based ethanol plants generate a considerable amount of vinasse (8-15 liters per liter of ethanol), the leftovers of fermentation/distillation. Vinasse is rich in organic matter with a chemical oxygen demand of about 130 g/L and the highly acidic stream with an initial pH of 4.0-4.5 makes it an ideal feedstock for fungal cultivation. In this study, the food-grade fungus Rhizopus microsporus var. oligosporus was cultivated using dilute vinasse as the substrate. Preliminary data in shaker flask experiments showed that vinasse sustained fungal growth under non-sterile conditions. The soluble chemical oxygen demand (SCOD) removal of up to 48 % was obtained in seven days. The effluent after fungal biomass separation has a potential to be recycled as process water with minimal treatment. The fungal biomass could be utilized as protein-rich aquaculture feeds. Fungal processing may increases the revenue of the residue, vinasse, resulting in improved profitability for ethanol industries as current market value of fishmeal are close to $800 per dry ton.
Pasteurization of Kava Juice using a Nobel Continuous Flow Magnetron Microwave System: The developed continuous flow microwave pasteurizer for kava juice will provide a rational approach for alternating the traditional heating method and enhancing the microbial quality of kava juice while maintaining the overall taste. Unpasteurized kava drinks have a shelf life of less than three days with refrigeration at 4°C. Kava beverage has a high starch content, kavalactones that gels upon heating at or above the required traditional pasteurization temperature. The developed pasteurization technique is expected (1) to maintain the outlet temperature of kava products below the threshold value for kavalactones degradation and (2) to still acquire significant microbial reductions after treatment due to strong wave functions. Therefore, we can extend the shelf life of kava juice product to 5-7 days at the refrigeration temperature. The developed microwave pasteurizer is portable, easy to use with a minimum training, continuous, and high energy efficient (only 500W power requirement) so that small farmers and operations will enable to produce safe, high quality juice products with maximized profits at local markets. Also Unpasteurized or under-pasteurized kava juice products produced by small producers would be a high risk for the consumers, especially for children and elderly people; thus, the broader impact of this project can include its anticipated contribution to our public health.
ADODR monitored this project meetings with cooperator, progress reports, emails and phone calls.