Submitted to: American Society of Agricultural Engineers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2003
Publication Date: 5/1/2003
Citation: Lamsal, B.P., Koegel, R.G., Boettcher, M.E. 2003. Separation of protein fractions in alfalfa juice: effects of some pretreatment methods. American Society of Agricultural Engineers. 46:715-720.
Interpretive Summary: The value of alfalfa can be increased by fractionating it into higher-value components. We found that a combination of heating and application of a high-speed centrifugal force could recover valuable protein fractions from a juice fraction squeezed from alfalfa. We also defined conditions of centrifugation that improved product recovery. This research has defined process improvements to increase the recovery of high-value nutritious proteins from alfalfa fiber, making the use of alfalfa as a food protein source more practical.
Technical Abstract: Particulates, insoluble proteins, and chlorophyll were removed from extracted alfalfa juice by heating to 55 degrees C, followed by centrifugation. The decant absorbance was monitored at 435 and 675 nm in a spectrophotometer to compare relative chlorophyll removal. Laboratory-scale experiments with batch-type centrifugation at a relative centrifugation force (RCF) of 10,000g reduced juice absorbance by up to 98%. Continuous centrifugation in a decanter-type centrifuge was initially less successful in removing particulates. After modification of the inlet to gradually accelerate the particles to the peripheral speed, the separation was significantly improved and was comparable to batch-type centrifugation. Lower flow rates improved removal. Fermentation prior to centrifugation was also tested as a juice pre-treatment method for removal of particulates, insoluble proteins, and chlorophyll.