Production of SCP and animal feed for entire utilization of LPC processing effluents

To make use of brown juice from the leaf protein concentrate (LPC) production process, concentration of the juice and production of single-cell protein (SCP) with use of residual sugars in the juice were carried out. A six-fold concentrate of the juice could be obtained by reverse-osmosis procedure. Inhibition effects of plant phenolics on the growth of yeast were observed and attempts to remove the phenolics with various adsorbents were carried out. A hydrophobic resin (Diaion HP-20) was the most effective for adsorption of the phenolics, and the resin could be regenerated by use of ethanol. Productivity of SCP was enhanced by concentration, and the biomass obtained in a batch culture with the condensed brown juice (CBJ) attained 45.7 kg/m3. It was possible to evaluate the treatment efficiency of CBJ from inhibition and adsorption experiments for typical polyphenols such as pyrocatechol or resorcinol.