Single cell protein and oil production from solid cocoa fatty acid distillates co-fed ethanol

Abstract

The use of solid lipid sidestreams have been overlooked as a feedstock for the production of microbial biomass for food and feed applications and little to no recent work has examined the utilization of solid fatty acid distillates (FADs), which are a significant residue from vegetable oil processing. Yarrowia lipolytica and Rhodosporidium toruloides cultivated on cocoa fatty acid distillates (CFAD) generated final cell dry weight values > 40 g/L, with strong productivity (3.3 g/L·h) and rich protein (>45%) and lipid content (>25%). Interestingly, microbial oils were > 65% unsaturated fatty acids, compared < 20% unsaturated content in FAD. Importantly, to overcome mass-transfer limitations associated with bioconversion of solid lipid residues, ethanol was applied as a co-substrate to solubilize FAD residues. Here, FAD residues from cocoa deodorization have been demonstrated to be high energy feedstocks that represent an attractive substrate for the production of both single cell protein and oil (SCPO).