Food Waste and Single-Cell Proteins

Single-cell proteins (SCPs) have the potential to mitigate the global pressures of food waste and protein demand. Food waste can be used as a feedstock and growth substrate for microorganisms that produce SCPs. SCPs can be produced through submerged fermentation, semisolid fermentation, or solid-state fermentation, which differ in substrate preparation and cultivation conditions, depending on the species selected (i.e., algae, bacteria, fungi, or yeast). Innovative technologies have been adopted for SCP analysis, but traditional methods mainly rely on spectrometry. The SCPs generated from food waste are nutritious and contain amino acids, vitamins, minerals, glucose, and other nutrients. Due to their high nutritional value, SCPs can replace plant- and meat-derived proteins in animal feed and also in human diet. However, SCPs may contain toxic substances, such as nucleic acids, mycotoxins, and bacterial toxins, generated during production. Therefore, further purification steps are often required. SCP production offers a potential alternative to traditional food production pathways given its economic and nutritional value.