Processes for separating and isolating proteins and fats from biomass matter utilizes a pH adjustment of a slurry. The biomass feedstock is derived from commingled animal and/or plant-based streams with highly variable concentrations of fat, proteins and impurities present in the biomass. A wide range of pH adjustment spanning highly acid to highly basic has been shown to be effective at separating the commingled streams into their constituent products. The processes do not rely on the proteins being solubilized into the solution, but rather solubilizing the fat portion, physically separating the constituents and precipitating the fat in a downstream process, resulting in two value streams: a highly digestible protein component and a fat component. The protein component has nutritional value as companion pet, animal and aquaculture feed ingredient and the fat component has value as standalone or blended solid or liquid biofuels, greases or specialty chemicals.

Aspects of the present disclosure include methods for fractionating whole stillage using one or more hydrocyclones and optional screening device. Aspects of the present disclosure include a stillage fractionation and/or clarification system for carrying out the methods described herein.

A process of extracting or purifying proteinaceous material and/or fibraceous material from brewer's spent grain (BSG), the process comprising the steps of: Providing brewer's spent grain; Performing saccharification by enzymatic treatment of the brewer's spent grain and a fermentation of the saccharified brewer's spent grain with lactic acid bacteria and/or acetic acid bacteria and/or probiotics to obtain a fermented broth; and extracting and/or purifying proteinaceous and/or fibraceous material from the fermented BSG.

Provided is a method of processing stillage from an ethanol production process. The method comprises treating stillage comprising oil, protein, and water upstream of a separation, concentration or evaporation step with at least one coagulant and at least one flocculant, thereby forming treated thin stillage comprising solids which include at least a portion of the oil and protein; and clarifying the treated stillage via a solid/liquid separation process thereby forming clarified stillage and a separated solids phase comprising at least a portion of the solids from the treated stillage.

A method of collecting proteins from a washwater and/or wastewater stream by means of a pH shift technique, aided with dissolved bubbles of air or gases, in order to substantially reduce the environmental impact of wastewater discharge and improve the value of the recovered protein. The pH shift process can coagulate and recover the protein at low temperatures (1 to 10 degrees Celsius) making the proteins recovered suitable for human food applications, without heating.

According to the present invention, a method for recovering useful fish meat proteins from waste water generated during fish paste or fishmeal production is provided. The provided is a method for recovering water-soluble proteins from fish paste leaching waste water or stick water, comprising: adjusting the pH of fish paste leaching waste water or stick water to 4.5-5.5 to insolubilize water-soluble proteins; heating the insolubilized proteins to 30 C. to 90 C. to cause the proteins to flocculate so as to form flocs; subjecting the flocs to solid-liquid separation using a decanter centrifuge during heating; and recovering proteins in the form of solid content.