For any solute extraction in a single stage solid-liquid maceration the extraction yield (extracted solute/total solute in solid) depend on solvent/solid ratio (R). The yield tends to one when R tends to infinite. That is, in a single stage solid-liquid maceration increasing R increase yield but the solute extract concentration decrease. At lower R (as example 1) extract concentration may reach saturation but the yield is poor. It is possible to increase yield and extract concentration simultaneously with counter-current multiple extraction stages. All of these concepts are detailed in the paper

http://dx.doi.org/10.1016/j.compchemeng.2016.03.004

Other alternative is a column with a fixed bed of solids with a continuous flow of solvent. In this last case the outlet extract at the beginning of process (when yield is poor) is concentrated (may be saturated), but its concentration decrease continuously with time and solvent consumption increase drastically (yield tends to 1 when time tends to infinite).

Miguel Angel García-Alvarado Thank you Professor, that was quite insightful and helpful in understanding this, I appreciate your help.

There are practically two ways of producing plant proteins from legumes/pulses. The first one is fine milling of the seeds (using pin mills) and simple air classification of the components, which produces a product commenrically called "Protein Concentrates" that has protein contents of 55-65% depending on the seed type and milling/classification efficiency. The second (a more advanced and recent technique) uses solvents (usually alkaline solutions) to completely solubilize the proteins and then separate the solutions from other impurities like starch and then adjusting the pH to an isoelectric point at which the protein starts to precipitate and separate from the solutions. This technique results into protein products commercially known as "Protein Isolates" which has 90-96% pure protein. I hope this info is helpful and I am also sure that you will find numerious articles on these. Good Luck!