Process for the recovery of substantially water-soluble non-toxic protein compounds from fresh non-woody vegetation

A process for treating alfalfa to recover a substantially water-soluble, non-toxic protein product, comprising the steps of:

• (a) contacting said alfalfa with an aqueous alkaline medium containing sodium bisulfite in an amount sufficient to increase the moisture content thereof to at least about 80% by weight and to increase the pH thereof to at least about 8.0;
• (b) mechanically comminuting the moisturized and alkalinized alfalfa in a manner which prevents said alfalfa from reaching a temperature above about 50.degree. C;
• (c) mechanically expressing said comminuted alfalfa in a manner which prevents said alfalfa from reaching a temperature above about 50.degree. C, to obtain an aqueous protein-containing fraction therefrom;
• (d) acidulating said protein-containing fraction to a pH of from about 2.5 to about 5 to precipitate a water-containing protein-lipid complex;
• (e) mechanically removing from about 60 to about 70% of the water from said water-containing protein-lipid complex at ambient temperature;
• (f) contacting said protein-lipid complex with a non-polar, water immiscible volatile organic solvent to extract from said precipitate lipids and other compounds soluble in said solvent;
• (g) heating said mixture of volatile solvent and protein complex so as to expel substantially all the water therefrom at a temperature below the boiling point of water;
• (h) removing said volatile solvent from the remaining substantially water-free protein complex at a temperature below about 80.degree. C;
• (i) countercurrently extracting said protein complex with polar organic alcohol to isolate a substantially water-soluble, non-toxic protein product;
• (j) recovering alcohol soluble compounds from said alcohol and recycling the alcohol to said countercurrent extraction stage;
• and
• (k) alkalinizing the water removed in step (e) and recycling said water to the contact of alfalfa in step (a).