Systems and methods for producing hexane-free food products and ingredients therefor

A process for preparing a seed protein concentrate, the process comprising:

• pressing a seed material using a screw press and injecting a gas into the screw press to produce a defatted hexane-free seed flour;
• mixing the hexane-free seed flour with water and adding a hydrochloric acid solution to produce a low-pH mixture having a pH of about 4.5;
• mildly agitating the low-pH mixture;
• separating the low-pH mixture into a curd and a whey;
• diluting the curd with water and mixing with sodium hydroxide to produce a 10% dry solids mixture having a pH of about 7.0;
• pasteurizing the 10% dry solids mixture using a direct steam injection heater to produce a heated slurry;
• and
• cooling the heated slurry with a flash cooling system using a vacuumed tank to produce the seed protein concentrate.

A process for preparing a seed protein concentrate, the processing comprising:

• pressing a seed material to obtain a defatted hexane-free seed flour;
• mixing the hexane-free seed flour with an aqueous ethanol solution having a concentration of about 68% to produce an aqueous ethanol mixture;
• washing out and evaporating the aqueous ethanol mixture to recover soy sugar molasses, an ethanol stream for recycling, and an insoluble protein concentrate fraction;
• and
• desolventizing and drying the insoluble protein concentrate fraction under vacuum conditions at a low temperature to produce a seed protein concentrate.

A process for preparing a seed protein isolate powder product, the process comprising:

• feeding a seed material into a screw press and injecting a gas into the screw press to produce a defatted hexane-free seed flour;
• subjecting the hexane-free soy flour to water extraction to produce an extraction slurry;
• adjusting the extraction slurry to have a pH in the range of 8.0 to 8.5 by adding sodium hydroxide to the extraction slurry and holding to produce pH-adjusted slurry;
• applying centrifugation to the pH-adjusted slurry to separate seed flour extracts from insoluble wet seed fiber material in the pH-adjusted slurry;
• adding a hydrochloric acid solution to the seed flour extracts to produce a low-pH mixture having a pH of about 4.5;
• mildly agitating the low-pH mixture;
• separating the low-pH mixture into a curd and a whey;
• diluting the curd with water and mildly agitating to achieve a 6% dry solids mixture;
• separating the 6% dry solids mixture into a second curd and a second whey;
• diluting the second curd with water and mixing with sodium hydroxide to produce a 10% dry solids mixture having a pH of about 7.0;
• pasteurizing the 10% dry solids mixture using a direct steam injection heater to produce a heated slurry;
• and
• cooling the heated slurry with a flash cooling system using a vacuumed tank to produce a seed protein isolate;
• and
• spray drying the seed protein isolate to produce a seed protein isolate powder product having a moisture content of about 5.5%.