Method of preparing mushroom growing supplements from corn gluten meal

The method of preparing a mushroom growing supplement, comprising:

• (a) obtaining a corn gluten meal containing by weight less than 15% moisture and from 50 to 75% protein (dry basis), said meal being in particulate free-flowing condition and having an pH within the range from 20. to 5.5;
• (b) mixing and reacting said meal proportionately with a 20 to 50% by weight concentration of aqueous formaldehyde added and reacted as a liquid solution, the selected proportions of formaldehyde solution to meal providing from 0.05 to 1.0% by weight formaldehyde based on the meal (starting wet basis), said mixing being effective to distribute said aqueous formaldehyde solution throughout the meal, the amount of water thereby added to said meal being less than an amount increasing the water content of the meal above 16.0%, said meal remaining in a free-flowing condition throughout the mixing, the reaction of the meal with the formaldehyde solution being carried out under ambient room conditions and being completed in less than 60 minutes after the addition of the formaldehyde solution;
• and
• (c) without heating or drying the reacted meal packaging it in containers for shipment to mushroom growers.