Neither the rice nor the potatoes showed changes in their starch, protein, total carbohydrate, or vitamin C content. "Mineral density" and "micronutrients" are

Neither the rice nor the potatoes showed changes in their starch, protein, total carbohydrate, or vitamin C content. "Mineral density" and "micronutrients" are not the primary criteria by which we judge the quality of staple crops. There is no particular reason to suspect that your reasoning by analogy from CO2 to demethylation enzymes is valid.