Nutrition

Fermentation Frees Minerals in Grains and Beans.

A bowl of maize porridge or chickpeas can contain plenty of iron and zinc on paper, yet deliver less of those minerals than the nutrition label suggests. The main obstacle is phytate, or phytic acid: the phosphorus-storage molecule that plants pack into seeds. Its phosphate groups readily bind positively charged minerals, forming complexes that are harder to dissolve and absorb during digestion.

That does not make phytate a poison, nor does it mean every mineral in a bean is trapped. The effect depends on the amount of phytate, the mineral, the rest of the meal, and a person’s overall diet. It matters most when unrefined cereals and legumes provide a large share of daily calories and there are few alternative sources of easily absorbed iron or zinc.

Broccoli does not store much ready-made sulforaphane. Instead, it keeps two ingredients apart: glucoraphanin, a relatively stable precursor, and myrosinase, an enzyme that converts that precursor into sulforaphane when plant cells are damaged by chopping or chewing.

That arrangement works well in raw broccoli. It works less well after boiling, microwaving, or other sustained heating, because the enzyme is much easier to damage than the precursor. The useful twist is that the missing enzyme does not have to come from the broccoli itself. Mustard seed carries its own myrosinase, so a little dry mustard powder added after cooking can restart the reaction.

Vitamin B12, or cobalamin, is structurally one of the most complex non-polymer molecules in human biology. It is absolutely essential for the healthy functioning of our nervous system, the formation of red blood cells, and the synthesis of DNA. However, there is a fundamental quirk in its biological origin: neither plants nor animals possess the genetic blueprint to manufacture it. In the entirety of the natural world, cobalamin is synthesized exclusively by a select group of bacteria and archaea.