Fermenting greens alters their nutritional value in several ways. In a sense,
fermentation moves green leaves up the trophic pyramid in much the same way that feeding leaves to meat or milk animals does. After the bacteria have had their fill, there is less energy, or calories, remaining in the leaves but many of the nutrients are pre-digested and easier to absorb in our intestinal tract. Fibrous cell walls are softened, making their contents more readily available to our digestive enzymes. While some vitamin C and beta-carotene is lost, the levels of B-vitamins, especially vitamin B-1 and B-2, are often increased. Protein quality is also enhanced as the bacterial enzymes alter the vegetable’s amino acid profile. Fermentation also can break down some of the compounds that inhibit nutrient absorption, including phytates, tannins, oxalic acid and nitrates. Carcinogenic aflatoxins from molds can be broken down into harmless molecules by bacterial fermentation. Hydrocyanic acid yielding compounds, such as linamarin in cassava, can also be neutralized through fermentation.