I am currently reading this, not finished yet.
http://www.fao.org/docrep/x2184e/x2184e06.htm
"Most bacterial fermentations produce lactic acids; while yeast fermentation results in alcohol production. Many of the indigenous fermentation products of cereals are valued for the taste and aroma active components produced and are used as seasonings and condiments. A summary of flavor compounds formed in such products was compiled by Chaven and Kadam (1989). A number of fermented products utilize cereals in combination with legumes, thus improving the overall protein quality of the fermented product. Cereals are deficient in lysine, but are rich in cystine and methionine. Legumes on the other hand are rich in lysine but deficient in sulfur containing amino acids. Thus, by combining cereals with legumes, the overall protein quality is improved. The Chinese concept of "fan" (rice) and "tsai"(other vegetables) for a balanced and interesting diet is seen throughout the world (Campbell-Platt 1994)."
"Fermentation causes changes in food quality indices including texture, flavor, appearance, nutrition and safety.
The benefits of fermentation may include improvement in palatability and acceptability by developing improved flavors and textures; preservation through formation of acidulants, alcohol, and antibacterial compounds; enrichment of nutritive content by microbial synthesis of essential nutrients and improving digestibility of protein and carbohydrates; removal of anti-nutrients, natural toxicants and mycotoxins; and decreased cooking times."