Editing Miso (section)

=== Chemical properties of flavor and aroma compounds ===
[[File:Miso Saba.jpg|thumb|Miso used to flavor ''[[mackerel|saba]]'']]
The distinct and unique aroma of miso determines its quality. Many reactions occur among the components of miso, primarily the Maillard reaction, a non-enzymatic reaction of an amino group with a reducing sugar. The volatile compounds produced from this reaction give miso its characteristic flavor and aroma. Depending on the microorganism in combination with the variety of soybean or cereal used, many flavor compounds are produced that give rise to the different types of miso. Fermentation products such as [[furanone]] compounds, including 4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone (HEMF) and 4-hydroxy-2,5 dimethyl-3(2H)-furanone (HDMF) are novel flavor compounds of miso.<ref name=":3">{{Cite book |title=Industrialization of Indigenous Fermented Foods, Revised and Expanded |last=Steinkraus |first=Keith |publisher=CRC Press |year=2004 |pages=99–142 }}</ref> HEMF is especially known for its sweet aroma and is very important for the sensory evaluation of the aroma of rice miso.<ref name=":3" />

The unique sensory properties of miso are complex. The key factor in the final product's overall quality is the microorganisms' enzymatic activity. They use the composition of miso (rice, barley, and soybeans) to produce different pigments, flavors, and aroma compounds.

[[Proteolysis]] of soybean protein produces constituent amino acids that impart an [[umami]] taste that enhances the relatively dull taste of soybean by itself.<ref name=":3" /> Soy protein contains a substantial amount of [[glutamate]], the salt of which is known as MSG or [[monosodium glutamate]], a popular ingredient used by food manufacturers to improve the taste of their products.<ref>{{Cite journal |last=Inoue |first=Yutaka |title=Analysis of the cooked aroma and odorants that contribute to umami aftertaste of soy miso (Japanese soybean paste) |journal=Food Chemistry |volume=213 |pages=521–528 |pmid=27451212 |year=2016 |doi=10.1016/j.foodchem.2016.06.106 }}</ref> The umami effect of MSG itself is one-dimensional. The umami taste of miso is multidimensional because of the myriad amino acids and fermentation products.

Barley miso is a traditional farmhouse variety made for personal use. Often called "rural miso", domestic barley is used more than imported barley. Containing glutamic acid and aromatic compounds such as [[ferulic acid]] and [[vanillic acid]], barley miso is distinguished by a characteristic flavor.<ref name=":3" />