Enantiomer
Japanese: エナンチオマー（鏡像異性体）
One mirror-image form of a chiral compound. Despite identical formulas and bonds, enantiomers can differ in biological activity.
An enantiomer is one of the two mirror-image forms of a chiral compound. Most physical and chemical properties are identical, but optical rotation is opposite and biological activity can differ significantly.
In fermentation, enzyme stereospecificity determines enantiomers' fates. Proteases cleave peptide bonds of L-amino acid sequences but not D-amino acid sequences. Natural enzymes almost invariably recognize only one enantiomer.
Recently, D-amino acids (enantiomers of L-amino acids) have been reported to increase during miso aging—attributed to racemase enzymes and the Maillard reaction, potentially contributing to flavor 'complexity.' A world changed by a molecule's orientation—fermentation converts even these subtle differences into taste.