Abstract:

The contents and kinds of free amino acids (FAAs) in apple pomace and fermented apple pomace were
determined by amino acid analyzer. The aroma components in the unfermented and fermented samples were identified by
gas chromatography-mass spectrometry (GC-MS). Results showed that the content of FAAs was increased from 3.25 to
15.68 mg/mL, and the content of flavor amino acids was increased from 2.73 to 11.45 mg/mL after fermentation. Fermented
apple pomace contained 7 essential amino acids and their total content was increased from 0.87 to 5.33 mg/mL. Seventeen
and thirty eight volatile compounds were identified in the unfermented and fermented apple pomace, respectively. The types
and contents of aromatic substances were increased. In the fermented apple pomace, esters, furans, and nitrogen-containing
substances were produced. Fermentation improved the flavor of apple pomace.

Key words: apple pomace, fermention, free amino acids, volatile aroma components