Key aroma-active compounds identification of Ziziphus jujuba cv. Huizao: Effect of pilot scale freeze-drying

Abstract

Aroma profile and key aroma-active of red jujube subjected to pilot scale freeze drying (FD) were investigated based on molecular sensory science. After FD, 41 aroma compounds were identified through gas chromatography-olfactometry-mass spectrometry (GC-O-MS) and quantified through calibration curves. The total aroma compounds content was decreased 26.71% compared with raw red jujube, of which ketones and acids contents were decreased 63.33% and 62.88%, while, the esters, lactones and alcohols contents were increased 34.10%, 8.52% and 480.17%, respectively. Through the GC-O-MS, odor active values combined with recombination and omission tests, 14 key aroma-active compounds were identification in freeze-dried red jujube. In which, 2-ethyl-3,5-dimethyl-pyrazine had the highest OAV (2687.00) and dominated the roast note of aroma profile. In addition, ethyl heptanoate, hexyl acetate, 2,3-butanediol, ethyl dodecanoate and 5-heptyloxolan-2-one were newly identified as the key aroma-active compounds in freeze-dried red jujube.