Mechanisms of off-flavor formation in thermally sterilized strawberry juices: Insights from GC-IMS, multivariate statistics, and sensomics.

The theoretical basis for dissimilating distinctive aroma profile of strawberry juice during thermal sterilization remains insufficient. In this study, the aroma profiles of 6 strawberry juice subjected to different thermal sterilization times were analyzed using gas chromatography-ion mobility spectrometry (GC-IMS), gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and odor activity value (OAV) calculation. A total of 18 key aroma-active compounds were determined as contributors to the characteristic flavors of strawberry juice. Among these, ethyl hexanoate, r-γ-decalactone, (E)-2-octenal, and heptanal decreased by 28 %, 29 %, 100 %, and 100 % respectively after thermal sterilization, causing the weakening of fresh and fruity attributes. Additionally, dimethyl trisulfide (3.61 μg/kg), (E)-3-hexenol (12.54 μg/kg), and hexanoic acid (106.15 μg/kg) were confirmed as major responsible for the generation of off-flavors during thermal sterilization, through partial least squares regression (PLSR), aroma recombination, and omission experiments. These findings provide foundation for researching the formation pathways of off-flavor compounds in thermally sterilized strawberry juice.