Abstract: To investigate the effect of adding different levels of edible oil on the storage quality and volatile flavor of Longjing tea, we combined solid phase microextraction followed by gas chromatography-mass spectrometry (SPME-GC-MS) with partial least squares-discriminant analysis (PLS-DA) and sensory evaluation to examine the volatile flavor compounds and sensory quality of Longjing tea prepared with the addition of edible oil at 0.5% and 3.0% and stored for 36 months at 15 ℃ and 60% relative humidity (RH) under aerobic or anaerobic conditions. The results showed that the addition of edible oil had a significant effect on the sensory characteristics such as stale aroma and taste during the storage of Longjing tea. After 36 months of storage, aerobically packaged Longjing tea with 3.0% edible oil had the highest stale aroma and taste values (both 3.0), and the tea infusion exhibited the highest yellowish darkness with b* value of 17.00 and L* value of 93.8. Furthermore, under both aerobic and anaerobic packaging conditions, (Z)-hexanoic acid 3-hexenyl ester, 4-methyl-3-penten-2-one, n-pentanol, 1-octen-3-ol, n-pentanal, and 2-methylbutanal were identified as key differential metabolites between Longjing tea with the addition of 0.5% and 3.0% tea oil. Propionaldehyde, 1-penten-3-ol, hexanoic acid, (Z)-2-pentenol, (E)-3-hexen-1-ol, 2-heptanone, methyl heptenone, n-hexanol, 1-octen-3-ol, nerol, linalool, dimethyl sulfide, isobutyraldehyde, and benzaldehyde were identified as key differential volatile components between Longjing tea stored under aerobic and anaerobic packaging conditions. This study provides a scientific basis for the rational use of edible oil in Longjing tea processing and the optimization of packaging and storage methods.

Key words: Longjing tea; storage; edible oil for tea processing; flavor substances; key aroma compounds; sensory evaluation