Abstract: The pattern of changes in the odor-active compounds of Chinese sausage added with black and white pepper during storage (at time points of 0, 7, 21, 35, 49, and 77 d) was investigated using purge & trap-thermal desorption-gas chromatography-olfactometry-mass spectrometry (P&T-TDS-GC-O-MS) combined with odor activity value (OAV), sensory evaluation, and multivariate statistical analysis. The characteristic off-flavor compounds were identified, and an effective method for flavor deterioration and shelf life prediction was proposed. The results showed that a total of 56 volatile flavor compounds with OAV ≥ 0.1 were detected in all samples. Among them, aldehydes showed the highest total OAV (1 724.58–4 682.24), contributing to 85.85%–90.35% of the overall flavor, and totally 15 aldehydes were identified, accounting for the highest proportion of the total number of volatile flavor compounds. As the storage time increased, the OAV values of all flavour substances except esters and olefins continued to increase, especially between days 35 and 49. Furthermore, the color became dark, the cured meat-like and pepper-like flavor became light, the off-flavor became strong, and the acceptability decreased. The correlation analysis showed that 17 odor active substances were significantly correlated with storage time and sensory flavor score, indicating that these compounds can be seen as the optimal indicators to predict the storage period and flavour deterioration. According to OAV analysis and GC-O identification, hexanal, E,E-2,4-decanodienal, heptanal, octanal, E-2-octenal, nonanal, 1-octene-3-ol and E-2-decenal might be the main sources of sausage off-flavor. Based on odor-active compounds with OAV > 1, an objective method was established to distinguish sausage samples added with black and white pepper at different storage times using principal component analysis (PCA) and cluster analysis.

Key words: Chinese sausage added with black and white pepper; storage; odor active compounds; odor activity value; off-flavor