Effects of Pixian Douban and Douchi on the Volatile Flavor Compounds of Fried Pork with Salted Pepper Based on GC-MS

Head space solid phase microextraction coupled with GC-MS (HS-SPME-GC-MS) was used to study the effects of Pixian Douban and Douchi on the volatile flavor components of fried pork slices with salted pepper, one of the typical Sichuan flavour foods, by chemometrics method. The key flavor substances of fried pork slices with salted pepper were determined according to the odor activity value (OAV). The results showed that, 137 volatile flavor compounds were detected by GC-MS, including 21 hydrocarbons, 12 alcohols, 6 phenols, 8 ethers, 22 aldehydes, 6 ketones, 6 acids, 12 esters, 40 heterocycles and 4 other compounds. The sample without Pixian Douban and Douchi was the blank control, namely sample 1. When Douban and Douchi were added separately, m (Douban)=8 g in sample 2, m (Douchi)=10 g in sample 3. When Douban and Douchi were mixed with a total mass of 18 g, set sample 4~sample 7 through different mixing ratios, as Douban:Douchi=3:6 in sample 4, Douban:Douchi=4:5 in sample 5, Douban:Douchi=6:3 in sample 6, Douban:Douchi=7:2 in sample 7. The number of volatile flavor compounds contained in samples 1 to 7 were: 60, 64, 63, 72, 57, 66, 69. The concentrations of volatile flavor compounds contained in samples 1 to 7 were 78.08, 250.77, 71.22, 85.62, 116.12, 44.43, 55.77 μg/kg, respectively. The analysis of OAV showed that the key flavor substances in common among the seven samples were 2-octanol, cineole, caproic acid, 2-dimethylpyrazine and 2-dimethyl-3-ethyl pyrazine. Principal component analysis (PCA) showed that the PCA_1 (99.18%) and PCA_2 (0.19%) of sample 5 were significantly different from other samples, consistent with the sensory flavor profile, and sample 5 had the highest acceptance. Therefore, the mixture ratio of Pixian Douban and Douchi in sample 5 is the best.