Effect of Supercritical CO2 Extraction Process Parameters on Chemical and Flavor Compounds of Zanthoxylum bungeanum Oleoresin

In this study, oleoresin was extracted from Zanthoxylum bungeanum produced in Hanyuan, Sichuan by supercritical CO2 extraction. The effect of three process parameters (temperature, pressure and extraction time) on the yield, total phenol, total flavonoid and tingling compound (sanshools) contents of oleoresin was examined. The compositions of volatile flavor compounds and tingling compounds were analyzed using gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC). Flavor contributions were quantitatively evaluated based on odor activity values (OAVs) and aroma character impact (ACI) values and validated by aroma sensory evaluation. The results showed that the highest yield of oleoresin of (15.98 ± 1.05)% was obtained after 120 min of extraction under medium/high-temperature and high-pressure conditions (40 ℃/50 ℃, 30 MPa), and the retention rate of tingling compounds in the oleoresin was as high as (94.82 ± 1.12)%. Low-temperature and low-pressure conditions (30 ℃, 10 MPa) resulted in the maximum retention rates of total phenolics and flavonoids ((79.70 ± 1.35)% and (83.41 ± 1.14)%, respectively). In addition, a total of 43 volatile compounds were identified in the oleoresin, among which linalool and linalyl acetate were the key aroma components, being significantly regulated by temperature gradient. Among the five identified sanshools, the proportion of hydroxy-α-sanshool was 60.66%–75.30%, which was the key tingling component of Z. bungeanum. This study provides a theoretical basis for the targeted preparation and quality control of Z. bungeanum oleoresin through process-composition-flavor multi-dimensional analysis, which has important guiding significance for the development of the Z. bungeanum deep processing industry.