Analysis of Flavor Components and Shelf-Life Stability of Walnut Kernels Flavored with Zanthoxylum armatum Using Solid-Phase Micorextraction Coupled with Gas Chromatography-Mass Spectrometry and Electronic Nose

This study aimed to clarify the characteristic sensory attributes and key flavor compounds of walnut kernels flavored with Zanthoxylum armatum and to explore the effects of packaging methods and storage temperatures on its sensory quality and shelf life for the purpose of providing a theoretical basis for its flavor regulation, storage, and preservation. Solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS) and electronic nose technology were integrated to analyze flavor compounds. Two types of packaging materials: polyethylene terephthalate (PET) and polyethylene (PE)/aluminium (AL)/PET and three packaging methods (atmospheric, vacuum, and vacuum + deoxygenation) were selected, and storage experiments were conducted at 4, 25, and 37 ℃. A shelf-life prediction model was constructed based on kinetic models. The results showed that the characteristic sensory profile of the flavored walnut kernels was centered on a roasted aroma and a chicken fat-like flavor, accompanied by a lily of the valley aroma and fresh floral and herbal aromas, featuring the distinctive characteristics of Z. armatum. A total of 52 volatile compounds were identified, and the key compounds contributing to these sensory attributes included (E,Z)-2,4-decadienal (dominating the roasted aroma and the chicken fat flavor with a relative odor activity value (ROAV) of 100.00), linalool (responsible for the lily of the valley aroma), and terpenes/sulfides (enhancing the distinctive characteristics of Z. armatum). Storage experiments indicated that vacuum deoxygenated packaging with PE/AL/PET provided optimum preservation of the sensory attributes and the key flavor compounds. At 4 ℃, the shelf life of the product was 164 and 157 days based on peroxide value (POV) and acid value (AV), respectively. The constructed prediction model showed excellent goodness of fit with a relative error < 14%. In conclusion, vacuum deoxygenated PE/AL/PET packaging combined with storage at 4 ℃ is the optimal method for maintaining the characteristic sensory attributes and key flavor quality of Z. armatum-flavored walnut kernels, providing support for its industrial quality control.