Exploring the material basis and formation pathways of the burnt aroma during the stir-frying process of Gardeniae Fructus using Sensomics and chemical components approach

Gardeniae Fructus (edible and medicinal) is unsuitable for spleen-stomach deficiency patients due to its bitter-cold property, but stir-frying (JZZ) alleviates this and generates a burnt aroma with unclear substances and pathways. This study used electronic eye, high-performance liquid chromatography (HPLC), electronic nose, headspace–solid–phase microextraction–gas chromatography–mass spectrometry (HS–SPME–GC–MS), gas chromatography–ion mobility spectrometry (GC – IMS) and relative odor activity value (ROAV) to analyze color, non-volatile components and aroma of raw (SZZ) and fried samples. Results showed that fried samples had decreased chromaticity (the browning reaction). Nitrogen oxides, sulfides and aromatics caused odor differences. 28 key flavor components were identified. Correlation analysis linked precursors (e.g., galacturonic acid, gardenoside) to the Maillard/Caramelization reactions and lipid oxidation. Burnt aroma mainly comprised nitrogen heterocycles, furans, aldehydes, ketones and acids. This reveals material basis and formation pathways of the burnt aroma in JZZ for stir-frying process monitoring. • 116 volatile components were detected by GC–MS, 286 volatile components were detected by GC-IMS. • Nitrogen-containing heterocyclic compounds, furan derivatives, aldehydes, ketones and acids are the main types of the burnt aroma. • The precursor substances might be conjugated galacturonic acid, free glucose, free galactose, gardenoside, crocin I, crocin II, and involved Maillard reaction and caramelization reaction.