In order to evaluate the effect of spices on the storage quality of thermal reaction-derived flavorings, the volatiles of beef flavoring produced by thermal reaction with and without the addition of spices were analyzed by solid phase microextraction (SPME) or solvent-assisted flavor evaporation (SAFE) combined with gas chromatography-olfactometry-mass spectrometry (GC-O-MS), and the aroma quality was investigated by sensory evaluation. Results revealed that 217 and 163 volatile compounds were identified by SPME and SAFE, respectively, mainly including aldehydes, ketones, terpenes, phenols, sulphur-containing compounds and nitrogen-containing compounds. Nitrogen-containing or sulphur-containing compounds with low odor thresholds were the key volatile aroma active compounds (flavor dilution factor ≥ 27, and odor activity value ≥ 1). Correlation analysis indicated that eucalyptol, diallyl disulfide and furaneol were the key odorants that maintain the spicy and meaty notes of beef flavoring during storage. Therefore, the addition of spices not only affected the types of volatile compounds, but also slowed down the decrease in the intensity of meaty note and the increase in burnt and soybean paste-like notes. This study can provide a theoretical basis for the development of high-quality thermal reactionderived flavorings and a reference for the diversification of thermal reaction-derived flavorings.

To investigate the behavior of all-trans-β-carotene during digestion, in-vitro digestion coupled with HPLC-DAD, Raman spectroscopy and Fourier transform-infrared spectroscopy were used to monitor it. All-trans-β-carotene reduced by 75% during the in-vitro digestion and had a highest degradation during intestinal digestion compared with oral and gastro digestion. All-trans-β-carotene occurred isomerization and degradation during oral digestion and occurred degradation during gastro and intestinal digestion. Isomers were identified as 15-cis-β-carotene and 9-cis-β-carotene, degradation products were compounds with function group of C–O, C–O–C or C=C–C=C. The biological fate of β-carotene during digestion was clarified, and one of the reasons for low bioavailability of β-carotene was explained by high degradation rate during digestion.