The aroma types of cream cheese affect its commercial value and consumer acceptability. However, the types of volatile substances and sensory characteristics of cream cheese at different fermentation stages are still unclear. Therefore, in this study, headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) were used to analyze the volatile substances in cream cheese fermentation. Orthogonal partial least squares discriminant analysis (OPLS-DA), odor activity value (OAV), relative odor activity value (ROAV) and variable projection importance (VIP) were used to identify the characteristic flavor substances in cream cheese fermentation. Finally, the relationship between key flavor substances and sensory characteristics was determined by partial least squares (PLS) analysis. A total of 34 and 36 volatile organic compounds were identified by HS-SPME-GC-MS and HS-GC-MS, respectively, and 14 characteristic flavor substances were found, based on VIP, ROAV and OAV models. Combined with sensory analysis and flavor substance changes, it was found that the cream cheese fermented for 15 d had the best flavor and taste. This study reveals the characteristics and contribution of volatile substances in cream cheese at different fermentation stages, which provides new insights into improving flavor and quality control.

Lycium barbarum seed meal contains a variety of bioactive compounds, but the use of L. barbarum seed meal in the food industry is rare. This study aimed to evaluate the effect of reducing sugars on the structural and flavor properties of the Maillard reaction products (MRPs) of the Lycium barbarum seed meal hydrolysate (LSH). The results showed that the flavors and tastes of the MRPs were affected by reducing sugars. In comparison to oligosaccharides, monosaccharides were more suitable for the development of MRPs with good sensory qualities. The structural characteristics of L. barbarum seed meal precursor MRPs were also affected by reducing sugars. The MRPs produced with the participation of monosaccharides had higher ultraviolet absorption and browning than the MRPs produced with oligosaccharides. The molecular weights of the MRPs were found to be 128–500 Da and 500–1000 Da. Compared to the MRPs made from other sugars, xylose-meridian products (X-MRPs) had a stronger meaty flavor. The mellowness and continuity of the MRPs made from monosaccharides were superior to those made from oligosaccharides. The MRPs formed by L. barbarum seed meal exhibited the characteristics of umami and meat flavor. MRPs with better flavors may be used to develop new types of seasoning salts.

• Peptides-MRPs had high umami, mouthfulness, and continuity enhancement. • DLSFIP and ELPGSP accounted for 42.22% and 20.41% of total consumption. • Sulfur and nitrogen flavors was dependent on cysteine and peptides, respectively. • This study also revealed the flavor formation mechanism of flaxseed derived MRPs.