Min Li,Pengxiang Wang,Xu Zhang,Hongyu Wang,Ke Li,Yanhong Bai
Heterocyclic aromatic amines (HAAs) generated during the cooking of meats cause adverse effects on human health. The purpose of the current research was to develop a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) method using magnetic multi-walled carbon nanotubes (Fe3O4-MWCNTs) as clean-up adsorbents for the rapid determination of HAAs in braised sauce beef. The significant parameters in extraction and clean-up processes were screened and optimized. Under optimal conditions, the LODs ranged from 3.0 ng/g to 4.2 ng/g. The recoveries (78.5–103.2%) and relative standard deviations RSDs (<4.6%) of five HAAs were obtained. These are in accordance with the validation criteria (recovery in the range of 70–120% with RSD less than 20%). Compared with conventional clean-up adsorbents (PSA or C18), Fe3O4-MWCNTs displayed equivalent or better matrix removal efficiency, while making the pretreatment process easier and more time-saving through magnetic separation. Less usage of adsorbent makes the method possess another advantage of being lower in cost per sample. The method developed was successfully applied to analyze real samples collected from local deli counters, demonstrating Fe3O4-MWCNTs could be considered as an effective alternative adsorbent with great potential in the QuEChERS process.Keywords:heterocyclic aromatic amines;QuEChERS;Fe3O4-MWCNTs;braised sauce beef
In this study, we investigated the volatile flavor compounds and sensory perceptions of Yanbian-style sauced beef prepared from raw meats subjected to different treatments (hot fresh, chilled, and frozen beef). The results indicated that the treatment of raw beef significantly impacted the quality and flavor of sauced beef. Sauced chilled beef (CRSB) exhibited the highest content of fatty acids and total amino acids. A total of 48 volatile compounds were identified. Moreover, a relative odor activity value analysis identified hexanal, nonanal, heptanal, 1-octen-3-ol, and 2,3-octanedione as the characteristic flavor compounds in Yanbian-style sauced beef. The sensory evaluation demonstrated that CRSB was the most palatable and flavorful. Additionally, correlation loading plot analysis indicated strong correlations between sensory evaluation, fatty acids, amino acids, and volatile flavor compounds. These results suggest that chilled beef meat is the best raw material for the production of Yanbian-style sauced beef.
The inhibitory mechanism of CUM on Staphylococcus aureus exotoxins and invasive enzyme, and the effect of CUM on sauced beef were investigated. Treatment with sub-minimum inhibitory concentrations of CUM observed very little decrease in cell density after 24 h. Additionally, CUM reduced hemolytic activity by inhibiting the formation of heptamer, and inhibited the content of enterotoxin in culture medium and sauced beef. The transcription of genes encoding α-hemolysin, staphylococcal enterotoxin A and Panton-Valentine leukocidin were down-regulated after treatment with CUM. Compared with the control group, the addition of CUM caused a significant decrease in S. aureus counts, total volatile base nitrogen, acid value, and thiobarbituric acid reactive substances of sauced beef after 9 d. Furthermore, CUM improved the redness (a*) of sauced beef. These results confirmed that CUM could effectively restrain the synthesis of S. aureus toxin, and the addition of CUM to sauced beef was the potential way to inhibit the growth of food pathogens and maintain quality profiles.
危险品化学品经营许可证（带存储）