Food Chemistry-X
·
2024
·
IF 6.5
Jinyu Xu,Xiaodan Wang,Xiaoxuan Zhao,Hongyu Cao,Yunna Wang,Ning Xie,Xu Li,Xiaoyang Pang,Jiaping Lv,Shuwen Zhang
The quality issues of ultra-high-temperature (UHT) milk, such as protein hydrolysis and aging gels throughout shelf life, are caused by proteases from psychrophilic bacteria. However, existing enzyme activity detection techniques have low sensitivity and cannot accomplish the detection of product deterioration caused by low enzyme activity. In this study, an attempt was made to analyze the relationship between enzymatically cleaved peptides and product quality using peptidomics techniques. The impact of psychrophilic bacteria proteases on the quality of UHT milk was investigated based on peptidomics by exogenously adding proteases. The results indicated that the protease activity and protein hydrolysis increased significantly in UHT milk over the storage period. Through peptidomic analysis, 2479 peptides were identified, in which 32 proteins linked to the identified peptides. 17 potential marker peptides, including αS 1 -casein 143–156 , β -lactoglobulin 99–108 , and β -casein 39–66 , were screened. The correlation of all identified peptides with protease activity and protein hydrolysis was explored by the weighted gene co-expression network analysis (WGCNA) method. The peptidomics technology helps to study the release or degradation of peptides in UHT milk during storage, which can be applied to monitor the shelf life of UHT milk and predict spoilage.
研究领域:
食品科学
·
微生物学
·
蛋白质组学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Chemistry-X
·
2024
·
IF 6.5
Yanan Qin,Jingshuai Sun,Wanting Huang,Haitao Yue,Fanxing Meng,Minwei Zhang
In this study, a rapid, inexpensive, and accurate colorimetric sensor for detecting psychrophilic bacteria was designed, comprising gold (Au) nanoparticles (NPs) modified by D-amino acid (D-AA) as color-metric probes. Based on the aggregation of Au NPs induced by psychrophilic bacteria, a noticeable color shift occurred within 6 h. Depending on the various metabolic behaviors of bacteria to different D-AA, four primary psychrophilic bacteria in raw milk were successfully distinguished by learning the response patterns. Furthermore, the quantification of single bacteria and the practical application in milk samples could be realized. Notably, a rapid colorimetric method was constructed by combining Au/D-AA with antibiotics for the minimum inhibitory concentration of psychrophilic bacteria, which relied on differences in bacteria metabolic activity in response to diverse antibiotic treatments. Therefore, the method enables the rapid detection and susceptibility evaluation of psychrophilic bacteria, promoting clinical practicability and antibiotic management.
研究领域:
微生物学
·
分析化学
·
机器学习
·
食品安全
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Bioscience
·
2024
·
IF 4.8
Han Huang,Yudi Liu,Yanjun Tong,Wei Zhao,Xiaomei Lyu,Ruijin Yang
Pickled aquatic products are often susceptible to spoilage, which can significantly affect their edibility and flavor. This study aimed to improve the safety and quality aspects of pickled crabs by treated with high-pressure processing (HPP, 400 MPa for 5 min). The physical, chemical, microbiological, and flavor properties of the crabs before and after HPP were assessed, correlation and cluster analysis and orthogonal partial least squares discriminant analysis (OPLS-DA) were conducted on specific indicators influencing crab spoilage. The results indicated that HPP effectively reduced the total viable count, psychrophilic bacteria count (PBC), and Escherichia coliform ( E. coli ) count during storage at 4°C (reduced by 30.61%, 36.72%, 100%, day 0, respectively; 19.02%, 21.95%, 100%, day 42, respectively). Moreover, HPP treatment reduced the total volatile basic nitrogen (TVBN) content (35.33 mg/100 g to 31.81 mg/100 g) and the production of putrescine (1858.7 mg/kg to 1293.04 mg/kg) and cadaverine (753.47 mg/kg to 422.08 mg/kg) in the end of storage stage, which extend the shelf life of the pickled crab by 12 days. Furthermore, the application of HPP facilitated the penetration of ethanol into the crab meat, thereby enhancing the development of the characteristic pickled crab flavor. The OPLS-DA analyses indicated that TVBN, TBA, and histamine as deteriorative factors for quality deterioration are key factors determining spoilage of crab, which are significantly correlated with other corruption products. This study provides valuable insights into improving the safety and flavor of crab products, establishing a theoretical basis for ensuring quality control throughout the production process.
研究领域:
食品科学
·
微生物学
·
化学
·
食品安全
✓ 已验证
产品关联
DOI
高影响因子
Foods
·
2023
·Vol. 12
·期 20
·3752
·
IF 5.2
Xue Qin,Jingqi Cheng,Xuehe Qi,Ning Guan,Qing Chen,Xiaoyan Pei,Yujun Jiang,Xinyan Yang,Chaoxin Man
Ultra-high temperature sterilized milk (UHT) is a popular dairy product known for its long shelf life and convenience. However, protein gel aging and fat quality defects like creaming and flavor deterioration may arise during storage. These problems are primarily caused by thermostable enzymes produced by psychrotrophic bacteria. In this study, four representative psychrotrophic bacteria strains which can produce thermostable enzymes were selected to contaminate UHT milk artificially. After 11, 11, 13, and 17 weeks of storage, the milk samples, which were contaminated withPseudomonas fluorescens,Chryseobacterium carnipullorum,Lactococcus raffinolactisandAcinetobacter guillouiae, respectively, demonstrated notable whey separation. The investigation included analyzing the protein and fat content in the upper and bottom layers of the milk, as well as examining the particle size, Zeta potential, and pH in four sample groups, indicating that the stability of UHT milk decreases over time. Moreover, the spoiled milk samples exhibited a bitter taste, with the dominant odor being attributed to ketones and acids. The metabolomics analysis revealed that three key metabolic pathways, namely ABC transporters, butanoate metabolism, and alanine, aspartate, and glutamate metabolism, were found to be involved in the production of thermostable enzymes by psychrotrophic bacteria. These enzymes greatly impact the taste and nutrient content of UHT milk. This finding provides a theoretical basis for further investigation into the mechanism of spoilage.Keywords:psychrotrophic bacteria;UHT milk;thermostable enzymes;quality
研究领域:
食品科学
·
微生物学
·
乳品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）