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
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微生物学
·
蛋白质组学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL DAIRY JOURNAL
·
2023
·
IF 3.1
Hongjuan Li,Yifei Wu,Dongyu Hou,Shujing Zhao,Dan Li,Xiaopeng Wang,Hongbo Li,Jinghua Yu
The emulsion and emulsion gel obtained by pre-emulsifying butter with whey protein isolate (WPI) were applied in processed cheese making. The processed cheese was sterilised at 121 °C or pasteurised at 100 °C for 15 min, then stored at 25 °C or 4 °C. The effects of pre-emulsification and pasteurisation on texture, functional characteristics and Maillard reaction of processed cheese during storage were investigated. WPI emulsions significantly improved the texture and inhibited the free oil released from 25 °C stored cheese, while WPI emulsion gels softened the texture and increased the free oil released. Scanning electron microscopy revealed decreased uniformity of cheese microstructure and an increase in the number of large free fat pools after pre-emulsification. Pre-emulsification process slowed the Maillard reaction of refrigerated stored cheese and reduced the content of Maillard reaction products. This study provided a method for improving the texture defects of room temperature stored cheese.
研究领域:
食品科学
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生物化学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2021
·
IF 5.268
Qiwei Du,Shunyu Wang,Fei Lyu,Jianhua Liu,Yuting Ding
In this study, the effect of high-pressure steam sterilization (121 °C for 15 min) on whey protein hydrolysate-pectin solutions and emulsions was studied. The interaction and emulsification characteristics of pectin and whey protein concentrate (WPC) were evaluated from the solution system to the emulsion system. Enzymatic hydrolysis of WPC (WPH, 2 % and 8 % degree of hydrolysis) increased the covalent binding with pectin, which reduced the heat-induced aggregation of protein and improved emulsification. The thermodynamic incompatibility between WPC and pectin was not conducive to the covalent bonding under high temperature sterilization and produced serious aggregates, which also made a rapid increase in particle size (up to ∼3 μm), compared to WPH-pectin emulsion (∼ 400 nm). In addition, if emulsion was stirred during the sterilization, the creaming and protein aggregation could be avoided. By comparing low methoxy pectin (LMP) and high methoxy pectin (HMP), it was found that the whey protein-HMP complex had better emulsification stability, and the steric stabilization played a more important role in emulsion stability than the electrostatic repulsion. The changes of whey protein and pectin at the oil-water interface of the emulsion during the sterilization process may provide a reference for the sterilized bioactive ingredient delivery system.
研究领域:
食品科学
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生物化学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY
·
2025
·Vol. 78
·期 2
·e70015
·
IF 2.8
Yuxin Sun,Hongchao Dai,Wenwen Ge,Dan Xiong,Zhenquan Yang,Zhenbo Xu,Lei Yuan
Foodborne pathogen Bacillus cereus is widely distributed in dairy products and the processing environment. Beyond its threat to human health, the production of thermostable protease also poses a significant challenge to the dairy industry, particularly in pasteurised or ultra-high-temperature (UHT) processed milk products. Despite this, our understanding of dairy spoilage caused by B. cereus is very limited. This study aimed to evaluate the spoilage potential of a thermostable protease produced by B. cereus 12–1 in fluid milk. Specifically, crude protease characterisation, including optimum pH and temperature, the influence of Ca 2+ on enzyme activity and heat stability of protease, was studied. Moreover, the effects of this protease on the quality of both whole and skim UHT milk were evaluated, including zeta potential and particle size of milk, hydrolysis of milk protein, release of free amino acids and change of milk microstructure. This crude protease has relatively good stability at wide-ranging pH values from 5.0 to 10.0 (79.67–166.67 U/mL) and temperatures from 20°C to 70°C (92.67–165 U/mL), and maintained stability of 46.04% and 38.31% after heat treatment by 65°C/30 min or 100°C/10 min. Spoilage patterns in skim and whole UHT milk differ significantly due to variations in fat content. The protease caused protein hydrolysis in whole milk (15.25%) and skim milk (17.09%), effectively hydrolysed κ-casein and β-casein, caused the release of free amino acids (Lys, Val, Tyr, Phe, Ile, Met and Leu) in UHT milk and significantly increased particle size (increase by 940 nm for skim milk and 1319 nm for whole milk), and reduced zeta potential (reduction by 4 mV for skim milk and 3.83 mV for whole milk) of UHT milk. Results indicate the spoilage potential of crude protease from B. cereus and highlight the need to prevent dairy spoilage caused by B. cereus .
研究领域:
食品科学
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微生物学
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产品关联
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2025
·
IF 8
Yi Zhao,Xiufang Bi,Chunlei Ni,Ruifeng Ying,Khizar Hayat,Meigui Huang
This research utilized a laser particle size distribution analyzer, stability analyzer, atomic force microscope, fluorescence spectrophotometer, and ultra – performance liquid chromatography - mass spectrometry instrument to compare the impacts of pasteurization (PAST), ultra - high temperature instantaneous (UHT) sterilization, and ultra - high pressure (UHP) sterilization on the structure and stability of yak milk fat globules (MFGs). The findings indicated that all three sterilization methods led to a reduction in the diameter of fat globules and damaged the edge structure of the milk fat globule membrane (MFGM). Nevertheless, the stability was enhanced through the reduction of Young's modulus and micropolarity of the MFGM, with UHT milk fat globules exhibiting the highest stability. Lipidomic analysis revealed a decrease in the phospholipid content in UHT milk and UHP milk, whereas the phospholipid content in PAST milk increased. Therefore, the yak milk system after UHT sterilization is the most stable. These data can contribute to the improvement of the quality of yak milk products and facilitate the further development and utilization of yak milk resources.
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产品关联
DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2022
·
IF 7.425
Qiwei Du,Yang Wu,Xiaoqun Zeng,Maolin Tu,Zhen Wu,Jianhua Liu,Daodong Pan,Yuting Ding
Whey protein hydrolysate (WPH), maltodextrin (MD), low methoxy pectin (LMP) and high methoxy pectin (HMP) were used to study the interface binding under high temperature sterilization conditions (121 °C, 15 min). The effect of competitive binding of MD and pectin with interface protein on the storage stability and gastrointestinal fate of fish oil emulsion was studied. The low-molecular-weight MD and the interface protein undergo a wide range of covalent binding through the Maillard reaction, while a small amount of high-molecular-weight pectin can form a protective shell with the interface protein through electrostatic interaction to inhibit the covalent reaction of MD, which was called competitive binding. However, due to the bridging and depletion flocculation of pectin, the emulsification stability of fish oil emulsion reduced. After 13 days of storage, compared with the particle size of the WPH fish oil emulsion (459.18 nm), the fish oil emulsion added with LMP and HMP reached 693.58 nm and 838.54 nm, respectively. In vitro digestion proved that WPH fish oil emulsion flocculated rapidly in the stomach (1.76 μm), while WPH-MD and WPH-MD-pectin fish oil emulsions flocculated slightly (less than800 nm). WPH-MD-pectin delayed digestion in the gastrointestinal tract, and HMP exhibited a better slow-release effect. This study provides reference for the design of multi-component functional drinks and other bioactive ingredient delivery system.
研究领域:
食品科学
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生物化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF DAIRY SCIENCE
·
2022
·
IF 4.225
Fan Yang,Xin Ma,Wei Hu,Ziyi Xiong,Meijiang Huang,Yong Wu,Xuanyi Meng,Zhihua Wu,Anshu Yang,Xin Li,Hongbing Chen
ABSTRACT Dairy processing can alter the digestion stability and bioavailability of cow milk proteins in the gastrointestinal tract. However, analysis of stable linear epitopes on cow milk allergens that could enter into intestinal mucosal is limited. Thus, this study aimed to investigate the digestion and transportation properties and residual allergen epitopes entering into gastrointestinal mucosa of 3 commercial dairy products, including pasteurized milk (PM), ultra-heat-treated milk (UHTM), and dried skim milk (DSM). In this work, the digestive stability of the 3 kinds of dairy products has been performed in a standard multistep static digestion model in vitro and characterized by Tricine-SDS-polyacrylamide gel electrophoresis and reversed-phase HPLC. With respect to gastrointestinal digestion in vitro, the main allergens including β-lactoglobulin (β-LG), α-lactalbumin (α-LA), and caseins were degraded gradually, and the resistance peptides remained in the PM with a molecular weight of range from 3.4 to 5.0 kDa. Simultaneously, the potential allergenicity of the cow milk proteins was diminished gradually and is basically consistent after 60 min of gastrointestinal digestion. After gastrointestinal digestion, the remaining peptides were transported via an Ussing chamber and identified by liquid chromatography-MS/MS. By alignment, 10 epitopes peptides were identified from 16 stable peptides, including 5 peptides (AA 92–100, 125–135, 125–138, and 149–162) in β-LG, 2 peptides in α-LA (AA 80–93 and 63–79), 2 peptides in α S1 -casein (AA 84–90 and 125–132), and 1 peptide (AA 25–32) in α S2 -casein were identified by dot-blotting mainly exist in UHTM and PM. This study demonstrates dairy processing can affect the digestion and transport characteristics of milk proteins and in turn alter epitope peptides release.
研究领域:
食品科学
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过敏原学
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蛋白质组学
·
营养学
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DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2024
·
IF 7
Yanmei Xi,Yan Yang,Xuelu Chi,Weizhe Wang,Baoguo Sun,Nasi Ai
Ultra-high temperature (UHT) milk is popular among consumers. However, its flavor and texture change in its shelf life. Flavor is highly determinative for the success of dairy products and for consumers’ willingness to buy. It is important to milk producers to ensure the optimal flavor of their products in the shelf life. In order to be able to control and predict the flavor quality of UHT milk during the shelf life, this study compared the variations in sensory quality, volatile aroma release and backbone flavor factors and developed a discriminant model to assess flavor quality based on flavouromics data of five competing milk sample during storage. Using partial least squares discriminant analysis (PLS-DA) with Electronic-nose (E-nose) data excellent classification sensitivity and specificity were achieved compared to models based on gas chromatography-mass spectrometry (GC–MS) data. The PLS-DA model using E-nose data exhibited a 100% correct classification rate for the storage period, and a 92% correct rate based on the eight variable importance in the projection (VIP) elements screened for volatile components from different groups. The discriminative model developed herein based on E-nose combined with chemometrics demonstrated advantages such as speed, efficiency, and environmental friendliness. This method shows promise as a precise tool for analyzing aroma changes in UHT milk during its shelf life, and provide support for controlling the flavor substances and milk product development.
研究领域:
食品科学
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化学计量学
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分析化学
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乳品科学
✓ 已验证
产品关联
DOI
PubMed
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）