Abstract
Destabilization of UHT milk during its shelf life is mainly promoted by the residual proteolytic activity attributed to the psychrotrophic bacterial proteases and native milk proteases. In this study, we built skim UHT milk-based model systems to which either the major bacterial protease (AprX from Pseudomonas fluorescens), or the major native milk protease (plasmin) was added, to allow a direct comparison between the destabilization of skim UHT milk by both categories of enzymes. The physical and chemical properties were studied during 6 weeks. Our results showed AprX induced compact gels when almost all the κ-casein was hydrolyzed and the degree of hydrolysis (DH) exceeded 1.3%. Plasmin induced soft gels when around 60% of both β- and αs1-casein were hydrolyzed and the DH reached 2.1%. The knowledge gained from this study may be used for developing diagnostic tests for determining the protease responsible for UHT milk destabilisation.
| Language | English |
|---|---|
| Pages | 127-134 |
| Number of pages | 8 |
| Journal | Food Chemistry |
| Volume | 263 |
| DOIs | |
| Publication status | Published - 15 Oct 2018 |
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Keywords
- AprX
- Destabilization
- Gelation
- Hydrolysis
- Plasmin
- Shelf life
- UHT milk
Cite this
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Destabilization of UHT milk by protease AprX from Pseudomonas fluorescens and plasmin. / Zhang, Chunyue; Bijl, Etske; Hettinga, Kasper.
In: Food Chemistry, Vol. 263, 15.10.2018, p. 127-134.Research output: Contribution to journal › Article › Academic › peer-review
TY - JOUR
T1 - Destabilization of UHT milk by protease AprX from Pseudomonas fluorescens and plasmin
AU - Zhang, Chunyue
AU - Bijl, Etske
AU - Hettinga, Kasper
PY - 2018/10/15
Y1 - 2018/10/15
N2 - Destabilization of UHT milk during its shelf life is mainly promoted by the residual proteolytic activity attributed to the psychrotrophic bacterial proteases and native milk proteases. In this study, we built skim UHT milk-based model systems to which either the major bacterial protease (AprX from Pseudomonas fluorescens), or the major native milk protease (plasmin) was added, to allow a direct comparison between the destabilization of skim UHT milk by both categories of enzymes. The physical and chemical properties were studied during 6 weeks. Our results showed AprX induced compact gels when almost all the κ-casein was hydrolyzed and the degree of hydrolysis (DH) exceeded 1.3%. Plasmin induced soft gels when around 60% of both β- and αs1-casein were hydrolyzed and the DH reached 2.1%. The knowledge gained from this study may be used for developing diagnostic tests for determining the protease responsible for UHT milk destabilisation.
AB - Destabilization of UHT milk during its shelf life is mainly promoted by the residual proteolytic activity attributed to the psychrotrophic bacterial proteases and native milk proteases. In this study, we built skim UHT milk-based model systems to which either the major bacterial protease (AprX from Pseudomonas fluorescens), or the major native milk protease (plasmin) was added, to allow a direct comparison between the destabilization of skim UHT milk by both categories of enzymes. The physical and chemical properties were studied during 6 weeks. Our results showed AprX induced compact gels when almost all the κ-casein was hydrolyzed and the degree of hydrolysis (DH) exceeded 1.3%. Plasmin induced soft gels when around 60% of both β- and αs1-casein were hydrolyzed and the DH reached 2.1%. The knowledge gained from this study may be used for developing diagnostic tests for determining the protease responsible for UHT milk destabilisation.
KW - AprX
KW - Destabilization
KW - Gelation
KW - Hydrolysis
KW - Plasmin
KW - Shelf life
KW - UHT milk
U2 - 10.1016/j.foodchem.2018.04.128
DO - 10.1016/j.foodchem.2018.04.128
M3 - Article
VL - 263
SP - 127
EP - 134
JO - Food Chemistry
T2 - Food Chemistry
JF - Food Chemistry
SN - 0308-8146
ER -