Destabilization of UHT milk by protease AprX from Pseudomonas fluorescens and plasmin

Chunyue Zhang, Etske Bijl, Kasper Hettinga

Research output: Contribution to journalArticleAcademicpeer-review

4 Citations (Scopus)

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.

LanguageEnglish
Pages127-134
Number of pages8
JournalFood Chemistry
Volume263
DOIs
Publication statusPublished - 15 Oct 2018

Fingerprint

UHT milk
Pseudomonas fluorescens
plasmin
Fibrinolysin
Milk
Peptide Hydrolases
proteinases
Caseins
hydrolysis
gels
Hydrolysis
milk
Gels
kappa-casein
diagnostic techniques
casein
physical properties
shelf life
Routine Diagnostic Tests
physicochemical properties

Keywords

  • AprX
  • Destabilization
  • Gelation
  • Hydrolysis
  • Plasmin
  • Shelf life
  • UHT milk

Cite this

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title = "Destabilization of UHT milk by protease AprX from Pseudomonas fluorescens and plasmin",
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.",
keywords = "AprX, Destabilization, Gelation, Hydrolysis, Plasmin, Shelf life, UHT milk",
author = "Chunyue Zhang and Etske Bijl and Kasper Hettinga",
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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 journalArticleAcademicpeer-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 -