Effect of heat treatment on bacteriostatic activity and protein profile of bovine whey proteins

Ling Xiong, Chengkang Li, Sjef Boeren, Jacques Vervoort, Kasper Hettinga*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Bovine milk shows bacteriostatic activity mainly due to the presence of antibacterial proteins, like lactoferrin, lactoperoxidase and immunoglobulins. Heat treatment is applied to kill bacteria and thereby extend shelf life of dairy products. Such heat treatment may, however, impair the activity of native antibacterial proteins in milk. The aim of this study was to investigate bacteriostatic capacity and retention of antibacterial proteins in unheated and heated bovine milk. Skim milk samples were heated at 65 °C, 70 °C, 75 °C, 80 °C and 85 °C, for 30 min. Whey was isolated from the heat-treated skim milk and the bacteriostatic capacity of this whey was tested against Streptococcus thermophilus, Escherichia coli, Lactococcus lactis and Pseudomonas fluorescens. The proteomic profile of native whey was determined using LC-MS/MS-based proteomics. Results showed that the bacteriostatic activity of whey negatively correlated with intensity of heat treatment, which was also reflected in the reduced level of native antibacterial proteins. There is a significant difference between milk samples treated for 30 min at <75 °C and milk samples treated at ≥75 °C in both bacteriostatic capacity and native antibacterial proteins. Growth rates of Streptococcus thermophilus, Lactococcus lactis and Pseudomonas fluorescens were negatively correlated with retention of lactoferrin and lactoperoxidase. In conclusion, our study shows that the bacteriostatic capacity of whey decreases with increasing heating intensity, which is strongly correlated with the denaturation of antibacterial proteins. Bacteriostatic activity can be a biomarker for loss of function of antibacterial proteins, and can thereby be used as an indicator for the extent of heat processing of dairy products including antibacterial proteins in a mild heat treatment.

Original languageEnglish
Article number108688
JournalFood Research International
Volume127
DOIs
Publication statusPublished - 1 Jan 2020

Fingerprint

antibacterial proteins
whey protein
Milk
Hot Temperature
heat treatment
whey
cattle
Streptococcus thermophilus
Lactoperoxidase
Pseudomonas fluorescens
Lactococcus lactis
Proteins
Lactoferrin
milk
Dairy Products
proteins
Proteomics
lactoferrin
skim milk
proteomics

Keywords

  • Antibacterial
  • Milk
  • Milk enzymes
  • Pasteurization
  • Proteomics
  • Thermal treatment

Cite this

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title = "Effect of heat treatment on bacteriostatic activity and protein profile of bovine whey proteins",
abstract = "Bovine milk shows bacteriostatic activity mainly due to the presence of antibacterial proteins, like lactoferrin, lactoperoxidase and immunoglobulins. Heat treatment is applied to kill bacteria and thereby extend shelf life of dairy products. Such heat treatment may, however, impair the activity of native antibacterial proteins in milk. The aim of this study was to investigate bacteriostatic capacity and retention of antibacterial proteins in unheated and heated bovine milk. Skim milk samples were heated at 65 °C, 70 °C, 75 °C, 80 °C and 85 °C, for 30 min. Whey was isolated from the heat-treated skim milk and the bacteriostatic capacity of this whey was tested against Streptococcus thermophilus, Escherichia coli, Lactococcus lactis and Pseudomonas fluorescens. The proteomic profile of native whey was determined using LC-MS/MS-based proteomics. Results showed that the bacteriostatic activity of whey negatively correlated with intensity of heat treatment, which was also reflected in the reduced level of native antibacterial proteins. There is a significant difference between milk samples treated for 30 min at <75 °C and milk samples treated at ≥75 °C in both bacteriostatic capacity and native antibacterial proteins. Growth rates of Streptococcus thermophilus, Lactococcus lactis and Pseudomonas fluorescens were negatively correlated with retention of lactoferrin and lactoperoxidase. In conclusion, our study shows that the bacteriostatic capacity of whey decreases with increasing heating intensity, which is strongly correlated with the denaturation of antibacterial proteins. Bacteriostatic activity can be a biomarker for loss of function of antibacterial proteins, and can thereby be used as an indicator for the extent of heat processing of dairy products including antibacterial proteins in a mild heat treatment.",
keywords = "Antibacterial, Milk, Milk enzymes, Pasteurization, Proteomics, Thermal treatment",
author = "Ling Xiong and Chengkang Li and Sjef Boeren and Jacques Vervoort and Kasper Hettinga",
year = "2020",
month = "1",
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doi = "10.1016/j.foodres.2019.108688",
language = "English",
volume = "127",
journal = "Food Research International",
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Effect of heat treatment on bacteriostatic activity and protein profile of bovine whey proteins. / Xiong, Ling; Li, Chengkang; Boeren, Sjef; Vervoort, Jacques; Hettinga, Kasper.

In: Food Research International, Vol. 127, 108688, 01.01.2020.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Effect of heat treatment on bacteriostatic activity and protein profile of bovine whey proteins

AU - Xiong, Ling

AU - Li, Chengkang

AU - Boeren, Sjef

AU - Vervoort, Jacques

AU - Hettinga, Kasper

PY - 2020/1/1

Y1 - 2020/1/1

N2 - Bovine milk shows bacteriostatic activity mainly due to the presence of antibacterial proteins, like lactoferrin, lactoperoxidase and immunoglobulins. Heat treatment is applied to kill bacteria and thereby extend shelf life of dairy products. Such heat treatment may, however, impair the activity of native antibacterial proteins in milk. The aim of this study was to investigate bacteriostatic capacity and retention of antibacterial proteins in unheated and heated bovine milk. Skim milk samples were heated at 65 °C, 70 °C, 75 °C, 80 °C and 85 °C, for 30 min. Whey was isolated from the heat-treated skim milk and the bacteriostatic capacity of this whey was tested against Streptococcus thermophilus, Escherichia coli, Lactococcus lactis and Pseudomonas fluorescens. The proteomic profile of native whey was determined using LC-MS/MS-based proteomics. Results showed that the bacteriostatic activity of whey negatively correlated with intensity of heat treatment, which was also reflected in the reduced level of native antibacterial proteins. There is a significant difference between milk samples treated for 30 min at <75 °C and milk samples treated at ≥75 °C in both bacteriostatic capacity and native antibacterial proteins. Growth rates of Streptococcus thermophilus, Lactococcus lactis and Pseudomonas fluorescens were negatively correlated with retention of lactoferrin and lactoperoxidase. In conclusion, our study shows that the bacteriostatic capacity of whey decreases with increasing heating intensity, which is strongly correlated with the denaturation of antibacterial proteins. Bacteriostatic activity can be a biomarker for loss of function of antibacterial proteins, and can thereby be used as an indicator for the extent of heat processing of dairy products including antibacterial proteins in a mild heat treatment.

AB - Bovine milk shows bacteriostatic activity mainly due to the presence of antibacterial proteins, like lactoferrin, lactoperoxidase and immunoglobulins. Heat treatment is applied to kill bacteria and thereby extend shelf life of dairy products. Such heat treatment may, however, impair the activity of native antibacterial proteins in milk. The aim of this study was to investigate bacteriostatic capacity and retention of antibacterial proteins in unheated and heated bovine milk. Skim milk samples were heated at 65 °C, 70 °C, 75 °C, 80 °C and 85 °C, for 30 min. Whey was isolated from the heat-treated skim milk and the bacteriostatic capacity of this whey was tested against Streptococcus thermophilus, Escherichia coli, Lactococcus lactis and Pseudomonas fluorescens. The proteomic profile of native whey was determined using LC-MS/MS-based proteomics. Results showed that the bacteriostatic activity of whey negatively correlated with intensity of heat treatment, which was also reflected in the reduced level of native antibacterial proteins. There is a significant difference between milk samples treated for 30 min at <75 °C and milk samples treated at ≥75 °C in both bacteriostatic capacity and native antibacterial proteins. Growth rates of Streptococcus thermophilus, Lactococcus lactis and Pseudomonas fluorescens were negatively correlated with retention of lactoferrin and lactoperoxidase. In conclusion, our study shows that the bacteriostatic capacity of whey decreases with increasing heating intensity, which is strongly correlated with the denaturation of antibacterial proteins. Bacteriostatic activity can be a biomarker for loss of function of antibacterial proteins, and can thereby be used as an indicator for the extent of heat processing of dairy products including antibacterial proteins in a mild heat treatment.

KW - Antibacterial

KW - Milk

KW - Milk enzymes

KW - Pasteurization

KW - Proteomics

KW - Thermal treatment

U2 - 10.1016/j.foodres.2019.108688

DO - 10.1016/j.foodres.2019.108688

M3 - Article

VL - 127

JO - Food Research International

JF - Food Research International

SN - 0963-9969

M1 - 108688

ER -