Influence of Guar Gum on the Thermal Stability of Listeria innocua, Listeria monocytogenes, and γ-Glutamyl Transpeptidase during High-Temperature Short-Time Pasteurization of Bovine Milk

1999 ◽  
Vol 62 (8) ◽  
pp. 861-866 ◽  
Author(s):  
PUNIDADAS PIYASENA ◽  
ROBIN C. McKELLAR
Keyword(s):  
High Temperature ◽  
Laminar Flow ◽  
Protective Effect ◽  
Guar Gum ◽  
Listeria Innocua ◽  
Water Mixture ◽  
High Temperature Short Time ◽  
Whole Milk ◽  
Short Time ◽  
Glutamyl Transpeptidase

Mathematical models describing the thermal inactivation of γ-glutamyl transpeptidase (TP) and Listeria innocua in milk during high-temperature short-time (HTST) pasteurization were validated with data from TP, L. innocua, and L. monocytogenes trials in guar gum–milk. Holding tube times were determined for turbulent flow using water, and for laminar flow using a guar gum (0.27% wt/wt)–sucrose (5.3% wt/wt)–water mixture. Inactivation of TP and L. innocua was lower in a solution of guar gum (0.25% wt/wt) in whole milk than was predicted by models derived from studies with whole milk alone. Use of laminar flow timings improved model fit but did not completely account for the observed protective effect. L. monocytogenes survival was close to that predicted by the L. innocua model, although some protection was afforded this pathogen under laminar flow. Considerable intertrial variability was noted for L. monocytogenes. Risk analysis simulations using @RISK, a Lotus 1-2–3W add-in, were used to account for intertrial variability. Simulated log10 %reductions consistently underpredicted experimental L. monocytogenes survival (fail-safe), thus the L. innocua model derived in milk is suitable for estimating L. monocytogenes survival in viscous products. Increased thermal tolerance during laminar flow may be attributed to the protective effect of stabilizer.

Factors Influencing Survival of Listeria monocytogenes in Milk in a High-Temperature Short-Time Pasteurizer

1992 ◽  
Vol 55 (12) ◽  
pp. 946-951 ◽  
Author(s):  
J. M. FARBER ◽  
E. DALEY ◽  
F. COATES ◽  
D. B. EMMONS ◽  
R. McKELLAR
Keyword(s):  
High Temperature ◽  
Listeria Monocytogenes ◽  
Most Probable Number ◽  
Probable Number ◽  
High Temperature Short Time ◽  
Whole Milk ◽  
Different Temperatures ◽  
Margin Of Safety ◽  
Short Time ◽  
Adequate Margin

Heat resistance experiments were carried out with Listeria monocytogenes which had been grown at three different temperatures (30, 39, and 43°C). Heated whole milk was inoculated with L. monocytogenes and then passed through a high-temperature short-time system at 72, 69, 66, and 63°C for a minimum holding time of 16.2 s. Heated cells were recovered both aerobically and anaerobically using four different methods: direct plating, most probable number, cold enrichment, and warm enrichment. Significant differences in recovery of L. monocytogenes were observed depending on the growth temperature. Cells grown at 43, 39, or 30°C, held 1 d at 4°C, and then heated at 69°C showed an overall decrease in numbers of approximately 2.1, 2.8, and 4.1 logs, respectively. Cells grown at 39°C and then held 3 d at 4°C appeared to be the most heat sensitive. Although cells grown at 43 and 39°C were capable of surviving at the minimum high-temperature short-time temperature (72°C), those grown at 30°C were not. In some instances, anaerobic incubation enhanced the recovery of L. monocytogenes, as compared to cells recovered aerobically, although these differences were not statistically significant. While L. monocytogenes can survive minimum pasteurization treatment (71.7°C/16 s) under certain conditions, common methods of handling, processing, and storing fluid milk will provide an adequate margin of safety.

Effect of High-Temperature Short-Time Pasteurization, Freezing and Thawing and Constant Freezing, on the Survival of Yersinia enterocolitica in Milk

1992 ◽  
Vol 55 (10) ◽  
pp. 803-805 ◽  
Author(s):  
SYED TOORA ◽  
EBO BUDU-AMOAKO ◽  
RICHARD F. ABLETT ◽  
JIM SMITH
Keyword(s):  
High Temperature ◽  
Yersinia Enterocolitica ◽  
Skim Milk ◽  
Negligible Effect ◽  
Distilled Water ◽  
Freezing And Thawing ◽  
Viable Cells ◽  
High Temperature Short Time ◽  
Whole Milk ◽  
Short Time

The clinically important serotypes of Yersinia enterocolitica were shown to be highly heat sensitive, and none of the strains of serotypes 0:3; 0:5;27; 0:6,30; 0:8 and 0:9, ATCC 23715, and ATCC 27729 used in this study could survive high-temperature short-time pasteurization at 71.8°C for 18 s at 108 cell/ml. D62.8 was found to be 10.53 and 10.35 s in skim milk and whole milk, respectively. Destruction of the viable cells of Y. enterocolitica under freezing-thawing and constant freezing conditions at −20°C was more rapid in distilled water than in milk. Constant freezing at −20°C for 30 d had a negligible effect on the survival of Y. enterocolitica in milk.

Predictive Modeling of Alkaline Phosphatase Inactivation in a High-Temperature Short-Time Pasteurizer

1994 ◽  
Vol 57 (5) ◽  
pp. 424-430 ◽  
Author(s):  
R. C. MCKELLAR ◽  
H. W. MODLER ◽  
H. COUTURE ◽  
A. HUGHES ◽  
P. MAYERS ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
High Temperature ◽  
Predictive Modeling ◽  
Dairy Products ◽  
Residual Activity ◽  
Lethal Effect ◽  
Predictive Equations ◽  
High Temperature Short Time ◽  
Whole Milk ◽  
Short Time

In order to support regulations directed towards ensuring the safety of heat processed dairy products, data on inactivation of alkaline phosphatase (AP) in whole milk in a pilot plant high-temperature short-time (HTST) pasteurizer were obtained. A Computer program was designed to calculate the integrated lethal effect, or pasteurization effect (PE), at temperatures of 60 to 74°C and with holding tubes for 3 to 60 s. An equation was derived which related values of PE to log % residual activity (r2 of 0.964). These results suggest that predictive equations based on PE could be used to assess the effectiveness of commercial pasteurization processes.

scholarly journals Decay of Mycobacterium bovis in whole milk submitted to pasteurization parameters

2016 ◽  
Vol 37 (5Supl2) ◽  
pp. 3727
Author(s):  
Leandro Ribeiro ◽  
Maurício Roberto Tosti Narciso ◽  
Tatiane Hoshida Felipe ◽  
Karina Ramirez Starikoff ◽  
Gisele Oliveira de Souza ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Resistance ◽  
Mycobacterium Bovis ◽  
Maintenance Phase ◽  
High Temperature Short Time ◽  
Whole Milk ◽  
Milk Pasteurization ◽  
Long Time ◽  
The Difference ◽  
Short Time

Parameters for milk pasteurization were established a long time ago, considering the thermal resistance of Mycobacterium bovis, and the systematic adoption of this process has drastically reduced the incidence of human tuberculosis caused by this pathogen. However, more recently, molecular methods have allowed the identification of genetic variations in this bacterium that may lead to greater thermal resistance. The aim of this study was to investigate whether genetic variation leads to variation in the death pattern of this bacterium during the milk pasteurization process. Samples of UHT (ultra-high temperature)-treated whole milk were artificially contaminated with four different Mycobacterium bovis spoligotypes and were subjected to pasteurization by low-temperature long-time (LTLT) and high-temperature short-time (HTST) treatments. The M. bovis spoligotypes were quantified (Colony Forming Unit per milliliter of milk) before and during the thermal process. The decay of the pathogen was quantified by calculating the difference between the measurements at the beginning and at the end of the thermal treatment. The data demonstrated that the LTLT and HTST pasteurization processes considerably reduced the M. bovis load in the milk; however, the bacterium was not eliminated. There was no difference in the thermal resistance of the spoligotypes tested or in the efficiency of pasteurization processes (LTLT versus HTST). However, heating phase was more effective in reducing the M. bovis load than the target temperature maintenance phase.

scholarly journals Differential impact of Holder and High Temperature Short Time pasteurization on the dynamic in vitro digestion of human milk in a preterm newborn model

2020 ◽  
Vol 328 ◽  
pp. 127126 ◽  
Author(s):  
Stefano Nebbia ◽  
Marzia Giribaldi ◽  
Laura Cavallarin ◽  
Enrico Bertino ◽  
Alessandra Coscia ◽  
...  
Keyword(s):  
High Temperature ◽  
Human Milk ◽  
In Vitro Digestion ◽  
Preterm Newborn ◽  
Differential Impact ◽  
High Temperature Short Time ◽  
Short Time

scholarly journals High-Temperature Short-Time and Holder Pasteurization of Donor Milk: Impact on Milk Composition

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 114
Author(s):  
Diana Escuder-Vieco ◽  
Juan M. Rodríguez ◽  
Irene Espinosa-Martos ◽  
Nieves Corzo ◽  
Antonia Montilla ◽  
...  
Keyword(s):  
High Temperature ◽  
Human Milk ◽  
Milk Composition ◽  
Donor Human Milk ◽  
High Temperature Short Time ◽  
Lactose Concentration ◽  
C 30 ◽  
Milk Banks ◽  
Short Time

Holder pasteurization (HoP; 62.5 °C, 30 min) is commonly used to ensure the microbiological safety of donor human milk (DHM) but diminishes its nutritional properties. A high-temperature short-time (HTST) system was designed as an alternative for human milk banks. The objective of this study was to evaluate the effect of this HTST system on different nutrients and the bile salt stimulated lipase (BSSL) activity of DHM. DHM was processed in the HTST system and by standard HoP. Macronutrients were measured with a mid-infrared analyzer. Lactose, glucose, myo-inositol, vitamins and lipids were assayed using chromatographic techniques. BSSL activity was determined using a kit. The duration of HTST treatment had a greater influence on the nutrient composition of DHM than did the tested temperature. The lactose concentration and the percentage of phospholipids and PUFAs were higher in HTST-treated than in raw DHM, while the fat concentration and the percentage of monoacylglycerides and SFAs were lower. Other nutrients did not change after HTST processing. The retained BSSL activity was higher after short HTST treatment than that following HoP. Overall, HTST treatment resulted in better preservation of the nutritional quality of DHM than HoP because relevant thermosensitive components (phospholipids, PUFAs, and BSSL) were less affected.

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