Control of high temperature short time milk pasteurization plant with centralized and decentralized linear quadratic regulators

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.

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

Food Chemistry ◽

10.1016/j.foodchem.2020.127126 ◽

2020 ◽

Vol 328 ◽

pp. 127126 ◽

Cited By ~ 2

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

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

Life ◽

10.3390/life11020114 ◽

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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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

Journal of Food Protection ◽

10.4315/0362-028x-62.8.861 ◽

1999 ◽

Vol 62 (8) ◽

pp. 861-866 ◽

Cited By ~ 12

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.

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