scholarly journals Effect of High Temperature, Short Time (HTST) Pasteurization on Milk Quality Intended for Consumption

2021 ◽  
Author(s):  
Aissam Bousbia ◽  
Yassine Gueroui ◽  
Sofiane Boudalia ◽  
Mhamed Benada ◽  
Mabrouk Chemmam
Keyword(s):  
Heat Treatment ◽  
Raw Milk ◽  
Resistant Bacteria ◽  
Hygienic Quality ◽  
High Temperature Short Time ◽  
Aerobic Flora ◽  
Short Time ◽  
Sensory Profiles ◽  
Reconstituted Milk

Background: In the dairy industry, hygienic quality and safety of milk and dairy products are very important for human health.Methods: The samples taken at the inlet and outlet of the HTST pasteurization process were subjected to physicochemical, bacteriological and sensory analysis.Result: showed that pasteurization has not only been beneficial, as in the case of the hygienic quality of raw milk, where the number of the Total Mesophilic Aerobic Flora dropped by 94% after heat treatment, to reach an average of 5.62 × 104 CFU ml-1 of the thermo-resistant bacteria. Heat treatment resulted in a decrease of protein and lactose values for both types of milk. In fact, this loss is more marked in raw milk than in reconstituted milk (4% against 1.8%, respectively, p less than 0.05). Wetting was more marked after pasteurization for raw milk (0.102°C) compared to reconstituted milk (0.014°C). Sensory profiles were modified in both milk types, with a significant decrease in color, viscosity and flavor descriptors and a significant increase in the intensity of smell and taste (p less than 0.05).

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.

scholarly journals Effect of Heat Treatment on Rheological Properties of Bambangan (Mangifera pajang kosterm) Fruit Juice

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Jumardi Roslan ◽  
Hay Chye Ling ◽  
Mohd Dona Sintang ◽  
Suryani Saallah
Keyword(s):  
Heat Treatment ◽  
Rheological Properties ◽  
Fruit Juice ◽  
Market Potential ◽  
Pseudoplastic Fluid ◽  
Treatment Conditions ◽  
High Temperature Short Time ◽  
Long Time ◽  
Mild Temperature ◽  
Short Time

Bambangan (Mangifera pajang Kosterm) is an indigenous fruit that can be found in Borneo Island including Sabah and Sarawak (Malaysia), Kalimantan (Indonesia), and Brunei. Besides being freshly eaten, the pulp of bambangan fruit can be processed for juice production to expand its market potential. During the processing of fruit juice, the application of heat treatment such as pasteurization and sterilization might influence their rheological behavior. Thus, the present study aims to investigate the effect of heat treatment on the rheological properties of bambangan fruit juice (BFJ). The freshly squeezed BFJ was subjected to different heat treatment conditions; sterilization (121°C, 3 minutes), mild temperature long time (MTLT) pasteurization (65°C, 15 minutes), and high temperature short time (HTST) pasteurization (90°C, 1 minute). Rheological analysis of the heat-treated BFJ was performed using a rheometer at a shear rate ranging from 1 to 250 s-1 and a temperature between 5 °C to 70 °C. Pasteurization at 90 °C for 1 minute (HTST) was found to be the most suitable heat treatment for the BFJ. At this condition, the BFJ exhibited a non-Newtonian pseudoplastic fluid behavior (n < 1), fitted well with the Herschel-Bulkey model. The value of parameters obtained from Herschel-Bulkley equation for HTST treatment of bambangan juice were n= 0.83, k= 0.32 and yield stress= 3.96. The viscosity values of HTST bambangan juice at the temperature of 5, 20, 40 and 70 °C were 3.53, 2.33, 1.53 and 1.76 Pa.s respectively. This rheological information is of fundamental importance in optimizing equipment design, process control, and sensory evaluation.

Thermal Resistance of Listeria spp. in Milk

1991 ◽  
Vol 54 (1) ◽  
pp. 12-14 ◽  
Author(s):  
JOE G. BRADSHAW ◽  
JAMES T. PEELER ◽  
ROBERT M. TWEDT
Keyword(s):  
High Temperature ◽  
Thermal Resistance ◽  
Heat Resistance ◽  
Raw Milk ◽  
The Other ◽  
Time Processing ◽  
Listeria Ivanovii ◽  
High Temperature Short Time ◽  
The Difference ◽  
Short Time

The thermal resistance of one strain each of Listeria ivanovii, L. seeligeri, and L. welshimeri and three L. monocytogenes strains was determined in raw and sterile milk. Listeria spp. suspended in milk at concentrations of 1 × 105 cells/ml were heated at temperatures ranging from 52.2 to 71.1°C for various contact times. The heat resistance of L. monocytogenes appeared somewhat greater than that of the other Listeria spp. in both milks, but the difference was not statistically significant (α = 0.05). High-temperature, short-time processing is adequate for pasteurization of raw milk.

Thermal Resistance of Bacillus stearothermophilus Heated at High Temperatures in Different Substrates

1997 ◽  
Vol 60 (2) ◽  
pp. 144-147 ◽  
Author(s):  
F. RODRIGO ◽  
P. S. FERNÁNDEZ ◽  
M. RODRIGO ◽  
M. J. OCIO ◽  
A. MARTÍNEZ
Keyword(s):  
Heat Treatment ◽  
Thermal Resistance ◽  
Heat Resistance ◽  
Bacillus Stearothermophilus ◽  
Distilled Water ◽  
Water Acidification ◽  
Mushroom Extract ◽  
Overnight Incubation ◽  
High Temperature Short Time ◽  
Short Time

The effect of mushroom extract, with or without acidification with glucono-δ-lactone, and the overnight incubation of the spores in CaCl2, on the heat resistance of B. stearothermophilus ATCC 12980 spores was studied. The temperature range considered was 121 to 140°C for mushroom extract and CaCl2 and 121 to 145°C for double-distilled water as a reference substrate. The results indicated that mushroom extract without added acid significantly reduces the thermal resistance of the spores in comparison to the double-distilled water. Acidification of the mushroom extract reduces the heat resistance of spores of B. stearothermophilus at 121 °C. However, above 130°C lowering of the pH did not significantly reduce the thermal resistance of the spores, and so no generalizations should be made with regard to the effect of the pH when high temperature-short time (HTST) processes are being considered. Overnight incubation in CaCl2 and subsequent heat treatment lead to increased heat resistance at 121 °C compared to that observed in double-distilled water. However, at 130°C and above CaCl2 did not increase the apparent heat resistance of the spores.

scholarly journals Effect of Commercial-Scale High-Temperature, Short-Time Pasteurization on the Viability of Mycobacterium paratuberculosis in Naturally Infected Cows' Milk

2002 ◽  
Vol 68 (2) ◽  
pp. 602-607 ◽  
Author(s):  
Irene R. Grant ◽  
Edward I. Hitchings ◽  
Alan McCartney ◽  
Fiona Ferguson ◽  
Michael T. Rowe
Keyword(s):  
High Temperature ◽  
Cetylpyridinium Chloride ◽  
Raw Milk ◽  
Holding Time ◽  
Mycobacterium Paratuberculosis ◽  
Pasteurized Milk ◽  
Milk Samples ◽  
Commercial Scale ◽  
High Temperature Short Time ◽  
Short Time

ABSTRACT Raw cows' milk naturally infected with Mycobacterium paratuberculosis was pasteurized with an APV HXP commercial-scale pasteurizer (capacity 2,000 liters/h) on 12 separate occasions. On each processing occasion, milk was subjected to four different pasteurization treatments, viz., 73�C for 15 s or 25 s with and without prior homogenization (2,500 lb/in2 in two stages), in an APV Manton Gaulin KF6 homogenizer. Raw and pasteurized milk samples were tested for M. paratuberculosis by immunomagnetic separation (IMS)-PCR (to detect the presence of bacteria) and culture after decontamination with 0.75% (wt/vol) cetylpyridinium chloride for 5 h (to confirm bacterial viability). On 10 of the 12 processing occasions, M. paratuberculosis was detectable by IMS-PCR, culture, or both in either raw or pasteurized milk. Overall, viable M. paratuberculosis was cultured from 4 (6.7%) of 60 raw and 10 (6.9%) of 144 pasteurized milk samples. On one processing day, in particular, M. paratuberculosis appeared to have been present in greater abundance in the source raw milk (evidenced by more culture positives and stronger PCR signals), and on this occasion, surviving M. paratuberculosis bacteria were isolated from milk processed by all four heat treatments, i.e., 73�C for 15 and 25 s with and without prior homogenization. On one other occasion, surviving M. paratuberculosis bacteria were isolated from an unhomogenized milk sample that had been heat treated at 73�C for 25 s. Results suggested that homogenization increases the lethality of subsequent heat treatment to some extent with respect to M. paratuberculosis, but the extended 25-s holding time at 73�C was found to be no more effective at killing M. paratuberculosis than the standard 15-s holding time. This study provides clear evidence that M. paratuberculosis bacteria in naturally infected milk are capable of surviving commercial high-temperature, short-time pasteurization if they are present in raw milk in sufficient numbers.

scholarly journals Organic versus Conventional Raw Cow Milk as Material for Processing

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2760
Author(s):  
Aneta Brodziak ◽  
Joanna Wajs ◽  
Maria Zuba-Ciszewska ◽  
Jolanta Król ◽  
Magdalena Stobiecka ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Dairy Products ◽  
Whey Proteins ◽  
Raw Milk ◽  
Cow Milk ◽  
Animal Origin ◽  
Organic Milk ◽  
Hygienic Quality ◽  
Health Promoting

Milk, as one of the basic raw materials of animal origin, must be of adequate hygienic and physicochemical quality for processing. The aim of the article was to compare the quality of raw milk from three production systems, intensive, traditional (together referred to as conventional), and organic, as material for processing, as well as the quality of products made from it. Particular attention was focused on hygienic quality (somatic cell count and total bacterial count), physical characteristics (acidity), basic nutritional value (content of dry matter, total protein, casein, fat, and lactose), content of health-promoting substances (whey proteins, fatty acids, vitamins, and minerals), and technological parameters (rennet clotting time, heat stability, and protein-to-fat ratio). Research assessing the quality of organic milk and dairy products is significantly less extensive (if available at all) than for milk from conventional production (intensive and traditional). The available reports indicate that raw milk from organic farms is more valuable, especially in terms of the content of health-promoting compounds, including vitamins, fatty acids, whey proteins, and minerals. This applies to organic dairy products as well, mainly cheese and yoghurt. This is explained by the fact that organic farming requires that animals are kept in the pasture. However, the hygienic quality of the raw milk, and often the products as well, raises some concerns; for this reason, organic milk producers should be supported in this regard, e.g., through consultancy and training in Good Hygienic Practices. Importantly, milk production in the traditional and organic systems is in line with the concept of the European Green Deal.

Method for Predicting Minimum Detectable Residual Alkaline Phosphatase in High-Temperature, Short-Time Processed Dairy Products

1980 ◽  
Vol 43 (1) ◽  
pp. 46-48 ◽  
Author(s):  
G. K. MURTHY ◽  
J. T. PEELER
Keyword(s):  
Alkaline Phosphatase ◽  
High Temperature ◽  
Control Sample ◽  
Rank Correlation ◽  
Raw Milk ◽  
Milk Product ◽  
Colorimetric Test ◽  
High Temperature Short Time ◽  
Highly Correlated ◽  
Short Time

High-temperature, short-time (HTST) processed milk, cream and buttermilk were mixed with small portions (0 to 0.6%) of the raw milk product to obtain desired levels of residual alkaline phosphatase. Samples were subjected to the differential test to discern reactivation and analyzed for phosphatase activity by the rapid colorimetric test. The experimental data were fitted to a linear statistical model to determine the minimum detectable residual phosphatase (Eo) in the product. These observed values and the computed expected values were highly correlated, with a rank correlation coefficient of 0.956, which was significant at a = 0.05 level. The values of [Eo] varied depending upon the extent of phosphatase reactivation in the HTST product when the residual phosphatase was zero. As the differential values of reactivation (reactivated [E] of the control sample minus the reactivated [E] of diluted sample containing magnesium) increased, the [Eo] increased also. In general, the [Eo] in cream was greater than that in milk. A method is proposed for predicting [Eo] in liquid HTST products.

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