Milk Pasteurization Temperature Research Articles

СИНТЕЗ НЕЧІТКОГО РЕГУЛЯТОРА ТЕМПЕРАТУРИ ПАСТЕРИЗАЦІЇ МОЛОКА

The article solves the actual scientific and technical task of reducing the energy intensity of pasteurization of milk in the POU5 apparatus by means of research and development of an automated system for controlling the pasteurization temperature regime. A study of the features of the device's functioning, setting the parameters of the control process was carried out; the improvement of the mathematical model and the algorithm for regulating milk pasteurization parameters was carried out; an automated system for controlling the temperature of milk pasteurization in the POU5 installation was created. The synthesis of a fuzzy regulator of milk pasteurization temperature was carried out. Constructed response surface of milk temperature changes depending on the consumption of milk for pasteurization and the temperature of the hot water of the heat exchange r. The application of the fuzzy logic apparatus for building an adaptive system makes it possible to create adaptive systems with optimal control for the purpose of approximating the output variable of the fuzzy controller.A structural scheme of the milk pasteurizer was created, as well as effective methods of temperature control and para-metric schemes of sections (recovery, pasteurization and cooling of the plate milk pasteurizer) were developed, which allow improving the accuracy of technological process control.As a result of conducting theoretical research, a dynamic characteristic of the pasteurization section was obtained ac-cording to the channel «hot water consumption - temperature of pasteurized milk». The specified model will allow to develop temperature control algorithms to increase pasteurizer productivity

Modification of Biotesting-Based Fermented Dairy Product Design for Curd and Curd Products

The key trends driving the global dairy market are shelf-life extension and generating consumer demand for new products. Healthy diets and special foods meet the criteria based on the protein digestibility-corrected amino acid score, while other factors affecting the digestibility and actual biological value of the protein are not considered. Express biological evaluation tests are very important for choosing the optimal formulation and efficient manufacturing process in order to maximize the biological value (BV). Such tests adequately represent the food properties: safety, nutrition value, digestibility, health benefits, etc. This study deals with the procedures for the quick biological evaluation of dairy products using indicator organisms. We adapted the relative biological value evaluation procedure, involving Tetrahymena pyriformis, for curd (cottage cheese) and curd products. The experiments showed that the most significant parameters are the milk pasteurization temperature and the curd heating temperature. The full factorial experiment identified the optimal curd production conditions to maximize the relative biological value (RBV): 81 °C milk pasteurization temperature and 54 °C curd heating temperature using the acid method of curd production. With these parameters, the RBV is at least 282%. Biotesting confirmed the optimal curd product component ratio of 60% curd to 40% fermented dairy beverage.

The effect of whey type on the yield and quality characteristics of Urda

In this research, whey cheese Urda was produced in industrial conditions by thermal denaturation, followed by protein aggregation and precipitation of whey which was obtained during production of white brined cheese and Kashkaval. The impact of milk pasteurization temperature, pH values, protein content, and whey type on the Urda quality and yield was examined. The impact of whey pH on Urda yield was evaluated in the pH range from 4.5 to 6.0. Urda yield reached a maximum pH value between 5.2 and 5.4. The highest Urda yield from white brined cheese whey was obtained at pasteurization temperature of 72 °C. By increasing the temperature to 80 °C, the whey protein content and the Urda yield decreased. Whey type had no significant impact on the sensory and textural characteristics of Urda. Urda was classified as a low-fat soft albumin cheese. Valorisation of whey generated after production of white brined cheese, and manufacturing of Urda with maximum yield and optimal functional properties, is not only of economic importance, but can be conducive to improve waste water quality.

Effect of Storage and Heat Treatment of Milk Destined for Cheese Production on Its Oxidative Characteristics

The oxidative stability of milk and dairy products is a very interesting topic for the dairy industry due to the growing demand for foods containing bioactive compounds with positive health effects. The aim was to evaluate the oxidative stability of milk intended for cheese production. The effect of storage time, heat pre-treatment, and milk pasteurization temperature on the characteristics of milk and cheese was investigated. The cheese samples were produced with pasteurized milk at both 72 and 77 °C for a time of 15 s using three types of milk: raw fresh milk processed within 48 h of milking, raw stored milk processed within 96 h, and thermized milk that was heat-treated upon arrival at the dairy and processed within 96 h of milking. In total, three repetitions were carried out for each type of milk and pasteurization. Samples of milk before and after pasteurization and cheese at 14 days of storage were analyzed. Antioxidant activity decreased from starting milk to milk after pasteurization to final cheese. The longer storage time of the milk had significant effects on the antioxidant stability of the cheese (64.95 vs. 59.05% of antioxidant activity). Thermization of the milk further reduced the stability of the cheese (54.05% of antioxidant activity). The greater antioxidant stability of fresh milk and cheeses produced with fresh milk is the first result that encourages the production of cheese from a milk that best preserves its original characteristics.

Effect of N-Photovoltaic thermal integrated parabolic concentrator on milk temperature for pasteurization: A simulation study

In this study, an effort has been done to develop the thermal modeling of solar milk pasteurization system operated through N number of fully covered semitransparent photovoltaic thermal integrated parabolic concentrator (N/PVT/IPC). The thermal mathematical model of the present proposed system has been exhaustively demonstrated for the assessment of performance parameters namely, solar cells electrical efficiency, electrical power output, useful thermal energy gain and temperature of milk (which is to be pasteurized) in terms of both design and climatic conditions. Moreover, effect of operating parameters such as mass flow rate of withdrawn milk, number of collector, packing factor, and mass flow rate of collector fluid on milk pasteurization temperature have been comprehensively discussed. The present numerical simulations have been carried out for New Delhi, India climatic condition. Based on mathematical computation, it has been found that milk temperature for pasteurization increases significantly with increase in number of PVT/IPC collectors at lower packing factor. Further, it is also concluded that the proposed pasteurization system under optimal design and operating parameters can produce 216 kg of pasteurized milk and 5.7 kW h of electrical energy. Correspondingly, after simulation it is inferred that the proposed system is self-sustained under 6 h of operation.

Effect of local taro starch (Colocasia esculenta) towards the nutritional value of yogurt with commercial probiotic starter

This research was aimed to determine the effect of adding local taro starch (Colocasia esculenta) toward the nutritional value of yogurt with commercial probiotic combination of lactic acid bacteria (BAL) S. thermophillus, L. bulgaricus, and L. acidhopilus. The materials were used in the manufacturing yogurt including raw cow milk, local taro starch, skim milk powder 4%, starter BAL 3%. The method used a laboratory experiment using a completely randomized design (CRD) with 6 treatments and 4 replications. The treatment used level of local taro starch: 0%; 0.5%; 1%; 1.5%; 2%; and 2.5%. The milk pasteurization temperature at 85°C for 30 minutes and the time of incubation at 24 hours. The variables observed were fat, protein and carbohydrate of yogurt. Data were analyzed by one-way ANOVA, and followed by Duncan's multiple range test (DMRT). The results showed the addition of local taro starch had a very significant effect (P <0.01) on the fat, protein and carbohydrate content of yogurt. Fat have decreased, while protein and carbohydrate of yogurt have increased with the addition of taro starch levels. It could be concluded that the addition of local taro starch to produce optimal nutritional value of yogurt with commercial probiotic starter.

Proteolysis and lipolysis of white-brined (Beyaz) cheese during storage: Effect of milk pasteurization temperature

Beyaz cheeses were produced from milk pasteurized at 65 °C for 20 min, 75 °C for 5 min, or 85 °C for 5 min, and investigated at 7, 30, 60, and 90 days of storage. Pasteurization temperature affected significantly the parameters of total solids, fat, titratable acidity, pH, salt, and total free fatty acid of Beyaz cheese. Water-soluble nitrogen fraction (% WSN/TN), caseins (αs1- and β-casein), and individual free amino acids were analyzed to evaluate the proteolysis of Beyaz cheese during 90-day storage period. Pasteurization norm did not affect % WSN/TN levels in direct proportion to pasteurization temperature. αs1-Casein hydrolysis of Beyaz cheeses increased with elevated pasteurization temperature. As the pasteurization temperature increased, β-casein hydrolysis grade showed a slight decrease. Leucine, lysine, phenylalanine, and valine were found to be dominant in Beyaz cheeses. The total free fatty acid content in cheeses decreased as the pasteurization temperature increased. Practical applications High pasteurization temperature could be used to incorporate more whey proteins into white-brined cheeses. This process directly affects the course of proteolysis and lipolysis in white-brined cheese. Thus, innovative cheeses which have desired proteolytic and lipolytic characters may be obtained by this process.

Responding to Bioterror Concerns by Increasing Milk Pasteurization Temperature Would Increase Estimated Annual Deaths from Listeriosis

In a 2005 analysis of a potential bioterror attack on the food supply involving a botulinum toxin release into the milk supply, the authors recommended adopting a toxin inactivation step during milk processing. In response, some dairy processors increased the times and temperatures of pasteurization well above the legal minimum for high temperature, short time pasteurization (72 °C for 15 s), with unknown implications for public health. The present study was conducted to determine whether an increase in high temperature, short time pasteurization temperature would affect the growth of Listeria monocytogenes, a potentially lethal foodborne pathogen normally eliminated with proper pasteurization but of concern when milk is contaminated postpasteurization. L. monocytogenes growth during refrigerated storage was higher in milk pasteurized at 82 °C than in milk pasteurized at 72 °C. Specifically, the time lag before exponential growth was decreased and the maximum population density was increased. The public health impact of this change in pasteurization was evaluated using a quantitative microbial risk assessment of deaths from listeriosis attributable to consumption of pasteurized fluid milk that was contaminated postprocessing. Conservative estimates of the effect of pasteurizing all fluid milk at 82 °C rather than 72 °C are that annual listeriosis deaths from consumption of this milk would increase from 18 to 670, a 38-fold increase (8.7- to 96-fold increase, 5th and 95th percentiles). These results exemplify a situation in which response to a rare bioterror threat may have the unintended consequence of putting the public at increased risk of a known, yet severe harm and illustrate the need for a paradigm shift toward multioutcome risk benefit analyses when proposing changes to established food safety practices.

Effect of milk pasteurization temperature and in situ whey protein denaturation on the composition, texture and heat-induced functionality of half-fat Cheddar cheese

Abstract In recent years, many dairy product manufacturers pasteurize milk at temperatures higher than 72°C, so as to reduce further the risk of survival of Mycobacterium avium ssp. paratuberculosis. However, little information is available on the effect of these temperatures on cheese quality. Half-fat Cheddar cheeses (∼15%, w/w, fat) were manufactured from milk pasteurized at 72°C, 77°C, 82°C or 87°C for 26 s, and analyzed over a 360 d ripening period. The mean levels of whey protein denaturation in the pasteurized milks were 2.8%, 8.4%, 20.2% and 34.1% of total whey protein, respectively. Increasing pasteurization temperature significantly increased the levels of moisture and non-expressible serum and decreased the levels of protein, fat, calcium and free oil. Pasteurization temperature did not significantly affect the levels of pH 4.6-soluble N but influenced the degradation profiles of αs1- and β-caseins. Increased pasteurization temperature significantly reduced fracture stress, fracture strain and firmness of cheeses. Raising the pasteurization temperature from 72°C to either 82°C or 87°C significantly reduced the flowability and stretchability of the heated cheese and increased its apparent viscosity; in contrast, increasing pasteurization from 72°C to 77°C did not affect these properties.

The influence of milk pasteurization temperature and pH at curd milling on the composition, texture and maturation of reduced fat cheddar cheese

Reduced fat milks were pasteurized, for 15 s, at temperatures ranging from 72 to 88°C to give levels of whey protein denaturation varying from ˜ 3 to 35%. The milks were converted into reduced fat cheddar cheese (16–18% fat) in 500 litre cheese vats; the resultant cheese curds were milled at pH values of 5.75 and 5.35. Raising the milk pasteurization temperature resulted in impaired rennet coagulation properties, longer set‐to‐cut times during cheese manufacture, higher cheese moisture and moisture in the non‐fat cheese substance, lower levels of protein and calcium and lower cheese firmness. Increasing the pH at curd milling from 5.35 to 5.75 affected cheese composition and firmness, during ripening, in a manner similar to that of increasing milk pasteurization temperature. Despite their effects on cheese composition and rheology, pasteurization temperature and pH at curd milling had little influence on proteolysis or on the grading scores awarded by commercial graders during ripening over 303 days.

Keeping quality of milk in relation to the copper content and temperature of pasteurization

SUMMARYFor milk from four herds of cows, maintained under different conditions of feeding and management, the natural Cu content and the stability of the ascorbate were highly correlated. Low Cu levels in milk from cows at pasture at farms A and B during the summer were associated with low storage losses of ascorbate. During this period, the milk of cows at farms C and D (on forage and Cu-supplemented concentrate) was richer in Cu, and losses of ascorbate were high. Heat treatment of the milk stabilized the ascorbate. Thus, in ‘high Cu’ milk (60 µg Cu/l), loss of ascorbate in the raw milk was 58% at 2 d, as against 17% after pasteurization at 72 °C and no loss after treatment at 82 °C. Storage of milk in light caused rapid destruction of ascorbate, equally with 72 and 82 °C heat treatments. The effects were examined of milk pasteurization temperature (72–82 °C) on flavour stability, bacteriological quality and vitamins of the B-complex. Heat treatment at 82 °C increased the susceptibility of vitamin B12to destruction by light, but otherwise caused no greater losses of B-complex vitamins than did treatment at 72 °C. Taste panel ratings showed an initial preference for milk heated at 72 °C, but on storage of this milk in darkness the flavour score fell progressively and at 5 d it was judged ‘stale’. Treatment at 82 °C gave a faint ‘cooked’ flavour although, unlike that of the 72 °C-treated milk, the flavour remained stable throughout 14-d storage and after d 8 was increasingly preferred. On exposure to light after treatment at 72 °C milks rapidly acquired an unpleasant‘oxidized’ flavour, but after treatment at 82 °C, exposure to light had no such adverse effect on flavour during the early days of storage. Pasteurization at ∼ 80 °C offers a potential for improvement in the oxidative stability of milk and its contribution of vitamin C to the diet.

Pasteurization of naturally contaminated water with solar energy.

A solar box cooker (SBC) was constructed with a cooking area deep enough to hold several 3.7-liter jugs of water, and this was used to investigate the potential of using solar energy to pasteurize naturally contaminated water. When river water was heated either in the SBC or on a hot plate, coliform bacteria were inactivated at temperatures of 60 degrees C or greater. Heating water in an SBC to at least 65 degrees C ensures that the water will be above the milk pasteurization temperature of 62.8 degrees C for at least an hour, which appears sufficient to pasteurize contaminated water. On clear or partly cloudy days, with the SBC facing magnetic south in Sacramento, bottom water temperatures of at least 65 degrees C could be obtained in 11.1 liters of water during the 6 weeks on either side of the summer solstice, in 7.4 liters of water from mid-March through mid-September, and in 3.7 liters of water an additional 2 to 3 weeks at the beginning and end of the solar season. Periodic repositioning of the SBC towards the sun, adjusting the back reflective lid, and preheating water in a simple reflective device increased final water temperatures. Simultaneous cooking and heating water to pasteurizing temperatures was possible. Additional uses of the SBC to pasteurize soil and to decontaminate hospital materials before disposal in remote areas are suggested.