scholarly journals On the Thermal Effusivity of Bovine Milk

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Daniel Acosta-Avalos ◽  
Daniel Soares Velasco
Keyword(s):  
Thermal Diffusivity ◽  
Linear Function ◽  
Regional Differences ◽  
Bovine Milk ◽  
Thermal Effusivity ◽  
Thermal Characterization ◽  
Milk Composition ◽  
Fat Content ◽  
First Time ◽  
Photoacoustic Techniques

Thermal diffusivity, conductivity, and effusivity are parameters that can be measured using photoacoustic techniques. Both thermal diffusivity and conductivity have already been measured for bovine milk. To complete its thermal characterization, this paper deals with the thermal effusivity of commercial bovine milk with a different fat content. The thermal effusivity ε obtained for skimmed, partly skimmed, and whole milks is 0.153 W cm−2 s1/2 K−1, 0.144 W cm−2 s1/2 K−1, and 0.140 W cm−2 s1/2 K−1, respectively, with the uncertainty being less than 5%. It was observed that the thermal effusivity decreases with the increase in the fat content. For the first time, it is observed that the thermal effusivity is a linear function of the logarithm of the fat content. The comparison of our results with previous results for milk from Slovakia revealed different thermal effusivity values. This might be due to regional differences in the milk composition and could be used as a criterion to identify the milk provenience.

scholarly journals Effect of Sunflower, Almond, and Rapeseed Oils as Additives on Thermal Properties of a Machinery Oil

2021 ◽  
Vol 11 (16) ◽  
pp. 7441
Author(s):  
José de Jesús Agustín Flores Cuautle ◽  
Oscar Osvaldo Sandoval González ◽  
Carlos Omar González Morán ◽  
José Pastor Rodríguez Jarquin ◽  
Citlalli Jessica Trujillo Romero ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Vegetable Oils ◽  
Thermal Effusivity ◽  
Thermal Characterization ◽  
Tocopherol Content ◽  
Lubricating Oil ◽  
Wave Resonance ◽  
Resonance Cavity

Vegetable oils are considered to be eco-friendly and to offer good lubricant properties; however, their low thermo-oxidative stability makes their use as a lubricant base challenging. In this research, sunflower, almond, and rapeseed vegetable oils were added in volumes of 5, 10, 15, and 20% to a machinery oil, and the thermal properties of the resulting fluids were studied. Sunflower, almond, and rapeseed oils were chosen considering their fatty acid composition and the tocopherol content. During this investigation, thermal diffusivity was measured by using the thermal wave resonance cavity technique, while thermal effusivity was determined by the inverse photopyroelectric method, and the obtained values ranged from 4.63 to 5.75 Ws1/2m−2K−1 × 102. The thermal conductivity was calculated by obtaining a complete thermal characterization. The results showed a linear relationship between the percentage of vegetable oil and the thermal diffusivity. It was also noted that the thermal properties of diffusivity and effusivity could be tuned when using almond, sunflower, and rapeseed oils in the appropriate percentages. Hence, the influence of vegetable oils on the thermal properties of lubricating oil were closely related to the number of fatty acids.

scholarly journals Temperature Dependence of Thermophysical Properties of Full-Scale Corium of Fast Energy Reactor

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Mazhyn K. Skakov ◽  
Nurzhan Ye. Mukhamedov ◽  
Alexander D. Vurim ◽  
Ilya I. Deryavko
Keyword(s):  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Fast Reactor ◽  
Thermophysical Properties ◽  
Heat Conductivity ◽  
Nuclear Reactor ◽  
Reactor Vessel ◽  
Full Scale ◽  
Temperature Fields ◽  
First Time

For the first time the paper determines thermophysical properties (specific heat capacity, thermal diffusivity, and heat conductivity) of the full-scale corium of the fast energy nuclear reactor within the temperature range from ~30°С to ~400°С. Obtained data are to be used in temperature fields calculations during modeling the processes of corium melt retention inside of the fast reactor vessel.

Thermal Inactivation of Escherichia coli in Camel Milk

2003 ◽  
Vol 66 (9) ◽  
pp. 1708-1711 ◽  
Author(s):  
SHLOMO SELA ◽  
RIKY PINTO ◽  
UZI MERIN ◽  
BARUCH ROSEN
Keyword(s):  
Escherichia Coli ◽  
Thermal Inactivation ◽  
Bovine Milk ◽  
Milk Composition ◽  
Camel Milk ◽  
E Coli ◽  
Death Time ◽  
Thermal Death ◽  
Milk Industry ◽  
Thermal Death Time

Camels subsist and produce milk in desert pastures not utilized by other domesticated herbivores. Developing the camel milk industry can improve the economy of desert inhabitants. To comply with sanitary ordinances, camel milk is pasteurized by procedures specified for bovine milk. It is widely accepted that milk composition might affect bacterial thermal death time (TDT). Camel and bovine milks markedly differ in their chemical composition, yet data regarding TDT values of bacteria in camel milk is missing. As a first step toward developing specific heat treatments appropriate for camel milk, TDT curves of Escherichia coli in artificially contaminated camel and cow milks have been compared. Heating the milks to temperatures ranging from 58 to 65°C yields similar thermal death curves and derived D- and z-values. These findings suggest that, in this temperature range, E. coli might behave similarly in bovine and camel milk. Additional TDT studies of various pathogenic species in camel milk are required before establishing pasteurization conditions of camel milk.

Diphenyl diselenide subcutaneous supplementation of dairy sheep: effects on oxidant and antioxidant status, inflammatory response and milk composition

2019 ◽  
Vol 59 (3) ◽  
pp. 461 ◽  
Author(s):  
Angelisa H. Biazus ◽  
Chrystian J. Cazarotto ◽  
Gustavo Machado ◽  
Nathieli B. Bottari ◽  
Mariana S. Alves ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Interleukin 10 ◽  
Milk Composition ◽  
Fat Content ◽  
Control Group ◽  
Lactation Period ◽  
Diphenyl Diselenide ◽  
Dairy Sheep ◽  
Positive Effects ◽  
Anti Inflammatory

Diphenyl diselenide ((PhSe)2) is a organoselenium compound with potent antioxidant properties. Therefore, the aim of the present study was to evaluate whether subcutaneous supplementation of (PhSe)2 in dairy sheep has positive effects on milk composition, as well as on the prevention of oxidative stress and exacerbated inflammatory response. For this, 16 primiparous recently calved sheep were divided into the following two groups, with eight animals in each: Group A, the control group; and Group B, the group subcutaneously supplemented with five doses of (PhSe)2 of 3.0µmol/kg each every 7 days. Blood samples from supplemented animals showed increased concentration of antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase and glutathione-S-transferase), and reduced reactive oxygen species and lipid peroxidation, which prevented oxidative damage in the lactation period, as well as increased seric interleukin-10, an anti-inflammatory cytokine. In the sera, supplemented animals showed increased total antioxidant capacity and ferric-reducing ability of plasma compared with the control group. As a consequence, supplemented animals showed increased antioxidant variables, as well as reduced protein oxidation in milk samples. Moreover, milk from supplemented sheep showed a higher fat content, and lower total protein and lactose contents in some periods in the study, than did not-supplemented ewes. Seric concentrations of interleukin-1 were lower on Days 30 and 45 in supplemented animals, as well as the concentrations of tumour necrosis factor α in all periods, than were those in the control group, whereas the interleukin-10 concentrations were higher. Thus, dairy sheep supplementation of (PhSe)2 activated antioxidant and anti-inflammatory responses, and increased milk fat content. Moreover, this protocol increased the antioxidant and, consequently, reduced the oxidant concentration in milk, which is desirable for product quality.

scholarly journals Microstructure of kajmak skin layer made during kajmak production

2020 ◽  
Vol 70 (3) ◽  
pp. 150-161
Author(s):  
Mira Radovanovic ◽  
Predrag Pudja ◽  
Vladimir Pavlovic ◽  
Jelena Miocinovic ◽  
Aleksandar Nedeljkovic
Keyword(s):  
Dairy Product ◽  
Whey Proteins ◽  
Skin Layer ◽  
Milk Composition ◽  
Fat Content ◽  
Protein Distribution ◽  
Compact Structure ◽  
Reducing Conditions ◽  
Sds Page ◽  
Lower Temperature

Kajmak is a unique dairy product with a long tradition in Balkan countries and the Middle East. Kajmak skin layers are formed during 60 minutes of kajmak production, influencing the quality and determining the structure of the final product. The influence of milk composition and heat treatments (75-95 °C/5min) on the composition, microstructure and protein distribution of kajmak skin layers was investigated in this study. Microstructure was determined using scanning electron microscopy (SEM), while the distribution of protein fractions was studied by SDS PAGE in reducing and non-reducing conditions. Kajmak skin layers obtained from milk treated at common intense heat regime were characterized with β-LG and α-LA mainly as disulfide-linked complexes, while lower temperature (75 °C) caused the presence of whey proteins in dominantly individual form. More severe treatments (85 °C, 90 °C and 95 °C) caused the full involvement of β-LG in the complexes, since a certain amount of α-LA was found as a monomer. The kajmak skin layer composition, severity of the applied milk heat treatment and the linked whey proteins exhibited a very strong influence on kajmak skin layer microstructure. The microstructure of kajmak skin layer with a low fat content and fat/protein (F/P) ratio was characterized by a compact structure with a dense protein matrix. High fat content and F/P ratio resulted in a dispersive form of the stretched protein network. Kajmak skin layers produced from milk with added whey proteins were characterized by fibrous, thread-like segments, due to the incorporated denatured whey proteins, especially linked β-LG.

scholarly journals Impact of milk and nutrient intake of piglets and sow milk composition on piglet growth and body composition at weaning

2020 ◽  
Vol 98 (3) ◽  
Author(s):  
Camilla Kaae Hojgaard ◽  
Thomas Sønderby Bruun ◽  
Peter Kappel Theil
Keyword(s):  
Body Composition ◽  
Weight Gain ◽  
Body Fat ◽  
Milk Protein ◽  
Live Weight ◽  
Milk Composition ◽  
Fat Content ◽  
Milk Intake ◽  
Body Fat Content ◽  
Piglet Growth

Abstract The main objective of this study was to evaluate the impact of milk intake, milk composition, and nutrient intake on piglet growth in lactation and body composition at weaning. To evaluate the body composition of piglets, data from one experiment (44 Danish Landrace × Yorkshire × Duroc piglets) were used to develop prediction equations for body pools of fat, protein, ash, and water based on live weight and deuterium dilution space (exp. 1). Furthermore, a total of 294 piglets (Danish Landrace × Yorkshire × Duroc) from 21 sows of second parity were included in a second experiment (exp. 2). In exp. 2, piglet live weight was recorded on days 3, 10, 17, and 25 of lactation. On the same days, the milk intake and body composition were measured, using the deuterium oxide (D2O) dilution technique. Piglet weight gain was highly positively correlated with the intake of milk and the intake of milk constituents each week and on an overall basis having r values ranging from 0.65 to 0.93 (P < 0.001). When evaluating regressions for piglet growth, the milk intake in combination with the milk protein concentration explained 85% and 87% of the total variation in piglet gain in the second and third week of lactation, respectively, whereas milk intake was the only predictor of piglet gain in the first week of lactation explaining 81% of the variation. Fat, protein, and energy retention rates were all highly positively correlated with the daily intake of milk and intake of milk nutrients with r values ranging from 0.76 to 0.94 (P < 0.001). Piglet gain and retention rates were rather weakly correlated with the milk composition with r values ranging from 0.01 to 0.50 (being either negative or positive). Curvilinear response curves were fitted for live weight gain and body fat content at weaning in response to milk protein concentration, showing that live weight gain was slightly greater and body fat content was slightly lower at 4.9% milk protein, but it should be emphasized that the quadratic effects did not reach significance. Body fat content at weaning was positively related with the intake of milk (R2 = 0.44, P < 0.001) and milk fat (R2 = 0.46, P < 0.01). In conclusion, milk intake had a major impact on the piglet growth rate, and milk fat intake greatly influenced the body fat percentage at weaning, whereas milk composition per se only played a minor role for these traits.

Genomic selection in relation to bovine milk composition and processability

2011 ◽  
Vol 79 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Maria Glantz ◽  
Helena Lindmark Månsson ◽  
Marie Paulsson ◽  
Hans Stålhammar
Keyword(s):  
Genomic Selection ◽  
Milk Yield ◽  
New Technology ◽  
Bovine Milk ◽  
Milk Composition ◽  
Milk Traits ◽  
New Approach ◽  
Selection Decisions ◽  
Morning Milk ◽  
Linear Correlations

Genomic selection is a new technology in which selection decisions are based on direct genomic values (DGVs) or genomic enhanced breeding values (GEBVs). The objective of this study was to evaluate the relations between DGVs and several milk traits important for both the nutritional value and processability of milk. This is a new approach and can be used to increase the knowledge on how genomic selection can be used in practice. Morning milk samples from Swedish Holstein cows were analyzed for milk composition and technological properties. DGVs were received for each cow for milk, protein and fat yield, milk index, udder health, Nordic total merit and a quota was calculated between fat and milk yield as well as protein and milk yield. The results show that linear correlations exist (P<0·10) between the studied DGVs and contents and yields of parameters in the protein (P=0·002–0·097), fat (P=0·024–0·055) and mineral profiles (P=0·001–0·099) as well as for cheese characteristics (P=0·004–0·065), thus making it possible to obtain detailed information on milk traits that are not registered in the milk recording scheme. Hence, genomic selection will be an efficient tool for breeding and dairy industry to select cows early in life for targeted milk production.

Sign in / Sign up

Export Citation Format

Share Document