casein protein
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Author(s):  
Oumayma Bahou ◽  
Naima Belayachi ◽  
Brahim Ismail

The use of bio-based composite as building materials is one of the innovative solutions for dealing with environmental disorders caused by the construction sector. Among these materials we find biocomposites based on vegetable aggregates, which have proven their effectiveness as insulating materials in numerous studies. Despite the growing interest in these materials and the recognition of their performance, their use remains hampered by the lack of implementation rules specific to these materials to move towards a control of their use and their durability affected by the climate and use conditions to which they will be exposed at the level of a building. The objective of this work is to study the compatibility of a protective coating with a block substrate of biocomposites based on cereal straw. It is in fact a mixture of vegetable aggregates (straw), a binder composed of lime and additives also obtained from a renewable source (Ismail et al., 2020). These additives (air-entraining agent, casein protein and a biopolymer) have been added to improve both the fibre-binder interface and the porosity of the binder. The use of these bio-based materials for external or internal thermal insulation of the building requires the application of a coating to protect them against climatic aggressions and to give them an aesthetic appearance. The lime-based coatings, air-entraining agent and casein protein selected for this study have been the subject of an experimental investigation (Brahim Ismail, 2020). In order to assess the compatibility of these coatings with the straw-based insulating material, we were interested in studying the adhesion between the biocomposite and the coating after aging cycles in accordance with the EN 1015-21 standard. The samples (biocomposite + coating) were subjected to two types of aging, one using water and the other using a saline solution of sodium sulphates (Na2SO4). The results of the bond tests after aging showed that the cohesive fracture (at the level of the substrate) is a pattern observed in all the studied systems. In Addition, It has been found that the coating to which a percentage of fine fibers has been added undergoes considerable degradation after aging with salt solution, demonstrating the need of an additional layer of outer coating without fibers in order to ensure the sustainability of the system.


Author(s):  
Chafic Achour ◽  
Naima Belayachi ◽  
Brahim Ismail

In view of the climate emergency and the need for energy transition, the use of materials with low environmental impact based on plant co-products or from recycling is strongly encouraged. Biobased materials have been developed in recent years and have shown interesting performances, particularly for the thermal insulation of buildings. Nevertheless, their use is still hampered by the lack of rules for their use and control of their behaviour in normal or accidental conditions of use such as excess water or fire. In this work, the behaviour of biocomposites based on cereal straw exposed to high temperatures was studied. The objective is to evaluate the effect of this temperature increase on the mechanical strength of the material and its thermal properties using different heating scenarios. The biocomposites considered for this study were developed as part of the PEPITE project funded by the “Region Centre Val de Loire”. They are materials composed of two different binders: lime, and plaster, straw aggregates and additives (air entraining agent, casein protein and biopolymer). In order to simulate fire, two temperatures were chosen for the study 200°C and 210°C, using four different heating rates to study their impact on the behaviour of dry and wet conditions of biocomposites. The purpose of this tests is to examine whether the material retains its insulating properties and its buildability. The results showed that the use of additives had negative effects on the behaviour of the materials with respect to temperature increase. Their use accelerates the degradation and burning of biocomposites faster than for samples without additives. Plaster based composites show a better behavior to high temperature than lime-based composites. Nevertheless, lime composites have a higher strength than plasters. Furthermore, the thermal conductivity of plaster is lower than that of lime. It should be noted that the heating rate has a significant impact on the behaviour of the material, the slower the rate, the more the material is degraded.


2022 ◽  
Author(s):  
Zahran Khaldi ◽  
Mounir Nafti ◽  
Mohamed Tabarek Jilani

Abstract Characteristics and quality aspects of milk from native ovine queue fine de l’Ouest (QFO) and the local goat population were investigated and compared with those of the local Maghrebi camel. A total of 378 individual milk samples were collected from lactating animals reared in the continental oasis region of Tunisia. Samples were analyzed for physical parameters (pH, density, and acidity), chemical composition (dry matter, fat, protein, lactose, casein, ash, and casein-protein ratio), mineral concentrations (Ca, P, Na, and K) and microbiological features (total mesophilic aerobic bacteria (TMAB), total coliform count (TCC), lactic acid bacteria (LAB), sulphite-reducing Clostridium (CSR), yeast and molds (Y/M), Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Salmonella) according to standard methods. The results obtained for milk characteristics revealed noticeable disparities between the three species. The mean values of pH, density, and acidity in milk collected from sheep appeared higher than those in milk collected from goat species. Compared to the camel populations, sheep species produced milk with similar pH but higher density and acidity. Between camel and goat species, pH and acidity were higher in Negga, while the density was similar. For milk composition, the results showed a remarkable variation among all studied species and an obvious superiority of the ovine species over the caprine and camel populations in all the chemical contents being studied, except for the casein-protein ratio, which is in favor of goat species. The milk of QFO sheep, the richest in casein and protein, was expressed with significantly higher levels of calcium and phosphorus than goat and camel milk. Compared to small ruminants, milk from camels is the richest in Na and K. Additionally, more Ca is present in milk from camels than goats. Goat milk, the poorest type of milk in Ca and Na, contains on average more P than camel milk and more K than sheep's milk. The poor bacteriological quality was that of camel milk for all microbial counts. The microbial quality of goat milk was higher than that of ewe milk based on TMAB, TCC, and E. coli counts, while ovine milk was of better quality, referring to LAB, Y/M, and S. aureus values. No significant differences were found for Staphylococcus aureus and Escherichia coli between the examined species. The obtained results highlighted the complete absence of the two dangerous pathogens Salmonella and CSR in all investigated milk samples. The microbiological examination evidenced that the milk of small ruminant species complies with standard criteria required by Tunisian legislation on the hygiene of milk and dairy products. Regarding camel milk, the microbial analysis revealed poor quality that exceeds standard criteria.


Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3146
Author(s):  
Ritika Puri ◽  
Francesca Bot ◽  
Upendra Singh ◽  
James A. O’Mahony

Low temperature microfiltration (MF) is applied in dairy processing to achieve higher protein and microbiological quality ingredients and to support ingredient innovation; however, low temperature reduces hydrophobic interactions between casein proteins and increases the solubility of colloidal calcium phosphate, promoting reversible dissociation of micellar β-casein into the serum phase, and thus into permeate, during MF. Crosslinking of casein proteins using transglutaminase was studied as an approach to reduce the permeation of casein monomers, which typically results in reduced yield of protein in the retentate fraction. Two treatments (a) 5 °C/24 h (TA) and (b) 40 °C/90 min (TB), were applied to the feed before filtration at 5 °C, with a 0.1 µm membrane. Flux was high for TA treatment possibly due to the stabilising effect of transglutaminase on casein micelles. It is likely that formation of isopeptide bonds within and on the surface of micelles results in the micelles being less readily available for protein-protein and protein–membrane interactions, resulting in less resistance to membrane pores and flow passage, thereby conferring higher permeate flux. The results also showed that permeation of casein monomers into the permeate was significantly reduced after both enzymatic treatments as compared to control feed due to the reduced molecular mobility of soluble casein, mainly β-casein, caused by transglutaminase crosslinking.


2021 ◽  
Vol 12 ◽  
Author(s):  
Amanda H. W. Chong ◽  
Ruth E. Mitchell ◽  
Gibran Hemani ◽  
George Davey Smith ◽  
Robert H. Yolken ◽  
...  

The burden of infections on an individual and public health is profound. Many observational studies have shown a link between infections and the pathogenesis of disease; however a greater understanding of the role of host genetics is essential. Children from the longitudinal birth cohort, the Avon Longitudinal Study of Parents and Children, had 14 antibodies measured in plasma at age 7: Alpha-casein protein, beta-casein protein, cytomegalovirus, Epstein-Barr virus, feline herpes virus, Helicobacter pylori, herpes simplex virus 1, influenza virus subtype H1N1, influenza virus subtype H3N2, measles virus, Saccharomyces cerevisiae, Theiler’s virus, Toxoplasma gondii, and SAG1 protein domain, a surface antigen of Toxoplasma gondii measured for greater precision. We performed genome-wide association analyses of antibody levels against these 14 infections (N = 357 – 5010) and identified three genome-wide signals (P < 5×10-8), two associated with measles virus antibodies and one with Toxoplasma gondii antibodies. In an association analysis focused on the human leukocyte antigen (HLA) region of the genome, we further detected 15 HLA alleles at a two-digit resolution and 23 HLA alleles at a four-digit resolution associated with five antibodies, with eight HLA alleles associated with Epstein-Barr virus antibodies showing strong evidence of replication in UK Biobank. We discuss how our findings from antibody levels complement other studies using self-reported phenotypes in understanding the architecture of host genetics related to infections.


Author(s):  
A.S. Meena ◽  
Rajiv Kumar ◽  
S.S. Misra ◽  
Arun Kumar ◽  
Samlesh Kumari ◽  
...  

The objective of the study is impotance of casein protein genetic polymorphism of goat milk. Goat milk is highly digestible and has medicinal properties in human being. Goat milk and its value added dairy products have higher demand in many contries of world. Due to evolution process, much genetic variability has been developed in casein protein genes. This is originatd due to point mutation; addition/deletion and many other factors lead to huge genetic variation in goat casein genes. Because of this goat milk, chemical and biological properties have been affected. Goat milk casein contents decide the cheese making properties as well as nutritional and medicinal values. Goat milk is good alternative source of nutrition in human when people have cow milk problems. Goat milk has humerous inactive bioactive peptides in their casein protein. These have important place for human health and nutrition. In the future, this is great possibility for development of medicinal value functional dairy products from functional bioactive peptides.


2021 ◽  
pp. 22-28
Author(s):  
А.А. Чаицкий ◽  
Н.С. Баранова

Среди сложных белков молока – казеинов – чаще всего встречаются α- и β-казеин. Ген бета-казеина имеет 12 аллельных вариантов, среди которых получили преимущество варианты А1 и А2. При этом, А2 – естественная для человеческого организма разновидность белка бета-казеина, а тип А1 возник в результате природной генетической мутации. Для получения максимального объёма продукции лучшего качества при переориентации производства на молоко А2 необходимо учитывать как основные количественные показатели продуктивности крупного рогатого скота, так и коэффициенты, определяющие эффективность использования коров с точки зрения биологической полноценности продукции, такие как биологической эффективности коров (БЭК), биологической полноценности молока (КБП), кормового коэффициента (FCR) и валовой эффективности использования кормов (GFE). Представлено сравнение количественных и качественных показателей животных разного возраста и групп с учётом степени кровности по улучшающей породе, а также с учётом генотипа по бета-казеину. Впервые проведён анализ реализации биологического потенциала крупного рогатого скота костромской породы с разными аллельными вариантами гена бета-казеина. В ходе исследования установлено, что животные генотипа А2А2 по бета-казеину отличались высоким уровнем БЭК и КБП, а также характеризовались достоверно более высоким уровнем реализации сухого вещества корма в молоко (FCR, GFE), чем у животных А1А2. Так, удои у коров с генотипом А2А2 с кровностью 50% по улучшающей породе за полновозрастную лактацию на 2514 кг больше, чем у животных генотипа А1А2, а коэффициенты БЭК, КБП и FCRвыше на 39,79%, 15,81% и 0,57 кг соответственно. Among the complex proteins of milk – caseins – most often there are α- and β-casein. The beta-casein gene has 12 allelic variants, among which the A1 and A2 variants have gained advantage. At the same time A2 is a natural variety of beta-casein protein for the human body and type A1 arose as a result of a natural genetic mutation. To obtain the maximum volume of production of better quality when reorienting production to milk A2 it is necessary to take into account both the main quantitative indicators of cattle productivity and the coefficients that determine the efficiency of cows use in terms of biological usefulness of products, such as the biological efficiency of cows (BEC), the biological usefulness of milk (BUC), feed coefficient rate (FCR) and gross feed efficiency (GFE). A comparison of quantitative and qualitative indicators of animals of different ages and groups is presented, taking into account the degree of blood relationship by improving breed, as well as taking into account the genotype by beta-casein. For the first time an analysis of the implementation of the biological potential of cattle of the Kostroma breed with different allelic variants of the beta-casein gene was carried out. During the research it was established that animals of a genotype A2A2 on beta casein differed in the BEC and BUC high level and also were characterized by significantly higher level of implementation of dry matter of feed into milk (FCR, GFE), than at animals A1A2. Thus, yields in cows with a genotype A2A2 with a blood relationship of 50% for the improving breed for full-age lactation 2514 kg more than in animals of the genotype A1A2 and the coefficients of BEC, BUC and FCR are higher by 39.79%, 15.81% and 0.57 kg, respectively. Keywords:


2021 ◽  
Author(s):  
Amanda HW Chong ◽  
Ruth E Mitchell ◽  
Gibran Hemani ◽  
George Davey Smith ◽  
Rebecca C Richmond ◽  
...  

The burden of infections on an individual and public health is profound. Many observational studies have shown a link between infections and the pathogenesis of disease; however a greater understanding of the role of host genetics is essential. Children from the longitudinal birth cohort, the Avon Longitudinal Study of Parents and Children, had 14 antibodies measured in plasma at age 7: Alpha-casein protein, beta-casein protein, cytomegalovirus, Epstein-Barr virus, feline herpes virus, Helicobacter pylori, herpes simplex virus 1, influenza virus subtype H1N1, influenza virus subtype H3N2, measles virus, Saccharomyces cerevisiae, Theiler's virus, Toxoplasma gondii, and SAG1 protein domain, a surface antigen of Toxoplasma gondii measured for greater precision. We performed genome-wide association analyses of antibody levels against 14 infections (N = 357-5010) and identified three genome-wide signals (P < 5x10-8), two associated with measles virus antibodies and one with Toxoplasma gondii antibodies. In an association analysis focused on the human leukocyte antigen (HLA) region of the genome, we further detected 15 HLA alleles at a two-digit resolution and 23 HLA alleles at a four-digit resolution associated with five antibodies, with eight HLA alleles associated with Epstein-Barr virus antibodies showing strong evidence of replication in UK Biobank. Our findings provide a useful resource for any future studies using the ALSPAC infection data and contributes to the understanding of the architecture of host genetics related to infections.


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