Changes in casein composition of goats' milk during the course of lactation: physiological inferences and technological implications

1995 ◽  
Vol 62 (3) ◽  
pp. 431-439 ◽  
Author(s):  
Joanna R. Brown ◽  
Andrew J. R. Law ◽  
Christopher H. Knight
Keyword(s):  
Cation Exchange ◽  
Protein Concentration ◽  
Stage Of Lactation ◽  
Sds Page ◽  
Lower Protein ◽  
Kjeldahl Method ◽  
Compositional Changes ◽  
The Individual ◽  
Cheese Production ◽  
Peak Lactation

SummaryFive British Saanen goats were milk sampled during the first 39 weeks of lactation to determine changes in casein composition. Caseins were separated by anion- and cation-exchange FPLC to determine the relative amounts of the individual caseins. Acid, alkaline and SDS-PAGE were used to determine possible genetic polymorphisms and observe any lactational changes. Total casein nitrogen was determined using a micro-Kjeldahl method and this allowed the concentrations of individual caseins to be calculated. The milk of one animal, which had the deduced genotype αs1-CnAB, showed higher concentrations of both total and αs1-casein. The remainder of the group were either heterozygous αs1-CnBE or, more probably, homozygous αs1-CnE and produced milk of a generally lower protein concentration. Both FPLC and PAGE results showed that the relative amounts and concentrations of αs2-casein decreased with stage of lactation, consistent with its susceptibility to proteolysis. The relative amounts of the breakdown products of plasmin attack on β-casein, γ-caseins, were highly negatively correlated with milk yield (r = –0·942, P < 0·001) in the declining phase of lactation, reflecting the gradual involution of the gland at this time. The relative amount of κ-casein increased by ∼ 50% after peak lactation and its concentration almost doubled near the end of lactation. These compositional changes may alter the processing qualities of goats' milk in relation to cheese production.

scholarly journals Quality Attributes of Ultra-High Temperature-Treated Model Beverages Prepared with Faba Bean Protein Concentrates

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1244
Author(s):  
Malik Adil Nawaz ◽  
Tanoj Kumar Singh ◽  
Regine Stockmann ◽  
Hema Jegasothy ◽  
Roman Buckow
Keyword(s):  
Physicochemical Properties ◽  
Faba Bean ◽  
Protein Concentration ◽  
High Concentration ◽  
Molecular Weights ◽  
Oil In Water ◽  
Sds Page ◽  
Lower Protein ◽  
7S Globulin ◽  
Bean Protein

The objective of this research was to develop a model faba bean drink with a high concentration of protein (>4% w/w). The protein molecular weights and frequency for both faba and soy were assessed using SDS-PAGE. Results showed similarities in the protein molecular weight of both faba and soy (mainly 11S globulin ~Glycinin and 7S globulin ~β-conglycinin). Thus, faba can be considered as a potential soy replica in plant-based milk beverages. Oil-in-water emulsions (5–8% w/w available protein) were prepared using faba bean protein concentrate (FPC), 1% sunflower oil, and 0.2% sunflower lecithin. These emulsions were used as model beverages and were further investigated for UHT processibility, stability, and physicochemical properties. The physicochemical properties of emulsions at various processing stages viz., coarse emulsification, homogenisation, and UHT, were measured. An increase in the protein concentration and thermal treatment resulted in an increased oil droplet size, coalescence and flocculation, and protein aggregation. Lower protein concentrations viz., 5–6%, showed greater negative ζ-potential, and thereby, high dispersibility through enhanced electrostatic repulsions than those of higher concentrations (7–8%). Furthermore, an increase in protein concentration and UHT treatment resulted in an increased creaming index. In total, 21 different volatile compounds were detected and quantified, representing different chemical classes, namely alcohols, aldehydes, ketones, esters, furan, and acids. These volatiles have major consequences for the overall flavour chemistry of the model beverage product. Overall, this study showed the potential for application of faba bean as a protein source in UHT-treated legume-based beverages and identified areas for further development.

Purification and Characterization of Lupus Anticoagulant Like Protein from Agkistrodon Halys Brevicaudus Venom

1996 ◽  
Vol 76 (06) ◽  
pp. 0993-0997
Author(s):  
Zhao-Yan Li ◽  
Xiao-Wei Wu ◽  
Tie-Fu Yu ◽  
Eric C-Y Lian
Keyword(s):  
Amino Acid ◽  
Lupus Anticoagulant ◽  
Inhibitory Effect ◽  
Clotting Factor ◽  
Acid Oxidase ◽  
Crude Venom ◽  
Amino Acid Oxidase ◽  
Sds Page ◽  
The Individual ◽  
Reducing Condition

SummaryBy means of CM-Sephadex C-25, DEAE-Sephadex A-50, Sephadex G-200, and Sephadex G-75 chromatographies, a lupus anticoagulant like protein (LALP) from Agkistrodon halys brevicaudus was purified. On SDS-PAGE, the purified LALP had a molecular weight of 25,500 daltons under non-reducing condition and 15,000 daltons under reducing condition. The isoelectric point was pH 5.6. Its N terminal amino acid sequencing revealed a mixture of 2 sequences: DCP(P/S)(D/G)WSSYEGH(C/R)Q(Q/K). It was devoid of phospho-lipaseA, fibrino(geno)lytic, 5′-nucleotidase, L-amino acid oxidase, phosphomonoesterase, phosphodiesterase and thrombin-like activities, which were found in crude venom. In the presence of LALP, PT, aPTT, and dRVVT of human plasma were markedly prolonged and its effects were concentration-dependent but time-independent. The inhibitory effect of LALP on the plasma clotting time was enhanced by decreasing phospholipid concentration in TTI test. The individual clotting factor activity was not affected by LALP when higher dilutions of LALP-plasma mixture were used for assay. Russell’s viper venom time was shortened when high phospholipid confirmatory reagent was used. Therefore, the protein has lupus anticoagulant property.

scholarly journals Determination of organic components of milk as method for evaluating energy status of dairy cows

2010 ◽  
Vol 64 (1-2) ◽  
pp. 21-32
Author(s):  
Djordje Savic ◽  
D. Matarugic ◽  
N. Delic ◽  
D. Kasagic ◽  
M. Stojanovic
Keyword(s):  
Dairy Cows ◽  
Milk Fat ◽  
Protein Concentration ◽  
High Yield ◽  
Energy Status ◽  
Milk Samples ◽  
Organic Components ◽  
Physiological Values ◽  
The Individual

The objective of the investigations described in this work was to determine the energy status and to make recommendations for correcting the cow diet at a farm of high-yield dairy cows, on the grounds of values for the concentration of organic components of milk and their ratios in individual milk samples. A total of 147 cows were examined, including 97 in the first and 50 in the second lactation. Average concentrations of milk fat and urea were within the physiological values. Namely, the milk fat concentration in cows in the first lactation was 38.88?5.07 g/l, and it was 36.47?4.82 g/l in cows in the second lactation, while the urea concentration in cows in the first lactation 3.16?0.58 mmol/l and it was 3.72?0.64 mmol/l in cows in the second lactation. The protein concentration in both groups of cows was below the physiological values, being 30.33?2.35 g/l in cows in the first lactation and 30.17?2.27 g/l in cows in the second lactation. Based on the ratio of urea and protein concentrations, as well as of fat and proteins in the individual milk samples, it was concluded that in most examined cows, both in those in the first and those in the second lactation, there is a deficit of energy, along with a deficit or relative surplus of proteins. On the grounds of the obtained results, recommendations were given for correcting the feed rations in the coming period. .

Peculiarities of extraction of β-lactoglobuline in protein mineral concentrates at electroactivation of whey

2020 ◽  
Vol 2 (1) ◽  
pp. 52-68
Author(s):  
Mircea BOLOGA ◽  
Elvira VRABIE ◽  
Irina PALADII ◽  
Olga ILIASENCO ◽  
Tatiana STEPURINA ◽  
...  
Keyword(s):  
Protein Content ◽  
Whey Proteins ◽  
Sodium Dodecyl ◽  
Total Protein Content ◽  
Treatment Regimens ◽  
Sds Page ◽  
Different Types ◽  
Lower Protein ◽  
Β Lactoglobulin ◽  
Excellent Source

Introduction. Whey is a by-product and an excellent source of proteins that is rather aggressive due to a large amount of organic substances it contains. The electro-activation of whey applied in the experiments is a wasteless method that allows the va-lorification of all whey components. β-lactoglobulin (β-Lg) makes up 50% of the whey proteins and 12% of the total protein content in milk. Material and methods. The recovery of β-Lg in protein-mineral concentrates (PMC) by electro-activation processing of different types of whey with different initial protein content was investigated in seven configurations. The recovery of protein fractions in the PMCs were analyzed via electrophoresis with sodium dodecyl sulfate (SDS-PAGE) and 15% non-denaturing polyacrylamide gel (PAAG).      Results. Whey electro-fractionation and the obtaining of PMCs with predetermined protein content, namely of β-Lg, were studied on three whey types, processed at different treatment regimens and in seven configurations. The proper management of electroactivation by varying the treatment regimens will allow the electro-fractionation of different types of dairy by-products. Conclusions. The maximum amount of β-Lg recovered in PMCs on electroactivation is  66-71% depending on the processed whey and on the treatment regimens. Obviously, the extraction of β-Lg from initially lower protein content shows a higher recovery degree of β-Lg. The registered temperatures allows formation of PMCs without thermal denaturation.

scholarly journals Preparation and Characterization of Whey Protein-Based Polymers Produced from Residual Dairy Streams

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 722 ◽  
Author(s):  
Chalermthai ◽  
Chan ◽  
Bastidas-Oyanedel ◽  
Taher ◽  
Olsen ◽  
...  
Keyword(s):  
Whey Protein ◽  
Protein Concentration ◽  
Milk Proteins ◽  
Protein Isolate ◽  
Whey Protein Concentrate ◽  
Polymer Sheets ◽  
Lower Protein ◽  
Poly Ethylene ◽  
The One

The wide use of non-biodegradable, petroleum-based plastics raises important environmental concerns, which urges finding alternatives. In this study, an alternative way to produce polymers from a renewable source—milk proteins—was investigated with the aim of replacing polyethylene. Whey protein can be obtained from whey residual, which is a by-product in the cheese-making process. Two different sources of whey protein were tested: Whey protein isolate (WPI) containing 91% protein concentration and whey protein concentrate (WPC) containing 77% protein concentration. These were methacrylated, followed by free radical polymerization with co-polymer poly(ethylene glycol) methyl ether methacrylate (PEGMA) to obtain polymer sheets. Different protein concentrations in water (11–14 w/v%), at two protein/PEGMA mass-ratios, 20:80 and 30:70, were tested. The polymers made from WPI and WPC at a higher protein/PEGMA ratio of 30:70 had significantly better tensile strength than the one with lower protein content, by about 1–2 MPa (the best 30:70 sample exhibited 3.8 ± 0.2 MPa and the best 20:80 sample exhibited 1.9 ± 0.4 MPa). This indicates that the ratio between the hard (protein) and soft (copolymer PEGMA) domains induce significant changes to the tensile strengths of the polymer sheets. Thermally, the WPI-based polymer samples are stable up to 277.8 ± 6.2 °C and the WPC-based samples are stable up to 273.0 ± 3.4 °C.

Production responses by cows to grass-clover swards maintained at different heights with or without concentrate supplementation

1993 ◽  
Vol 1993 ◽  
pp. 99-99
Author(s):  
C. A. Huckle ◽  
A. J. Rook ◽  
R. J. Wilkins
Keyword(s):  
Milk Yield ◽  
Present Experiment ◽  
Protein Concentration ◽  
Fertilizer Nitrogen ◽  
Concentrate Supplementation ◽  
Sward Height ◽  
Holstein Friesian ◽  
Lower Protein ◽  
Mixed Grass ◽  
Friesian Cows

Clements, Huckle and Wilkins (1991) reported that milk yield did not differ significantly between cows grazing grass-clover swards with compressed sward heights maintained at either 4.5 or 6 cm in early season. However, cows grazing the shorter sward produced milk with a lower protein concentration. The feeding of 4 kg concentrates/day resulted in an increase in milk yield at both sward heights but there was no effect on milk constituent concentrations. The present experiment was designed to investigate the effect of a wider range of sward heights and their interaction with concentrate supplementation.Forty eight, multiparous, Holstein Friesian cows with a mean calving date of 21 March were continuously stocked on mixed grass-clover swards. The cows were blocked by calving date, parity and milk yield and randomly allocated to one of six treatments, 0 (U) or 4 kg concentrate supplementation (S) with swards maintained at 4, 6 or 8 cm compressed sward height. Sward heights were maintained by adjusting the grazed area. The swards were permanent pastures which had received no fertilizer nitrogen.

Serum glycoproteins in growing pups

1962 ◽  
Vol 203 (1) ◽  
pp. 119-121 ◽  
Author(s):  
Otakar V. Sirek ◽  
Anna Sirek
Keyword(s):  
Weight Gain ◽  
Sialic Acid ◽  
Serum Protein ◽  
Total Protein ◽  
Protein Concentration ◽  
Total Serum Protein ◽  
Total Serum ◽  
Albumin Fraction ◽  
The Individual ◽  
Serum Protein Concentration

Total protein-bound hexose, hexosamine, and sialic acid were determined in sera of six littermate mongrel pups at monthly intervals from the 4th day after birth up to the age of 7 months. The concentration of the individual constituents fluctuated considerably from month to month, but the values showed neither a definite trend nor a relationship to weight gain. When the carbohydrate moiety was expressed as percentage of total serum protein concentration, the values were high in newborn pups and diminished after the 1st month of life. This was due to a rise in the concentration of total serum protein, brought about by an increase of the albumin fraction which is low in carbohydrate.

Chemical composition of milk from a herd of Norwegian goats

1986 ◽  
Vol 53 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Johanne Brendehaug ◽  
Roger K. Abrahamsen
Keyword(s):  
Chemical Composition ◽  
Protein Concentration ◽  
Lactation Period ◽  
Stage Of Lactation ◽  
Intensity Score ◽  
Lactose Concentration ◽  
Mountain Pasture ◽  
The University ◽  
Β Lactoglobulin ◽  
Total P

SUMMARYThe chemical composition of Norwegian bulk collected goats' milk from the University herd was analysed during one lactation period (30 weeks, 20 samples during 1983). There was considerable variation in chemical composition during the year. Fat content decreased over the first 4 months of lactation and increased during the mountain pasture period. Protein concentration decreased during the first 4 months, and then increased until the end of lactation. Lactose concentration decreased throughout lactation. Casein nitrogen (casein N) was highest at mid lactation and lowest at the beginning and end of lactation. β-Lactoglobulin N showed the opposite trend. Citrate content showed a significantly quadratic decrease and total ash content an increase with advancing lactation. Mutual significant correlations between total P, K, Na, Ca and Mg were calculated, and all increased throughout lactation. There was significant positive correlation between concentrations of individual medium-chain fatty acids and stage of lactation. They remained more or less constant during the first part of the lactation, decreased to minima when the goats were on pasture, and increased during the last phase of lactation. Concentration of C16fatty acid was negatively correlated with C18and C18:1. Goat flavour intensity score and quality flavour score were highest at mid lactation, and positively correlated with the acid degree value.

PROTEIN LEVELS IN DEVELOPING AND MATURE PEA SEEDS

1975 ◽  
Vol 55 (1) ◽  
pp. 185-190 ◽  
Author(s):  
S. PANDEY ◽  
E. T. GRITTON
Keyword(s):  
Correlation Coefficient ◽  
Protein Concentration ◽  
Dry Weight ◽  
Protein Determination ◽  
Protein Levels ◽  
Dye Binding ◽  
Percent Protein ◽  
Kjeldahl Method ◽  
Pea Seeds ◽  
Pea Seed

Nine cultivars of peas (Pisum sativum L.) were grown in 1971 and 1972 to study the changes in percent crude protein levels during maturation. Percent protein was found to vary with years, cultivars, and stages of maturity. The year × cultivar, year × maturity, and cultivar × maturity interactions were also important. On a dry weight basis, pea protein concentration as determined by the Kjeldahl method showed a decrease with increasing pea seed maturity through the canning stage. The correlation coefficient between the Kjeldahl and Udy dye-binding methods of protein determination was 0.86 at the mature seed stage, and negligible at the canning stage. There was a highly significant correlation (r = 0.91) between protein concentration at the canning and mature stages of seeds (Kjeldahl method). The correlation coefficient between protein values obtained by the dye-binding method of Ashworth et al. and the Kjeldahl method was lower than between the Kjeldahl and Udy methods.

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