bluuebunny/crossref_metadata_2025_split huggingface dataset:
577. The chemical composition of the colostrum and milk of the sow
Authors: Perrin Dawn R. 
Published: June 2009

1. Detailed analyses for the major constituents of the colostrum and milk of four sows are reported. In all cases the initial colostrum is characterized by a very high protein, and a low lactose and fat content. As with the colostrum of other species, the transition to milk occurs progressively during the course of about 4–7 days.2. Analyses for mineral constituents, calcium, magnesium, phosphorus and chloride are reported on a range of samples covering the whole lactation of two sows. In contrast to the ash of the colostrum of most other species, the ash of the colostrum of the sow is lower than that of normal milk, and as lactation is established there is a rise in the total ash content, and in its main constituents, calcium and phosphorus.
597. Microscopic appearance of fat on the milk surface as affected by mechanical disturbance of the surface
Authors: King N. 
Published: June 2009

The freshly formed surface of milk or cream obtained by overflowing in a double funnel is nearly free from microscopically visible fat.When this surface is disturbed, either by repeated touching with a platinum ring or by allowing air bubbles to burst there, the fat globules and clumps are brought on to the surface, appearing there as such, or being stretched to lenses, or being spread as patches.The amount of fat brought onto the surface increases with the extent of disturbance, viz. the number of touches with a platinum ring or the number of air bubbles burst, and with the fat percentage of cream.Ageing of milk or cream slightly promotes the transfer of fat globules onto the surface.At 30° C. the bursting of about 10–15 air bubbles is enough to cover the milk surface in the overflow outfit with an almost continuous fat blanket, while at 20° C. the globules and clumps occur separately.The fat globules rendered hydrophobic by mechanical treatment of the milk surface, as well as the fat patches on the surface, are likely to be accessible to the action of lipase. This may explain the agitation activation of lipolysis in raw milk during certain stages in machine milking and during transportation.
614. Variations in the chemical composition of milk with particular reference to the solids-not-fat: II. The effect of heredity
Authors: Robertson Alan , Waite R. , White J. C. D. 
Published: June 2009

1. A statistical analysis has been made of lactation records from 500 dam-daughter pairs of the Ayrshire breed. Measurements were taken of milk yield, fat, S.N.F., crude protein, casein and lactose.2. A correction was made for the age of the cow. This contributed a substantial fraction of the total variation for milk yield, S.N.F. and lactose contents. Month of calving had a trivial effect on the lactation average for the characters when compared with the individual variation between cows.3. After correction for age, the variation between lactations was highest for fat content (standard deviation 0·35%) and slightly less for S.N.F. (0·26%).4. The heritability was estimated by the dam-daughter correlation within herds. Values in the neighbourhood of 0·5 were obtained for S.N.F., crude protein, casein and ‘ash’ (determined by difference), about 0·35 for fat and lactose, 0·25 for milk yield and 0·13 for non-casein nitrogen.5. The phenotypic correlations between yield and lactose were positive for both dam and daughter groups. The correlations between yield and the other constituents were more negative in the daughter group than in the dam group. The correlation between yield and S.N.F. was, in fact, positive in the latter. The correlation between fat and S.N.F. averaged 0·36, being derived mainly from the correlation between fat and casein (0·43), though that with lactose was also positive (0·13).6. The variation in S.N.F. was mostly determined by that in casein (r=0·85). There was a positive correlation between lactose and casein (0·24), and a negative one between lactose and non-casein nitrogen (–0·41). Lactose was negatively correlated with ‘ash’ (–0·31). ‘Ash’ was positively correlated with non-casein nitrogen (0·23)7. There were positive and significant genetic correlations between casein and both fat and lactose, and that between the last two was almost significant.8. No significant genetic correlations were found between yield and the chemical constituents, although figures of practical importance may exist which did not reach significance in an experiment of this size.9. The practical significance of these results is discussed. It is concluded that selection for yield alone is not likely to cause any great decline in S.N.F. content of the milk, and that this could probably be held in check by paying some attention to the fat content of the milk.
662. The comparative efficiency of some methods of estimating the live weight of dairy cows
Authors: Burt A. W. A. 
Published: June 2009

1. Data from 133 Dairy Shorthorn cows in three herds have been used in a study of various methods of estimating live weight from body measurements based on logarithmic relationships and indices of body volume.2. Regression equations are presented relating live weight to several combinations of chest girth, paunch girth, length of body and age.3. The most satisfactory estimate of weight from a single body measurement was given by the regression of log live weight upon log chest girth.4. Appreciable increases in the efficiency of estimation were obtained by including log paunch girth or log length of body as second variates in the regression, and a further increase by including them together.5. Indices of body volume using chest girth and length of body, or chest girth, paunch girth and length of body gave good estimates of live weight, and there was very little difference in efficiency of estimation from that when the three measurements were used in a logarithmic regression.6. The effects of the addition of age to regressions involving chest girth, paunch girth and length of body were slight but statistically significant.7. The most satisfactory practical method of estimation using the three body measurements is given by the equationLive weight (lb.)=0·000935LB(CG2+PG2+ PG.CG)+57 (all measurements in inches).8. Comparison of fiducial limits showed that these covered a range 4–5 times as great for live weights estimated from chest girth than for live weights determined directly, and that the inclusion of length of body and paunch girth reduced this range by 25–30%.
664. The effect of thyrotropin on milk yield and heart rate of the goat
Authors: Owen E. C. , Darroch R. A. 
Published: June 2009

1. The effects of thyrotropin on milk yields and heart rates of goats were compared with the effects of growth hormone.2. As expected, the milk yields from the goats which received growth hormone were markedly increased.3. Thyrotropin caused increases of heart rate in two goats in one of which a large increase of milk yield was also produced.
668. The influence of cream rising upon the activity of bacteria in heat-treated milk
Authors: Wright R. C. , Tramer J. 
Published: June 2009

1. Criticism is directed towards the method of assessing cheese-starter activities, whereby pasteurized milk (vat milk) is inoculated with starter and its activity judged by the acidity developed after 6 hr. at 30° C.2. It has been found that certain starters are slow when subjected to this laboratory test, owing to the fact that they are agglutinated in such milk and consequently carried up into the cream layer, thus producing a lower acidity in the milk.3. Whilst such starters show higher activity in homogenized or autoclaved milk, it is suggested that starter activity tests should be carried out in the presence of agar in order to prevent cream rising and thus simulate conditions in the cheese vat. Agar is preferred to rennet for this purpose.4. It is emphasized that such apparently slow starters are not slow when used in the cheese vat.5. Evidence is given that keeping-quality tests on pasteurized and homogenized milks involving storage of the milk are also affected by the same factors, which may result in homogenized milk having a poorer keeping quality than pasteurized milk.
670. Further studies of the effect of processing on some vitamins of the B complex in milk
Authors: Chapman Helen R. , Ford J. E. , Kon S. K. , Thompson S. Y. , Rowland S. J. , Crossley E. L. , Rothwell J. 
Published: June 2009

1. Pasteurized, sterilized, U.H.T. treated, U.H.T. treated-sterilized, evaporated, sweetened condensed, roller- and spray-dried milks were prepared simultaneously from one bulk of raw whole milk.2. The preparation of any of these products entailed little or no apparent loss of riboflavin, pantothenic acid, nicotinic acid, vitamin B6or biotin.3. Thiamine was destroyed in amounts ranging from less than 10% to 40–50%, increasing with the severity of the heat treatment.4. Prolonged high temperature used in the sterilization of evaporated milk and of in-bottle sterilized milk caused nearly complete loss of vitamin B12.5. The new process of sterilization by the U.H.T. treatment alone when it was not followed by the, so far necessary, in-bottle sterilization caused little more loss of the vitamins measured than did H.T.S.T. pasteurization.
694. Observations on the cell count and solids-not-fat content of cows' milk
Authors: McKenzie D. A. , Booker Elizabeth M. K. , Moore W. 
Published: June 2009

Tests over a 2-year period of milk from an Ayrshire herd showed that there was a greater incidence of low S.N.F. samples from milk with a high cell count compared with samples from that of a low cell count.While a wide variation in S.N.F. was found at any particular cell count level, there was a broad correlation between cell count and S.N.F., the average S.N.F. for cows in the same lactation being lower for those animals with high cell counts in the milk.It is suggested that a cell count > 100,000/ml. in bulk milk should be regarded as significant.Bacteriological examination of the high cell count samples showed that in a large proportion of cases no typical mastitis-producing organism could be isolated.The authors wish to thank their colleagues in the Bacteriology, Chemistry and Veterinary Investigation Departments for assistance in this work.
709. The calorific value of milk of different species
Authors: Perrin Dawn R. 
Published: June 2009

The gross energy content of the milk of the cow, sow, ewe, goat and of human milk has been determined by bomb calorimeter, and compared with results obtained using conversion factors and chemical analysis.Correction for non-protein nitrogen content led to values agreeing within 0·5–1·0% for the milk of all species. For human colostrum other factors may be involved, and a closer estimate of gross energy value of human milk was obtained by treating all nitrogenous constituents as being protein.
Factors influencing the lactic acid-producing properties of streptococci used in the manufacture of Cheddar cheese: II. Observations relating susceptibility with insusceptibility
Authors: Jago G. R. , Swinbourne M. F. 
Published: June 2009

1. Continuous growth of lactic acid streptococci in autoclaved milk allows strains, originally insusceptible, to become susceptible to inhibition by raw milk.2. Variants of the original organisms, the growth of which is inhibited in raw milk but not in autoclaved milk, appear to predominate in strains maintained in autoclaved milk.3. The time required to allow these changes to occur in autoclaved milk varies with the strains used.
The colloidal phosphate of milk: II. Influence of citrate
Authors: Pyne G. T. , McGann T. C. A. 
Published: June 2009

SummaryA new method for determining the composition of the colloidal phosphate of milk has been developed, based on analysis of milk free from colloidal phosphate. Preparation of this material is described.The results suggest that the so-called colloidal calcium phosphate of milk should be more properly described as a colloidal phosphate—citrate.This colloidal phosphate—citrate shows considerable analytical resemblance to the precipitate formed on neutralizing acidified milk serum. Both can be represented approximately by the empirical formula of a hypothetical citrate apatite.
A note on the availability of the calcium of milk submitted to ultra-high-temperature sterilization with or without subsequent in-bottle sterilization
Authors: Henry Kathleen M. , Toothill Joyce 
Published: June 2009

SummaryThe effect of ultra-high-temperature (U.H.T.) sterilization and of subsequent in-bottle sterilization on the availability of milk calcium has been studied in experiments with rats. The heated milks and the raw milk from which they were prepared were freeze-dried and added to a diet low in Ca so that the resulting diets contained some 0·11% Ca and 0·42% P.Ca retention by groups of six litter-mate male weanling rats was 98·4, 98·4 and 98·5% respectively from diets containing raw milk, U.H.T.-treated milk and milk treated by U.H.T. followed by in-bottle sterilization. It is clear that these processes did not affect the availability of milk Ca.
The use of ultrafiltration and dialysis in isolating the aqueous phase of milk and in determining the partition of milk constituents between the aqueous and disperse phases
Authors: Davies D. T. , White J. C. D. 
Published: June 2009

SummaryA description is given of various methods for the ultrafiltration and dialysis of milk and of the composition of the sera obtained. Ultrafiltrate prepared by the procedure recommended is reasonably representative of the aqueous phase of milk, but its content of lactose and citric acid, and consequently also of calcium, is determined to a slight degree by the sieving phenomenon known to occur often in ultrafiltration. The composition of diffusate obtained from milk at 20°C is not thought to be controlled to any significant extent by a Donnan effect and is regarded as identical with that of the aqueous phase of milk. The lactose content of diffusate suggests that about 2% of the water in milk is bound to protein, and allowance should be made for this when calculating the concentrations of the soluble constituents in milk from the composition of diffusate. Diffusate prepared from milk at 3°C contains slightly more total calcium, ionized calcium and phosphorus than diffusate prepared at 20°C. These differences are attributed to a change in the partition of calcium and phosphorus between the disperse and aqueous phases at the lower temperature, an explanation that is supported by the reversibility of the change. The composition of diffusate prepared by the procedure recommended indicates that about 5% of the sodium and about 6% of the potassium and citric acid in milk are in the disperse phase.
The oxidation-reduction potential of sterilized milk
Authors: Higginbottom Constance , Taylor Margaret M. 
Published: June 2009

SummaryFor milk sterilized under partial vacuum in closed bottles the oxidation-reduction potential measured under nitrogen was markedly lower (—280 to —300 mV) than that of milk heated in bottles open to the air, measurements being made in air (+10 to —30 mV).TheEh(under nitrogen) of commercial sterilized milk and of ultra-high-temperature short-time heated milk was in the range —200 to —300 mV and of the same order as that obtained in the laboratory for deaerated milk sterilized in closed bottles.
Lactobacilli in milk used for commercial cheesemaking
Authors: Sharpe M. Elisabeth , Mattick A. T. R. 
Published: June 2009

SummaryThe numbers of lactobacilli, including pediococci and some leuconostocs, in raw and heat treated milks at twenty-six cheese factories in different parts of the country were determined over a period of 12 months, by plating on acetate agar. Counts in the raw milks varied from < 1 to > 100000/ml, but were usually within the range 100 to 10000/ml. Widely different times and temperatures of heat treatment were in use at the different creameries, some of which destroyed most of the lactobacilli present, whilst others had less effect. Post heat treatment re-infection of the milk in the vat with lactobacilli usually occurred.
Microscopic observations on the dispersibility of milk powder particles in some organic liquids
Authors: King N. , Shimmin P. D. 
Published: June 2009

SummaryBy the application of different water-soluble organic compounds and some protein-denaturing reagents dissolved therein, several stages in the dispersion of milk powder particles can be distinguished. The particles first swell, and agglomeration or coalescence follows. However, no dispersion necessarily takes place at this stage, as indicated by the absence of casein micelles in the surrounding liquid. In the initial stage of self-dispersion, ‘dispersion streams’ emanating from the powder particles may be observed. In certain cases, particularly with spray dried skim-milk, thin membranes may be perceived around the swollen and dispersing powder particles. The dispersibility is dependent upon the fat content of the powder and the method of manufacture.With propylene glycol and butylene glycol no dispersion of powder particles took place. However, the hydrogen-bond breaking reagents, urea, guanidine hydrochloride and sodium salicylate, as well as an anionic detergent, sodium dodecyl sulphate dissolved in propylene glycol, caused dispersion of powder particles, particularly in spray dried powders. The limited dispersibility of roller dried powders in water could be greatly enhanced by the same reagents.With water-insoluble liquids enough moisture penetrated through the medium to cause the crystallization of lactose in powder particles.
The reactivation of milk alkaline phosphatase after heat treatment
Authors: Lyster R. L. J. , Aschaffenburg R. 
Published: June 2009

SummaryA simple system was developed, consisting of a solution of β-glycerophosphate, β-lactoglobulin and magnesium ions, in which alkaline phosphatase isolated from milk became strongly reactivated following heat treatment for 45 sec in boiling water. From 10 to 30% of the original enzyme activity reappeared after incubation at 37°C. Variations in the components of the system, and factors affecting it, were studied. Salts of Hg, Zn and Cd inhibited reactivation at low concentrations.Milk which, after the same heat treatment, became reactivated to a much smaller extent (about 1%), was found to contain a dialysable, heat labile inhibitor whose presence is thought to be largely responsible for the low level of reactivation, though other factors, e.g. the suboptimal concentration of phosphate esters must be considered as contributory causes.Milk contains also a non-dialysable, heat stable activator of the reactivation process, capable of replacing β-lactoglobulin in the simple system and active at very low concentration, e.g. 0·2% (v/v).
A quantitative study of changes in dried skim-milk and lactose-casein in the ‘dry’ state during storage
Authors: Richards E. L. 
Published: June 2009

SummaryChanges in dried skim-milk and in lactose-casein in the ‘dry’ state during storage at 45 °C and 75% r.h. have been studied by the determination of free amino-N, ε-amino groups of lysine, galactose, lactulose, tagatose and 1-amino-1-deoxy-2-ketoses, and by the measurement of changes in colour, solubility and ferricyanide reducing power.In both systems there is initially a close relationship between the formation of 1-amino-1-deoxy-2-ketoses and the decrease in free amino-N. This conforms with an Amadori rearrangement of an initially formed lactose-protein complex. Change in colour is rapid only after there has been a rapid formation of 1-amino-1-deoxy-2-ketoses and a corresponding decrease in free amino-N. This conforms with browning being due to a breakdown of the Amadori rearranged complex.It is postulated that galactose and tagatose may be formed by both the basecatalysed degradation of lactose and also by breakdown of the Amadori rearranged lactose-protein complex. Lactulose is postulated to be formed only by base-catalysed degradation of lactose.
Occurrence of variants sensitive to agglutinins and to lactoperoxidase in a lactenin-resistant strain ofStreptococcus lactis
Authors: Auclair J. , Vassal Yvonne 
Published: June 2009

SummaryA strain ofStreptococcus lactis, C10, known to be resistant to lactenins, was found to be composed of 47% resistant cells, 10% cells sensitive to lactoperoxidase and 43% cells sensitive to both agglutinins and lactoperoxidase. By subculturing a strain composed of 100% resistant cells in different conditions of medium, temperature and incubation time, it was possible to obtain cultures composed of resistant and sensitive cells in various proportions. These findings help to explain how, after numerous subculturings in autoclaved milk, a resistant strain may become sensitive to the natural inhibitors of milk.
The detection of volatile components of milk by gas-liquid chromatography and its possible application in assessing keeping quality and flavour
Authors: Mabbitt L. A. , McKinnon Gillian 
Published: June 2009

SummaryThe volatile components of milk have been isolated in a form suitable for application to a gas chromatograph, using the simple rapid technique of entraining them in a gas stream and trapping in a syringe barrel cooled in liquid nitrogen.The souring process in milk which occurred during incubation at 22 °C was followed by observing the differences between chromatograms of samples taken at intervals. Onset of souring was detected with a sensitivity similar to that obtained by measurement of pH, but the chromatographic method had the advantage of being independent of the initial pH and buffering power of the milk.With suitable chromatographic apparatus the total analysis time including the preparation of the sample could be about 3 min. Modifications are discussed which would increase the speed of analysis, and thus form a basis for the development of a practical method of assessing the odour of milk before processing.
n-Alkan-1-ols in oxidized butter
Authors: Stark W. , Forss D. A. 
Published: June 2009

SummaryThe C1,2,5–8 n-alkan-1-ols were identified from oxidized butter prepared from cream treated with cupric chloride and ascorbic acid. The six n-alkan-1-ols occurred in approximately equimolar amounts and in concentrations of approximately 1 μmole/kg, the same order of magnitude as that of the C6–9 n-alkanals. The amounts increased rapidly during the first 4 weeks of storage, but only slowly during the succeeding 4–20 weeks. Only insignificant amounts of the C3–8 alkanols formed in the untreated samples. It is suggested that C1–8 alkanols are formed by the oxidation of unsaturated fatty acids according to the theory of Farmer, Koch & Sutton (1943) from primary alkoxy radicals resulting from the decomposition of lipid hydroperoxides.
The stability of milk protein to heat: II. Effect on heat stability of ageing milk at different temperatures
Authors: Davies D. T. , White J. C. D. 
Published: June 2009

SummaryThe effect on heat stability as measured by coagulation time, of storing separated milk at 20, 4 and −20 °C has been examined. Milk with a good coagulation (initial clots large) could be stored for at least 30 h at 20 °C, 1 week at 4 °C and 1 month at −20 °C with no significant change in coagulation time. With milks giving a poor coagulation (initial clots small), a common occurrence during storage at 20 °C was a marked progressive increase in coagulation time; the rate of increase was reduced by storage at 4 °C. The increase in coagulation time of these labile milks, which are usually obtained from cows with subclinical mastitis, may occur to the same extent in darkness as in light, may be enhanced by exposure to light or may occur only when the milk is exposed to light. From these results, together with others reported by Davies & White (1966) and White & Davies (1966) it is concluded that, in studying heat stability, milks giving a good coagulation should be regarded as in a different class from milks giving a poor coagulation.