bluuebunny/crossref_metadata_2025_split huggingface dataset:
351. The estimation of copper and iron in cream, butter and dry butterfat
Authors: McDowell A. K. R. 
Published: June 2009

1. A method is described based on wet-ashing in micro-Kjeldahl flasks for the accurate estimation of iron and copper in 10g. samples of butter or dry butterfat or in 5g. samples of cream.2. An acid extraction method for the routine estimation of copper and iron in dry butterfat is described. This method is shown to give a reliable estimate of the quantities of the metals present.3. A simplified method for the estimation of iron in cream and butter is described in which the iron is first freed from its protein complex by the addition of thioglycollic acid. Copper is estimated by a similar method, but without the addition of a reducing agent. Both methods give results agreeing reasonably well with the wet-ashing method and are suitable for the routine estimation of these metals in cream and butter.
355. Cheese starter ‘recovery’ after attack by bacteriophage. (Strain dominance in multiplestrain starters)
Authors: Nichols Agnes A. , Ineson P. June 
Published: June 2009

1. Three experimental starters were prepared by mixing three unrelated phaging strains ofStr. cremoris. The corresponding phages were used to determine whether changes occurred in the relative numbers of these strains on daily subculture.The results indicated that (a) in a multiple-strain starter one strain may overgrow the others and become responsible for most of the acid produced by that starter about 1 week after mixing the strains. The starter may soon become virtually a single-strain starter. (b) Even during the day's making, one of three strains, mixed together at the time of introduction into the cheese vat, may partly overgrow the other two strains, (c) The dominance of a particular strain in a starter mixture may be affected by the temperature of propagation.
359. A note on the effect of the temperature of pre-heating of spray-dried whole milk on the biological value of its proteins
Authors: Henry K. M. , Kon S. K. 
Published: June 2009

Previous work from this laboratory has indicated that the biological value of the proteins of milk is not affected by pasteurization (1), by evaporation and condensation (2) or by spray or roller-drying (3). Sterilization (4), on the other hand, caused a statistically significant decrease of 6% in the biological value; with this process heating at a high temperature is more prolonged than in the other forms of heat treatment.It was of interest to find out whether the difference of 30°F. in the pre-heating temperature of the spray-dried whole milks described by White, Smith & Lea (5) in the preceding paper would have any effect on the biological value of the proteins.
405. The composition of the soluble and insoluble portions of reconstituted milk powders
Authors: Waite R. , White J. C. D. 
Published: June 2009

1. The mode of distribution of the constituents of centrifuged reconstituted whole-milk powder manufactured by different processes has been determined at 20 and 50° C.2. Where considerable ‘insolubility’ exists, protein is carried into the fat layer and fat into the sediment layer in quantities directly related to the degree of ‘insolubility’. The fat in the sediment of roller powders appears to be associated almost entirely with the protein which remains insoluble at 50° C.3. The sediments from reconstituted whole- and separated-milk powders made by different manufacturing processes have been obtained in bulk by vigorous centrifuging (14,500 ×g). Analysis of these sediments reveals considerable similarity between them, and it is concluded that a well-washed sediment would consist mainly of denatured calcium caseinate together with calcium and phosphorus in the same proportions as in normal tricalcium phosphate, Ca3(PO4)2, the calcium caseinate and most of the calcium phosphate probably being in the form of a casein-phosphate complex.4. The accuracy of some published methods of measuring milk powder solubility has been considered, and the inaccuracies arising from the non-homogeneity of the fat and sediment layers are stressed.
Keeping quality and raw-milk grading: I. Dye tests as measures of the keeping quality of milk
Authors: Mattick A. T. R. , Rowlands A. , Barkworth H. , Hosking Zena , Kempthorne O. 
Published: June 2009

The experiments analysed in this series of papers were undertaken as the result of a discussion on methods of measuring the keeping quality of milk, at a Conference of Advisory Bacteriologists of the Ministry of Agriculture and Fisheries.Owing to the disturbance and difficulty following the outbreak of war and the dislocation of handling and distribution, a serious decline in the keeping quality of raw-milk supplies was threatened.
The phosphatase test of Aschaffenburg and Mullen: Use of permanent colour standards and comparison with the Kay-Graham test
Authors: Tramer J. , Wight J. 
Published: June 2009

1. A method has been developed for measuring the intensity of colour produced in the Aschaffenburg & Mullen phosphatase test in which use is made of permanent colour standards.2. Using this method, the relationship between this phosphatase technique and the official Kay-Graham test has been investigated.3. The limiting standards corresponding to 2.3 Lovibond Blue Units in the KayGraham test have been established for the 30 min. and 2 hr. procedures of Aschaffenburg & Mullen.4. The advantages of the improved technique of the Aschaffenburg & Mullen test are discussed.
432. The condition and average live and carcass weights of ‘wastage’ animals in west Wales (1943–46)
Authors: Phillips R. 
Published: June 2009

1. The body size and grading of the wastage cattle have been described. It was found that the average wastage cow is relatively small in size with an average live weight of 1100 lb. or 9¾ cwt. The condition was also disappointingly poor since over one-half of the total wastage cows are in grade C or are ungraded.2. The seasonality of the sales shows an autumn glut, which appears to increase as the grade or condition deteriorates.3. The annual variations in body size during the 4 years are very slight, which seems to indicate that under present circumstances the region can only maintain cows of this size.4. It was shown that the region can be subdivided into four parts in which the average body size for each section falls into one of four well-defined ranges of weight.
459. The deterioration of milking rubbers: II. The effect of fat
Authors: Gardner E. R. , Berridge N. J. 
Published: June 2009

The presence of fat in milking machine liners is probably the chief cause of their deterioration. The primary effect of the fat is to cause softening and swelling of the rubber and greasiness of its surface; the secondary effect is to increase greatly the rate of oxidation. The primary effect may be reversed by removing the fat by solvent extraction or prolonged treatment with cold caustic soda; the secondary effect is irreversible.Although the fat is derived chiefly from milk, rubber absorbs fat only slowly from liquid milk. Thus it is likely that most of the absorption is from milk residues remaining on liners between milkings, under conditions which favour the breaking of the natural emulsion. Such conditions would include drying, souring or other bacterial activity, and the presence of traces of detergents which act as protein denaturing agents.Thus, if the widely recommended technique of cold or tepid rinsing is properly practised (8), fat absorption is kept to a minimum, and the life of liners will be prolonged. Under such conditions the absorption of fat from the cow's skin will be more important and methods of removal, or of prevention, such as the use of fat-resistant rubber may be advantageous.
471. The role of micro-organisms in dye-reduction and keeping-quality tests: I. The change in dominant bacterial flora during incubation at 37·5 and 22° C. and the part played by staphylococci and thecoli-aerogenesgroup
Authors: Garvie Ellen I. , Rowlands A. 
Published: June 2009

1. The present work was planned to provide an explanation of the lack of correlation for individual samples between the results of dye-reduction tests at 37·5° C. and keeping-quality tests at 22° C. A special study was made of the particular part played by the staphylococci (in thirty-eight samples) and thecoli-aerogenesgroup (in thirty-seven samples) in dye reduction at 37·5° C. and in keeping quality at 22° C. A detailed study was also made of the changes in bacterial flora of twelve samples during incubation at these temperatures.2. In milk, after overnight storage at 14° C., staphylococci were found to constitute only a small proportion of the bacterial flora, but their numbers increased during incubation at 37·5° C. (for the dye-reduction test) and at 22° C. (for the clot-on-boiling test). At the time of dye reduction staphylococci were found to constitute a major part of the bacterial flora, particularly in samples taking 5 hr. or more to reduce the dye. Although the staphylococci increased in numbers during incubation at 22° C. they constituted only a relatively small proportion of the flora at the time of the end-point of the clot-on-boiling test.3. Initially thecoli-aerogenesgroup were found to constitute only a small proportion of the total bacterial flora. Some growth usually occurred during incubation at 37·5 and 22° C.
510. Reactivation of milk phosphatase following heat treatment. I
Authors: Wright R. C. , Tramer J. 
Published: June 2009

1. Commercial samples of milk of Swiss origin, sterilized by rapid heating to high temperatures, developed a positive phosphatase reaction on storage.2. The optimum temperatures of storage for the development of this positive phosphatase reaction was 30° C.3. These commercial samples were sterile when received and remained sterile during storage.4. The developed phosphatase is apparently identical with the normal alkaline phosphatase of raw milk as judged by (a) heat stability, (b)pH optimum and rate of hydrolysis at different pHs, (c) comparison of results by Kay-Graham and Aschaffenburg & Mullen tests.
519. The cooling efficiences and water pressures of some surface milk coolers for farms
Authors: Scott J. K. 
Published: June 2009

The main types of surface milk coolers were tested using water at 95°F. instead of milk The coolers were tested: (a) for cooling efficiency at the nominal rated flow and a range of cooling-water flows; (b) for allowable flow at 3:1 cooling-water and cooling to within 3° F. of the cooling-water; (c) for the allowable flow (lb./hr. per square foot of cooling surface) for a range of cooling-water flows; (d) for the cooling-water pressures for various rates of flow.The results showed that no cooler reached the required efficiency at a cooling-water ratio of 3:1 or less, the temperature difference at the bottom of the cooler varying from 3·3 to 7° F. for normal coolers.The allowable flow per square foot of cooling surface varied from 33·8 to 114 lb./hr. when cooling to 3° F. difference with 3:1 water. The corrugated plate design had higher allowable capacity at low rates of flow of cooling·water than the tubular designs. Atmospheric cooling was small.
531. The influence of live weight on milk production during the first lactation
Authors: Bailey G. L. , Broster W. H. 
Published: June 2009

The relationship between live weight and lactation production was examined; records from ninety-nine animals, daughters of seven bulls, were used.A positive relationship was found to exist within each of the seven groups and within the entire population.The relationship did not exist between the mean values of the group.No correlation was found between the live weights at calving of forty-seven dam/daughter pairs; the daughters were the offspring of six bulls.It was shown that a herd breeding policy which selected animals according to their size would fail, except by chance, to improve the production of the herd.
563. The steam stripping of taints from liquids. II. Counterflow stripping with particular reference to possible use of Vacreator equipment
Authors: Scott J. K. 
Published: June 2009

The considerable increase in efficiency of taint removal which can be attained by counterflow methods is shown by the extension of the algebraic and graphical methods of Part I and confirmed by experiments with the reference substances diacetyl and acetoin in water. The treatment is mainly confined to multiple contact counterflow, and several methods are suggested by which existing Vacreator equipment may be used for counterflow connexion. The effect of a feed temperature below the temperature existing in the contacting vessels is shown to increase the amount of taint removal per pound of stripping steam used. Comparative curves are given for total steam consumption for systems preheating to various temperatures with waste heat.Results are given for experiments with a converted small size Tandem Vacreator. For diacetyl, the stripping steam used was one-tenth of that for a single contact process over the same range of diacetyl removal. Acetoin, being less volatile than diacetyl, did not show the same large steam saving.
571. The effect of menadione (2-methyl-l: 4-naphthoquinone) on the keeping quality of milk
Authors: Higginbottom Constance 
Published: June 2009

1. The addition of 1 µg. menadione/ml. to milk had no effect on the souring of the milk at 37° C. With higher concentrations of menadione the effect on the keeping quality at 37° C. varied with different milks. In some milks the clot-on-boiling stage was delayed by 1 hr. with 10 µg. menadione and by 2 to over 5 hr. with different milks containing 100 µg. menadione per ml. Some milks, however, showed no alteration in the keeping quality at 37° C. with as much as 1000 µg. menadione/ml.2. The response of individual milks to the presence of menadione appeared to be related largely to the bacterial flora of the milk, The relative insensitivity of Gram negative rods, including coliform bacteria and of enterococci, to menadione was confirmed. Milks containing large numbers of coliform bacteria showed the least and those free of such bacteria the greatest response to menadione.3. Menadione fed to milking cows at the rate of 100 mg·/day for a period of 3 weeks had no effect on the keeping quality of the milk when it was held at 37, 22 or 15·5° C. The time of incubation required for the milk to attain a titratable acidity equivalent to 2 ml. N/9-NaOH, to become unstable to 68 % alcohol or to boiling showed no difference between the milk from the cows given menadione and that from the control cows.4. The menadione had no demonstrable effect on the appetite or the well-being of the cows nor on their milk yield.5. When as much as 100 μg. menadione was given per cow per day, no menadione was detected in the milk under conditions suitable for the detection of 1 μg. menadione/ml.milk.
575. Colour changes in heated and unheated milk: III. The effect of variation in milk composition on the whitening and browning of separated milk on heating
Authors: Burton H. , Rowland S. J. 
Published: June 2009

The effect of natural variations in the pH, and in the casein, soluble-protein and lactose contents on the whitening and browning of separated milk has been studied by holding samples of known composition, obtained from individual cows, at a temperature of 110°C. for various times and determining their reflectances after treatment.The rate of browning, measured as a rate of loss of reflectance at a wave-length of 4260 Å., was found to depend on the pH of the milk. Apparent variations of the rate of browning with protein content are considered to have been caused by associated variations of pH with protein content in the milk from the different cows. The rate of browning varied over a range of 2:1 for the samples examined.The whitening of milk, measured as the maximum rise of reflectance occurring on heating, was found to be much more variable, and over the same range of samples varied by 5·5:1. The soluble-protein content and pH affect the amount of whitening, but there appears to be some other factor of importance which was not covered by the chemical analyses that were made.A considerable range of reflectances is shown by different milk samples after a fixed heat treatment. These differences are determined more by variations in the amount of whitening than by variations in the rate of browning.
579. A study of variation in twin cattle: IV. Emergence of permanent incisor teeth
Authors: Wiener G. , Donald H. P. 
Published: June 2009

1. Data are presented on variation in age at eruption of permanent incisor teeth in one-egg (MZ) and two-egg (DZ) twins and in pairs of half sisters (HZ). The 1st pair of incisors erupted when animals were on average 100 weeks old and the other three pairs came at roughly 26-week intervals thereafter. Variation in age at eruption increased from 1st to 4th incisors, but the coefficient of variation remained constant at about 8%. The mean interval between eruption and complete emergence was about 5 weeks for the first three pairs of teeth and nearly 10 weeks for the 4th pair.2. Variation in age at eruption within MZ pairs was no greater than that between left and right sides of the same animal. DZ displayed greater within-pair variances than MZ twins, and HZ pairs greater than DZ.3. Correlations of age at eruption of teeth with body weight and with gain in weight were negative but non-significant. Age at eruption of 1st and of 3rd teeth was positively correlated with age at 1st and 2nd calving, but eruption of 2nd and of 4th teeth was not.4. For 2nd, 3rd and 4th incisors, the intra-pair variance of the HZ group was in excess of that expected. This can be interpreted to mean that the estimates of environmental and genetic variation derivable from MZ and DZ pairs are not adequate to account for all the variation within HZ pairs.
601. The effect of salt and of antioxidants on the keeping quality of butter
Authors: McDowell A. K. R. 
Published: June 2009

Butterfat oxidation occurred in both salted and unsalted butters during storage at 14° F. Butterfat oxidation values, after storage, were much lower in unsalted and in highly salted butters than in butters of normal salt content.Butterfat oxidation in salted butters during storage was retarded by treatment with antioxidants. These included fat-soluble and water-soluble substances, surface-active agents and copper-complexing compounds.Unsalted butter, salted butter and salted butter treated with antioxidants all developed ‘storage’ flavour during storage for eight months.Many of the antioxidants added to salted butter were effective in retarding further fat oxidation and further increase in intensity of storage flavour when the butters were transferred to a temperature of 60–65° F. after storage.
604. The importance of lactobacilli in the production of flavour in cheddar cheese: I. Growth of lactobacilli in cheese serum
Authors: Mabbitt L. A. , Zielinska M. 
Published: June 2009

1. The serum prepared by subjecting Cheddar cheese to pressure becomes inhibitory to the growth of lactobacilli as the cheese ripens.2. One factor responsible for the inhibitory phenomena is the increasing osmotic pressure of the serum due mainly to the increasing amounts of amino-acids present.3. Observations made during the ripening of a normal Cheddar cheese suggest that other factors, e.g. amino-acid imbalance, are also important.
618. Host-phage relationship of cheese starter organisms: I. Interaction of phage races with a strain ofStreptococcus lactisand its lysogenic and resistant derivatives
Authors: Czulak J. , Naylor Jill 
Published: June 2009

A lysogenic culture, prepared in the laboratory from a strain ofStreptococcus lactis, was used as a cheese starter in commercial factories. It was attacked in turn by two other unrelated phage races. The lysogenic condition, which involved slight morphological and physiological changes, persisted in the subsequent forms resistant to one or both the new phage races. Acquired resistance to any one of the three phages did not protect the culture from the other two phages.In nature such interactions between phage races and lactic acid bacteria must be constantly taking place, giving rise to similarly related strains.Two of the three phage races produced spreading haloes around their plaques due to a lysin released during phage action. The lysin may also interfere with the survival of secondary growth after attack by these phage races. Production of this type of lysin is thus a property of the phage race and not of the bacterial strain.
621. Winter feeding of dairy cows: III. The influence on milk yield of high and low protein concentrates, each fed at two levels in addition to dried grass and grass silage
Authors: Reid D. , Holmes W. 
Published: June 2009

1. In a winter-feeding experiment with eight Ayrshire cows the effects of feeding a high- and a low-protein concentrate at two rates (4 and 2 lb./gal.), in addition to dried grass and silage, were studied.2. With these cows and the feeds used increasing the rate of concentrate feeding from 2 to 4 lb./gal. increased the total dry-matter consumption by 2 lb./day and the average milk yield by 1·2 lb./day.3. For every 1 lb. increase in concentrate fed there was a decrease of 0·68 lb. grass dry matter eaten.4. The level of protein in the concentrates had no effect on total dry-matter intake, and only a slight, though positive, effect on milk yield.5. It is concluded that in this work where the diet was made up with high-quality dried grass and silage, feeding either a high- or a low-protein concentrate mixture at the rate of 2 lb./gal. milk gave the greatest profit margin per cow.
630. The determination of lactose in milk
Authors: Grimbleby F. H. 
Published: June 2009

One of the most important stages governing the accuracy of lactose determinations in milk is the preparation of the protein-free serum. Factors influencing the lactose content of the serum are: (1) the complete precipitation of protein, (2) the formation of lactose-protein complexes, and (3) the degree of hydration of the protein coagulum.Experiments are described which show how these factors are influenced by different clearing agents operating at different pH values. On the basis of the results obtained a reagent containing zinc acetate, phosphotungstic acid and acetic acid is suggested; it reduces to a minimum any errors introduced by the above factors.
637. Acid production in milk by starter cultures—The effect of peptone and other stimulatory substances
Authors: Garvie Ellen I. , Mabbitt L. A. 
Published: June 2009

The rate of acid production by a slow variant ofStreptococcus cremorisin milk was raised to that of the fast parent strain when peptone or acid hydrolysed peptone were added. Lactose utilization was similarly affected. However, the stimulation took place without any change in the rate of growth. Other sources of available nitrogen gave similar results.It is concluded that the change from a fast to a slow culture which occurs on continued transfer is due to the loss of ability to utilize the nitrogen compounds of milk.
639. Some bacteriological aspects of commercially sterilized milk: I. Incidence and nature of spoilage
Authors: Nichols Agnes A. , Candy M. R. 
Published: June 2009

Samples of sterilized milk from fifteen dairies in the Midlands have been examined, and seasonal variations were detected in the incidence of mesophilic and thermophilic sporeformer contamination. Seasonal variation in the rate of spoilage at 30° C. was also apparent.The lower incidence of contamination in summer was considered to be due to (a) less sporeformer contamination during milk production at the farm in the period when the cattle are not housed, and (b) increased processing times and temperatures in warm weather.Cleansed milk bottles were examined and found to be an important source of contamination by mesophilic sporeformers, but the incidence of thermophiles of the type commonly found in sterilized milk was low.Methods of reducing contamination in sterilized milk were discussed.