bluuebunny/crossref_metadata_2025_split huggingface dataset:
150. The effect of certain metallic contaminants on the Cheddar cheese making process
Authors: Barnicoat C. K. 
Published: June 2009

Traces of certain metallic contaminants (copper, iron, lead, zinc, aluminium and manganese), when added at the rate of 3 and 7 p.p.m. to milk used for the manufacture of Cheddar cheese, cause certain flavour (and colour) defects in the matured cheeses, of which, however, no indication is given when the cheese is plugged and graded at about 14 days after manufacture.The distribution of copper, iron, manganese and lead between curd and whey during the cheese-making process is recorded and the action of traces of various metals on the acidity development in a typical "starter" culture has been followed.The discolorations noted for copper- and iron-contaminated cheeses are considered to be due not to the formation of their sulphides (although this is the case for lead discoloration), but to the atmospheric oxidation of a colourless metal: protein complex.
159. The resistance to infection with Bact. typhi-murium of mice fed on raw and pasteurized milk
Authors: Wilson G. S. 
Published: June 2009

1. In a series of virulence experiments a comparison was made between the resistance to infection of 551 mice fed on raw and 495 mice fed on pasteurized milk, each dietary being supplemented by a mineral mixture and a whiteflour biscuit. In one set of experiments the mice were inoculated intraperitoneally with about 100 or 1000 living Bact. typhi-murium and observed for a fortnight; in another set they were fed by the mouth with about 100–200 million living organisms of the same strain and observed for 4 weeks. All animals dying during, and all survivors killed at the end of the experiments were bacteriologically examined for evidence of specific infection.2. In the intraperitoneal inoculation experiments the results obtained with the raw and pasteurized groups respectively were as follows: Proportion of animals dying of specific infection 51·83 and 51·20 per cent; proportion of all animals found to be specifically infected at death or when killed 95·29 and 91·57 per cent; average survival time of animals dying of specific infection 8·06 and 6·93 days. The proportions of animals dying of specific infection when standardized for weight distribution were 55·1 and 50·6 per cent respectively.
225. The casein number for diagnosis of mastitis. II. The effect of advanced lactation, and of storage and preservation of the milk sample
Authors: Rowland S. J. , Zein-El-Dine M. 
Published: June 2009

1. An investigation was made of the effect on the casein number of (a) advanced lactation, (b) storage of the milk sample at room temperature and in the refrigerator, and (c) storage of the sample at room temperature after the addition of the following preservatives: potassium dichromate, mercuric chloride, formaldehyde, crystal violet and sodium azide.2. The casein number method of mastitis diagnosis is not applicable to cows in advanced lactation. It did not distinguish between infected and uninfected quarters, as all quarters in the drying-off stage produced milk with a number below normal. At the end of lactation the mean casein, soluble protein plus non-protein, and total nitrogen contents were 21, 86, and 36% greater respectively than when the cows were in full milk.3. There was a decrease in the casein number of the milk samples on keeping at 16–18° C. or with preservatives owing to the hydrolysis of casein to proteose-peptone and non-protein nitrogenous substances. For the diagnosis of mastitis from the casein number, samples should not be kept at room temperature for more than a few hours before analysis. Keeping at 0–2° C, and at room temperature with the addition of 0·2, 0·05, and 0·01 g. potassium dichromate, formalin or mercuric chloride respectively per 100 ml. of milk, prevented significant reduction of the casein number for 24–48 hr.
274. Preliminary experiments on the vapour pressure of dairy products
Authors: Blair G. W. Scott , Dix F. J. , Wagstaff A. 
Published: June 2009

1. Methods for measuring the vapour pressure of cheese and milk are discussed, and vapour pressure/moisture curves are given for a number of different varieties of cheese. The progressive artificial damping and drying of cheese produces no appreciable hysteresis in these curves.2. The vapour pressure curve is much influenced by the amount of salt in the cheese, but differences between varieties cannot be accounted for entirely in terms of differences in NaCl content.3. A preliminary experiment on the relationship between vapour pressure of Stilton cheese and amount of blueing indicated that such a relationship does in fact exist but that a much larger experiment is required before the connexion is fully understood.4. Preliminary experiments on the measurement of the vapour pressure of milk, although interrupted at rather an early stage, showed that, even so, additions of 2–3% of water in milk can be satisfactorily detected.
277. Vitamin A and C in cow's milk, with a note on the synthesis of vitamin C in bovines
Authors: Ray S. N. , Chand Karam , Rau K. Govind 
Published: June 2009

1. A simple method is described for the determination of carotene and vitamin A in milk. Figures for the carotene content of milk were higher and those for vitamin A were lower than similar figures reported by Western workers.2. Figures for vitamin C in milk are similar to corresponding figures of English and American workers. Previous low values for vitamin C, reported by Indian workers, are due to destruction of the vitamin by light.3. The vitamin C concentration of milk is not subject to great individual variation, probably because cows cannot excrete in milk any vitamin C taken in with the food and because vitamin C of milk is produced by synthesis within the mammary glands from some simple blood constituents.4. To test the ability of bovines to synthesize vitamin C, young calves were kept for long periods on a strictly vitamin C-free diet. The concentration of vitamin in the blood and other tissues of these animals remained, however, at a normal level. Calves appear therefore to be able to synthesize sufficient vitamin C for their normal growth and activity.5. Unsuccessful attempts were made to produce vitamin C in vitro by growing bacteria isolated from various parts of the alimentary canal on media prepared from ingesta taken from the regions from which they were isolated.
281. Volatile acids of cheese: III. Application of the extraction method
Authors: Hiscox E. R. , Harrison J. , Wolf J. Z. 
Published: June 2009

1.Details are given of the extraction method for the estimation of the volatile acids in cheese, as used in the study of some white and blue-veined varieties.2. On the basis of the distribution of valatile acids, hydrogen-ion concentration and nitrogen breakdown, distinctions could be drawn not only between the white and blue-veined varieties as a whole, but also between the Roquefort and Stilton groups of the latter varieties.3. A high total quantity and a characteristic distribution of the volatile acids appeared to be related to the heavy pricking of cheese of the Roquefort group.
283. The keeping qualities of milk powders: Part I. Addition of antioxidants
Authors: Waite R. 
Published: June 2009

1. Hydroquinone is an effective antioxidant for the butter-fat of spray-dried whole-milk powder, but in a concentration equivalent to 0·5% of the weight of fat (0·12% on the weight of powder) it produces an objectionable ‘metallic’ flavour in the powder and reconstituted milk.2. Oat flour is much less efficient than hydroquinone as an antioxidant but 0·25% added to the milk, preferably before condensing, increases the resistance of the resultant powder to the development of tallowiness by the equivalent of about 4 months at normal temperatures. Raising the concentration of oat flour to 0·5% approximately doubles this increase but at the same time imparts a noticeable oat flavour to the powder.
360. Reactions to hot atmospheres of Jersey cows in milk
Authors: Riek R. F. , Lee Douglas H. K. 
Published: June 2009

Four grade Jersey cows were exposed for 7 hr. twice a week to each of several atmospheres having dry-bulb temperatures ranging from 85 to 110° F. and absolute humidities ranging from 6 to 16 gr./cu.ft. The following reactions were studied: rectal temperature; pulse rate; respiratory rate; respiratory volume; evaporative loss; calcium, phosphate and erythro-cyte composition of the blood; milk volume and butterfat content; behaviour.Rectal temperature rose to higher values with less ready establishment of equilibrium the hotter the condition, but exceeded 107° F. only in the hottest atmosphere. (Dry-bulb temperature 110° F., absolute humidity 16 gr./cu.ft.)Respiratory rate was similarly and markedly affected. In both cases, humidity had a marked effect as well as temperature, an increment of 0–4 gr./cu.ft. (approx. 4%) in humidity having the same effect as 1° F. rise in air temperature. The highest average respiratory rate was 200/min. Respiratory minute volume rose less than the rate, so that tidal volume was reduced.Pulse rate was essentially unaffected by a rise in temperature but tended to rise somewhat with humidity.Evaporative loss was markedly increased by temperature, much less so by humidity. Increased pulmonary ventilation was inadequate to account for the observed losses, which are attributed to sweat-gland activity.Behavioural changes included some licking, panting, salivation, mild agitation, cessation of rumination and refusal of water. Weakness and staggers did not occur under these conditions.Neither milk nor butterfat production was essentially affected by the exposures. Blood calcium and phosphate levels fell, but the erythrocyte count was unchanged.These findings provide basic data with which subsequent observations under varying conditions can be compared.
365. The bacteriological quality of british spray-dried milk powder
Authors: Higginbottom Constance 
Published: June 2009

The increased use of dried-milk products in human feeding during recent years stimulated investigations into and more rigid control of the bacteriological quality.Spray-dried milk powder from the same eight British plants has been examined for bacteriological quality at this Institute in several different years and the results show the marked improvements which have been made.
373. Inhibitory strains of lactic streptococci and their significance in the selection of cultures for starter
Authors: Hoyle Margery , Nichols Agnes A. 
Published: June 2009

1. Inhibitory strains of lactic streptococci have been encountered amongst strains of Str. cremoris isolated from starter and amongst strains of Str. lactis, isolated from sour milk, which had otherwise been regarded as suitable for cheesemaking.2. Methods are described for determining the concentration of inhibitory substance produced and the effect of these inhibitory strains on a wide selection of lactic streptococci.3. The significance of the presence of strains of lactic streptococci having inhibitory properties, if incorporated in starters, particularly when the strains are prepared separately and mixed in the vat, is discussed. Recommendations for the exclusion of inhibitory strains from such starter mixtures are made.
387. Bacteriophage in typing lactic streptococci
Authors: Nichols Agnes A. , Hoyle Margery 
Published: June 2009

1. The present position in the problem of ‘slow’ starter due to phage lysis has been reviewed.2. The sources of some 450 strains of lactic streptococci, collected from a wide field, are given. The methods used in their selection for use as starter together with storage conditions, suitable to maintain their activity, have been discussed.3. The sources from which phages for the lactic streptococci have been obtained and the methods of ‘building up’ a phage of high titre from dairy products, have been discussed. Attempts have been made to isolate phages from pig-faeces, after feeding starter strains to pigs, to adapt phages to strains previously unattacked and to establish interrelationship of the phages and strains of lactic streptococci with phages and strains of enterococci.4. The strains of lactic streptococci have been classified in eleven phage types by modifying a method described for the phage typing of staphylococci. Identification of a type has been based on the reactions of a ‘phage pattern’ and not on the reaction of a single phage. It has not been possible to adapt one phage to lyse all the strains of one type and to replace the several phages on which type identification originally depended but, adapted phages have indicated the subdivision of some types.5. The application of the ‘phage-resistant carrier’ strain phenomenon to phage typing has been investigated. The results have helped in the typing of some strains.6. Phages used in typing the strains have been classified by means of antiphage sera, prepared from a selection of the test phages. On the data presented the majority of the phages were divided into three groups and the results have been discussed with reference to the phage types suggested.7. The significance of phage typing, adaptation of phage and phage carrying in the selection of starter strains has been considered and the best method of applying this information to the control of ‘slowness’ in cheese factories has been discussed.
390. The estimation of losses of butterfat in churning
Authors: McDowall F. H. , McDowell A. K. R. 
Published: June 2009

The Bird & Derby method of calculating percentage butterfat loss in buttermilk is in error because it assumes that all the buttermilk in the granules at draining is retained in the buttermilk, whereas much of it is washed out in the wash water. Lactose estimations in butter and buttermilk confirm Udy's finding that butter contains about 10% of buttermilk. The Udy formula, viz.is therefore in this respect correctly based and can be applied to individual churnings of butter in the same way as the Bird & Derby formula has been applied. The Bird & Derby formula should be discarded except for use when the granules are not washed with chill-water.Both the Udy and the Bird & Derby formulae do not allow for the content of fat in the buttermilk retained in the butter or for the influence of fat content of the buttermilk on the calculated quantity of serum lost. When these factors are taken into account the Udy formula becomesThe correction +0·0012f F is not significant.
428. The acid phosphatase of mammary tissue of the cow and the rat
Authors: Mullen J. E. C. 
Published: June 2009

1. Mammary tissue of the cow and the rat contains acid phosphatase. The respective pH optima are 5·5–5·8 and 6·0.2. The enzyme in cow mammary tissue is probably one of type AII in the Folley & Kay (10) classification.3. The acid phosphatase of cow mammary tissue is inhibited by a factor in raw cows' milk. This factor is destroyed by heat.4. On the basis of rate of hydrolysis of phenylphosphate at the optimum pH there is about 5 times more alkaline phosphatase in the mammary tissue of the cow than acid phosphatase.5. The effect of adrenalectomy and replacement therapy through the administration of cortical steroids has no marked effect on the acid phosphatase of rat mammary tissue.
458. Clinical mastitis in six herds freed from Streptococcus agalactiae
Authors: Neave F. K. , Phillips Mary , Mattick A. T. R. 
Published: June 2009

The difficulty of keeping herds free from Strep. agalactiae for long periods has been demonstrated in five herds. In one sense, however, these herds were not representative of the majority of herds for they were relatively large and under the same management. Furthermore, if one herd became infected with the streptococcus, there was a real risk of the infection spreading to all herds via the hands of the relief milker, particularly if hand stripping was practised and no special precautions were taken by the relief milker.There is no doubt that herds under the same management should take stringent precautions against the spread of infection between herds.
473. The serological classification ofStreptococcus cremoris
Authors: Briggs C. A. E. , Newland L. G. M. 
Published: June 2009

1. Attempts to produce in rabbits group N sera forStreptococcus cremoris, using suspensions of living, disintegrated and heat-treated bacterial cells, yielded only non-specific products, cross-reactions occurring most commonly and intensively with HCl extracts of the streptococci of groups K and L.2. The non-specific antibodies in these sera were completely removed by absorption with streptococci of group K or L, the group N reactions being only partially impaired.3. In order to inactivate, before immunizing rabbits, that antigen in the ‘cremoris’ cells responsible for stimulating the production of non-specific antibodies, the organisms were ‘absorbed’ with an excess of group K or L antiserum.4. With suspensions of organisms treated in this way, potent group N specific precipitating sera were obtained for both freshly isolated and freeze-dried strains ofStr. cremoris.5. The identity ofStr. cremoriswith serological group N is thus established.
479. Studies on the biological value of the proteins (nitrogen) of dried skim milk: effects of the addition of certain amino-acids, of age of rat and of level of protein intake
Authors: Henry K. M. , Kon S. K. 
Published: June 2009

1. It has been shown that the biological value of undeteriorated dried skim milk is depressed to the same extent by the addition of 1·25% L-lysine as by the addition of 1·25% D-lysine. The latter is not used by the rat. It is therefore concluded that the added L-lysine is surplus to the animal's needs and that the apparent lowering of the biological value is due to excretion of the lysine in the urine.2. The slightly greater loss in the biological value of milk stored in air-pack compared with gas-pack was eliminated by the addition of 0·5% L-histidine to the former. Histidine is not a limiting amino-acid in the control or stored gas-pack milks for either young or adult rats.3. A lower biological value was found for the control milk with adult than with young rats at 4 and 8% levels of intake. No further lowering in the biological value of the stored milk, deficient in lysine, was observed with adult rats, the value obtained for this milk being independent of the age of the rat. These results are in keeping with the known lowered requirements of the adult rat for lysine.4. The significance of these findings in relation to the known amino-acid requirements of young and adult rats is discussed.
480. The role of micro-organisms in dye-reduction and keeping-quality tests: II. The effect of micro-organisms when added to milk in pure and mixed culture
Authors: Garvie Ellen I. , Rowlands A. 
Published: June 2009

1. A study of the ability of pure cultures to reduce methylene blue and resazurin at 37·5° C., to reduce methylene blue at 22° C. and to cause milk spoilage as measured by precipitation with 68 % alcohol, and the clot-on-boiling test has revealed marked differences in behaviour between cultures.2. At 37·5° C., with the exception of two cultures, there was good agreement between the time of reduction of methylene blue and resazurin. The two exceptions were a group BStreptococcuswhich reduced methylene blue but failed to reduce resazurin during the 9 hr. period of observation and an unclassifiedStreptococcusgrowing at 45° C. which reduced resazurin before methylene blue; the latter dye was found to retard the multiplication of the culture slightly.
501. The effect of storage at different relative humidities on the survival of micro-organisms in milk powder and in pure cultures dried in milk
Authors: Higginbottom Constance 
Published: June 2009

1. Two spray-dried milks, one separated and one whole milk, have been stored at 25°C. for 48 and 103 weeks respectively at relative humidities ranging from 0 to 100%. At high humidities (80–100% r.h.) a rapid fall in the numbers of bacteria was followed by rapid growth of bacteria and by overgrowth by moulds. At relative humidities below 80% the number of surviving bacteria increased with decreasing humidity to maximum survival at about 10% r.h. and then tended to fall again towards 0% r.h.2. The changes in the distribution of the different types of bacteria in the dried milks at different relative-humidities are discussed.3. Maximum survival at 5–15% r.h. has been confirmed with pure cultures (dried in milk) of a Streptococcus and a Micrococcus originally isolated from dried milks.4. The marked loss of viability of bacterial spores noted in dried milks stored over P2O5 or concentrated H2SO4 has been confirmed for a dried suspension of the spores of a typical strain of Bacillus subtilis.
503. The properties of New Zealand butters and butterfats: III. Seasonal variations in the nature of the unsaturated acids of butterfat as estimated by spectrophotometric methods
Authors: McDowell A. K. R. 
Published: June 2009

Variations in the unsaturated acid constituents of butterfat samples from the Manawatu district of the North Island of New Zealand over the months October to April were studied by the spectrophotometric technique, applied both before and after alkali isomerization of the fat.The seasonal variations in the iodine values of the butterfats were found to be closely related to the changes in oleic acid content. Conjugated dienoic acids, though present in relatively small amounts, showed a somewhat similar seasonal trend in values to oleic acid. The results for percentage content of non-conjugated dienoic acids were low, and they fluctuated considerably from month to month. Conjugated trienoic and tetraenoic acids were absent or present only in traces. Small but fairly consistent quantities of nonconjugated trienoic and tetraenoic acids were found in all samples.
517. Reactivation of milk phosphatase following heat treatment. II
Authors: Wright R. C. , Tramer J. 
Published: June 2009

1. Using the capillary technique previously described, examination has been made of various factors in relation to the reactivation of raw milk phosphatase. Of these, ageing of the raw milk was found to affect considerably the level of reactivation, this increasing as the bacteriological quality of the milk deteriorated.2. It has been found that absence of air and the presence of reducing conditions in the raw milk increases the reactivation obtained.3. The influence of reducing conditions on the reactivation of a bacterial phosphatase has been demonstrated.
568. The rate of secretion of milk and fat
Authors: Bailey G. L. , Clough P. A. , Dodd F. H. 
Published: June 2009

1. The effects of variations in the length of the milking interval and of the preceding milking interval were measured for five cows.2. The yield of milk increased with the lengths and decreased with the square of the lengths of the milking interval and of the previous milking interval.3. The yield of fat increased with the length of the milking interval and the length of the preceding milking interval and decreased with the square of the length of the milking interval.4. The biological implications of each of the mathematical terms are discussed.5. The effect of the preceding interval was through a direct carry-over of residual milk and also by an effect on the metabolic rate of the alveoli throughout the following interval.6. The rate of secretion of both milk and fat declined with increasing milking interval; there was evidence that the rate of decline for the milk was greater than that for the fat, for the fat percentage of the milk tended to increase.