bluuebunny/crossref_metadata_2025_split huggingface dataset:
135. Studies on the Chemistry of Cheddar Cheese making
Authors: McDowall F. H. , Dolby R. M. 
Published: June 2009

1. Determinations have been made of lactose and lactic acid in whey, curd and curd juice throughout the cheese-making process.2. The effect of adding salt to curd at various stages of the process on the concentration of lactose and lactic acid in the whey has been investigated.3. The rate of penetration of salt into curd has been determined, and it has been shown that by the time the cheese is normally hooped but little salt has reached the centre of each curd strip. Within 12 hours after hooping the distribution of salt is substantially uniform.4. It has been shown that the conversion of lactose to lactic acid by starter bacteria in the cheese vat is almost quantitative.5. Evidence has been brought forward indicating the presence of bound water in cheese curd.6. It has been shown that a Donnan equilibrium controls the partition of electrolytes between curd and whey.
138. Effect of Breed, Size of Cow, Yield of Milk and Stage of Lactation upon Efficiency of Milk Production
Authors: Edwards Joseph 
Published: June 2009

The records of 2400 cows on test at the London Dairy Show between the years 1922 and 1934 have been examined for the relationship between the gross physiological efficiency of milk production and the factors of breed, size of cow within a breed, actual yield of milk and stage of lactation. (“Gross Efficiency” is here the ratio of energy in the milk to the energy in the digestible nutrients consumed.)(1) It is shown that among the best representatives of the various dairy breeds there is little difference in gross efficiency of milk production. The lactation stimulus has been bred approximately in proportion to the size of the breed.(2) Cows, in spite of their greater weight, are more efficient than heifers, and animals milked thrice daily than those milked twice daily.(3) Within the breed there is a slight though definite tendency for gross efficiency to decrease with increase in live weight.(4) Greater than any of the foregoing differences in gross efficiency is that which exists within a breed due to differences in actual milk yield.(5) Stage of lactation has also much to do with gross efficiency. There is a steady decline in efficiency with advance in lactation from 38·75 to 29·25 per cent.
151. The reactions and properties of annatto as a cheese colour, with particular reference to the chemistry of cheese discoloration
Authors: Barnicoat C. R. 
Published: June 2009

The properties of commercial annatto solutions have been examined from the point of view of the cheese-making process.(1) The effect of initial colour strength, pH of the medium and distribution during manufacture are recorded.(2) Methods are described for the extraction of the annatto colour from milk products.(3) The effects of old annatto solutions, metallic impurities (copper and iron) and sulphydryl are shown.(4) It is suggested that the mechanism underlying the development of “bleached” and “pink” discoloration in cheese is an oxidation process, and the effect of oxidation on annatto solutions has been studied in some detail.(5) Suggested standards for annatto extracts for use as cheese colours are appended.
152. Studies on the chemistry of Cheddar cheese making. V. Factors influencing the acidity and mineral content of cheese
Authors: Dolby R. M. , McDowall F. H. , McDowell A. K. R. 
Published: June 2009

It has been shown that the acidity developed in a vat of milk at the “running” stage has a very important influence on the quality of the resultant cheese. A high acidity causes increased mineral losses in the whey and a corresponding lowering of the mineral content of the cheese, while it also has a detrimental effect on the body of the cheese. The acidity at “running” also controls to a great extent the acidity of the cheese produced. Even where the acidities at the late stages of the process are kept the same, vats of cheese made at a high “running” acidity show more acid characteristics than cheese made at low “running” acidity.The quantity of lactose incorporated in the cheese is also of importance in determining the acidity of the cheese. An increase in the lactose content, either by raising the lactose concentration of the cheese milk or by the addition of lactose to the curd, produces a more acid type of cheese at maturity, although some unfermented lactose is still present in the cheese at 4 months after manufacture.
166. The relative values of raw and pasteurized milk in the feeding of calves
Authors: Wilkie J. , Edwards S. J. , Fowler A. B. , Wright N. C. 
Published: June 2009

1. Bull calves from tuberculin-tested Ayrshire herds were fed on raw or commercially pasteurized milk up to 12 weeks of age, in amounts strictly in relation to their body weight. This diet was supplemented from the eighth week by hay at the rate of 2/3 lb. per head per day.The milk used was mixed milk from untested herds, the raw and pasteurized milk being derived from the same bulk sample. The quality of the milk was controlled by daily butterfat and phosphatase tests and by inoculation of grouped daily aliquots twice weekly into duplicate guinea-pigs.2. The total number of calves used in the experiment was ninety-two. Of these, forty-two received pasteurized milk and fifty raw milk. Nineteen calves died before completion of the experiment, five in the pasteurized milk-fed group and fourteen in the raw milk-fed group. The mean ages of these calves at death were 44 and 27 days respectively.Seventy-three calves completed the full 12 weeks of the experimental feeding. Of these, thirty-seven received pasteurized milk and thirty-six raw milk. The former group showed a mean percentage gain in live weight of 80·2 ± 3·1, the corresponding figure for the latter group being 74·5 ± 2·7. The difference, i.e. 5·7 + 4·1, was not significant. Reasons are given for the relatively low growth rate observed.3. No appreciable differences were noted in the skeletal growth of the two groups. Marks awarded by experienced stock judges showed consistent differences in favour of the pasteurized milk-fed group, although the significance of such differences cannot be assessed.4. Inoculations of grouped daily aliquots of raw milk twice weekly into duplicate guinea-pigs resulted in finding viable tubercle bacilli in 70% of the samples and Br. abortus in 38% of them. The pasteurized milk samples were uniformly negative to both tests.The differences in tuberculous infection of the two types of milk were reflected in the results of tuberculin tests and post-mortem examinations on the calves at the conclusion of the experiment. Twenty-four out of thirty-six calves fed on raw milk reacted to the test, and the presence of tuberculous lesions was confirmed in twenty-three by post-mortem examination. One calf in the pasteurized milk-fed group reacted to the test, but exhaustive post-mortem examination and inoculation of glandular material into guineapigs failed to confirm the presence of any tuberculosis.5. This work has failed to show any significant differences in the nutritive value of raw and of pasteurized milk for the rearing of young calves. The use of pasteurized milk, however, had a clear advantage in that it preserved the animals from infection through drinking milk containing living tubercle bacillli.
221. The effect of serum and blood on the growth of lactic acid bacteria in milk
Authors: Davis J. G. 
Published: June 2009

Generally speaking, serum and blood do not have a marked effect on the growth of lactic acid bacteria in milk, although certain types appear to be specifically stimulated or inhibited. Heated serum and, to a greater extent, heated blood, usually stimulate growth.Unheated serum may inhibit certain types, e.g.Str. lactis, when a small inoculum of washed cells is used. Under conditions similar to those in practice, no effect was noticeable. It is unlikely, therefore, that “slow starter” is ever attributable to infiltration of serum or the constituents of serum.Small amounts of dextrose are without effect on growth (apart from fermentation of the added sugar) and do not initiate the fermentation of lactose.
223. Bacteriological studies of canned milk products
Authors: Nichols Agnes A. 
Published: June 2009

1. A survey of evaporated milk and canned cream samples from three condensed milk factories and from general sources has been undertaken to determine to what extent non-sterility occurred in commercial practice. In addition to the examination of sound samples many others have been tested which were obviously defective or which were associated with defective packs. 100% of the tins examined from general sources were sterile. The factory samples, especially those of canned cream, had a lower sterility percentage, although it appeared that this was associated with some special circumstance of operation and that a sterile pack should ordinarily be quite attainable.2. An account is given of the methods used for sampling the can contents and for the recovery of bacteria from unsterile cans and their identification. The necessity for a large inoculum in such sampling is emphasized, since although the bacteria may survive for many months in the tins, they may be present in small numbers.3. Data are presented regarding the types of defective samples encountered and the associated bacteriological flora. “Bloats” in evaporated milk and thin bitter and putrid cream were the two main causes of spoilage encountered.4. By using the heat resistance of the organisms which were recovered from the cans as a basis of classification the. defects have been divided into two groups, namely (1) a mixed general flora which does not withstand high temperatures, and (2) a restricted heat resistant flora which is of the sporeforming type.
261. A study of the mortality rates of calves in 335 herds in England and Wales (together with some limited observations for Scotland)
Authors: Lovell R. , Hill A. Bradford 
Published: June 2009

1. With the assistance of the Central Council of Milk Recording Societies of England and Wales and its affiliated Societies, particulars were obtained of the calf losses, pre-natal and post-natal, sustained in 1936–7 by 315 herds situated in different counties of England and Wales. Further data were collected from twenty private owners in England and from forty-seven herds in a limited area in Scotland.2. The herds in England and Wales were chosen in such a way as to give a fair representation of the geographical distribution of the cow population throughout the country. It is obvious, however, that they are a selected sample in which a relatively high standard of husbandry might be expected to prevail and their rates of mortality, therefore, will probably be below that of the general run of herds.3. Owing to the early disposal of bull calves the losses of males after the first week of life are likely to be considerably understated. It is, therefore, wise to confine attention mainly to the figures for females.4. In the 335 herds of England and Wales 12,544 female calves were born and of these 693, or 5°5 %, died before the age of 6 months.5. Of 26,440 total births reported in England and Wales, 1231, or 4°4 %, were of stillborn animals.
282. A preliminary study of the effects of varying pitching consistency and rate of scald on the physical and chemical properties of Cheddar cheese and on the firmness of the cheese as judged by cheese-makers, bakers and others
Authors: Blair G. W. Scott , Coppen F. M. V. , Dearden D. V. 
Published: June 2009

1. Six cheese of Cheddar type were made under conditions as similar as possible, except that the consistency of the curd at pitching, and in two cases the rate of scald, were varied.2. Chemical and rheological analyses, as well as measurements of moisture content and vapour pressure, were made on the cheese and also judgements of firmness under various conditions were given by cheese-makers, bakers and non-experts.3. A table is given in which the orders of placing of the cheese are compared as between the objective tests and the subjective judgements. The cheese-makers and the non-expert testers gave, in general, characteristically different orders, the orders given by the bakers tending to fall between the two.4. It appears that the consistency of the curd at the pitching point (W/h as determined by the Scott Blair-Coppen method) and probably the rate of scald, are prime factors in determining the firmness of the cheese.5. The whole experiment is preliminary in character and it is intended to repeat it in an extended form in the near future.
294. The estimation of solids in milk: Part I. Determination of solids-not-fat by various methods of hydrometry
Authors: Boden S. M. , Campbell C. H. 
Published: June 2009

1. Estimations of solids-not-fat by evaporation and by hydrometry were made in two laboratories on samples of the same raw and pasteurized milks.2. General agreement was found between the results by stated evaporation techniques and those by Richmond's formula (S.N.F. = 0·25G + 0·2F + 0·14) when the latter was applied to milks which had been stored cold (i.e. Recknagel contraction complete as required by Richmond).3. General agreement at a lower level of S.N.F. (0·2% approx.) was found between Richmond's formula and the density formula (S.N.F. = 0·25D + 0·21F + 0·66) when both were applied to milks heated as required by B.S.S. no. 734 (1937) (i.e. Recknagel effect absent).4. Adoption of the B.S.S. technique and formula placed a very much greater proportion of samples, below the presumptive legal standard of 8·5% S.N.F.5. The need is indicated for the standardization of evaporation technique before attempting a permanent revision of the density formula.6. Seasonal variations between ‘calculated’ and ‘found’ results have been observed.
313. Bacteriological studies of roller-dried milk powders, roller-dried buttermilk and of roller- and spray-dried whey
Authors: Higginbottom Constance 
Published: June 2009

1. Bacteriological studies have been made of some 400 samples of dried milk products comprising roller-dried separated milk, roller-dried full-cream milk, roller-dried buttermilk, roller-dried whey and spray-dried whey. The samples were derived from a total of plants operating throughout Great Britain.2. The mean values for the plate counts at 37 and 55°C. of the roller-dried products were all below 1000 per g· as against ½–2½ million at 37°C. and 10,000–30,000 at 55°C. for the spray-dried products. The spray-dried products also gave three times as many positive presumptive coliform tests at all dilutions as did the roller-dried products.3. The roller-dried whey and the roller-dried buttermilk both gave more variable counts at 37°C. and higher counts at 55°C. than the roller-dried separated milk and the roller-dried full-cream milk. The spray-dried whey gave higher and more variable counts at both 37 and 55°. than the spray-dried milk.4. Marked differences were observed in the plate counts of samples derived from different plants, some plants giving consistently low counts and others giving higher and more variable figures. Differences were also observed in the counts at different stages of handling.5. Evidence was obtained which indicates that mould counts do not provide a reliable indication of recontamination subsequent to drying.
341. The effect of the pre-heating temperature on the bacterial count and storage life of whole milk powder spray-dried by the Krause process
Authors: Findlay J. D. , Higginbottom Constance , Smith J. A. B. 
Published: June 2009

1. Storage tests on spray-dried full-cream milk powders prepared from milk preheated at 160,170,180, 190 and 200° F. for approximately 20 sec. and dried by the Krause process have been carried out at 47, 37 and 15° C. or room temperature. The storage tests were carried out independently at two different research stations. At the Hannah Institute the powders were packed in plain tin-plate containers as received from the factory. At Cambridge grease-free plain tin-plate and lacquered tin-plate containers were used. Deterioration was followed at both stations by a tasting panel and by determination of the amount of oxygen absorbed by the powder and of the accumulation of peroxide in the fat.2. When fresh the powder pre-heated at 180° F. had the best flavour, followed in order of preference by those pre-heated at 190 and 200° F., which had a definite but quite pleasant ‘boiled’ or ‘cooked’ flavour, and by those pre-heated at 160 and 170° F. which had an incipient tallowy flavour, but were nevertheless still acceptable. The 200 and 190° F. powders gave a strong reaction for volatile sulphur, the 180° F. powder a much weaker but quite definite reaction, and the 170 and 160° F. powders a negative reaction. The copper content of the 180° F. powder which, with the 170° F. sample, was the highest of the group, may have been partly responsible for the weakness of the reaction for volatile sulphur given by this sample. The solubility of the 180, 190 and 200° F. powders was not adversely affected by the high pre-heating temperatures, and the moisture contents of all the powders were sufficiently low to prevent any obvious loss of solubility, which remained very good indeed throughout the storage tests.
345. Experiments on milking technique
Authors: Dodd F. H. , Foot A. S. 
Published: June 2009

1. During the first 2 weeks and last 2 weeks of a 9-week period nine cows, milked by machine, were prepared for milking by hosing and washing the udders with cold water 15 min. to 1 hr. before milking, while in the intervening 5 weeks the udders only were washed with water at 115 to 120° F. immediately before milking.2. The hot-water routine had no pronounced effect on the yield and quality of the milk from the majority of the cows, although one reacted unfavourably to a change back to the cold water routine and had to be stripped by hand.3. The gradual restriction, over an interval of 4–6 weeks, in the milking time from 100 to 60% of the previous normal flow period for three cows in mid-lactation had no great influence on the maximum rate of milk flow from the udder, even when hot-water washing of the udder immediately before milking was introduced late in the experiment. The maximum rate of flow was, however, reached slightly sooner after putting on the teat cups.4. The restriction in milking time caused only a small reduction in yield as the flow during the latter part of the flow period had in any case been small.5. The fat content of the milk of the cows whose milking time was restricted fell somewhat while the solids-not-fat content remained steady.6. Washing the udder with hot water or restricting milking time showed no clear-cut effect on the incidence of mastitis.
356. Bacteriophage in cheese manufacture: Contamination from farm equipment
Authors: Whitehead H. R. , Hunter G. J. E. 
Published: June 2009

Bacteriophage infection of the starter streptococci, which commonly causes ‘slowness’ in cheese manufacture, may arise from whey infection of milk cans used for the cartage of cheese whey from factory to farm. Thus ‘slowness’ can occur even when the starter itself and all the factory utensils are free from infection. The pasteurizing treatment which the cheese milk receives is not sufficient to destroy the traces of phage derived from infection of the milk cans.Three methods for eliminating this trouble were investigated:(i) Pasteurization of the whey at 190° F. for a few seconds immediately after removal from the cheese vat.(ii) Treatment of the whey with chloride of lime.(iii) The use of a series of single-strain starters in daily rotation in the cheese factory.All three methods proved practicable, although some mechanical difficulties were encountered in the particular pasteurization system which was tried. The third method is at present undergoing an extensive trial on a commercial scale. It is preferred in the first place because it is costless, whereas the first two methods would involve a regular additional cost in steam of chloride of lime.
357. Apparatus for routine estimation of oxygen in tins of milk powder
Authors: Thiel C. C. , Hills G. Loftus , Scharp L. R. 
Published: June 2009

An apparatus has been developed for the routine estimation of oxygen in the headspace gas of tins of dried milk. The sampling device is an integral part of the apparatus, which is constructed mainly of metal and is simple to operate. As many as twenty samples may be taken and analysed in an hour.Our thanks are due to the Drawing Office and Workshop staffs of the Division of Industrial Chemistry, Council for Scientific and Industrial Research, who designed and manufactured the equipment, and to the Maffra Co-operative Milk Products Co. Ltd., who permitted the apparatus to be tested in their laboratories under factory conditions.
362. Studies in the bacteriology of milk: I. The streptococci of milk
Authors: Abd-El-Malek Y. , Gibson T. 
Published: June 2009

The streptococci occurring in raw and pasteurized milks of varying purity have been investigated. The organisms were placed in five main groups by testing for the hydrolysis of arginine, growth at 45 and at 8–12° C, survival in milk at 63° C. for 30 min. (measured by a semi-quantitative plating method), action on litmus milk, and the ability to form CO2from glucose (tested by a cultural method). The groups thus distinguished are:(1) Organisms of bovine mastitis.(2)Str. bovisandStr. thermophilus. A clear-cut separation of these species was not obtained by tests for growth at 50° C, the hydrolysis of aesculin, or the fermentation of maltose or salicin; but, with suitable precautions, action on both maltose and salicin provides a differentiation. Certain strains ofStr. bovisdiffer from the typical form of that species in their ability to proliferate over a wider range of temperature and in higher concentrations of salt and methylene blue and in their failure to split aesculin.(3)Str. lactisandStr. cremoris, which were differentiated by tests for the hydrolysis of arginine and ability to grow at 40° C.(4)Str.faecalisand its varieties. Many of the strains are non-haemolytic but otherwise indistinguishable fromStr. durans. The formation of acetoin from citrate and from glucose are common but not universal properties in the enterococcus group.(5) Heterofermentative streptococci. The majority of the strains were identified asStr. kefir. Str. citrovorus, which was isolated only occasionally, was distinguished by its low maximum temperature (under 37° C), weak resistance to heat and by fermentation reactions.Raw milk was found to containStr. kefir, Str. lactisand the mastitis organisms more frequently than the other species.Str. thermophilusandStr. boviswere the dominant forms in freshly pasteurized milk. Pasteurized milk held at 10–22° C. until it became tainted yieldedStr. kefirandStr. faecalisand, at the higher temperatures,Str. bovisandStr. thermophilus.
370. The reaction between milk protein and reducing sugar in the ‘dry’ state
Authors: Lea C. H. 
Published: June 2009

‘Dry’, dialysed milk protein was stored for 6 months at 37° C. and 55% relative humidity alone and in the presence of small proportions of glucose, of high proportions of lactose and of sucrose, and of mixtures of these sugars.The reducing sugars combined with free amino-groups of the protein, apparently in a 1:1 ratio; sucrose did not. The reaction did not proceed to completion, probably owing to difficulty of access of the reactive groups to one another. Only when the sugar-amino reaction occurred did discoloration ensue.Glucose reacted more rapidly with the protein than did lactose, and the complex formed became discoloured and insoluble in both cold and hot water much more rapidly.Sucrose and lactose both greatly delayed the onset of glucose-induced insolubility, lactose being the more efficient of the two. They did not prevent discoloration.The protein alone became insoluble in cold but not in hot water after prolonged storage; but did not discolour. This change was prevented by sucrose. The behaviour of lactose was inconsistent, loss of solubility being accelerated in one experiment and retarded in another.