bluuebunny/crossref_metadata_2025_split huggingface dataset:
455. The ripening of Stilton cheese: changes in the volatile acid content
Authors: Hiscox E. R. , Harrison J. , Wolf J. Z. 
Published: June 2009

The changes in the volatile acidity and other factors during the ripening process of Stilton cheese have been studied. The growth of the mould was characterized by an increase in the fat-soluble fatty acids derived from the cheese fat.Pricking the cheese ensured a more uniform blueing and hastened the ripening. There was no evidence that judicious pricking at 2 months after manufacture seriously affected the course of the ripening. Excessive pricking, however, produced abnormal cheese of poor keeping quality.
456. The calcium and phosphorus of Cheddar and Stilton cheese: I.Cheddar and Stilton cheese of normal manufacture: II. The distribution of calcium between the crumb and coat of Stilton cheese
Authors: Mattick E. C. V. 
Published: June 2009

The loss of calcium and phosphorus during the manufacture of hard pressed (Cheddar) and impressed (Stilton) cheese made from the same bulk of milk has been studied. It is found that there is little loss of mineral salts from the hard pressed variety either after cutting the curd during making, or while the cheese is ripening. In the case of the unpressed variety there is constantly increasing percentage loss of minerals, correlated with an increase of titratable acidity in the whey, until the last stages of manufacture when the cheese are removed from the hoops for scraping.The figures confirm those previously found (i) that in the cheese examined 57–58% of the calcium and 50–51% of the phosphorus present in the milk originally used, remains in the hard pressed ripe cheese, but that only 6–8 % of the calcium and 27 % of the phosphorus are left in the unpressed variety when ripe.
499. The inhibition of micro-organisms by raw milk: I. The occurrence of inhibitory and stimulatory phenomena. Methods of estimation
Authors: Auclair J. E. , Hirsch A. 
Published: June 2009

1. A diffusion cup technique using Micrococcus lysodeikticus has been found suitable for lysozyme estimation. By this method raw milk gave only small zones of inhibition. The inhibitory substance of milk was shown not to be lysozyme.2. Dose-response curves (dilution v. pH) were obtained with Streptococcus pyogenes as the test organism. They indicated that the effect of milk on this organism was the result of the interaction of one stimulatory and at least two inhibitory substances.3. The existence of two inhibitory substances was confirmed by dilution assays, one, L1, occurring mainly in colostrum, the other, L2, occurring mainly in milk. The inhibition is greatest when L1 and L2 act simultaneously.4. The pH and heat stabilities of the two substances are slightly different. L1 is most stable at pH 6−6·5, 90% being destroyed at 68° C. L2 is most stable at pH 7 and 95% is destroyed at 74°C.
505. The accuracy of measurements of the mammary glands by the method of palpation
Authors: Sheppard D 
Published: June 2009

1. An investigation was carried out, using objectively measurable stimuli, to examine the method of assessing the size of the mammary glands of calves by palpation. The method was that described by Swett.2. The results indicate that the estimated sizes may be very different from the true sizes, although the two are generally highly correlated. In most cases the estimated sizes are significantly smaller than the true sizes.3. Different judges give very different estimated sizes for the same true sizes, thus it is not justifiable to compare directly glands which have been stated to be of the same size by different judges.
541. A note on the vitamin D content of Indian butters
Authors: Henry K. M. , Kon S. K. 
Published: June 2009

1. The vitamin D potency of three samples of south Indian butter has been determined in prophylactic tests with rats.2. Two samples of butter from Bangalore contained 0·56 and 0·41 i.u. vitamin D/g. fat, a sample from Coimbatore contained 0·29 i.u./g. fat.
617. Variations in the carotene and vitamin A contents of herd butterfats throughout lactation
Authors: McDowell A. K. R. 
Published: June 2009

The carotene and vitamin A contents of the butterfat from the milk yielded by the cow in early lactation may be higher than normal for a period of up to 10 or 12 days after parturition.Seasonal changes in carotene content of butterfat from small herds of cows were governed almost entirely by the availability of carotene in the pasture and not by lactational influences.Seasonal changes in vitamin A content of the herd butterfats were relatively small during most or all of the lactational period. In certain years an increase in the vitamin A content during the autumn months was probably due to seasonal conditions and not to a lactational effect.
624. Udder infections in the ‘dry period’: II. The effect of withdrawing secretion from the dry udder on the incidence of infection
Authors: Oliver J. , Dodd F. H. , Neave F. K. , Lee J. M. 
Published: June 2009

1. An experiment was carried out with seventy-five dry cows to study the effect of taking samples of udder secretion for bacteriological examination on the incidence of new infection in the early dry period. The incidence of new infection in two quarters of each cow, sampled at weekly intervals after drying off, was compared with that in the remaining two quarters sampled in the fourth and fifth week of the dry period.2. No difference in the new infection rates was found between the quarters that were sampled early in the dry period and those that were not.3. Significantly fewer (P <0·05) staphylococcus infections occurred in quarters sampled in the early dry period compared with those sampled at a later stage.4. About half of all the new infections persisted until the next lactation.5. It was concluded that if natural sealing of the teat orifice or teat sinus takes place it is of minor importance in preventing infection in the early dry period.
634. The determination of the coagulating power of commercial rennet extracts using an automatic tester
Authors: Storrs F. C. 
Published: June 2009

1. A method for preparing rennet reference standards by freeze-drying is described.2. A substrate has also been developed using ordinary spray dried separated milk powder which will give reproducible results under specified conditions. These include:(i) A constant temperature (37° C.) for the duration of the test.(ii) The exclusion of added calcium ions until actual testing begins.(iii) The equilibration of the milk at 37° C. for 2 hr. before use.3. The construction and use of an automatic apparatus for recording rennet coagulation time is also described.4. The instrument error of a single observation is about 1·0%.5. With liquid rennet extracts, the total experimental error, based on one sample of three replicates, is 2% or less: with two samples, it is 1% or less.6. With freeze-dried rennet preparations, the experimental error with two ampoules, sampled thrice with three replicates per sample, was ±2·.0%. With three ampoules it was ±1% or less.
705. A comparison of dried skim-milk and white fish meal as protein supplements for fattening pigs: II. On all-meal feeding under commercial conditions
Authors: Braude R. , Clarke Pamela M. , Mitchell K. G. , Cray A. S. , Franke A. , Sedgwick P. H. 
Published: June 2009

1. Results are reported of an experiment carried out under commercial conditions to obtain information on the comparative value of dried skim-milk and white fish meal as protein supplements for fattening pigs.2. There were four treatments. Control pigs (i) received a meal mixture containing 10% white fish meal, reduced to 7% from 130 lb. live weight. In the other experimental groups, the fish meal was replaced by dried skim-milk, (ii) on a weight for weight basis, (iv) on a protein basis and (iii) intermediate between (ii) and (iv). All pigs were fed the meal dry and ad lib. up to a maximum of 6½ lb./head daily. Unrestricted water was available.There were five pens of nine group-fed pigs on each treatment, involving a total of 180 pigs. The pigs were on experiment from approximately 10 weeks of age to bacon weight. Comprehensive carcass measurements were made on all the pigs.3. The results showed that a significantly better rate of growth was obtained when the white fish meal was replaced by dried skim-milk on a weight for weight basis. Increasing the percentage of skim-milk in the diet up to 15% resulted in a slightly better performance of the pigs, but no further improvement was obtained by raising the level of skim-milk to 20%. These results were discussed in relation to an apparent set-back that the control pigs suffered at the start of the experimental period.4. The inclusion of dried skim-milk in the diet had an adverse effect on the carcass grading, particularly in so far as it resulted in a thicker layer of back fat over the loin as compared with that in the control pigs.5. There was also some indication that the carcasses from the animals given dried skim-milk had slightly thicker bellies and a smaller breadth of eye muscle than the carcasses of the control animals that received fish meal.6. The results have been compared with those of an earlier trial, which was in most details the same as that reported here, the main difference being that in the earlier experiment individual feeding and one breed of pig were used.
707. Phospholipids in New Zealand dairy products: I. The estimation of the total phospholipids and of lecithin, cephalin and sphingomyelin in butter
Authors: McDowell A. K. R. 
Published: June 2009

A method has been described for the routine estimation of total phospholipids and of lecithin, cephalin and sphingomyelin in butter. Butter serum was treated with ether and light petroleum in a modified Röse-Gottlieb procedure to extract the phospholipids which then were estimated in the extract.Chloroform-methanol extracted from the butter serum slightly more phosphorus than did the ether-light petroleum mixture. Ethanol-ether, benzene-ethanol and benzene-isopropanol, when used to extract a protein-phospholipid precipitate formed by the addition of trichloroacetic acid to butter serum, also removed slightly more phosphorus than did the ether-light petroleum mixture. The higher phosphorus contents of these extracts was due partly to a slightly more efficient extraction of phospholipids and partly to extraction of non-phospholipid phosphorus compounds.
717. Physical changes in milk caused by the action of rennet: II. Heats of reaction
Authors: Phipps L. W. 
Published: June 2009

The rennet-catalysed coagulation of milk casein has been examined calorimetrically. The heat of coagulation and syneresis was found to be less than 0·1 cal.'40 ml. of milk, the limiting sensitivity of the apparatus.Heats of reaction approaching 0·5 cal. were observed when the milk was acted upon by the enzymes trypsin and papain. It is doubtful whether, at this stage, the results can be correlated with the several phases of the reaction.
Steam distillation of taints from cream: VI. Butterfat/lactose-solution distribution coefficients of some reference substances
Authors: McDowall F. H. 
Published: June 2009

1. Coefficients of distribution for acetoin, diacetyl and acetylpropionyl between butterfat and skim-milk were measured over a range of temperatures up to 190° F. by passing preheated milk containing the reference substance through an hermetic cream separator and analysing the cream and skim-milk obtained.2. The coefficients increased with rise in temperature, and the relationship between change in coefficient and change in temperature was linear for all three substances.3. Coefficients of distribution for acetyl-iso-butyryl, acetylvaleryl, acetylcaproyl and acetylbenzoyl between butterfat and 4·5% lactose solution were measured at 40° and 60° C. by direct separation after equilibration, followed by estimation of the diketone in the lactose solution.4. Coefficients of distribution at 100° C., obtained by linear extrapolation from these results, were: acetoin, 0·255; diacetyl, 1·27; acetylpropionyl, 5·9; acetyl-iso-butyryl, 20; acetylvaleryl, 23; acetylcaproyl, 152; acetylbenzoyl, 48.5. The coefficients of distribution for diacetyl and acetylpropionyl between butterfat and 4·5% lactose solution were not affected by change in concentration of the diketone in the lactose solution.
Physical changes in milk caused by the action of rennet: IV. Effects of varying rennet concentration and temperature.
Authors: Blair G. W. Scott , Burnett J. 
Published: June 2009

1. Under carefully standardized conditions, the increase in the over-all rigidity modulus of curd when the time after rennetting is doubled, varies inversely as the cube root of the rennet concentration. The intercepts of the extrapolated setting curves on the time axis and the observed coagulation times vary inversely as the concentration.2. With the same (normal) rennet concentration, some rheological parameters increase or decrease progressively as temperature is increased from 21° to 41° C.; others pass through maxima or minima, all between 29° and 35° C.3. Long-term ‘creep’ experiments have been done over the above temperature range, creep and slow recovery increasing progressively with temperature. Relaxation experiments, though showing the simplest distribution of relaxation times at about 32° C., are too greatly influenced by unavoidable differences in firmness at the different temperatures for it to be possible, at this stage, to draw conclusions about their temperature dependence.4. A comparison of some of these results with data published by a few other workers is attempted.
Isolation and identification of the high molecular weight saturated fatty acids of butterfat
Authors: Hansen R. P. , Shorland F. B. , Cooke N. June 
Published: June 2009

Butterfat has been shown to contain thenormalodd-numbered saturated acidsn-nonadecanoic acid (C19),n-heneicosanoic acid (C21), andn-tricosanoic acids (C23).The presence of the normaleven-numbered acidsn-octadecanoic acid (C18),n-docosanoic acid (C22),n-tetracosanoic acid (C24) andn-hexacosanoic acid (C26) is conclusively established.n-Eicosanoic acid (C20) formerly assumed to be present in butterfat has been isolated and identified by its physical and chemical properties.
Chemical changes in dried skim-milk during storage
Authors: Richards E. L. , Chandrasekhara M. R. 
Published: June 2009

SummaryDried skim-milk stored at 55°C in air at 70% relative humidity has been found to contain lactulose, galactose, tagatose, glyceraldehyde and maltol; and formic, acetic and glycollic acids. These compounds are not present, or are present only in trace quantities, in fresh dried skim-milk. It is suggested that while the proteinsugar reaction is responsible for most of the browning of the powder, many of the compounds found are formed by degradation of lactose catalysed by the free basic amino groups of the casein. The compounds so formed probably then react with amino groups in a Maillard reaction and thus contribute to the browning of the milk powder.
Studies on the manufacture of sweet cream starter butter: I. Effect of cream-holding temperature
Authors: McDowall F. H. , Singleton J. A. , Le Heron B. S. 
Published: June 2009

SummaryBatches of cream inoculated with 1% of a culture of Streptococcus diacetilactis or of one or other of two mixed starters were held at different temperatures over the range 37–57°F before churning. Diacetyl and acetoin were estimated in the creams at churning and in the butters fresh and after storage.The diacetyl production of all three starters in the cream increased with increase in temperature, although at the lower temperatures there was no indication of any rise in titratable acidity. At 52 and 57°F there was some rise in acidity during the holding period.The butters were of good keeping quality. There was a small but definite reduction in the diacetyl content of the butters during storage, but the extent of the change was not related to the holding temperature of the creams.It was concluded that if sweet cream starter butter is to be made with uniform intensity of flavour the proportion of starter added must be adjusted to counterbalance changes in the cream-holding temperature.
Studies on the manufacture of sweet cream starter butter: II. Effect of variation in proportion of starter added to cream
Authors: McDowall F. H. , Singleton J. A. , Le Heron B. S. 
Published: June 2009

SummaryProduction of diacetyl and acetoin by starters in cold skim-milk and cream was shown to increase with increase in the proportion of starter culture added, with some limitations at the higher rates of starter addition.With Streptococcus diacetilactis starter in skim-milk at 50°F the relation between proportion of starter added and production of diacetyl was linear up to addition at the 4% level, whereas at 43°F it was approximately linear up to the 10% level. At both 50 and 43°F the relation between the proportion of starter added and the production of acetoin was linear up to the 10% level.With Camb starter in skim-milk at both 50 and 43°F there were regular increases in production of diacetyl up to the 4% level of addition, but only minor changes thereafter with increase in the proportion of starter added up to 10%. At both temperatures the maximum production of acetoin was reached with the 7% rate of addition.Production of diacetyl and acetoin in skim-milk was greater at 50°F than at 43°F with both starters for all proportions up to 10%, and it was greater for Str. diacetilactis than for the mixed cultures.Except at the higher rates of addition of starter and at the higher temperature there were no concomitant increases in the acidity of the milk or lowering of the pH values. It appears that at low temperatures production of diacetyl by starters in sweet milk and cream proceeds independently of production of lactic acid.Similar results were obtained in a series of experimental buttermaking trials and some small commercial-scale trials, in which varying proportions of starter were added to creams after pasteurizing and before holding overnight for churning. With the cream-holding temperatures used, mainly 40–50°F, the pH values of the butters were not appreciably lowered by the starter additions to the cream. At all the rates of addition there were with Str. diacetilactis starter higher contents of diacetyl in the butter than with Camb starter. There was no indication of any relationship between the proportion of starter added and the keeping quality of the butter.
A comparison of biochemical and paper chromatographic methods for the identification of group D Streptococci from Cheddar cheese
Authors: Steenson T. I. , Robertson P. S. 
Published: June 2009

SummaryForty-four strains of tributyrolytic group D streptococci isolated from Cheddar cheese were identified by physiological, biochemical and serological tests. They were also independently grouped using two-way paper chromatography in which patterns of ninhydrin positive spots were developed from 10% acetic acid extracts of the bacteria. The groupings obtained by the chromatographic and conventional techniques were then compared. Strains of Str. durans were well differentiated by chromatography from the other species of group D streptococci examined, but with the remainder less clear differentiation was obtained.
A note on a method of overcoming the effect of udder disease or injury in experiments involving milk yield and composition
Authors: Waite R. 
Published: June 2009

SummaryIn experiments to determine the effect of feeding changes on milk yield and composition, udder disease or injury may easily invalidate the results, particularly those for milk composition. It is suggested that regular examination of the milk from each quarter of the udder would allow a diseased or injured quarter to be recognized and a true value for the effect of the feeding treatment to be obtained from the composition of the milk from at least two healthy quarters. Examples to illustrate the suggestion are given.
Surface oxidation in cold-stored butter: the effects of desiccation and moisture absorption
Authors: Pont E. G. , Rogers W. P. 
Published: June 2009

SummaryUnwrapped samples of salted sweet-cream butter were stored in darkness at 1°C for 6–8 weeks over silica gel, water, isotonic salt solutions, and in free air. Moisture and fat peroxide gradients from the surfaces to the interior of the stored samples were measured in thin sections obtained by a simple macrotome technique. The surface oxidized at the same rate as the rest of the butter and its rate of oxidation was not affected by moderate drying or moisture uptake. With severe surface drying, especially when induced by silica gel, fat oxidation was inhibited, while moisture uptake by the more heavily salted butters promoted surface oxidation.
The use of quarter samples in the assessment of the effects of feeding treatments on milk composition
Authors: Waite R. , Abbot J. , Blackburn P. S. 
Published: June 2009

SummaryTo investigate whether milk of abnormal quality from some quarters of twelve cows on a Latin square type feeding trial would bias the results for chemical composition, the compositions of milk from normal and affected quarters were compared with each other and with that of the milk obtained from the whole udder by normal milking.The average number of quarters producing abnormal milk in each of the four periods was eighteen, with only small variation between periods. Cell counts ranged from 50000 to 25 × 106/ml with 31% of them below 500000/ml; as cell count increased, lactose percentage and casein number fell. Pathogenic bacteria were detected in only 70% of the abnormal milks. The solids-not-fat (S.N.F.) percentage of milk from affected quarters was lower on average than that from healthy quarters by 0·43, the decrease resulting entirely from a lowered lactose percentage. The total nitrogen content was the same in both types of milk, but there was 4·5% less casein in milks from affected quarters.Because in this particular experiment the distribution of the abnormal milks was almost uniform over the four feeding treatments, the results obtained for treatment effect on milk composition by the normal milking method were not biased by the occurrence of disease, but the general level of composition was depressed by 0·2% fat and 0·2% S.N.F. In other experiments the incidence of disease might happen by chance to differ between treatments, with the result that the findings about milk composition could be erroneous.
Determination of leucocyte concentrations in cow's milk with a Coulter counter
Authors: Phipps L. W. , Newbould F. H. S. 
Published: June 2009

SummaryA technique for determining the concentration of leucocytes in cow's milk is described which is more rapid and accurate as well as much less tedious than conventional microscope methods. The leucocytes are isolated from the fat globules of comparable size by a novel centrifuging procedure. Sizing of the leucocytes with a Coulter electronic counter shows that their volumes range from about 45 to 1770 µm3but a partially overlapping distribution of other particulate matter prevents the accurate determination of the total number of cells present. The numbers counted in truncated leucocyte distributions, however, correlate linearly with total cell counts determined with an improved microscope method up to 6 × 106cells/ml of milk.