bluuebunny/crossref_metadata_2025_split huggingface dataset:
583. The effect of steam, hypochlorite and caustic soda used for treating direct-to-can milking equipment, on the bacteriological quality and flora of milk
Authors: Carreira D. F. C. , Clegg L. F. L. , Clough P. A. , Thiel C. C. , Akam D. N. , Gruber Marie , Hirons Elizabeth 
Published: June 2009

Two farms, using direct-to-can milking, were used to compare utensil cleaning with hot detergent solution followed by hypochlorite on one farm and steam on the other, with immersion of the complete milking equipment in 5% caustic soda between milkings. Control and caustic treatments were used alternately for periods of 8 weeks for a total of 8 months.Bacteriological tests made at weekly intervals on fresh milk and milk aged for 24 hr. at 22° C. showed little difference between the control methods, which involved brushing the milk contact surfaces, and the caustic soda method where there is no brushing.The majority of micro-organisms in the bulk milk came from the udder and the utensils contributed little to the milk. It appeared that where utensils are satisfactorily cleaned, milking technique will be the factor which mainly affects keeping quality.A study of the predominant flora revealed that milk from equipment cleaned by immersion in caustic soda had a simpler flora (mainly micrococci) than the control treatments.
588. The influence of the content and composition of protein in milk on the manufacture of cottage cheese
Authors: Henson J. H. , Miller T. B. 
Published: June 2009

1. The problem of unsatisfactory curd formation in cottage-cheese manufacture has been studied in relation to milk composition.2. Addition of calcium chloride to the milk did not produce significant improvement.3. There was a distinct breed difference in the curd formation; Jersey milk produced satisfactory curd whilst Friesian milk invariably produced unsatisfactory curd.4. Dilution of Jersey milk to the same level of precipitable casein as Friesian milk resulted in unsatisfactory curd.5. The presence of 10 % Friesian milk in Jersey milk rendered the latter unsatisfactory.6. The Walker formol titration for determination of casein gave significantly high values with Friesian milk. This is attributed to the different distribution of nitrogen in Friesian milk.
596. Steam distillation of taints from cream: I. Theoretical considerations and properties of the reference substances, diacetyl and acetoin
Authors: McDowall F. H. 
Published: June 2009

The rate of removal of a dissolved tainting substance from cream by steam-distillation treatment is dependent in part on the relative volatility (or boiling point) of the pure substance, in part on the temperature of steam distillation, and in part on the influence of water on the vapour pressure of the tainting substance in dilute solution (i.e. on the activity coefficient, γ).The application of Raoult's law and Henry's law to the problem of removal of taints from cream is discussed. For the dilute solutions commonly encountered in cream Henry's law can be expected to apply.The equilibrium relationships for diacetyl and acetoin used as reference substances in investigations on cream-deodorizing equipment have been determined. The equilibrium coefficient for diacetyl in water at concentrations up to 50 p.p.m. in the liquid, as measured by the continuous equilibrium vaporization method, is 39·3. With rise in concentration above 50 p.p.m. in the liquid the coefficient decreases. At 100 p.p.m. it is 32 and at 1000 p.p.m. it is 20. The coefficient for acetoin in water at all concentrations up to 1·2% in the liquid is constant at 1·29. The activity coefficient for diacetyl in concentrations up to 50 p.p.m. was found to be 26·4 and for acetoin at concentrations up to 1·2%, 5·4.For diacetyl the solubility partition coefficient as between butterfat and water rises from 0·47 at 100° F. to 0·74 at 180° F. For acetoin the partition coefficient remains constant at 0·18–0·19 over this range of temperatures. Correspondingly diacetyl is removed equally easily from butterfat and from water, whereas acetoin steam-distils much more readily from butterfat than from water.
657. Factors influencing the vitamin content of milk fat: III. Seasonal changes in the vitamin A and carotenoid content of the blood plasma and milk fat of cows on pasture
Authors: McGillivray W. A. 
Published: June 2009

1. The levels of vitamin A alcohol and ester, carotene and xanthophyll in the blood plasma of six cows, grazed out-of-doors on pasture under typical New Zealand conditions, have been followed throughout one lactation. The same constituents have also been followed in the milk fats of these animals and in commercial factory butters over the same season.2. The seasonal trend in the vitamin A and carotenoid content of New Zealand milk fat is a reflexion of the changing level of these substances in the blood plasma.3. The decreased level of carotene, xanthophyll and vitamin A ester in the blood plasma over the summer months is consistent with a decreased absorption or utilization of carotenoids over this period.4. Throughout the year the vitamin A in the milk fat is predominantly in the ester form with no increase in vitamin A alcohol indicative of any increased utilization of hepatic vitamin A reserves.The author is indebted to the Department of Scientific and Industrial Research for a grant towards this investigation; to Mr M. R. Patchell and the farm staff of The Dairy Research Institute (N.Z.) for assistance in the collection of milk and blood samples; to Dr F. H. McDowall, Mr A. K. R. McDowell and the staff of the Chemistry Laboratory, The Dairy Research Institute (N.Z.), for the preparation of the fat samples and for the supply of factory butters. The assistance of Miss Fay Frecklington and Miss Jane Monroe with part of the experimental work is also acknowledged.
701. A comparison of dried skim-milk and white fish-meal as protein supplements for fattening pigs
Authors: Barber R. S. , Braude R. , Mitchell K. G. 
Published: June 2009

1. Thirty-six 9–11-week-old Large White pigs in nine blocks of four litter-mates were individually fed on diets containing either white fish-meal or various amounts of dried skim-milk as the protein supplement. The pigs were fed according to live weight and a scale up to a maximum of 6½ 1b. of meal/pig/day.2. There were no significant differences in rate of growth or efficiency of food utilization between pigs given the diets containing as protein supplements either 10% white fish-meal reduced to 7% at 130 1b. live weight, 10% dried skim-milk reduced to 7%, or 15% dried skim-milk reduced to 10½%.There was, however, a trend towards an improvement in both rate of growth and efficiency of food utilization with increasing levels of skim-milk in the ration, and the differences between the high skim-milk diet (20 reduced to 14%) and the low (10 reduced to 7%), and also between the former and the fish-meal diet, reached statistical significance.3. The difficulties of drawing any definite conclusions from the results about the relative value of the protein in white fish-meal and dried skim-milk were discussed in relation to (a) the probability that the white fish-meal diet used contained over-generous supplies of protein, and (b) the higher energy value of dried skim-milk as compared with white fish-meal.4. The commercial grading of pigs on all four treatments was very good. The carcass measurement data indicated a tendency for the skim-milk diets, particularly those containing either 10 or 15%, to result in some increase in both back fat and belly thickness. The possibility that this was associated with the higher energy/protein ratios in the skim-milk as compared with the white fish-meal diets was discussed.
702. Winter feeding of dairy cows: V. A comparison of the relative value for milk production of artificially dried cocksfoot and a timothy/meadow-fescue mixture grown both in spring and in autumn
Authors: Campling R. C. , Holmes W. 
Published: June 2009

1. An experiment was conducted to compare the relative value for winter milk production of artificially dried cocksfoot and a mixture of timothy and meadow-fescue each cut in the spring and autumn.2. A double balanced 4×4 Latin square design with eight Ayrshire cows and four periods each of 3 weeks' duration was used.3. The dried grasses were fed in equal amounts (17 lb./cow/day) and equal quantities of each grass were consumed in terms of dry matter. Approximately half the total dry matter intake was grass.4. No differences were detected between the cocksfoot and the timothy/meadow-fescue mixtures in their value for milk production.5. With both cocksfoot and timothy/meadow-fescue the spring-grown grass gave slightly higher milk yields than the autumn-grown grasses but the differences were not statistically significant.6. Feeding the spring-grown dried grasses led to a slightly higher solids-not-fat content in the milk than when the autumn-grown grasses were fed.7. The feeding of the autumn grown timothy/meadow-fescue grass mixture was associated with a significant loss of live weight in the cows. It was suggested that this loss of weight was due primarily to changes in the amount of the contents of the rumen and intestines.
712. The relation between the chemical composition of milk and the stability of the caseinate complex: I. General introduction, description of samples, methods and chemical composition of samples
Authors: White J. C. D. , Davies D. T. 
Published: June 2009

1. This paper is Part I of a series dealing with the relation between the chemical composition of milk and the stability of the caseinate complex to ethanol (Part II), rennet (Part III) and heat (Part IV).2. A description is given of the milk samples, which were taken from herd bulk milk, from individual cows in different stages of lactation and also from cows with subclinical mastitis.3. The methods used to measure the stability of the caseinate complex to the three coagulating agents are described, together with the methods used to make a detailed chemical analysis of the milk samples.4. The chemical composition of the samples is given and also the relation between composition and stage of lactation, and the interrelations of the concentrations of certain milk constituents.The authors thank Miss M. H. King and Miss R. E. M. Stevenson for technical assistance, Mr N. H. Strachan and Mr R. C. Voss (West of Scotland Agricultural College) for the sodium and potassium determinations and Dr P. S. Blackburn for the differential cell counts and bacteriological examination of the milks.
Steam distillation of taints from cream: VII. Butterfat/water distribution coefficients in relation to vapour/liquid equilibrium coefficients for tainting substances in cream
Authors: McDowall F. H. 
Published: June 2009

1. The relationship between vapour/liquid equilibrium coefficient for a tainting substance in cream (mc) as compared with the coefficient for the substance in skim-milk (ms) at 100° C. is given by the formulawhere F is the percentage fat content of the cream, and k is the butterfat/skim-milk distribution coefficient at 100° C.2. The values for the vapour/liquid equilibrium coefficients for acetoin, diacetyl, acetylpropionyl, acetyl-iso-butyryl, acetylvaleryl, acetylcaproyl and acetylbenzoyl in cream, computed by the formula from the equilibrium coefficients for the substances in 4·5% lactose solutions and the distribution ratios at 100° C, were in good agreement with the experimental results for these substances in cream.3. It was shown that high solubility of a substance in butterfat relative to solubility in skim-milk greatly reduces the steam volatility of the substance from cream.4. It was concluded that steam volatility of a substance from cream may be affected by temperature of deodorization because of the effect of temperature on the butterfat'skim-milk distribution coefficient.
Lactobacilli in Cheddar cheese
Authors: Johns C. K. , Cole Shirley E. 
Published: June 2009

The numbers of lactobacilli present in milk for cheese-making and in the cheese at various stages of ripening, have been determined for 38 Cheddar cheeses made during studies on flavour enhancement. These organisms multiplied rapidly even during the first few days of curing. Maximum levels were attained at 3–6 months; at 1 year counts had declined appreciably.Flavour intensity in the experimental cheese appeared to be correlated with the level of lactobacilli present in (a) milk at the start of cheese-making and (b) at subsequent stages of ripening. These two count levels were usually closely correlated. Factory raw milk had the highest counts and gave the highest degree of flavour, followed by similar milk pasteurized and inoculated with selected strains of lactobacilli.
Phage resistance in pure strains of cheese starter streptococci
Authors: Robertson P. S. 
Published: June 2009

SummaryThe ratio of phage-resistant to phage-susceptible chains in five strains ofStreptococcus cremorisand two ofStr. lactiswas investigated. It was shown that this ratio varied between strains and was decreased when the cultures were subcultured with extremely small inocula ( <50 chains/ml) and increased with relatively large inocula (1%). It is suggested that resistant cells arise by mutations occurring in the absence of phage.
Studies on the manufacture of sweet cream starter butter: III. Effect of age of starter cultures at time of inoculation
Authors: McDowall F. H. , Singleton J. A. , Le Heron B. S. 
Published: June 2009

SummaryThe use of starter cultures prepared 3 days, 2 days and 1 day before inoculation at the 1% level into cold cream in the making of sweet cream starter butter was investigated. With Streptococcus diacetilactis starter there was little effect of age of starter on diacetyl production in the cream and on the quality of the fresh butter, but when 3-day-old culture was used in the cream there was a slight reduction in the butter quality after 4 and 8 months' storage. With the mixed commercial cultures Camb and F.D. increase in age of the culture led to reductions in diacetyl production in the cream. The difference was attributed to the effect of holding for the longer time under acid conditions on the equilibrium between streptococci and leuconostocs in the mixed culture. The age of the Camb culture had no effect on the grade of the butter, but holding the F.D. culture for 3 and 2 days instead of for 1 day caused a fall in grade of the butter after storage for 4 and 8 months at 14 °F.
Physical properties of milk fat: I. Influence of chemical modification
Authors: de Man J. M. 
Published: June 2009

SummaryInteresterification of milk fats resulted in increased softening points, hardness and high melting glycerides (HMG). Increasing the content of trans-unsaturated acyl groups in milk fat resulted in increased softening points and hardness. While the increased solid fat content after interesterification occurred mostly at the higher measuring temperatures, the increase due to isomerization occurred mainly at the lower measuring temperatures. However, in both cases hardness was increased at all measuring temperatures. These results indicate that glyceride structure and trans-unsaturated acyl content influence the physical properties of the solidified fat.
The effect of hydrogen peroxide on the nutritive value of milk
Authors: Gregory Margaret E. , Henry Kathleen M. , Kon S. K. , Porter J. W. G. , Thompson S. Y. , Benjamin Margaret I. W. 
Published: June 2009

SummaryTreatment of milk with 0·05% (w/v) H2O2 for 8 h at 24°C had no significant effect on the concentrations of seven of the B-complex vitamins or of the fatsoluble vitamins A and E or of carotene. Rat tests showed that the nutritive value of the milk proteins was slightly reduced. This finding was confirmed by microbiological tests with Streptococcus zymogenes, which also showed that the loss was probably connected with that of methionine. The concentration of H2O2 used was effective in controlling bacterial growth during the incubation period, even in a sample of milk with a high initial bacterial count.
The effect of level of concentrate feeding before and after calving on the production of dairy cows
Authors: Castle M. E. , Watson J. N. 
Published: June 2009

SummaryTwo levels of steaming-up and two levels of concentrate feeding after calving were compared in a feeding trial extending over a complete lactation using sixteen autumn-calving Ayrshire cows in each of 2 years. On the high and low levels of steaming-up 3·3 and 1·6 cwt of concentrates respectively were fed per cow in the 5 weeks before calving. On the high and low levels of concentrate feeding after calving the concentrates were fed at rates of 4·1 and 2·2 lb per 10 lb of milk respectively from the third day after calving until spring grazing began. The total weight of concentrates fed after calving was 25·8 cwt per cow on the high treatment and 12·1 cwt on the low treatment. All the cows grazed good pasture in the autumn and the following spring and had a ration of 9–11 lb of hay and 50–90 lb of grass silage per day during the winter feeding period. During this period the estimated mean intakes of starch equivalent on the high and low concentrate treatments were 17 and 13 lb/day, which were equivalent to 122 and 103% of Woodman's standards respectively.Milk yield, milk quality, length of lactation and live weight were not affected by the difference between the steaming-up treatments, and no interaction between steaming-up and post-calving treatments was found. Average milk yields in the first 70 and 140 days after calving and in the complete lactations were all higher on the high post-calving concentrate treatment than on the low treatment, and the response per 1 lb additional starch equivalent fed was 1·05 lb milk. The fat content of the milk was similar on all treatments whereas the S.N.F. content increased from 8·64% on the low treatment to 8·82% on the high treatment, giving a response of 0·045% S.N.F. per 1 lb of additional starch equivalent.Larger losses in live weight occurred on the low treatment in the first 10 weeks after calving than on the high treatment, but in both groups the weights were almost identical after 45 weeks.
Estimation of oestrogenic activity in red clover (Trifolium pratense) using ovariectomized immature mice
Authors: Munford R. E. , Flux D. S. 
Published: June 2009

SummaryTwo experiments concerned with the testing of plant material for oestrogenic activity, utilizing vaginal reactions and uterine weight changes in immature ovariectomized mice are reported.In the first experiment the effects of varying the feeding period of an oestrogenic diet, containing 20% of freeze-dried red clover, and of varying the interval between the last feeding of this diet and slaughter were investigated. In general, uterine weight increased linearly with increased period of feeding and decreased linearly with delay in slaughtering. A feeding period of 4 days was satisfactory for comparisons based on uterine weight. If vaginal reactions were also to be utilized a feeding period of not less than 6 days was desirable.In the second experiment the dose-response relationships of diethylstilboestrol, genistein and oestrogenic red clover were investigated. All materials were incorporated in the diet of mice, and the level of plant material was kept at 20% of the mixed feed by adding inactive plant material where necessary. In general, either diethylstilboestrol or genistein could form a satisfactory standard for biological estimation of oestrogenic activity in red clover. Relative potencies based on uterine weight response and occurrence of vaginal opening and oestrus-type vaginal smears are given.
Studies on the properties of new zealand butterfat: VI. Comparison of the properties and vitamin A potencies of butterfats produced by clover-fed and ryegrass-fed dairy cows
Authors: McDowall F. H. , McGillivray W. A. 
Published: June 2009

SummaryIn an indoor feeding trial with three sets of monozygotic twin cows during late spring the effects of H1short rotation ryegrass and white clover as feeds for the cows on the characteristics and the carotene and vitamin A contents of the butterfat were compared. The butterfat from the cows fed ryegrass had a lower iodine value and refractive index, higher Reichert and saponification values, and lower carotene and vitamin A contents than the butterfat from the cows fed clover. The carotene and vitamin A contents of the blood of the cows fed ryegrass were also lower than those of the cows fed cloverIn a subsequent outdoor feeding trial with four sets of monozygotic twins the feeding of pure H1short rotation ryegrass or of perennial ryegrass was compared with the feeding of mixed pastures containing a high but varying proportion of clover. The results for the spring and early summer months were similar in direction but smaller in magnitude than those from the indoor feeding trial. In the result for the autumn months there was a reversal of the relationship for the characteristics and the carotene and vitamin A contents of the butterfat and for the carotenoid contents of the blood.It is suggested that the lack of consistency between the spring and autumn results could have been due to differences in the stage of growth of the ryegrass fed and that butterfat characteristics may be influenced more by the stage of maturity than by the botanical composition of the pasture.
Studies on thek-casein complex: I. The release of sialic acid-containing material by rennin
Authors: Beeby R. 
Published: June 2009

SummaryWhenk-casein was treated with rennin at neutral pH all the sialic acid contained in the protein was found in the glycopeptide released by the enzyme. From the known molecular weight of the glycopeptide and its proportion ink-casein, a molecular weight of the order of 50000 was calculated for the protein
Formation of methyl ketones as artifacts during steam distillation of Cheddar cheese and butter-oil
Authors: Lawrence R. C. 
Published: June 2009

SummaryA complete range of methyl ketones with odd numbers of carbon atoms from C3 to C15 was isolated by steam distillation at atmospheric pressure from fresh butter-oil, cream and Cheddar cheeses of various ages. Evidence was produced to show that the greater part of these methyl ketones was formed during the heat treatment of milk fat. The maximum quantities of methyl ketones obtainable from butter-oil, determined by exhaustive steam distillation at atmospheric pressure, averaged from 14 ppm. for undecan-2-one to 46 ppm. for pentadecan-2-one. Some artifact formation of methyl ketones also occurred, although to much less extent, when dairy products containing milk fat were steam distilled under reduced pressure at 40 °C. Possible mechanisms of formation of the methyl ketones are discussed.Since it proved possible to extract methyl ketones in low concentration from mature cheese at room temperature, it is evident that milk fat may contain precursors which break down to methyl ketones slowly during cheese ripening, this breakdown being accelerated at higher temperatures. Methyl ketones may therefore play a part in Cheddar flavour, but a previous report from this Institute that the time of first appearance of certain methyl ketones of odd numbers of carbon atoms above C5 in steam distillates, at atmospheric pressure from Cheddar cheese, coincided with the appearance of the typical Cheddar flavour was not confirmed.