bluuebunny/crossref_metadata_2025_split huggingface dataset:
576. The volatile compounds associated with oxidized flavour in skim milk
Authors: Forss D. A. , Pont E. G. , Stark W. 
Published: June 2009

Using chromatographic techniques, a number of compounds was isolated from the steam distillates of skim milk containing oxidized (cardboard) flavour. The following compounds were definitely identified: acetone, acetaldehyde, n–hexanal, crotonaldehyde, and the C5 to C11 2-unsaturated aldehydes. Presumptive evidence for the presence of several 2,4-diunsaturated aldehydes of medium chain length was obtained also. Acetaldehyde and acetone were also isolated from normal skim milk; these two compounds appear to play no part in the defect.2-Enals, in particular the C8 and C9, were considered to be the principal flavour-determining compounds. In milk at dilutions of 1 part in 107 to 109 they impart an oxidized type of flavour resembling that known as cardboard. Evidence was obtained that 2,4-dienals were also present and they produced a similar flavour.It may further be deduced that cardboard flavour in milk is caused by the preferential oxidation of di- and polyunsaturated fatty acids.
578. The composition of the milk of the blue whale
Authors: Gregory Margaret E. , Kon S. K. , Rowland S. J. , Thompson S. Y. 
Published: June 2009

The detailed composition of samples of milk from three blue whales (Balaenoptera sibbaldi) is reported in terms of total solids, fat, solids-not-fat, total protein, casein, soluble proteins, non-protein nitrogen, lactose, chloride, ash, calcium, phosphorus, sodium, potassium, magnesium, vitamin A, thiamine, biotin, riboflavin, nicotinic acid, vitamin B6, pantothenic acid and vitamin B12.The composition of the milk of the whale is compared with that of other species.
602. Experiments in cheesemaking without starter
Authors: Mabbitt L. A. , Chapman Helen R. , Berridge N. J. 
Published: June 2009

Cheese has been successfully made from raw and pasteurized milk by a process similar to that employed for Cheddar or Cheshire-type cheese but omitting the starter inoculum.In the preferred method gluconic acid lactone was used as the acidifying agent during the setting of the curd and after milling.The flavour of the best products was acceptable to a number of people not necessarily experienced in cheese-tasting, but it was different from that of normal Cheddar.No improvement in flavour was achieved by inoculation of the cheese milk with a strain of L. casei and L. brevis.Further detailed investigation is needed to perfect the process and to determine whether its use in industry is justified or desirable.
607. Winter feeding of dairy cows: I. The influence of level and source of protein and of the level of energy in the feed on milk yield and composition
Authors: Holmes W. , Waite R. , MacLusky D. S. , Watson J. N. 
Published: June 2009

1. The effect of feeding levels of protein and energy appreciably higher than the Woodman standards on the yield and composition of the milk from twelve Ayrshire cows has been studied in two winter-feeding experiments.2. In the first experiment the S.E. of the concentrate ration was held constant at 63½% and the D.C.P. content adjusted to 10, 15 and 17%. The 10 and 15% D.C.P. concentrates derived their protein from home-grown feedingstuffs, whereas the 17% D.C.P. concentrate was a bought-in commercial mixture. Feeding the three levels of D.C.P. led to no statistically significant differences in milk yield, milk composition or live-weight gain, although the commercial mixture (17% D.C.P.) resulted in milk with a slightly lower fat content.3. The second experiment reversed the feeding conditions of the first, i.e. D.C.P. was held constant at 16% and three concentrates were fed which contained 59, 67 and 75% S.E. respectively. The two rations of higher S.E. content gave significantly more milk than the low S.E. ration and tended to give slight increases in live weight. There was a slight increase in the S.N.F. content of the milk when the S.E. of the concentrate was raised from 59 to 67% S.E. This was due almost entirely to an increase in the protein content of the milk. There was no further increase in S.N.F. with the 75% S.E. concentrate, and this latter concentrate produced milk with a slightly lower fat content.4. Comparison of costs and returns showed that the cheap low protein concentrate, ration C, even though it gave the least milk, yielded the highest profit. It was shown, however, that at any reasonable fixed cost of starch equivalent the most profitable level of feeding above the Woodman maintenance standard was 3–3·3 lb. S.E./10 lb. of milk of 3·8–4·0% fat. Alternatively, the total ration should be 110–117% of the Woodman standard.
608. Winter feeding of dairy cows: II. Dried grass produced in spring and in autumn compared with other concentrates and with spring grazing
Authors: Holmes W. 
Published: June 2009

1. Two experiments were carried out to compare spring-dried grass and autumn-dried grass. In both experiments a 3×3 Latin square changeover design was used with periods of 4 weeks. In the first the control ration was a home-grown concentrate mixture (S.E. 58, D.C.P. 12·5%), in the second a high-quality mixture of imported feeds (S.E. 73·5, D.C.P. 16·6%). The concentrates or dried grass were fed in addition to a basal ration which supplied only the maintenance requirements of the cow.2. In both experiments the milk yield from spring grass was 3–5% higher than that from autumn grass, but the differences were not statistically significant. In Exp. 1 the yield from the home-grown mixture was the same as from spring grass. The yield from the imported mixture in Exp. 2 was significantly higher than from both grass rations. There was a significant increase in milk yield when the cows went on to spring grazing in Exp. 1.3. Expression of the feed input as a percentage of the Woodman standards showed that the level of feeding was similar in all three rations in the first experiment, and that the increased milk yield from the high-quality ration in the second experiment could be explained by the increased level of feeding which it gave. It was considered that the increased yield on spring grazing might have been caused simply by an increase in the amount of nutrients consumed.
612. Steam distillation of taints from cream: II. Investigations on commercial equipment with use of diacetyl and acetoin as reference substances
Authors: McDowall F. H. 
Published: June 2009

The extent of removal of the reference substances diacetyl and acetoin from water and cream in the Vacreator under varied conditions of operation has been investigated.1. It was not affected by change in diameter or length of the uptake-pipe, or, with water, by changing the position of the equilibrium-valve to the top of the uptake-pipe or by introduction of the steam at the bottom of the pasteurizer bend instead of at the normal steam inlet.2. It was affected only slightly by inclusion of baffles in the uptake-pipe, to provide a more intimate contact of steam and cream.3. With diacetyl in water it was not affected by introduction of the major proportion of the steam via the infuser connexion, and with diacetyl in cream it was not affected until the proportion of steam introduced via the infuser was greater than 50% of the total amount of steam used. With acetoin in both water and cream there was a progressive slight reduction in extent of reference substance removal with increase in proportion of steam introduced via the infuser.4. With diacetyl and acetoin in water it was not affected by increase in rate of flow of steam and cream at constant intensity of treatment.5. With diacetyl it was not affected by temperature of steam distillation over the range 138–197°F., but with acetoin there was a progressive reduction in extent of removal with decrease in distillation temperature.6. Steam is most effectively used if it is applied in separate stages instead of in one stage, i.e., a multiple Vacreator uses steam more efficiently than a single-unit machine. This effect is more marked with diacetyl, which has a high equilibrium coefficient, than with acetoin, which has a low coefficient.7. The equilibrium coefficient computed from steam treatment of diacetyl solutions in the Vacreator is of the same order as that determined by the laboratory continuous equilibrium vaporization apparatus.8. The efficiency of cream-deodorization equipment may be lowered by condensation of vapour back into the liquid, e.g. by use of excess cooling water in the Vacreator jackets.9. There are indications that removal of diacetyl from cream is somewhat slower than from water.The thanks of the author are due to Mr J. K. Scott for helpful discussion, to Mr E. R. Elley who did the analytical work, and to Mr B. Le Heron for assistance in the operation of the Vacreator and collection of samples.
619. Host-phage relationships of cheese starter organisms: II. Effect of phage activity on heterologous strains of lactic streptococci
Authors: Naylor Jill , Czulak J. 
Published: June 2009

A reaction closely resembling the nascent phage phenonomenon was studied. When lysing the homologous strains ofStr. lactis, two phage races were found to be capable of simultaneously inducing lysis of a heterologous strain and of other phage-resistant homologous strains. Seitz filtered potent lysates of the homologous strains also caused lysis. Subjecting the lysates to a temperature of 60°C. for 5 min. destroyed the lytic activity on heterologous strains but did not inactivate the phage.These two phage races produced haloes around their plaques while a third phage, unable to induce lysis of heterologous cultures, showed no haloes. Addition of I3-to the medium suppressed the appearance of haloes, providing further evidence that they are due to the production of bacterial lysins.Evidence was obtained to show that several other possible mechanisms were not responsible for the observed lysis, and it was concluded that a heat-labile lysin or lysins capable of destroying the heterologous strain was produced during lysis of the homologous strain. The relationship of this to the nascent phage and other similar phenomena observed elsewhere is discussed.
626. Udder infections in the ‘dry period’: IV. The relationship between the new infection rate in the early dry period and the daily milk yield at drying-off when lactation was ended by either intermittent or abrupt cessation of milking
Authors: Oliver J. , Dodd F. H. , Neave F. K. 
Published: June 2009

1. Records were collected from a herd where many cows were producing relatively high daily yields of milk at the time of drying-off. Animals giving 7 lb. of milk or less daily were dried off by intermittent milking, and those giving over 7 lb. daily were dried off by ‘stop’ milking. The data from 113 dry periods were analysed so that a comparison could be made of the new infection rate in the early dry period according to level of production at drying-off.2. The new dry-period infection rate was found to increase with yield at drying-off. This was not due to age differences between the groups of cows.3. The rise in total infection rate with yield was due mainly to an increase in Str. agalactiae infections.4. A high proportion of clinical quarters were detected in the dry period by the cowmen.5. The yield in the lactation following the dry period studied was not related to yield at drying-off.6. New dry-period infections were significantly (P <0·01) more numerous in quarters of cows that had been hand-stripped during lactation compared with quarters of machinestripped cows.
632. Reactivation of milk phosphatase following heat treatment: IV. The influence of certain metallic ions
Authors: Wright R. C. , Tramer J. 
Published: June 2009

1. Reactivation of alkaline milk phosphatase is affected by the presence of ions, Mg2+, Zn2+and Mn2+being activating and Cu2+, Ni2+and Co2+being inhibitory.2. Cu2+will inhibit reactivation induced by Mg2+, but has no effect upon Zn2+-induced reactivation.3. Using washed cream, either alone or in admixture with boiled whey treated with cationic resin, reactivation occurs in the presence of added Mg2+, but not when Zn2+is added.4. Experiments with EDTA. confirm that metallic ions play a part both in alkaline phosphatase activity and in reactivation.5. It is suggested that either Mg2+or Zn2+or both play a part in reactivation.
640. Some bacteriological aspects of commercially sterilized milk: II. Type of sporeforming bacteria isolated
Authors: Candy M. R. , Nichols Agnes A. 
Published: June 2009

Cultures of sporeforming bacteria isolated from commercially sterilized milk were examined and seasonal variations in the incidence ofB. subtilis/B. licheniformisstrains were apparent which may account for the increased rate of spoilage at 30° C. during the winter.B. subtiliswas the most common mesophilic sporeformer isolated, and under favourable conditions it produces rapid digestion of milk.Thermophilic sporeformers are frequently present, and usually produce a firm acid clot in milk held at temperatures favourable for their growth. The classification of the thermophiles isolated is uncertain and a review of the classification of the aerobic thermophilic sporeformers in general is required.Cl. thermosaccharolyticum, a gas-producing thermophile, was isolated from sterilized milk.
647. Winter feeding of dairy cows: IV. The influence of four levels of concentrate feeding in addition to a basal ration of grass products on the production obtained from milking cows
Authors: Holmes W. , Reid D. , MacLusky D. S. , Waite R. , Watson J. N. 
Published: June 2009

1. An experiment is described which assessed the effects on the production obtained from milking cows, of feeding a concentrate with a starch equivalent of 64 at four levels (0, 2, 4 and 6 lb./gal. of milk produced), in addition to a basal ration with limited amounts of hay and dried grass and with silage fed ad lib.2. The total daily dry-matter intake of the cows increased from 2·2 to 2·7% of the live weight as the rate of concentrate feeding was increased from 0 to 6 lb./gal., despite a reduction in the amount of roughages consumed.3. For each increase of 1 unit in silage dry-matter percentage, there were increases of from 1·18 to 0·42 lb. of silage bry-matter intake per cow per day as the level of concentrate feeding increased. For each increase of 1 lb. in silage dry-matter intake there was an increase of l lb. in total dry-matter intake per cow per day.4. The average daily milk yield per cow increased from 22·2 lb. when no concentrates were fed to 27·6 lb. when 6 lb. concentrates were fed per gallon of milk produced. This is an increase of 0·9 lb. milk/lb. increase in starch equivalent intake. A significant difference in response was found between higher yielding and lower yielding groups of cows. The higher yielding group gave an increase of 1·1 lb. and the lower yielding group only 0·6 lb. milk/lb. increase in starch-equivalent intake.5. At the general level of feeding and of milk yields obtianed in this experiment, no evidence of diminishing returns in milk production was detected when the rate of concentrate feeding was increased.6. The content of solids-not-fat in the milk rapidly increased from 8·3% when no concentrates were fed to 8·6% when 4 or 6 lb. of the concentrates were fed per gallon of milk produced.7. When concentrates were fed at the rate of 0 and 2 lb./gal. declines in live weight as well as in the yield and solids-not-fat content of the milk were noted, while at 6 lb./gal. there was an unnecessary gain in live weight. It is concluded, therefore, that with the particular animals and roughages used in this experiment, the optimal level of concentrate feeding was 4 lb./gal.
648. Weight Changes in grazing cows
Authors: Balch C. C. , Line C. 
Published: June 2009

1. Under various feeding regimes the entire contents of the reticulo-rumen of fistulated Shorthorn cows were repeatedly removed, weighed, sampled and returned.2. With cattle grazing grass/clover swards, but not with others grazing green cereals, there was a very marked tendency for less digesta to be found in the reticulo-rumen than with several winter diets.3. An average fall of 71±24 lb. was found in the weight of a mixed herd of thirty-eight Friesian and Shorthorn cows when they were changed suddenly from winter diets to grazing. Simultaneous observations on three fistulated cows showed that 84% of such short-term variation in weight could be explained by variation in the weight of the digesta in the reticulo-rumen. It is likely that smaller, parallel variations in the weight of the contents of the remainder of the gut accounted for most of the remaining differences.
653. A calorimetric study of milk, cream and the fat in cream
Authors: Phipps L. W. 
Published: June 2009

Specific heat data have been obtained for separated milk, whole milk, cream (15% fat content) and the fat in cream, under certain well-defined experimental conditions. With standardized techniques of sample preparation, the results were repeatable within the errors of the experimental methods employed.An examination of the effects on the specific heat curves of milk fat of different modes of thermal treatment has provided information on the melting and solidification behaviour of the fat. The degree of dispersion of the fat in cream has been shown to be an important consideration.My thanks are due to Miss H. R. Chapman of the Institute dairy, for supplying milk and cream samples, and to Mr J. H. Prentice and other members of the Physics department for useful discussion.
654. A rapid method for estimating the size distribution of fat globules in cream
Authors: Dolby R. M. 
Published: June 2009

The proportion of fat present in cream as small globules (approximately 1 μ and under) is estimated from the proportion of the total fat which remains in the serum when a sample of the cream, diluted to 10% fat, is centrifuged at 60° C. for 30 min. at 3000 r.p.m.The fat present as large globules (7 or 8μ and over) is estimated by finding the proportion of the fat which rises 1 cm. in 60 min. when the cream, diluted to 10% fat, is held at 60° C. in a modification of the Andreasen particle-size apparatus in which the jar is replaced by a conical flask and the tip of the sampling pipette is held 1 cm. from the flat bottom of the flask.The thanks of the author are due to Dr F. H. McDowall for helpful advice and criticism and to Miss R. P. Johnson for assistance with the experimental work.
658. Factors influencing the vitamin content of milk fat: IV. The source of milk fat vitamin A and carotene
Authors: McGillivray W. A. 
Published: June 2009

1. The effect of varying levels of vitamin A ester in the blood plasma of cows on the levels of vitamin A ester in their milk fat has been investigated.2. The milk fat levels reflect plasma levels, but it appears that, irrespective of the immediate carotene or vitamin A intake of the animals or of their liver reserves, some of the milk fat vitamin A ester is derived from vitamin A of other than immediate dietary origin.3. It is suggested that the bulk of the plasma carotene contributes little to the level of carotene in the milk fat. The latter derives mainly from the carotene of immediate dietary origin which, during transport from the intestines to the storage organs, is associated with dietary fat and vitamin A ester in the chylomicrons.The author is grateful to the Department of Scientific and Industrial Research for a grant towards this investigation; also to Mr M. R. Patchell and the farm staffs of The Dairy Research Institute (N.Z.) and Massey Agricultural College for assistance with the feeding and dosing of the animals and the collection of milk samples. The assistance of Miss Fay Frecklington with some of the experimental work and of Mr A. C. Glenday with statistical examination of the results is also acknowledged.
673. Bacteriology of Cheddar cheese: A study of starter organisms in manufacture and maturing
Authors: Dawson D. J. , Feagan J. T. 
Published: June 2009

1. The trends of starter bacteria population during the manufacture and maturing of Cheddar cheese have been investigated. Fourteen strains consisting of Str. lactis, Str. diacetilactis and Str. cremoris have been studied.2. Physiological and morphological characteristics of the fourteen strains were examined.3. Population studies during manufacture showed that the three species of starter organism attain quite different maximum populations and at different stages of the cheesemaking process. Str. lactis (4500 millions/g.) and Str. diacetilactis (2900 millions/g.) reached their maximum half way through Cheddaring, whereas Str. cremoris (960 millions/g.) reached its maximum at milling.4. Str. lactis was shown to maintain its maximum population until the cheese left the press, whereas Str. diacetilactis and Str. cremoris steadily declined after reaching their maximum.5. Counts of the different starter cultures used showed considerable variation between and within strains, particularly in the case of Str. cremoris.6. No relationship was shown to exist between acidity development and starter populations developed.7. The study of cell distribution in the cheese curd has shown that whereas Str. lactis and Str. diacetilactis gave an even scattering of diplococci, Str. cremoris showed colony formation.8. Str. lactis strains maintained a high but declining population during maturing of the cheese, the starter beginning to die out gradually after 8 weeks. Str. diacetilactis showed similar trends but at lower populations levels. Str. cremoris, on the other hand, gave much lower populations, the starter dying out rapidly after 2 weeks, and virtually disappearing at 8 weeks.9. Persistence of starter bacteria in the cheese appears to be correlated with salt tolerance and chain length.10. Starter bacteria isolated from the cheese made with Str. lactis have shown a low proportion of slow acid-producing types in contrast to a high proportion found with Str. cremoris.11. The non-starter bacteria in the cheese were found to consist on the average of 30% micrococci and 70% lactobacilli. Negligible numbers of other genera were isolated.
678. The effect of variations in nutrient intake upon the yield and composition of milk II. Factors affecting rate of eating roughage and responses to an increase in the amount of concentrates fed
Authors: Burt A. W. A. 
Published: June 2009

1. Rates of eating hay, kale and concentrates and responses to a 3 lb. increase in the daily concentrate allowances when roughage was rationed on a ‘group’ basis, were measured in fourteen Ayrshire cows and fifteen heifers.2. There were significant differences between animals, between days, and significant cow × period interactions, in rates of eating in both groups. The cows were a more variable group and generally ate faster than the heifers. Although the rate of eating fresh kale tended to decrease with increasing dry-matter percentage, the rate of eating kale dry matter was positively and significantly related to the dry-matter percentage.3. There were positive associations between the rates of eating of the three different foods, and of these with live weight, but no effects of milk yield or stage of lactation, and no marked effects of climatic conditions could be detected.4. The errors in the determination of mean rates of eating were such that observations made on 4–5 days gave satisfactory comparisons of individual rates of eating.5. Reponses in milk yield to additional concentrates were positively correlated with milk yield, and no independent effects of stage of lactation could be detected. Responses by the heifers were less then those of cows giving similar yields.6. Responses in solids-not-fat percentage were greatest in those cows with inherently low percentages.7. There was no relationship between rates of eating roughage and responses of milk yield to additional concentrates, but live-weight responses and, to a lesser extent, solids-not-fat responses were negatively correlated with rates of eating in the cows. It was concluded that the level of feeding, system of management and the roughage:concentrate ratio used were such as to eliminate the effects of rates of eating roughage upon milk yields, if indeed such effects exist.