bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a cows' milk identification test (COMIT) for field use
Authors: García Teresa , Martín Rosario , Rodríguez Elena , Hernández Pablo E. , Sanz Bernabé 
Published: June 2009

SummaryA cows' milk identification test (COMIT) has been successfully developed for the detection of defined amounts of cows' milk (3–100%) in ewes' milk. The assay uses polyclonal antibodies raised in goats against bovine whey proteins. The test, an agar-gel immunodiffusion technique, uses agar plates with a printed template for correct placement of the test components (antisera discs, positive and negative milk reference discs and sample discs). The presence of cows' milk in the sample was recorded as positive when the precipitin lines appearing between the sample disc and the antisera disc fuse completely with those from the positive cows' milk reference disc. This test is reliable, practical and easy to perform in the field and in dairy factories. Furthermore, the nature and stability of the components of the test make it suitable for commercial development into kits which should be highly practical in any kind of inspection programme concerned with milk species identification.
Ultraviolet spectroscopic studies on the feathering of cream in instant coffee
Authors: Hamboyan Lucie , Pink* David A. , Klapstein Dieter , MacDonald Lynn , Aboud Helen 
Published: June 2009

SummaryThe extent of cream feathering was observed in samples of six brands of instant coffee at 80 °C and classified on a scale of 0 (non-existent)–3 + (very severe). The hypothesis that it is caused by the amount of chlorogenic acid in the samples was tested. Ultraviolet spectra were recorded between 230 and 486 nm, and the amount of chlorogenic acid was measured from the absorbance at 340 nm. It was found that: (i) u.v. spectra of a given brand of coffee prepared at different concentrations could all be superimposed when concentration and dilution were taken into account, and the spectrum did not change between room temperature and 80 °C; (ii) for a given coffee a minimum amount of chlorogenic acid was needed to cause feathering, but that this amount differed by up to a factor of 10 depending upon the coffee; (iii) only two fundamental shapes of spectra were observed and coffees could be classified by a ratio, R, which lay between two ranges: 0·82 < R < 0·90 or 1·10 < R < 1·27; (iv) a knowledge of the chlorogenic acid content of a sample and the value of R appropriate to that coffee could be used to predict the occurrence of feathering.
Variation with season and lactation of plasmin and plasminogen concentrations in Montbeliard cows' milk
Authors: Benslimane Saloua , Dognin-Bergeret Mai J. , Berdague Jean-Louis , Gaudemer Yves 
Published: June 2009

SummaryPlasmin and plasminogen were determined monthly over a one year period in samples of bulk and herd milks from Montbeliard cows. Montbeliard milk showed a high content of plasmin and plasminogen in comparison with milk from other breeds. In bulk milk, the plasmin activity reached a minimum in September (O·15 μg/ml milk) and a maximum in June (0·32 μg/ml milk). The annual mean concentration was 0·23 μg/ml milk. The plasminogen content varied around a value of 1·28 μg/ml milk, with a marked decrease in September (0·83 μg/ml milk) and a maximum in October (1·59 μg/ml milk). In herd milk, the minimum plasmin activity occurred in October (0·17 μ/ml milk) and the maximum in spring (O·42 μg/ml milk in May) with an annual mean of 0·30 μg/ml milk. The plasminogen content varied in a similar way, from 0·87 μg/ml milk to 1·82 μg/ml milk, with an annual mean of 1·46 μg/ml. The ratio plasminogen: plasmin ranged from 1·4 to 9·2 with an average of 4·9. From early to late lactation, plasmin and plasminogen concentrations increased from 0·25 to 0·38 μg/ml milk and from 1·07 to 2·01 μg/ml milk respectively and the plasminogen: plasmin ratio increased from 4·5 to 5·3. Studies of milk from cows at similar stage of lactation within a single herd have shown the necessity for distinguishing between two phases in the early stage of lactation. The first, a very early period, is usually present up to one month and the second occurs in the second and third months. Milk samples with the highest proportion of γ-caseins were not those with the greatest plasmin content but were those with high plasminogen contents, which had increased suddenly from the levels of the preceding month. This suggests a role for the plasminogen activator and inhibitor system.
Local control of the onset of mammary extraction of plasma triglycerides during lactogenesis in the goat
Authors: Thompson Gordon E. 
Published: June 2009

SummaryIn five untreated goats, mammary extraction of plasma triglycerides increased at parturition. In five goats that had as much secretion as possible regularly removed from one mammary gland beginning on d 143 of gestation, the change of triglyceride extraction occurred several d before parturition in the emptied gland but at parturition in the contralateral control gland. The experimentally induced early increase of extraction of plasma triglycerides preceded the increase of prostaglandin Fα concentration in mammary secretion at parturition, and occurred despite abnormally high concentrations of progesterone in the secretion.
Interactions between the bovine milk fat globule membrane and skim milk components on heating whole milk
Authors: Houlihan Avis V. , Goddard Philippa A. , Nottingham Stephen M. , Kitchen Barry J. , Masters Colin J. 
Published: June 2009

SummaryHeating raw milk at 80 °C for 2·5–20 min was found to result in compositional changes in the milk fat globule membrane (MFGM). The yield of protein material increased with the duration of heating, owing to incorporation of skim milk proteins, predominantly β-lactoglobulin, into the membrane. Lipid components of the MFGM were also affected, with losses of triacylglycerols on heating.
Characterization of the 12% trichloroacetic acid-insoluble oligopeptides of Parmigiano-Reggiano cheese
Authors: Addeo Francesco , Chianese Lina , Salzano Antonio , Sacchi Raffaele , Cappuccio Ugo , Ferranti Pasquale , Malorni Antonio 
Published: June 2009

SummaryThe isolation and identification of low molecular mass peptides formed during the ripening of Parmigiano-Reggiano cheese is described. A strategy was used based on the fractionation of nitrogenous material using chemical methods followed by HPLC to isolate peptides and fast atom bombardment-mass spectrometry to identify them. It was found that the majority of cheese oligopeptides arose from the proteolysis of β-casein. Several phosphopeptides and oligopeptides known in vivo to be biologically active have also been identified during the ripening of cheese.
Gel electrophoresis and immunoblotting for the detection of casein proteolysis in cheese
Authors: Addeo Francesco , Garro Giuseppina , Intorcia Nunziatina , Pellegrino Luisa , Resmini Pierpaolo , Chianese Lina 
Published: June 2009

SUMMARYThe whole N fraction of six samples of hard and semi-hard pressed cheeses was analysed using PAGE, polyacrylamide gel isoelectric focusing and immuno blotting with polyclonal antibodies against β- and αs1-casein. The origin of some electrophoretic bands corresponding to peptides produced from the enzymic degradation of the casein fractions was established. A number of these peptides were also present in thein vitrohydrolysates of casein with plasmin and chymosin. Thus, it was also possible to determine which casein was the source of each peptide and which enzymes were active in cheese. Compared with the traditional Coomassie staining procedures, immunoblotting is more sensitive and specific, making the interpretation of each electrophoretic profile easy. Thus, it was also possible to obtain a clear picture of the state of each casein fraction in a cheese variety. Two main peptides were isolated from the pH 4·6-insoluble N fraction of Parmigiano-Reggiano using DEAE-cellulose chromatography and identified, from the amino acid sequence of the N- and C-terminal ends, as γ3-casein (β-casein(f108–209)) and αs1-PL1 (αs1-casein(f80–199)). In both cases, a Lys–X bond was hydrolysed, indicating the action of a trypsin-like enzyme in β- and αs1-casein hydrolysis during the ripening of this variety of hard pressed cheese.
Mordant factors that affect the fluorescence and counting of somatic cells by instruments
Authors: Clarke Timothy , Evans Michael E. , Hepworth Graham , Moate Peter J. , Stewart John A. 
Published: June 2009

SummaryThe requirement for accuracy in the counting of somatic cells in milk has been increased by the use of this measurement as a basis of payment for milk. This paper reports on several factors that can substantially affect efficiency of staining and cell detection in various types of fluorescent cell counters. These mordant factors include sample age, chemical preservative, other sample preservation treatments and reagent properties. Experiments were conducted in several laboratories with Fossomatic 215 and 360 cell counting instruments to measure the effect of these mordant factors on both cell fluorescence and cell count. Counting efficiency was as low as 20% for some instruments counting some particular samples, depending upon the combination of adverse mordant factors. The problem of poor counting efficiency was also not detected by calibration samples that had more favourable mordant treatments applied. The adverse mordant factors were shown to reduce the intensity of fluorescence of cells for all instruments. We suggest that a significant reduction in counting efficiency due to these adverse mordant factors is most likely to occur when the particular instrument already has an intrinsic inability to separate cell fluorescence properly from background noise. This paper also discusses quality control samples, the impact of various factors on discriminator curves and the use of appropriate measures to maintain good calibration adjustment.
Analysis and production of two exopolysaccharides fromLactococcus lactissubsp.cremorisLC330
Authors: Marshall Valerie M. , Cowie Eoin N. , Moreton Rod S. 
Published: June 2009

SUMMARYTwo polysaccharides produced concurrently byLactococcus lactissubsp.cremorisstrain LC330 have been identified. One had a high molecular mass (> 1 × 106Da) and was neutral. The second was smaller (∼ 10000 Da), charged and had a high phosphorus content. Sugar composition also differed. In chemostat culture the neutral polysaccharide was influenced by temperature and by nitrogen limitation. This polysaccharide was branched with terminal galactose moieties and contained galactose, glucose and glucosamine. The phosphopolysaccharide was more complex with glucose, rhamnose, galactose and glucosamine in an approximate ratio of 6:5:4:1.
Comparative study of methods for the isolation and purification of bovine κ-casein and its hydrolysis by chymosin
Authors: Coolbear Kate P. , Elgar David F. , Coolbear Tim , Ayers John S. 
Published: June 2009

Summaryκ-Casein was purified from a single batch of whole acid casein (κ-A variant) using different methods in order to compare their merits in producing a purified material with a carbohydrate and phosphate heterogeneity representative of the whole κ-casein complement in milk. Ion-exchange methods of purification gave products of higher purity than precipitation techniques involving final purification by ethanol fractionation, but all methods resulted in κ-caseins of apparently similar heterogeneity and chemical composition. The purified κ-caseins were hydrolysed with chymosin and the derived macropeptides isolated. These were all virtually identical as determined by reversed-phase chromatography and gel electrophoresis. Some observations on chymosin hydrolysis of κ-casein were made. In addition to formation of the major para-κ-casein (Glu1–Phe105) and macropeptide (Met106–Val169), chymosin hydrolysis at pH 6·6 also resulted in two minor para-κ-caseins with N-termini corresponding to Phe18 and Ser33 of κ-casein. At pH 5·5 and 4·5 para-κ-casein was rapidly hydrolysed into at least six fragments, one of which had an N-terminus corresponding to Trp76 of κ-casein. At pH 6·6, 5·5 and 4·5 the κ-casein macropeptide was stable to chymosin, but at pH 2·3 it was hydrolysed by chymosin into fragments with N-termini corresponding to Met106, He125, Ala138, Val139, Thr145 and Glu147 of κ-casein.
Influence of pulsationless milking on teat canal keratin growth and turnover
Authors: Lacy-Hulbert S. Jane , Hillerton J. Eric , Woolford Murray W. 
Published: June 2009

SummaryIn two separate experiments, the effects of pulsationless milking and milking vacuum on the rate of keratin removal from the teat canal were determined. Sixteen cows were milked with or without pulsation for either a single milking or for eight milkings. Milking without pulsation removed 10% of keratin present before milking, significantly less than milking with pulsation, which removed 32%. After eight milkings (4 d) without pulsation, up to 20% more keratin had accumulated within the teat canal but the rate of keratin regeneration reduced significantly upon return to pulsation milking. In a second experiment, ten cows were milked at 45 or 55 kPa and with or without pulsation. Only the absence of pulsation significantly reduced keratin loss during milking. Keratin loss during milking appears to be controlled by liner compression rather than by the rate of milk flowing through the teat canal. Pulsationless milking may increase penetrability of the teat canal to bacteria by reducing the natural rate of keratin removal during milking and reducing the rate of keratin regeneration.
328. Experiments on the use of antioxidants in spray-dried whole-milk powder
Authors: Findlay J. D. , Smith J. A. B. , Lea C. H. 
Published: June 2009

1. Of a number of substances tested for antioxidant activity in laboratory-made spray-dried milk powder, ascorbic acid and ethyl gallate proved most promising. Both of these substances materially increased the resistance of the powder to the development of tallowiness without producing any foreign flavour in the milk.2. The actitivy of both substances has been confirmed in factory-made spray-dried powder, ethyl gallate being much the more powerful of the two. Ethyl gallate at a concentration of 0·07% increased the storage life of powder in the accelerated tests 2½–3-fold.3. Ethyl gallate remained unchanged during storage of the powder, but the concentration of ascorbic acid decreased, rapidly at first and then more slowly.
Microfiltration of cheese brine
Authors: Merin Uzi , Gordin Salli , Tanny Gerald B. 
Published: June 2009

SUMMARYA new technique is described for the microfiltration of cheese brine. Soft cheese brine with viable counts/ml of up to 1·2 × 106bacteria and 2·2 × 104yeasts and moulds was filtered using a pleated tangential flow filtration cartridge of 0·2 εm pore size membrane. This filtration resulted in a 3–4 orders of magnitude reduction of bacteria and the complete rejection of yeast and mould from the permeate. Hard cheese brine with similar bacterial loads was treated with a 1·2 εm pore size membrane cartridge and the resulting permeate contained 2–3 orders of magnitude fewer bacteria and no yeasts or moulds. Flux decline during the filtration was a function of the number of microorganisms and the amount of N in the brine. A cleaning procedure using enzyme and acid washes was established in order to prolong membrane performance.
A fluorimetric method for determination ofPseudomonas fluorescensAR11 lipase in skim milk powder, whey powder and whey protein concentrate
Authors: Stead Donald 
Published: June 2009

SummaryA method which was developed for assaying the extracellular lipases of psychrotrophic bacteria in milk (Stead, 1983, 1984) and which uses the fluorogenic substrate 4-methylumbelliferyl oleate has been adapted for use with skim milk powder (SMP), whey powder (WP) and whey protein concentrate (WPC). A five-fold increase in the concentration of sodium taurocholate (NaTC), in the mixture of NaTC and cetyltrimethylammonium bromide needed to dissociate lipase from milk proteins, removed the excessive sensitivity of the assay to variations in the concentrations of SMP, WP or WPC incorporated. Commercially available pancreatic lipase provided a suitable standard of lipolytic activity and as little as 1–2 μ could be detected in each assay system.
Milk production in concurrently pregnant and lactating goats mated out of season
Authors: Knight Christopher H. , Wilde Colin J. 
Published: June 2009

SummaryFive lactating goats which had kidded normally in March were mated during seasonal anoestrus in May, at the time of peak milk production, after ovulation had been induced using gonadotrophin-releasing hormone (Knight et al. 1988). Milk yield was unaffected by the hormone treatment, and decreased at the same rate as that of control (non-pregnant) goats for the first 8 weeks of the pregnancy. Thereafter yield declined more quickly in the test goats and just before parturition (in October) was 57% of the control value. Following parturition in the test animals, yield rose rapidly as the second lactation was established. None became ‘dry’ at any stage. Yield continued to decline with advancing lactation in the controls, which were mated normally in October or November and dried-off in December. During their second (‘extra’) lactation in the winter the test animals produced 12% less than in a normal second lactation in summertime; during the year the extra lactation meant that the test animals produced 73% more milk than the controls. In some, a second concurrent pregnancy was established during the extra lactation, with the resuit that three lactations were obtained in the time normally taken for two. Mammary cell number and proliferation rate were both higher in the pregnant animals than in the controls in week 23 of the first lactation.
Optimization of the forewarming process with respect to deposit formation in indirect ultra high temperature plants and the quality of milk
Authors: Mottar Joseph , Moermans Renaat 
Published: June 2009

SummaryThe influence of preheating intensity was examined on deposit formation in an indirect ultra high temperature (UHT) plate heat exchanger and on some quality parameters of the UHT treated milk, such as taste, proteinase inactivation and protein destabilization during storage. Response surface methods were used to define the relationship between the forewarming conditions and the responses. More intense forewarming reduced the fouling rate in the UHT plate section, resulting in longer operation times. While a greater inactivation of the proteinase(s) in the milk was obtained, the taste of the UHT milk was adversely affected, as well as the physical stability during storage owing to higher sedimentation. An optimum temperature/time range for the preheating process could be defined within the temperature/time range of 76–80 °C/40–70 s at which adverse effects were minimal, and positive effects were maximized.
Study of acid milk coagulation by an optical method using light reflection
Authors: Banon Sylvie , Hardy Joël 
Published: June 2009

SummaryA turbidimetric method, based on light reflection, was used to study acid coagulation of reconstituted skim milk at low temperature. Capillary viscosimetry, gelograph and laser granulometer techniques were also employed. Acidification of milk was produced by hydrolysis of glucono-δ-lactone. The general shape of the turbidimetric signal as a function of pH or time can be divided into three stages: a lag phase followed by a significant decrease and then a final rise. Two factors have a great influence on the development of milk turbidity, pH and temperature. Dynamic viscosity measurements can be related to the turbidimetric signal while laser granulometrie measurements cannot be correlated with changes in turbidity: the micelle size distribution remains constant until the first signs of gelation. As previous work showed, dynamic viscosity diminishes with acidification until a particular pH is reached (pH 5·9 at 15°C and pH 5·75 at 20°C). We have related this latter period to the turbidimetric lag phase. As milk turbidity became lower than its initial value (pH 5·75 at 15°C and pH 5·55 at 20°C), dynamic viscosity increased significantly. The release of material from micelles (β-casein and Ca) could explain this phenomenon. In the same way, further increase of turbidity at a particular pH value (pH 5·3 at both 15 and 20°C) coulcl be partly due to the reincorporation of soluble casein monomers in the micelle framework. As the onset of gelation was approached, turbidity still increased as a result of gel network formation.
Influence of liposome-encapsulated Neutrase and heat-treated lactobacilli on the quality of low-fat Gouda-type cheese
Authors: Skeie Siv , Narvhus Judith , Ardö Ylva , Abrahamsen Roger K. 
Published: June 2009

SUMMARYLow-fat Gouda-type cheese (200 g fat/kg dry matter) was made on a pilot plant scale from cheesemilk to which heat-treated lactobacilli and/or Neutrase encapsulated in dehydrated rehydrated vesicles had been added. In cheese containing added Neutrase, there was increased proteolysis after the first day following cheesemaking. The cheese with added heat-treated lactobacilli developed increased amounts of amino N as well as increased amounts of acetaldehyde and other, unidentified, volatile compounds. The addition of heat-treated lactobacilli also influenced the texture of the cheese which was firmer but less cohesive.
Temporal variations in the infection of a population of Clypeomorus bifasciata (Gastropoda: Prosobranchia) by a digenean microphallid larva in Kuwait Bay
Authors: Abdul-Salam J. , Sreelatha B.S. , Al-Kandari W. 
Published: June 2009

AbstractThe prosobranch snail Clypeomorus bifasciata in Kuwait Bay was examined for digenean infections over a one year period during 1994/1995. A total of 1500 snails was examined and 567 (37.8%) were found to harbour nine digenean species. The prevalence of a microphallid species was 33.9% while each of the others occurred in less than 1.2% of the snails. The prevalence of infection increased with shell size. Multiple infections were observed in only five of the infected snails and the microphallid was involved in all of them. Snails were infected with the microphallid throughout the year and there appeared to be two peaks in the proportion of infected snails shedding cercariae, a winter peak from November to January and a summer peak from June to August. The crab Xantho exaratus collected from snail sampling sites was heavily parasitized by microphallid metacercariae of the genera Longiductotrema and Microphallus. This is the first report on microphallid metacercariae in crabs in the Arabian Gulf region.
Preliminary biochemical characterization of faeces from uninfected rats and rats infected with the tapeworm, Hymenolepis diminuta
Authors: Pappas P.W. , Wardrop S.M. 
Published: June 2009

AbstractFaecal pellets were collected from uninfected rats and rats infected with Hymenolepis diminuta, and analysed for caloric value, lipids, carbohydrates, glucose, amino acids, and proteins. Faeces from infected rats contained significantly more lipid and less carbohydrate and glucose than faeces from control rats. The total free amino acid content of faeces from infected and control rats did not differ, but there were significant differences in the amounts of individual free amino acids. The data support the hypothesis that the nutrient composition of faeces from infected and control hosts differ. Beetles that serve as the intermediate host for H. diminuta may be able to detect these differences, and this may explain why beetles preferentially ingest faeces containing the tapeworm's eggs.