bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adherence of psychrotrophic bacteria to dairy equipment surfaces
Authors: Suárez Beatriz , Ferreirós Carlos M. , Criado Maria-Teresa 
Published: June 2009

SummaryPsychrotrophic bacteria isolated from raw milk were tested for their ability to adhere to steel, two types of rubber, and glass, materials employed in the construction of milking equipment. The adherence assays were carried out by exposure of the materials to radioactively labelled bacteria in both a buffering solution (Ringer's) and milk. The degree of adherence of Gram-positive bacteria was lower (P< 0·001) than that of Gram-negative bacteria. Glass was the material least prone to bacterial adherence (P< 0·001); there were no significant differences between the other three materials. Milk was found to inhibit adhesion significantly (P< 0·05), this inhibition being more evident with the most adherent bacteria. There was no statistically significant correlation between bacterial surface hydrophobicity and adherence. Our results suggest that intrinsic bacterial adherence cannot be considered a relevant factor in the contamination of milking equipment.
Simple empirical and fundamental methods to determine objectively the stretchability of Mozzarella cheese
Authors: Apostolopoulos Christos 
Published: June 2009

SummaryThe ability of Mozzarella cheese to stretch and form long fibres was evaluated by two simple instrumental tests. The first test, which was basically a tensile test, resembled the way the consumer assesses the stretchability of cheese as a pizza topping. The extensibility measurements of the test correlated well with the sensory stringiness scores. The second, fundamental test was a compressive elongation of the melted cheese. The elongational viscosity of the melted cheese was calculated; this could be used as an index of the ability of the cheese to form strings when it is stretched.
Assessment of mammary gland metabolism in the sow: I. Development of methods for the measurement of cellular metabolites in milk and colostrum
Authors: Atwood Craig S. , Hartmann Peter E. 
Published: June 2009

SUMMARYWe have modified deproteinization methods and a number of spectrophotometric and bioluminescent methods in order to measure the concentrations of cellular metabolites in small volumes (< 0·3 ml) of sows' colostrum and milk. For the majority of the assays, recoveries ranged from 92 to 105%. The binding of ATP and UTP to a calcium phosphate–citrate–caseinate complex in milk, and the decrease in ATP (92%/h) and UTP (18·1 %/h) concentrations during in vitro incubation of the whey fraction suggested that it was unlikely ATP and UTP (both < 1 µM) could exist free in sows' milk. The mean concentrations (range) of cellular metabolites in milk (6–11 d post partum) were: glucose, 669 µM (220–1367); glucose 6-phosphate, 63·0 µM (27·6–101·4); glucose 1-phosphate, 18·3 µM (13·1–24·8); UDPglucose, 296 µM (170–494); UDPgalactose, 635 µM (230–945); lactose, 162 mM (124–187); UDP, 105 µM (85–130); UMP, 1760 µM (1326–2587); inorganic phosphate, 135 mM (1·4–29·3); ATP, <0·5 µM; ADP, 53·6 µM (10·5–171·25); AMP, 215 µM (61·6–491·6); cAMP, 22·3 µM (3·5–61·6); galactose, 198 µM (118–474) and fructose, 226 µM (172–283). Differences in the concentrations of glucose, glucose 6-phosphate, glucose 1-phosphate, UDPgalactose and cAMP between fore and hind milk samples indicated postsecretory changes in the concentrations of certain metabolites. Changes in the concentrations of metabolites during in vitro incubation of milk and of colostrum suggested that these postsecretory changes were probably due to the actions of enzymes present in mammary secretion. Collection of milk that has been most recently secreted (hind milk) will provide the most accurate indication of the intracellular concentrations of these metabolites. The concentrations of cellular metabolites in the milks from different species are compared.
Effect of pH on flux during ultrafiltration of sweet whey and buttermilk
Authors: Ramachandra Rao Harohally G. , Lewis Michael J. , Grandison Alistair S. 
Published: June 2009

SummaryThe flux patterns for sweet whey and buttermilk were strongly influenced by pH. Increasing the pH of buttermilk from 6·6 to 8·0 tended to reduce initial flux values and reduce deposit formation on the membrane as indicated by lower values for the fouling coefficient. Flux was mostly controlled by concentration polarization. Reducing the pH below 6·6 increased the flux but caused more deposit on the membrane as indicated by high fouling coefficient values. Almost the opposite was found for sweet whey. The initial flux increased as pH increased, followed by considerable flux decline, which was linked to greater fouling of the membrane. Reducing the pH reduced the initial flux considerably but also reduced further fouling. These changes are thought to be brought about by the combined effects of pH change on the proteins and minerals, and in particular on calcium.
Influence of κ-casein and β-lactoglobulin genetic variants on the heat stability of milk
Authors: Robitaille Gilles 
Published: June 2009

SUMMARYHeat coagulation time-pH curves at 140°C were obtained for 43 blended skim milk samples from Holstein cows to determine the effects of genetic variants of κ-casein and β-lactoglobulin on milk heat stability. The blended milk samples were similar in terms of protein content and milk salts, but were genotypically different for κ-casein (AA, AB) and β-lactoglobulin (AA, AB, BB). Type A curves were obtained for all milks. Maximum heat stability was affected by the κ-casein genotype (AB > AA, P < 0·01) but the influence of the β-lactoglobulin genotype was only significant when the κ-casein AA genotype was present (β-lactoglobulin AA > BB, P < 0·0001). Minimum heat stability was significantly higher (P < 0·0001) for milk genotyped κ-casein AB:β-lactoglobulin BB. The effects of milk genotyped κ-casein BB on maximum and minimum heat stability were determined by analysing individual milks: κ-casein BB:β-lactoglobulin AB (n=8) and reconstituted milks: κ-casein BB:β-lactoglobulin AA, AB and BB (n = 17). Type B curves were obtained on three occasions for individual κ-casein BB:β-lactoglobulin AB milk and on five occasions in the case of reconstituted milks with κ-casein BB:β-lactoglobulin AA, AB and BB. This suggests a relationship between the type B curve and the κ-casein B genetic variant. Comparison of the mean values of heat stability at the pH of maximum heat stability of each individual and reconstituted milk genotype suggested that the best genotype for κ-casein in terms of heat stability was BB.
Comparison of proteolytic activities in various lactobacilli
Authors: Sasaki Masahiro , Bosman Boukje W. , Tan Paris S. T. 
Published: June 2009

SUMMARYA total of 169Lactobacillusstrains from 12 species (Lb. acidophilus, Lb. brevis, Lb. buchneri, Lb. casei, Lb. delbrueckiisubsp.bulgaricus, Lb. delbrueckiisubsp.delbrueckii, Lb. delbrueckiisubsp.lactis, Lb. fermentum, Lb. helveticus, Lb. paracasei subsp. paracasei, Lb. plantarum and Lb. rhamnosus), isolated from raw milk and various milk products, and 9Lactococcus lactisstrains were evaluated for peptidase activities with five chromogenic substrates and a tryptic digest of casein. Within each species, the peptidase activity of the cell-free extracts of the strains varied. Furthermore, differences were observed between theLactobacilhisspecies andLc. lactis. Lb. helveticushad by far the highest hydrolysing activities towards all substrates, indicating the presence of powerful aminopeptidases, X-prolyl-dipeptidyl aminopeptidases and proline iminopeptidases.Lb. delbrueckiisubsp.bulgaricuspossessed high hydrolysing activities towards substrates containing proline, alanylprolyl–p–nitroanilide and prolyl–p–nitroanilide. On the other hand,Lb. fermentumandLb. breviscould be considered as weakly proteolytic species. A more detailed study with highly proteolyticLactobacillusstrains indicated that at least three different proteinases or endopeptidases were present. Compared withLc. lactis, theLactobacillusstrains had a much lower hydrolytic action on glutamyl-glutamic acid, suggesting that glutamyl aminopeptidase was absent in lactobacilli.
Immunological and electrophoretic study of the proteolytic enzymes from variousLactococcusandLactobacillusstrains
Authors: Sasaki Masahiro , Bosman Boukje W. , Tan Paris S. T. 
Published: June 2009

SUMMARYCell extracts of various lactobacilli and twoLactococcusstrains were investigated for their immunoresponse with monoclonal and polyclonal antibodies raised against various proteolytic enzymes fromLc. lactis. Except forLactobacillus caseiSBT 2233, none of the lactobacilli proteins showed immunoresponse with the monoclonal antibodies. With polyclonal antibodies raised against aminopeptidases N and C and endopeptidase ofLc. lactisan immunoresponse was observed. However, the molecular masses of the reactive bands on the blot were considerably different from those of the corresponding lactococcal peptidases, except for the band that reacted with polyclonal antibodies against aminopeptidase C. The polyclonal antibodies raised against X-prolyl-dipeptidyl aminopeptidase and tripeptidase did not show any immunoreaction. As a control, all antibodies reacted with the lactococcal proteins on the blot, with molecular masses corresponding to those reported for the proteinases and peptidases. The results clearly showed that most of the proteolytic enzymes of lactobacilli were immunologically different from those of lactococci. The proteolytic enzymes in the cell-free extracts were separated by non-denaturing PAGE and visualized by zymogram staining. The electrophoretic pattern of the proteolytic enzymes of lactobacilli was different from that ofLc. lactis. Both experiments indicate that the enzymes of the proteolytic system of lactobacilli are different from those of lactococci.
Development of an immunological method for studying the incorporation of ripening enzymes in cheese curd
Authors: Laloy Edith , Vuillemard Jean-Christophe , Abboudi Mouhsine El , Fliss Ismael , Grace Eric De , Simard Ronald E. 
Published: June 2009

SummaryPolyclonal antibodies raised against partly purified aminopeptidase were specific to cell-free extracts ofLactobacillus caseisubsp.pseudoplantarumUL 137, and did not cross react with any other proteins in Cheddar cheese, at least during the first week of maturation. A sandwich enzyme-linked immunosorbent assay (ELISA) was developed in order to quantify cell-free extracts in the cheese curd, and was also used to determine the efficiency of encapsulation of cell-free extracts in liposomes. This method was very sensitive and exhibited a detection limit of ∼10 μg total protein/g cheese and ∼1 μg total protein/ml liposome suspension. The efficiency of encapsulation of cell-free extracts into liposomes was ∼55–60%. The retention of liposome-encapsulated cell-free extracts was ∼14 times that of non-encapsulated extracts.
Identification of starter cultures in thermally treated plain yogurt using gene probes and polymerase chain reaction
Authors: Lick Sonja , Keller Martina , Krusch Uli , Heller Knut J. 
Published: June 2009

SummaryPlain yogurts (set type) fermented by three different starter cultures were subjected to different heat treatments (20 s at 72, 80 or 100 ·C, or 30 min at 60, 70, 80 or 100 ·C). DNA was extracted from each yogurt and analysed by agarose gel electrophoresis, by species-specific hybridization and by primer-specific polymerase chain reaction (PCR). Obvious degradation of DNA could be observed after heating at 80 ·C for 30 min and at 100 ·C for 20 s and 30 min. Identification ofLactobacillus delbrueckiiusing a species-specific hybridization fragment could be carried out in yogurt treated at 100 ·C for 20 s or for 30 min at lower temperatures. After treatment for 30 min at 100 ·C identification by hybridization was no longer possible. However, under the same conditions identification of starter microorganisms was still possible by primer-specific PCR, and this was demonstrated as an example forStreptococcus thermophilus.
326. The effect of temperature of pre-heating, of clarification and of bacteriological quality of the raw milk on the keeping properties of whole-milk powder dried by the Kestner Spray Process
Authors: Mattick A. T. K. , Hiscox Edith R. , Crossley E. L. , Lea C. H. , Findlay J. D. , Smith J. A. B. , Thompson S. Y. , Kon S. K. , Egdell J. W. 
Published: June 2009

(1) Increasing the pre-heating temperature of the milk from 165 to 190° F. before spray-drying greatly improved the resistance of the powder to the development of tallowy ‘off’-flavours on storage. From the results of accelerated tests at 47 and 37° C. a storage life (in air) of the order of 2 years could safely be predicted for the powders from milk pre-heated at the higher temperature. Confirmation has now been obtained by storage of the powders for 2½ years at 15° C. and at room temperature.(2) Improvement in the bacteriological quality of the milk supply, and more careful control during its passage through the plant, produced some improvement in the keeping properties of powders prepared from milk pre-heated at the lower temperature, but had relatively little effect on the keeping properties of the powder when the higher preheating temperature was used.(3) The shapes of the deterioration curves for the various powders showed that the effect of the higher pre-heating temperature and of improvement in the milk supply was to extend the induction period which precedes rapid deterioration. The protective effect of both factors was greater when measured at the ‘slightly tallowy’ or ‘fairly good’ stage than when comparison was made at a more advanced stage of decomposition.
Effect of stage of lactation, stage of pregnancy, milk yield and herd management on seasonal variation in spontaneous lipolysis in bovine milk
Authors: Chazal Marie-Paule , Chilliard Yves 
Published: June 2009

SummaryThe free fatty acid (FFA) levels after milking (initial FFA) and after 22 h storage at 4°C (FFA-22) were determined in milk from 57 cows every 2 weeks for one year. FFA levels which were higher in summer than in winter were explained by later stages of lactation occurring in summer. Initial FFA content increased regularly during lactation. FFA-22 content increased after 12 weeks, and further after 32 weeks of lactation. The first increase was due to stage of lactation. The second increase, which appeared in late lactation, was essentially due to the stage of pregnancy combined with the effect of milk yield. FFA-22 content increased in the second part of pregnancy, chiefly after 24 weeks. A low milk yield (≼ 5 kg) further increased lipolysis, but only after 16 weeks of pregnancy. The effect of stage of pregnancy may have been enhanced by management factors such as feeding conditions. In this investigation, the seasonal FFA variation in bulk tank milk could be explained entirely by physiological factors.
Effect of heat treatment on casein micelle profiles obtained by controlled pore-glass chromatography
Authors: Anderson Malcolm , Moore Carolyn , Griffin Mary C. A. 
Published: June 2009

SummaryThe effect of heat treatment on the profiles of casein micelles obtained at 340 and 280 nm from controlled pore-glass chromatography of milk was studied in a series of unhomogenized whole milk samples which had been heated in a pilot plant at 75, 90, 105, 120, 135 and 150 °C for holding times of 4, 16, 32, 72, 150 and 300 s. A second experiment was carried out in which whole milk was preheated at temperatures between 70 and 110 °C for 13, 60 and 180 s before being treated at 120 °C for 4 s or 150 °C for 16 s. The average micelle size in some of the samples was determined by photon correlation spectroscopy. Profiles were divided into four fractions in which micelle size decreased from fraction 1 to fraction 4. The dimensions of these fractions were expressed in terms of size relative to that of the total profile. Fraction 4 was not affected by any of the heat treatments. Fractions 1–3 were significantly affected only by temperatures above 120 °C. Between 120 and 150 °C fraction 1 increased significantly while fractions 2 and 3 showed a corresponding decrease. Holding time affected fraction 1 only above 120 °C. For fraction 2 there was no effect in < 32 s at temperatures less than 150 °C. Fraction 3 was the most sensitive to changes in holding time, but no effect was observed below 105 °C. Average micelle size measurements indicated that a substantial size increase only occurred in those milks heated at 135 °C for longer than 16 s and in all the samples at 150 °C. To assess whether this increase in micelle size was reversible, samples were dialysed against a 70 mm-NaCl solution containing 10 mm-EDTA and then separated by column chromatography on Sephacryl S-300. The proportion of materials which was undissociated by dialysis remained unchanged for temperatures below 120 °C, but progressively increased with treatments more severe than 120 °C for 16 s. Column profiles were not influenced by variations in the conditions of preheating
Psychrotrophic flora of raw milk: resistance to several common disinfectants
Authors: Suárez Beatriz , Ferreirós Carlos M. 
Published: June 2009

SummaryThe psychrotrophic bacterial flora of milk was examined after aseptic hand milking. A total of 409 strains were tentatively characterized and classified into 17 groups by a reduced set of tests and cluster analysis. Lipolytic organisms (53·7%) exceeded proteolytic organisms (29·6%), and a reported predominance of oxidase-positive organisms (54·5%) was not found. Gram-negatives were mainly Entero-bacteriaceae,Flavobacterium, AcinetobacterandPseudomonas. In the Gram-positive groups Micrococcaceae were the most abundant (44·4%) followed by coryneforms (16·3%). Only two of seven commonly used disinfectants acted differently with Gram-positive and Gram-negative organisms (P< 0·01), although in general Gram-positives were more resistant than Gram-negatives.
Capital Market Imperfections and the Sensitivity of Investment to Stock Prices
Authors: Ovtchinnikov Alexei V. , McConnell John J. 
Published: June 2009

AbstractPrior studies argue that investment by undervalued firms that require external equity is particularly sensitive to stock prices in irrational capital markets. We present a model in which investment can appear to be more sensitive to stock prices when capital markets are rational, but subject to imperfections such as debt overhang, information asymmetries, and financial distress costs. Our empirical tests support the rational (but imperfect) capital markets view. Specifically, investment–stock price sensitivity is related to firm leverage, financial slack, and probability of financial distress, but is not related to proxies for firm undervaluation. Because, in our model, stock prices reflect the net present values (NPVs) of investment opportunities, our results are consistent with rational capital markets improving the allocation of capital by channeling more funds to firms with positive NPV projects.
Ostertagia nianqingtanggulaensis K'ung & Li, 1965 (Nematoda: Trichostrongyloidea) from sheep and goats at high altitudes in Nepal
Authors: Joshi B.R. , Gibbons L.M. , Jacobs D.E. 
Published: June 2009

AbstractThe trichostrongyloid nematode Ostertagia nianqingtanggulaensis K'ung & Li, 1965, previously recorded only from sheep in Tibet, is redescribed and is shown to be a common parasite of both sheep and goats at higher altitudes in the Himalayan foothills of western Nepal. Herbage examination indicated that infective larvae can overwinter on snow covered slopes. Use of tracer animals confirmed that migratory flocks are exposed to infection when grazing on alpine pastures during the summer months. In contrast, nearby non-migratory flocks kept at lower altitudes did not harbour O. nianqingtanggulaensis and tracer animals grazed with these flocks did not become infected with this species.
Genomic identification of Anisakis simplex isolates
Authors: Siles M. , Cuéllar C. , Perteguer M.J. 
Published: June 2009

AbstractRAPD technique was used to differentiate individuals of Anisakis simplex obtained from Merluccius merluccius, Phycis blennoides, Conger conger and Lepidorhombus boscii, from the North Atlantic Ocean. The amplification patterns of the host DNA controls were markedly different from those obtained for the parasitic material. No variation within the same host was detected. The amplification patterns for larvae obtained from fish of the same genus were somewhat different. The amplification patterns of A. simplex isolates from M. merluccius, P. blennoides, C. conger and L. boscii, were different. These results suggest the possible existence of two populations with a considerable high genetic variability and a different adaptation to different host species.
The Bilharzia Complement Fixation Reaction in Goats infected with Schistosoma mattheei and Schistosoma bovis
Authors: Fairley N. Hamilton 
Published: June 2009

1. The sera of 18 goats were investigated for the bilharzia complement fixation reaction, using as antigen alcoholic extract of the livers of snails (Planorbis exustus) infected with cercariae of S. spindale.2. The sera of 5 out of 7 goats harbouring S. mattheei, and of 4 out of 4 goats exposed to alimentary infection with S. bovis yielded positive results, the range of complement fixation varying from 5 to 20 M.H.D.'s.3. The sera of non-infected goats and of 3 goats exposed to infection with cercariae of S. mansoni from which these animals appear naturally immune, yielded negative reactions.4. The complement fixation reaction with cercarial antigen (S. spindale) has now been applied to infestation with 3 human and 4 cattle schistosomes, and its group applicability to mammalian schistosomiasis may be regarded as proven.
A Review of the Plant Parasitic Members of the genus Aphelenchus
Authors: Goodey T. 
Published: June 2009

1. The paper deals with nematodes of the genus Aphelenchus causing diseases in cultivated plants. A list of these, with the main pathological conditions to which they give rise, is set out on page 144.2. Each parasite and the disease due to it is dealt with, and particulars are given concerning the structure of the worm, together with the symptoms and biology in each case.3. A general discussion on the problem of the appropriate treatment of these diseases is given, and the suggestion is made that some form of heat treatment of infective soils is likely to give the best results, owing to the fact that comparatively low temperatures are lethal to the parasites.
On Syngamus nasicola Linstow, 1899, from sheep and cattle in the West Indies
Authors: Buckley J. J. C. 
Published: June 2009

1. The occurrence of Syngamus nasicola Linstow, 1899, in sheep, cattle and goats in the West Indies is recorded.2. The species is re-described, on the basis of West Indian material and cotypes from deer and goat.3. The species is contrasted with S. laryngeus Railliet, 1899, with which it has affinities and has hitherto been thought to be identical.4. Special emphasis is laid on the use of the internal structure of the buccal capsule in differentiating the two species.5. Syngamus kingi is compared with S. nasicola and it is concluded that the two species are identical, in which case S. kingi becomes a synonym of S. nasicola.