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1.
Med Vet Entomol ; 36(1): 30-37, 2022 03.
Article in English | MEDLINE | ID: mdl-34545951

ABSTRACT

Wohlfahrtia magnifica (Diptera: Sarcophagidae) is an obligate myiasis-causing fly of livestock that is widely distributed throughout the Mediterranean basin. A total of 73 683 sheep from 122 flocks in Albacete Province (southeastern [SE] Spain) were examined to detect active traumatic myiasis. The influence of several individual and flock factors on the prevalence was also assessed. The overall flock prevalence of traumatic myiasis was 95.9%, with an individual prevalence of 7.1%. Wohlfahrtia magnifica was identified in all of the positive animals except one that was infested by Lucilia sericata (Diptera: Calliphoridae). Adults of both genders showed a higher risk of infestation than juveniles, whereas males of all ages displayed an increased risk of infestation than females of all ages; the existence of a lambing building on the farm, poor husbandry facilities and the location area were also identified as risk factors. Prevalence was highest in the summer, and the fly season lasted from March to November. Genitalia were the main location of infestation in males (94.4%) and females (76.3%). Our results reveal that traumatic myiasis by W. magnifica is widespread in southeastern Spain, hence preventive measures minimizing the attractiveness of sheep to gravid flies are necessary to avoid health and welfare problems and significant production losses in sheep flocks.


Subject(s)
Diptera , Myiasis , Sarcophagidae , Animals , Female , Male , Myiasis/epidemiology , Myiasis/veterinary , Prevalence , Risk Factors , Sheep , Spain/epidemiology
4.
J Dairy Sci ; 99(6): 4154-4159, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27060823

ABSTRACT

We report the evolution of phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), phosphatidylserine (PS), and sphingomyelin (SM) contents during the production of quark cheese from buttermilk by successive ultrafiltration concentration, enrichment with cream, concurrent homogenization and pasteurization, fermentative coagulation, and separation of quark from whey by further ultrafiltration. Buttermilk is richer than milk itself in phospholipids that afford desirable functional and technological properties, and is widely used in dairy products. To investigate how phospholipid content is affected by end-product production processes such as ultrafiltration, homogenization, pasteurization or coagulation, we measured the phospholipids at several stages of each of 5 industrial-scale quark cheese production runs. In each run, 10,000L of buttermilk was concentrated to half volume by ultrafiltration, enriched with cream, homogenized, pasteurized, inoculated with lactic acid bacteria, incubated to coagulation, and once more concentrated to half volume by ultrafiltration. Phospholipid contents were determined by HPLC with evaporative light scattering detection in the starting buttermilk, concentrated buttermilk, ultrafiltrate, cream-enriched concentrated buttermilk (both before and after concurrent homogenization and pasteurization), coagulate, and quark, and also in the rinsings obtained when the ultrafiltration equipment was washed following initial concentration. The average phospholipid content of buttermilk was approximately 5 times that of milk, and the phospholipid content of buttermilk fat 26 to 29 times that of milk fat. Although phospholipids did not cross ultrafiltration membranes, significant losses occurred during ultrafiltration (due to retention on the membranes) and during the homogenization and pasteurization process. During coagulation, however, phospholipid content rose, presumably as a consequence of the proliferation of the inoculated lactic acid bacteria. In spite of these changes in total phospholipid content, the relative proportions of the phospholipids studied remain fairly stable throughout quark production (PE>PC>SM>PS>PI) and similar to those found in the milk of the region, except that SM content was lower than in milk.


Subject(s)
Buttermilk , Cheese , Animals , Milk , Phospholipids , Sphingomyelins
5.
J Dairy Sci ; 98(1): 9-14, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25465571

ABSTRACT

The objective of this study was to compare the phospholipid content of conventional milk with that of organic milk and milk rich in conjugated linoleic acid (CLA). The membrane enclosing the fat globules of milk is composed, in part, of phospholipids, which have properties of interest for the development of so-called functional foods and technologically novel ingredients. They include phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), phosphatidylserine (PS), and the sphingophospholipid sphingomyelin (SM). Milk from organically managed cows contains higher levels of vitamins, antioxidants, and unsaturated fatty acids than conventionally produced milk, but we know of no study with analogous comparisons of major phospholipid contents. In addition, the use of polyunsaturated-lipid-rich feed supplement (extruded linseed) has been reported to increase the phospholipid content of milk. Because supplementation with linseed and increased unsaturated fatty acid content are the main dietary modifications used for production of CLA-rich milk, we investigated whether these modifications would lead to this milk having higher phospholipid content. We used HPLC with evaporative light scattering detection to determine PE, PI, PC, PS, and SM contents in 16 samples of organic milk and 8 samples of CLA-rich milk, in each case together with matching reference samples of conventionally produced milk taken on the same days and in the same geographical areas as the organic and CLA-rich samples. Compared with conventional milk and milk fat, organic milk and milk fat had significantly higher levels of all the phospholipids studied. This is attributable to the differences between the 2 systems of milk production, among which the most influential are probably differences in diet and physical exercise. The CLA-rich milk fat had significantly higher levels of PI, PS, and PC than conventional milk fat, which is also attributed to dietary differences: rations for CLA-rich milk production included linseed supplement and contained less maize meal than conventional rations and a greater proportion of unsaturated fatty acids and salts. The relative proportions of the phospholipids studied were similar in all 3 types of milk, descending in the order PE>(PC, SM)>PS>PI, with PC being slightly more abundant than SM in organic milk and vice versa in CLA-rich milk.


Subject(s)
Food, Organic/analysis , Linoleic Acids, Conjugated/analysis , Milk/chemistry , Phospholipids/analysis , Animals , Cattle , Diet/veterinary , Dietary Fats, Unsaturated/administration & dosage , Dietary Supplements , Fatty Acids, Unsaturated/administration & dosage , Female , Flax , Lactation , Linseed Oil/administration & dosage , Lipids
6.
Prev Vet Med ; 102(2): 157-63, 2011 Nov 01.
Article in English | MEDLINE | ID: mdl-21601298

ABSTRACT

The increasing awareness of animal welfare in public and science induces a need for objective evaluation. Particularly animal welfare during transport is discussed due to the variable transport conditions in Europe. Therefore an objective evaluation of animal transport is relevant and the first attempts to develop animal welfare risk assessment guidelines for animal transport are made. A report of the development of a guideline on animal welfare risk assessment during animal transport (Dalla Villa et al., 2009) bases on other recent reports and guidelines of animal welfare risk assessment published by EFSA (2009) and adapts the method to animal transport condition. For the implementation of a model for quantitative risk assessment, transport conditions were defined to develop multiple scenarios. Hazard identification was prepared for each scenario and for three selected scenarios a complete risk assessment was performed. Within the exemplary risk assessment potential hazards were initially identified and furthermore hazard description and exposure assessment were evaluated by expert opinion which resulted in risk characterisation. Within risk characterisation of each hazard, magnitude and risk estimate were calculated to afford an individual ranking of these values in order to obtain a graphical illustration of the ten highest estimated risks.


Subject(s)
Animal Welfare/standards , Risk Assessment/methods , Transportation/standards , Animals , Europe
7.
Rev Sci Tech ; 28(3): 1129-42, 2009 Dec.
Article in English | MEDLINE | ID: mdl-20462172

ABSTRACT

The disposition of enrofloxacin in sheep was investigated after single-dose intravenous administration of 2.5 mg/kg body weight. Blood samples were drawn from the jugular vein at predetermined times after drug administration. Plasma concentrations of enrofloxacin and its active metabolite ciprofloxacin were simultaneously determined by reverse-phase high performance liquid chromatography. The data collected were subjected to non-compartmental and compartmental kinetic analysis. Statistical model theory was used to determine non-compartmental pharmacokinetic parameters. Disposition of enrofloxacin was described by a three-compartment open model with elimination from the central compartment following intravascular administration. The elimination half-life, the volume of distribution, and the area under the concentration vs time curve (AUC) were 4.31 h, 1.10 l/kg and 9.24 microg x h/ml, respectively. Enrofloxacin was metabolised to ciprofloxacin and the ratio between the AUCs of ciprofloxacin and enrofloxacin was 0.26 after intravenous administration. With predictive models of efficacy (maximum plasma concentrations/minimum inhibitory concentrations [Cmax/MIC] and AUC/MIC ratios in plasma) for most of the sheep pathogen microorganisms, enrofloxacin produced scores higher than 15 and 50, respectively. After intravenous administration atthe dose of 2.5 mg/kg, enrofloxacin achieved concentrations several times above the MIC for major pathogen bacteria in plasma, and it may prove useful in the treatment of infectious diseases caused by sensitive pathogens in sheep.


Subject(s)
Anti-Bacterial Agents/pharmacokinetics , Fluoroquinolones/pharmacokinetics , Sheep/metabolism , Animals , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/metabolism , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/metabolism , Antineoplastic Agents/pharmacokinetics , Area Under Curve , Chromatography, High Pressure Liquid , Enrofloxacin , Female , Fluoroquinolones/administration & dosage , Half-Life , Injections, Intravenous/veterinary , Sheep Diseases/blood , Sheep Diseases/drug therapy
8.
Int J Food Microbiol ; 125(3): 357-61, 2008 Jul 31.
Article in English | MEDLINE | ID: mdl-18547666

ABSTRACT

The ATP bioluminescence method was used to evaluate the cleanliness of milking equipment surfaces (teat cup rubbers, teat dip containers, milk receivers, and pipeline joints) in dairy farms in Galicia (northwest Spain) with parlour, pipeline tie-stall or bucket tie-stall milking systems. The cleanest surfaces were teat cup rubbers. The use of non-chlorinated water for cleaning, and of pipeline or bucket tie-stall milking systems, was associated with high ATP bioluminescence values. However, ATP bioluminescence values only explained 12% of the variability in bulk-tank bacterial count; this is attributable to the importance of other factors (notably the correct functioning of the tank cooling system) for maintenance of low bacterial count.


Subject(s)
Bacteria/growth & development , Dairying/instrumentation , Equipment Contamination , Hygiene , Milk/microbiology , Adenosine Triphosphate/analysis , Animals , Bacteria/isolation & purification , Cattle , Colony Count, Microbial , Dairying/standards , Female , Luminescent Measurements , Mammary Glands, Animal/microbiology
9.
J Dairy Sci ; 90(11): 5083-8, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17954748

ABSTRACT

This cross-sectional study determined the prevalence of Listeria spp. in bulk-tank milk on dairy farms in the region of Galicia in northwest Spain. The aim was to identify management practices associated with the presence of Listeria spp. and possible effects on milk hygienic quality. A total of 98 farms was randomly selected on the basis of an expected prevalence of 6.5% for Listeria monocytogenes from 20,107 dairy farms in the region. Bulk-tank milk samples were obtained from 98 farms, fecal samples from lactating cows from 97 farms, and silage samples from 83 farms. Listeria monocytogenes was detected in 6.1, 9.3, and 6.0% of these samples, respectively. Statistical analyses confirmed the relationship between low silage quality (as indicated by high pH) and presence of Listeria spp. in silage (29.5 vs. 6.2% for pH above or below 4.5, respectively). Only milking system [tie-stall systems (28.6%) vs. parlor milking (10%)] and inadequately controlled milking order [yes (32.0%) vs. no (10.7%)] had statistically significant effects on management practices for increasing the risk of Listeria contamination of bulk-tank milk.


Subject(s)
Dairying/methods , Food Microbiology , Listeria/isolation & purification , Milk/microbiology , Animal Feed/analysis , Animal Feed/microbiology , Animals , Cattle , Cross-Sectional Studies , Feces/microbiology , Female , Listeria monocytogenes/isolation & purification , Milk/cytology , Prevalence , Risk Factors , Silage/microbiology , Spain/epidemiology
10.
Rev Argent Microbiol ; 39(2): 113-9, 2007.
Article in Spanish | MEDLINE | ID: mdl-17702260

ABSTRACT

Shiga toxin (Stx)-producing Escherichia coli (STEC) is an emergent pathogen associated with foodborne diseases, especially foodstuffs of animal origin. A total of 250 beef samples (ground beef and hamburgers) obtained from retail outlets in Santa Fe and Santo Tomé cities, and 150 milk samples from bulk tank milk from dairy barns of the region were analyzed by selective enrichment and immunomagnetic separation. Escherichia coli O157:H7 stx2, eae and ehxA positive strains were isolated from three (1.2%) beef samples. The strains could be differentiated by pulsed-field gel electrophoresis, phagetyping and genotyping of stx. The milk samples were negative for STEC O157. These findings confirm the role of food of animal origin in the epidemiology of E. coli O157:H7 - associated diseases.


Subject(s)
Escherichia coli O157/isolation & purification , Food Contamination , Food Microbiology , Meat Products/microbiology , Milk/microbiology , Adhesins, Bacterial/genetics , Animals , Argentina , Bacterial Typing Techniques , Cattle , Electrophoresis, Gel, Pulsed-Field , Escherichia coli O157/genetics , Escherichia coli Proteins/genetics , Hemolysin Proteins/genetics , Immunomagnetic Separation , Shiga Toxin 2/genetics , Virulence
11.
Rev. argent. microbiol ; 39(2): 113-119, abr.-jun. 2007. ilus
Article in Spanish | LILACS | ID: lil-634548

ABSTRACT

Escherichia coli productor de toxina Shiga (Stx) (STEC) O157:H7 es un patógeno asociado a enfermedades transmitidas por alimentos, fundamentalmente de origen animal. Se investigó la presencia de E. coli O157 en 250 muestras de carne picada y hamburguesas obtenidas de comercios de las ciudades de Santa Fe y Santo Tomé (Pcia. de Santa Fe) y en 150 muestras de leche provenientes de tanques de enfriado de tambos de la región, utilizando enriquecimiento selectivo y separación inmunomagnética. A partir de 3 muestras de carne (1,2%) se aislaron cepas E. coli O157:H7 stx2, eae, y ehxA positivas, que pudieron ser diferenciadas mediante electroforesis de campo pulsado, fagotipificación y genotipificación de stx. No se aislaron cepas STEC O157:H7 a partir de las muestras de leche. Estos hallazgos confirman la participación de los alimentos de origen animal en la epidemiología de las enfermedades producidas por E. coli O157:H7.


Shiga toxin (Stx)-producing Escherichia coli (STEC) is an emergent pathogen associated with foodborne diseases, especially foodstuffs of animal origin. A total of 250 beef samples (ground beef and hamburgers) obtained from retail outlets in Santa Fe and Santo Tomé cities, and 150 milk samples from bulk tank milk from dairy barns of the region were analyzed by selective enrichment and immunomagnetic separation. Escherichia coli O157:H7 stx2, eae and ehxA positive strains were isolated from three (1.2%) beef samples. The strains could be differentiated by pulsed-field gel electrophoresis, phagetyping and genotyping of stx. The milk samples were negative for STEC O157. These findings confirm the role of food of animal origin in the epidemiology of E. coli O157:H7 - associated diseases.


Subject(s)
Animals , Cattle , /isolation & purification , Food Contamination , Food Microbiology , Meat Products/microbiology , Milk/microbiology , Argentina , Adhesins, Bacterial/genetics , Bacterial Typing Techniques , Electrophoresis, Gel, Pulsed-Field , /genetics , Escherichia coli Proteins/genetics , Hemolysin Proteins/genetics , Immunomagnetic Separation , /genetics , Virulence
12.
Infect Control Hosp Epidemiol ; 28(5): 577-82, 2007 May.
Article in English | MEDLINE | ID: mdl-17464918

ABSTRACT

OBJECTIVE: To investigate the prevalence, duration, and etiology of bacteremia following dental extractions performed after a single administration of chlorhexidine mouthwash. DESIGN AND SETTING: A randomized, controlled trial performed in a university hospital. METHODS: A series of 106 patients with mental and behavioral disabilities who underwent dental extractions under general anesthesia were randomly assigned to a control group or chlorhexidine group. The exclusion criteria applied were use of antibiotics in the previous 3 months, use of oral antiseptics, any type of congenital or acquired immunodeficiency, and disease that predisposes the patient to infections or bleeding. The chlorhexidine group had 0.2% chlorhexidine mouthwash administered for 30 seconds before any dental manipulation. Blood samples were collected at baseline, 30 seconds, 15 minutes, and 1 hour after the dental extractions. Subculture and further identification of the isolated bacteria were performed by conventional microbiological techniques. RESULTS: The prevalence of bacteremia after dental extraction in the control and chlorhexidine groups were 96% and 79%, respectively, at 30 seconds (P=.008), 64% and 30% at 15 minutes (P<.001), and 20% and 2% at 1 hour (P=.005). The most frequently identified bacteria were Streptococcus species in both the control and chlorhexidine groups (64% and 68%, respectively), particularly viridans group streptococci. CONCLUSION: We recommend the routine use of a 0.2% chlorhexidine mouthwash before dental extractions to reduce the risk of postextraction bacteremia.


Subject(s)
Anti-Infective Agents, Local/administration & dosage , Antibiotic Prophylaxis/statistics & numerical data , Bacteremia/prevention & control , Chlorhexidine/administration & dosage , Mouthwashes/administration & dosage , Surgical Wound Infection/prevention & control , Tooth Extraction/adverse effects , Academic Medical Centers , Adolescent , Adult , Bacteremia/epidemiology , Bacteremia/microbiology , Bacteria/classification , Bacteria/isolation & purification , Causality , Child , Dental Service, Hospital , Female , Hospitals, University , Humans , Male , Middle Aged , Persons with Mental Disabilities/statistics & numerical data , Prevalence , Risk Factors , Spain/epidemiology , Staphylococcus aureus/isolation & purification , Surgical Wound Infection/epidemiology , Surgical Wound Infection/microbiology
13.
Meat Sci ; 73(4): 635-9, 2006 Aug.
Article in English | MEDLINE | ID: mdl-22062563

ABSTRACT

A total of 54 rabbits 50, 70 and 90 days old, were taken from farms in Galicia (NW Spain); 18 rabbits of each age were sampled. The minerals in the muscle meat from the back legs of the rabbits were analysed, and the following average concentrations were found: ash 1.21/100g, potassium 388mg/100g; phosphorus 237mg/100g; sodium 60mg/100g; magnesium 27mg/100g; calcium 8.7mg/100g; zinc 10.9mg/kg; iron 5.56mg/kg; copper 0.78mg/kg; and manganese 0.33mg/kg. The high potassium and low sodium concentration may make rabbit meat particularly recommended for hypertension diets. Rabbit meat is rich in phosphorus, and 100g provides approximately 30% of the recommended daily intake. However, rabbit meat provides less zinc and iron than meats of other species. The Galician rabbit meat analysed in this study, shows higher copper and manganese, and lower calcium contents than those found in the literature for rabbit meat of other origins.

14.
Oral Microbiol Immunol ; 19(5): 331-5, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15327647

ABSTRACT

BACKGROUND/AIMS: Systemic dissemination of oral bacteria to distant body sites may be the cause of focal infections. The unsuitable use and overexposure to antimicrobial therapy in clinical dental practice may contribute to the worldwide problem of antimicrobial resistance. The aim of this study was to determine the susceptibilities of streptococci isolated from the bloodstream after dental extractions against penicillin, ampicillin, amoxicillin, erythromycin, clindamycin, and a new fluoroquinolone, moxifloxacin. PATIENTS AND METHODS: Eighty-four patients who required dental extractions were studied. Venous blood samples were collected from each patient at baseline (before dental manipulation) and 30 s after dental extractions. The samples were processed in the Bactec 9240. The isolated bacteria were identified by conventional microbiological techniques. The antimicrobial susceptibility of 81 streptococci was determined by the E-test method. The NCCLS performance standards were followed. RESULTS: 88.9-92.5% of the streptococci were sensitive to beta-lactam agents tested with a minimum inhibitory concentration (MIC)(90s) ranging from 0.094 to 0.19 mg/l. The resistance to erythromycin and clindamycin was 40.8% (MIC(90HR) = 256 mg/l) and 21% (MIC(90HR) = 256 mg/l), respectively. The MIC(90) to moxifloxacin was 0.125 mg/l. CONCLUSION: Most of the streptococci isolated from the bloodstream after dental extractions were susceptible in vitro to penicillin, ampicillin, and amoxicillin. The high percentage of streptococci resistant to erythromycin and clindamycin could restrict their usefulness as prophylactic drugs. All the isolates showed a low MIC of moxifloxacin in vitro, making it a promising antimicrobial alternative for the prevention of streptococcal focal infections associated with certain dental manipulations, when the administration of beta-lactam agents is not indicated.


Subject(s)
Anti-Bacterial Agents/pharmacology , Aza Compounds/pharmacology , Bacteremia/microbiology , Fluoroquinolones/pharmacology , Quinolines/pharmacology , Streptococcal Infections/drug therapy , Streptococcus/drug effects , Tooth Extraction/adverse effects , Adolescent , Adult , Anti-Bacterial Agents/therapeutic use , Aza Compounds/therapeutic use , Bacteremia/drug therapy , Bacteremia/etiology , Drug Resistance, Bacterial , Female , Fluoroquinolones/therapeutic use , Focal Infection, Dental/drug therapy , Focal Infection, Dental/microbiology , Humans , Iatrogenic Disease , Male , Microbial Sensitivity Tests , Middle Aged , Moxifloxacin , Quinolines/therapeutic use , Spain , Statistics, Nonparametric
15.
Res Vet Sci ; 74(3): 283-6, 2003 Jun.
Article in English | MEDLINE | ID: mdl-12726748

ABSTRACT

Four hundred and twenty-two calves were examined for intestinal carriage of Shiga toxin-producing Escherichia coli O157:H7 using conventional plating. Two (0.5%) E. coli O157 were recovered. They were compared with 96 Argentine strains of different origin by pulsed-field gel electrophoresis, phage typing and PCR-RFLP of stx2 genes. One strain isolated from a calf, was closely related with 18 strains of clinical origin.


Subject(s)
Cattle Diseases/microbiology , Escherichia coli Infections/veterinary , Escherichia coli O157/isolation & purification , Shiga Toxins/biosynthesis , Animals , Argentina/epidemiology , Bacteriophage Typing/veterinary , Cattle , Cattle Diseases/epidemiology , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field/veterinary , Escherichia coli Infections/epidemiology , Escherichia coli Infections/microbiology , Escherichia coli O157/genetics , Escherichia coli O157/metabolism , Feces/microbiology , Polymerase Chain Reaction/veterinary , Polymorphism, Restriction Fragment Length , Prevalence
16.
J Agric Food Chem ; 50(3): 419-25, 2002 Jan 30.
Article in English | MEDLINE | ID: mdl-11804506

ABSTRACT

NIR transflectance spectroscopy was used to determine polarimetric parameters (direct polarization, polarization after inversion, specific rotation in dry matter, and polarization due to nonmonosaccharides) and sucrose in honey. In total, 156 honey samples were collected during 1992 (45 samples), 1995 (56 samples), and 1996 (55 samples). Samples were analyzed by NIR spectroscopy and polarimetric methods. Calibration (118 samples) and validation (38 samples) sets were made up; honeys from the three years were included in both sets. Calibrations were performed by modified partial least-squares regression and scatter correction by standard normal variation and detrend methods. For direct polarization, polarization after inversion, specific rotation in dry matter, and polarization due to nonmonosaccharides, good statistics (bias, SEV, and R(2)) were obtained for the validation set, and no statistically (p = 0.05) significant differences were found between instrumental and polarimetric methods for these parameters. Statistical data for sucrose were not as good as those of the other parameters. Therefore, NIR spectroscopy is not an effective method for quantitative analysis of sucrose in these honey samples. However, NIR spectroscopy may be an acceptable method for semiquantitative evaluation of sucrose for honeys, such as those in our study, containing up to 3% of sucrose. Further work is necessary to validate the uncertainty at higher levels.


Subject(s)
Honey/analysis , Spectroscopy, Near-Infrared/methods , Calibration , Reproducibility of Results , Sucrose/analysis
17.
J AOAC Int ; 83(6): 1345-8, 2000.
Article in English | MEDLINE | ID: mdl-11128136

ABSTRACT

The Direct Epifluorescent Filter Technique (DEFT) and the reference method of counting total bacterial colonies on Petri dishes were compared. IDF Standards 128 (1985) and 161A (1995) were applied. A total of 496 samples of milk were analyzed. Colony forming units per microL milk were transformed to decimal logarithmic units: log (cfu/microL). The repeatability standard deviation, Sr = 0.114, was typical for a routine microbiological method. To study the carryover at different levels of bacteria, 3 tests were performed on milk samples of approximately 100, 700, and >1000 cfu/microL. For the first 2 experiments, no carryover was detected; in the milk sample with >1000 cfu/microL, the carryover was <0.12%. When the DEFT counts were regressed versus the reference method, the values of the slope and intercept were 0.92 and 0.17, respectively; the correlation coefficient was r = 0.84; and the residual standard deviation was Syx = 0.287. The paired t-test showed that the reference method and DEFT do not give significantly different results (p = 0.05).


Subject(s)
Colony Count, Microbial/methods , Milk/microbiology , Animals , Calibration , Cattle , Filtration , Indicators and Reagents , Reference Standards , Reproducibility of Results , Solutions , Spectrometry, Fluorescence
18.
J Agric Food Chem ; 48(11): 5154-8, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11087451

ABSTRACT

NIR transflectance spectroscopy was used to analyze fructose, glucose, and moisture in honey. A total of 161 honey samples were collected during 1992 (46), 1995 (58), and 1996 (57). Samples were analyzed by instrumental, enzymatic (fructose and glucose), and refractometric (moisture) methods. Initially, different calibrations were performed for each of the 3 years of sampling. Good predictions were obtained for all three components with equations of the particular year. But good predictions were not always obtained when the equations calculated one year were applied to samples from another year. To perform a lasting calibration, unique calibration (121 samples) and validation (40 samples) sets were built; honeys of the 3 years were included in both sets. Good statistics (bias, standard error of validation (SEV), and R(2)) were obtained for all three components of the validation set. No statistically significant differences (p = 0.05) were found between instrumental and reference methods.


Subject(s)
Honey/analysis , Calibration , Fructose/analysis , Glucose/analysis , Reproducibility of Results , Spectrophotometry, Infrared/methods , Water/analysis
19.
Int J Food Microbiol ; 59(1-2): 37-46, 2000 Jul 25.
Article in English | MEDLINE | ID: mdl-10946837

ABSTRACT

Seven batches of Arzúa-Ulloa, a short-ripened soft cow's milk cheese produced in Galicia (NW Spain), were prepared from pasteurized milk. Two control batches of cheese (CB) were made with an acid-aromatic starter containing Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. lactis var. diacetylactis, isolated from raw-milk Arzúa-Ulloa cheeses. Five batches of cheese (LB) were made with the acid-aromatic starter plus one of five strains of mesophilic homofermentative Lactobacillus spp.: four of them isolated from raw-milk Arzúa-Ulloa cheese (characterized in previous works) and the remaining was a commercial Lactobacillus strain. Higher counts of mesophilic viable bacteria, lactic acid bacteria and citrate-fermenting bacteria were found on days 1 or 15 of ripening, while higher counts of lactobacilli were found on day 30 of ripening. On day 1 of ripening the highest diacetyl-acetoin content was noted in the CB, but after day 15 the diacetyl-acetoin content was similar or higher in three of the five LB. The mean degradation of beta-casein in CB was higher than in LB, while the degradation of alpha(s1)-casein was higher in LB. The mean contents of nitrogen-soluble fractions were slightly higher in the LB than in the CB. Volatile free fatty acid (VFFA) contents were, in general, greater in LB than in CB and maximum amounts were determined on day 15 of maturation. Sensorial analysis indicated a more acid taste was in LB, while bitter and astringent tastes were more intense in CB. A positive correlation was found between beta-casein degradation and bitter taste. Yogurt and butter aromas were more intense in CB and in two of the five LB. Firmness was lower in LB and a negative correlation was found between this parameter and alpha(s1)-casein degradation. Crumbliness showed a positive correlation with beta-casein degradation. The use of the Lactobacillus strains assessed in this study is recommended for Arzúa-Ulloa cheese manufacture, in order to enhance the desirable characteristics of this cheese variety, i.e., a soft texture due to alpha(s1)-casein proteolysis but without the bitter taste due to beta-casein degradation and a spicy and slightly rancid aroma and taste.


Subject(s)
Cheese/microbiology , Food Microbiology , Lactobacillus/isolation & purification , Acetoin/metabolism , Animals , Caseins/metabolism , Colony Count, Microbial , Diacetyl/metabolism , Fermentation , Humans , Hydrogen-Ion Concentration , Lactobacillus/metabolism , Sense Organs/physiology , Spain
20.
Int J Food Microbiol ; 48(2): 97-111, 1999 May 01.
Article in English | MEDLINE | ID: mdl-10426446

ABSTRACT

Ten batches of Cebreiro, a fresh or short-ripened acid-curd cheese, produced in the Galician mountains (NW Spain) were prepared from pasteurized milk inoculated with microorganisms isolated from raw-milk cheese. Two control batches were made with a Lactococcus lactis subsp. lactis starter; 8 batches were made with the lactococcal starter plus one of eight Enterococcus faecalis cultures: 4 E. faecalis var. liquefaciens (EFLB) and 4 E. faecalis var. faecalis (EFFB). Whey dry matter in the EFLB was notably higher than in the control batches and this was related to lower cheese yields. After over 15 days storage the highest counts of both aerobic bacteria and lactic acid bacteria were observed for the EFLB. The lower content in protein on dry matter was found in the EFLB. The beta-casein broke down to a greater extent in the EFLB than in the EFFB, the lowest values being obtained for the control batches. The higher level of hydrolysis of alphax1-casein and maximum peptide alpha(s1) - I/alpha(s1)-casein ratio were obtained for EFFB at day 15 of storage. In all the batches made with enterococci soluble nitrogen was higher than in the control batches, with the highest values in the EFLB. In all the batches made with enterococci, volatile free fatty acid, long-chain free fatty acids and diacetyl and acetoin contents at days 10 and 15 of storage were higher than in the control batches, the highest values being obtained for EFLB. Acetic acid in all batches accounted for the main proportion of the volatile free fatty acids. Butyric and caproic acids were not detected in the volatile free fatty acids fractions of the control batches, but both acids were detected in most of the batches made with enterococci. The more intense acid taste was found in the EFFB and control batches, the most bitter taste being found in the EFLB. Buttery, rancid and spicy flavors were more evident in the EFLB. The rancid and spicy flavors were positively correlated with the contents of volatile free fatty acids and long-chain free fatty acids. The cheeses of EFLB proved to be more crumbly than the EFFB, whereas the stickiness and deformability were higher in the EFFB. The batches with similar organoleptic characteristics to those of traditional cheese were the batch IV made with the less proteolytic strain of E. faecalis var. liquefaciens, and the batch VI made with a moderate lipolytic activity strain of E. faecalis var. faecalis.


Subject(s)
Cheese/microbiology , Enterococcus faecalis , Food Handling/methods , Animals , Cattle , Food Technology/methods , Taste
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