Destruction de Microbacterium lacticum, Escherichia coli et Staphylococcus aureus au cours du séchage du lait par atomisation. II. Influence des conditions de séchage

1977 ◽  
Vol 23 (6) ◽  
pp. 755-762 ◽  
Author(s):  
A. Chopin ◽  
G. Mocquot ◽  
Y. Le Graet
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Spray Drying ◽  
Survival Rates ◽  
Skim Milk ◽  
Outlet Temperature ◽  
Mathematical Equation ◽  
Spray Drier ◽  
Death Rates ◽  
Drying Conditions

Bacterial death during spray drying of skim milk is essentially related to the outlet temperature of the spray drier and the type of bacteria. Under industrial spray drying conditions, survival rates of Microbacterium lacticum, Staphylococcus aureus and Escherichia coli were 50, 2, and 0.002%, respectively. These rates may vary by a 104 factor for outlet temperatures between 65 and 105 °C. No simple mathematical equation could be derived to describe the relation between bacterial death rates and outlet temperature. Our results suggest that bacterial death is due in most cases to a heating effect during the last stages of drying when the temperature of the powder particle approaches that of the air at the outlet. [Traduit par le journal]

Addendum: Survie de Staphylococcus aureus au cours de la préparation et de la conservation de lait écrémé en poudre. Problèmes posés par le dénombrement des survivants

1979 ◽  
Vol 25 (2) ◽  
pp. 237-237
Author(s):  
A. Chopin ◽  
Silvia Tesone ◽  
J.-P. Vila ◽  
Y. LeGraet ◽  
G. Mocquot
Keyword(s):  
Staphylococcus Aureus ◽  
Spray Drying ◽  
Room Temperature ◽  
Milk Powder ◽  
Skim Milk ◽  
Egg Yolk ◽  
Test Strain ◽  
Cellular Damage ◽  
Concentrated Milk ◽  
Drying Conditions

Skim milk powders were contaminated with seven strains of Staphylococcus aureus previously isolated from dairy products. These organisms were either added to the concentrated milk before spray-drying or directly to the milk powder. Survival under spray-drying conditions similar to those used in commercial operations was dependent on drying conditions and on the test strain; 1/5 to 1/250 000 of the original populations could be recovered. Survival during storage of milk powder at room temperature depended on the test strain, moisture content, and the method used to contaminate the powder. Our results suggest that powder stored at room temperature for more than 3 months may contain enterotoxin but no detectable surviving S. aureus.Of the different media tested, direct inoculation of Baird–Parker agar and PPSA supplemented with Tweens reliably detected maximal numbers of viable cells. Other selective counting methods gave variable results dependent on the test strain, the age of the powder, and the method by which the powders were contaminated.The nature of cellular damage depended on whether or not the organisms had been exposed to the spray-drying process. Enumeration of populations in spray-dried samples was "superior" when selective media were supplemented with egg yolk or Tweens. [Translated by the journal]

Destruction de Microbacterium lacticum, Escherichia coli et Staphylococcus aureus au cours du séchage du lait par atomisation. I. Dénombrement sélectif des bactéries survivantes

1977 ◽  
Vol 23 (6) ◽  
pp. 716-720
Author(s):  
A. Chopin ◽  
G. Mocquot ◽  
Y. Le Graet
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Spray Drying ◽  
Skim Milk ◽  
Resistant Mutant ◽  
Plate Count ◽  
Mannitol Salt Agar ◽  
E Coli ◽  
Plate Count Agar ◽  
Plate Counts

In this paper a method which allows the measure of microbial death rate during spray-drying by means of a streptomycin-resistant mutant that can be grown on a streptomycin-containing agar is described. Plate counts of Microbacterium lacticum, Escherichia coli, and Staphylococcus aureus recovered from skim milk powders were done on plate count agar in the presence and absence of streptomycin and on various selective media. The powders were produced from evaporated milk previously inoculated with those organisms.Our results showed that the proposed method allows the recovery of 78% of M. lacticum, 61% of E. coli, and 100% of S. aureus that survived spray-drying. Recoveries of surviving E. coli on violet bile agar and brilliant green bile 2% were 34% and 29% respectively. Baird-Parker and mannitol salt agar media allow the recovery of all surviving S. aureus, thus showing that S. aureus cells did not lose their ability to grow in media containing 7.5% NaCl. Our results show that physiological injury of the cells during spray-drying differs from injury due to heating only. [Traduit par le journal]

scholarly journals Mikroenkapsulasi Strain Probiotik Leuconostoc mesenteroides ssp. cremonis BN12 menggunakan Berbagai Penyalut

2015 ◽  
Vol 10 (2) ◽  
pp. 133
Author(s):  
Irma Hermana ◽  
Arifah Kusmarwati ◽  
Ninoek Indriati
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Bile Salt ◽  
Spray Drying ◽  
Xanthan Gum ◽  
Leuconostoc Mesenteroides ◽  
Skim Milk ◽  
Soluble Fiber ◽  
Salmonella Spp

Penelitian ini bertujuan untuk mengetahui karakteristik produk mikroenkapsulasi strain probiotik Leuconostoc mesenteroides ssp. cremonis BN12 menggunakan berbagai penyalut. Mikroenkapsulasi strain probiotik Leuconostoc mesenteroides ssp. cremonis BN12 dilakukan dengan teknik spray drying. Media mikroenkapsulasi berupa campuran dari penyalut (soluble fiber) dengan larutan protein dan karbohidrat (skim milk, maltodekstrin dan glukosa). Adapun jenis-jenis penyalut yang digunakan adalah alginat 0,5%, xanthan gum 0,05% atau kitosan 0,5%. Parameter yang diamati meliputi viabilitas sel probiotik sebelum dan setelah proses spray drying, ketahanan sel probiotik pada kondisi bile salt dan pH3 serta daya hambat sel probiotik setelah spray drying. Hasil penelitian menunjukkan bahwa penyalut terbaik untuk mikroenkapsulasi strain probiotik Leuconostoc mesenteroides ssp. cremonis BN12 adalah xanthan gum dengan viabilitas setelah spray drying mencapai 8,36 log cfu/g. Viabilitas sel pada media bile salt adalah 7,69 cfu/ g dan pada pH 3 mencapai 2,7 log cfu/g setelah 24 jam masa inkubasi dengan daya hambat yang lebih baik terhadap patogen enterik Escherichia coli, Salmonella spp, Listeria monocytogenes dan Staphylococcus aureus. 

scholarly journals ANÁLISE DA COR E DA ATIVIDADE ANTIMICROBIANA DE MICROCÁPSULAS CONTENDO LACTOFERRINA BOVINA

2014 ◽  
Vol 32 (2) ◽  
Author(s):  
LUCIANA HELENA MAIA PORTE ◽  
MARIA HELENA MIGUEZ ROCHA LEÃO ◽  
ALEXANDRE PORTE
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Bacillus Subtilis ◽  
Candida Albicans ◽  
Spray Drying ◽  
Enterococcus Faecium ◽  
Micrococcus Luteus ◽  
Rhodococcus Equi ◽  
Streptococcus Faecium

Lactoferrina bovina (bLF), proveniente do soro de leite, foimicroencapsulada pela técnica de spray drying. Microcápsulascontendo 20 % de bLF foram produzidas, utilizando-se comomaterial de parede dextrina: amido octenilsuccinato (OSA) emdiferentes proporções: 100:00, 75:25, 50:50, 25:75 e 0:100 %.Foram avaliadas a cor e a estabilidade de cor das microcápsulassob armazenamento em ambientes com diferentes umidadesrelativas e a atividade antimicrobiana da lactoferrina liberadadas microcápsulas. As microcápsulas apresentaram cor clara etenderam a escurecer sob armazenamento em ambiente com altaumidade relativa. Verifi cou-se atividade inibitória das microcápsulasde bLF produzidas para diferentes bactérias Gram positivas(Bacillus subtilis CCT 2576, Staphylococcus aureus CCT 2740,Micrococcus luteus CCT 2692, Enterococcus faecium CCT 5079,Streptococcus faecium ATCC 10541, Rhodococcus equi CCT0541), Gram negativas (Pseudomonas aeruginosa ATCC 13388,Salmonella choleraesius CCT 4296, Escherichia coli CCT 0547) elevedura (Candida albicans ATCC 10231). A concentração inibitóriamínima (MIC) das microcápsulas variou de acordo com o microorganismotestado (MIC entre 2,5-100 mg.mL-1). Com exceção deB. subtilis (MIC entre 50-100 mg.mL-1 para as microcápsulas), aconcentração de bLF contida nas microcápsulas necessária parainibir o crescimento dos micro-organismos foi menor do que a bLFnativa. Esses resultados sugerem efeito de potencialização daatividade antimicrobiana da bLF após o processamento por spraydrying.

Growth and Death of Selected Microorganisms in Ultrafiltered Milk

1986 ◽  
Vol 49 (3) ◽  
pp. 233-235 ◽  
Author(s):  
PATRICIA HAGGERTY ◽  
NORMAN N. POTTER
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Skim Milk ◽  
Laboratory Scale ◽  
The Other ◽  
Streptococcus Faecalis ◽  
E Coli ◽  
Milk Samples ◽  
D Values ◽  
D Value

Studies were made to compare the growth and death of Staphylococcus aureus, Streptococcus faecalis and Escherichia coli in skim milk concentrated by ultrafiltration to that in unconcentrated skim milk. Skim milk was volume concentrated to 2× in laboratory-scale stirred UF cells. Behavior of the organisms was analyzed in four inoculated milk samples: 2× retentate, 1× water-diluted retentate, milk equivalent (retentate plus permeate) and unconcentrated skim milk. Growth of each organism and of total aerobes did not vary in the four milk samples at either 7 or 13°C. For S. faecalis and E. coli, D-values for samples heated to 62.7°C did not significantly differ in the four milk samples (p>0.01). The D-value of S. aureus in water-diluted retentate was slightly but significantly lower than those in the other three milk samples (p<0.01), possibly due to the lowered lactose level in this sample.

Death Kinetics of Lactobacillus bulgaricus in a Spray Drying Process

1995 ◽  
Vol 58 (8) ◽  
pp. 934-936 ◽  
Author(s):  
P. C. TEIXEIRA ◽  
M. H. CASTRO ◽  
R. M. KIRBY
Keyword(s):  
Spray Drying ◽  
Skim Milk ◽  
Lactobacillus Bulgaricus ◽  
Outlet Temperature ◽  
Thermodynamic Quantities ◽  
Survival Ratio ◽  
First Order Kinetics ◽  
Air Temperatures ◽  
Entropy Of Activation ◽  
Death Kinetics

Survival of Lactobacillus bulgaricus during spray drying was studied at various outlet air temperatures. During spray drying the logarithmic survival ratio decreased with increased outlet air temperature with first-order kinetics; the pseudo-z value for Lactobacillus bulgaricus was 17.3°C. Plots of the death-rate constant for Lactobacillus bulgaricus versus reciprocal outlet temperature during spray drying in skim milk show a curve with two different activation energies (Ea). The calculated Ea values were 33.47 kJ/mol above 70°C and 85.77 kJ/mol below 70°C. Thermodynamic quantities for spray drying of Lactobacillus bulgaricus are also presented. Results show that the relationship between the entropy of activation and the enthalpy of activation for both spray drying and heating in liquid medium is linear, with all the data for drying falling in the range of a negative entropy.

scholarly journals Viability of Bifidobacterium Pseudocatenulatum G4 after Spray-Drying and Freeze-Drying

2010 ◽  
Vol 3 ◽  
pp. MBI.S2728 ◽  
Author(s):  
Stephenie Wong ◽  
Barka Mohammed Kabeir ◽  
Shuhaimi Mustafa ◽  
Rosfarizan Mohamad ◽  
Anis Shobirin Meor Hussin ◽  
...  
Keyword(s):  
Spray Drying ◽  
Freeze Drying ◽  
Skim Milk ◽  
The Other ◽  
Outlet Temperature ◽  
Residual Moisture Content ◽  
Drying Process ◽  
Residual Moisture ◽  
Heat Adaptation ◽  
C 30

Viability of Bifidobacterium pseudocatenulatum G4 following spray-drying and freeze-drying in skim milk was evaluated. After spray-drying, the strain experienced over 99% loss in viability regardless of the air outlet temperature (75 and 85 °C) and the heat-adaptation temperature (45 and 65 °C, 30 min). The use of heat-adaptation treatment to improve the thermotolerance of this strain was ineffective. On the other hand, the strain showed a superior survival at 71.65%–82.07% after freeze-drying. Viable populations of 9.319–9.487 log10 cfu/g were obtained when different combinations of skim milk and sugar were used as cryoprotectant. However, the addition of sugars did not result in increased survival during the freeze-drying process. Hence, 10% (w/v) skim milk alone is recommended as a suitable protectant and drying medium for this strain. The residual moisture content obtained was 4.41% ± 0.44%.

Survival of Listeria monocytogenes During the Manufacture and Storage of Nonfat Dry Milk

1985 ◽  
Vol 48 (9) ◽  
pp. 740-742 ◽  
Author(s):  
MICHAEL P. DOYLE ◽  
LOUISE M. MESKE ◽  
ELMER H. MARTH
Keyword(s):  
Listeria Monocytogenes ◽  
Spray Drying ◽  
Skim Milk ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Drying Process ◽  
Dry Milk ◽  
Nonfat Dry Milk ◽  
And Storage ◽  
Moisture Resistant

The ability of Listeria monocytogenes to survive in skim milk during spray drying and to persist in nonfat dry milk during storage was examined. Concentrated (30% solids) and unconcentrated skim milks were inoculated with ca. 105 to 106 L. monocytogenes/ml and spray dried (inlet temperature, 165 ± 2°C; outlet temperature 67 ± 2°C) to a moisture content of 3.6 to 6.4%. The nonfat dry milk was packaged in moisture-resistant film and stored at 25°C for up to 16 wk. A reduction of ca. 1 to 1.5 log10 L. monocytogenes/g occurred during the spray drying process, irrespective of whether the milk was concentrated or not before spray drying. The organism progressively died during storage at 25°C, with a >4-log10 CFU/g decrease occurring within 16 wk of storage.

scholarly journals PERTUMBUHAN ISOLAT BAL ASAL BEKATUL DAN PROBIOTIK KOMERSIAL (Lactobacillus acidophilus dan Lactobacillus casei) PADA MEDIA BEKATUL DAN SUSU SKIM

2014 ◽  
Vol 1 (1) ◽  
pp. 27
Author(s):  
Elok Zubaidah ◽  
Erryana Martati ◽  
Ampu Marojahan Resmanto
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Staphylococcus Aureus ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Rice Bran ◽  
Skim Milk ◽  
Short Chain Fatty Acids ◽  
Salmonella Typhi ◽  
Total Acid

This research was aimed to study the influence of rice bran and skim milk fermentation media on the growth of lactic acid bacteria and their ability in fermenting complex carbohydrates into short chain fatty acids (SCFA). Indigenous lactic acid bacteria (LAB) were isolated from rice bran and commercial probiotic separately and used for fermenting rice bran and skim milk media. Randomized block design was used with 2 factors i.e. fermenting media type and LAB type. The results showed that fermenting rice bran gave significant effect on the LAB growth, indicated by total LAB cell count, total acid concentration, pH and antibacterial activity. The best treatment was J2-B with total LAB count 1.01 ´ 1010 cfu/mL, total acid 1.14%, pH 3.88 and clear zone diameters against Staphylococcus aureus 13.04 mm, Listeria monocytogenes 12.88 mm, Escherichia coli 12.83 mm and Salmonella typhi 12.53 mm. LAB fermenting rice bran for 48 hours produced lactic acid and SCFA. The highest concentrations of lactic acid (122.1313 mM), acetic acid (10.503 mM), and butyric acid (1.56 mM) were produced by fermentation using LAB J2, L. acidophilus, and L. casei isolate, respectively; whereas the highest propionic acid concentration (6,07 mM) was produced by control fermentation.Keywords: Probiotic, indigenous isolate, rice bran, SCFA, skimmed milk ABSTRAKPeneltian ini bertujuan untuk mengetahui pengaruh dedak dan skim milk sebagai media fermentasi bakteri asam laktat, dan kemampuannya mengubah sumber karbon komplek dedak menjadi asam lemak rantai pendek (short chain fatty acids, SCFA). Bakteri asam laktat lokal diisolasi dari dedak dan probiotik. Desain percobaan adalah acak kelompok dengan 2 faktor, yaitu jenis media fermentasi dan jenis bakteri asam laktat. Hasil penelitian menunjukkan bahwa media fermentasi dengan menggunakan dedak menunjukkan pengaruh yang signifikan terhadap pertumbuhan bakteri yang ditunjukkan dari total sel bakteri asam laktat, total asam yang dihasilkan, pH dan aktivitas antibakteri. Fermentasi dengan menggunakan isolat J2-B menghasilkan total bakteri asam laktat 1,01 ´ 1010 cfu/mL, total asam 1,14%, pH 3,88 dan zona hambatan dengan bakteri uji Staphylococcus aureus 13,04 mm, Listeria monocytogenes 12,88 mm, Escherichia coli 12,83 mm dan Salmonella typhi 12,53 mm. Proses fermentasi bakteri asam laktat menggunakan media dedak selama 48 jam mampu menghasilkan asam laktat dan SCFA. Konsentrasi tertinggi asam laktat (122,13 mM), asam asetat (10,50 mM), dan asam butirat (1,56 mM) masing-masing dihasilkan oleh fermentasi menggunakan BAL J2, isolat L. acidophilus, dan isolat L. casei; sedangkan konsentrasi tertinggi asam propionat (6,07 mM) dihasilkan oleh fermentasi kontrol.Kata kunci: Probiotik, isolat lokal, dedak, SCFA, susu skim

scholarly journals Effect of Pressure-Induced Changes in the Ionization Equilibria of Buffers on Inactivation of Escherichia coli and Staphylococcus aureus by High Hydrostatic Pressure

2013 ◽  
Vol 79 (13) ◽  
pp. 4041-4047 ◽  
Author(s):  
Elisa Gayán ◽  
Santiago Condón ◽  
Ignacio Álvarez ◽  
Maria Nabakabaya ◽  
Bernard Mackey
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Survival Rates ◽  
Practical Significance ◽  
Protective Mechanisms ◽  
Content Type ◽  
Monovalent Ions ◽  
Ion Effects ◽  
Ionization Equilibria ◽  
Reaction Volumes

ABSTRACTSurvival rates ofEscherichia coliandStaphylococcus aureusafter high-pressure treatment in buffers that had large or small reaction volumes (ΔV°), and which therefore underwent large or small changes in pH under pressure, were compared. At a low buffer concentration of 0.005 M, survival was, as expected, better in MOPS (morpholinepropanesulfonic acid), HEPES, and Tris, whose ΔV° values are approximately 5.0 to 7.0 cm3mol−1, than in phosphate or dimethyl glutarate (DMG), whose ΔV° values are about −25 cm3mol−1. However, at a concentration of 0.1 M, survival was unexpectedly better in phosphate and DMG than in MOPS, HEPES, or Tris. This was because the baroprotective effect of phosphate and DMG increased much more rapidly with increasing concentration than it did with MOPS, HEPES, or Tris. Further comparisons of survival in solutions of salts expected to cause large electrostriction effects (Na2SO4and CaCl2) and those causing lower electrostriction (NaCl and KCl) were made. The salts with divalent ions were protective at much lower concentrations than salts with monovalent ions. Buffers and salts both protected against transient membrane disruption inE. coli, but the molar concentrations necessary for membrane protection were much lower for phosphate and Na2SO4than for HEPES and NaCl. Possible protective mechanisms discussed include effects of electrolytes on water compressibility and kosmotropic and specific ion effects. The results of this systematic study will be of considerable practical significance in studies of pressure inactivation of microbes under defined conditions but also raise important fundamental questions regarding the mechanisms of baroprotection by ionic solutes.

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