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 Comparative Survival Rates of Human-Derived ProbioticLactobacillus paracasei and L. salivariusStrains during Heat Treatment and Spray Drying

2000 ◽  
Vol 66 (6) ◽  
pp. 2605-2612 ◽  
Author(s):  
G. E. Gardiner ◽  
E. O'Sullivan ◽  
J. Kelly ◽  
M. A. E. Auty ◽  
G. F. Fitzgerald ◽  
...  
Keyword(s):  
Spray Drying ◽  
Storage Temperature ◽  
Skim Milk ◽  
Scanning Laser ◽  
Confocal Scanning Laser Microscopy ◽  
Outlet Temperature ◽  
Laser Microscopy ◽  
Scanning Laser Microscopy ◽  
Confocal Scanning ◽  
Confocal Scanning Laser

ABSTRACT Spray drying of skim milk was evaluated as a means of preservingLactobacillus paracasei NFBC 338 and Lactobacillus salivarius UCC 118, which are human-derived strains with probiotic potential. Our initial experiments revealed that NFBC 338 is considerably more heat resistant in 20% (wt/vol) skim milk than UCC 118 is; the comparable decimal reduction times were 11.1 and 1.1 min, respectively, at 59°C. An air outlet temperature of 80 to 85°C was optimal for spray drying; these conditions resulted in powders with moisture contents of 4.1 to 4.2% and viable counts of 3.2 × 109 CFU/g for NFBC 338 and 5.2 × 107 CFU/g for UCC 118. Thus, L. paracasei NFBC 338 survived better than L. salivarius UCC 118 during spray drying; similar results were obtained when we used confocal scanning laser microscopy and LIVE/DEAD BacLight viability staining. In addition, confocal scanning laser microscopy revealed that the probiotic lactobacilli were located primarily in the powder particles. Although both spray-dried cultures appeared to be stressed, as shown by increased sensitivity to NaCl, bacteriocin production by UCC 118 was not affected by the process, nor was the activity of the bacteriocin peptide. The level of survival of NFBC 338 remained constant at ∼1 × 109 CFU/g during 2 months of powder storage at 4°C, while a decline in the level of survival of approximately 1 log (from 7.2 × 107 to 9.5 × 106 CFU/g) was observed for UCC 118 stored under the same conditions. However, survival of both Lactobacillus strains during powder storage was inversely related to the storage temperature. Our data demonstrate that spray drying may be a cost-effective way to produce large quantities of some probiotic cultures.

Survival of Selected Organisms During Spray Drying of Skim Milk and Storage of Nonfat Dry Milk1

1978 ◽  
Vol 41 (1) ◽  
pp. 16-19 ◽  
Author(s):  
S. S. THOMPSON ◽  
L. G. HARMON ◽  
C. M. STINE
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Moisture Content ◽  
Spray Drying ◽  
Skim Milk ◽  
Drying Temperature ◽  
E Coli ◽  
Air Temperatures ◽  
And Storage ◽  
Spray Dried

Pasteurized concentrated skim milk containing 35 to 40% total solids was inoculated with cultures of Bacillus subtilis, Micrococcus flavus, or Escherichia coli to contain 1 × 106 organisms per g and spray-dried to determine the effect of exit air temperatures of 93.3, 82.2, and 71.1 C on survival of the organisms and moisture content of the finished product. The numbers of survivors increased as the drying temperature decreased. The percent survivors varied from 27.57 in the product made from milk inoculated with M. flavus and dried at 71.1 C to 0.02 in the product made from milk inoculated with E. coli and dried at 93.3 C. The organism most resistant to drying and most persistent during storage was B. subtilis, followed by M. flavus and E. coli, with the latter showing low survival during drying and abrupt die-off during the first 4 weeks of storage. The moisture content of the dry milks varied from 2.75 to 4.80% with low moisture associated with high drying temperature.

Effect of Five Materials Including Sucrose, Lactose, Skim Milk, Yeast, Vitamin B2 on Survival of Lactobacillus bulgaricus during Freeze-Drying

2013 ◽  
Vol 700 ◽  
pp. 255-258 ◽  
Author(s):  
He Chen ◽  
Qiu Hong Zhang ◽  
Qian Luo ◽  
Guo Wei Shu
Keyword(s):  
Survival Rate ◽  
Freeze Drying ◽  
Skim Milk ◽  
Lactobacillus Bulgaricus ◽  
Vitamin B ◽  
Protective Agent ◽  
Survival Ratio ◽  
Minimal Impact ◽  
Viable Cells ◽  
Impact On Survival

effect of five materials including sucrose, lactose, skim milk, yeast, vitamin B2on survival rate ofLactobacillus bulgaricusduring freeze-drying was studied by measured survival and the number of viable cells. Designed different concentrations of these different protective agents, respectively, freeze-drying perfectly and then counted the survival ratio ofLactobacillus bulgaricusand the number of viable cells. Results were as follows: addition of skim milk and yeast had significant effects while addition of vitamin B2had minimal impact on survival rate ofLactobacillus bulgaricus. The optimum concentration of single protective agent ofLactobacillus bulgaricusduring freeze-drying was that 25% (W/V) sucrose, 20% (W/V) lactose, 25% (W/V) skim milk, 20% (W/V) yeast and 25% (W/V) vitamin B2, respectively, and survival rate was 24.5%, 35.6%, 64.4%, 62.2%, and 16.3%.

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]

scholarly journals Staphylococcal Food Poisoning Associated with Spray-Dried Milk

1955 ◽  
Vol 53 (4) ◽  
pp. 387-397 ◽  
Author(s):  
P. H. R. Anderson ◽  
Doris M. Stone
Keyword(s):  
Spray Drying ◽  
Clinical Features ◽  
Milk Powder ◽  
Food Poisoning ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Large Numbers ◽  
Heat Treated ◽  
Drying Chamber ◽  
Spray Dried

SummaryEight explosive outbreaks of food poisoning, occurring in school canteens in England during 1953 and affecting 1190 known cases, are described. The clinical features were characteristic of the toxin type of illness. No deaths occurred.The food causing all of these outbreaks was prepared from spray-dried skim milk powder. It was not subsequently heat-treated and was usually consumed 3–4 hr. after preparation.The spray-dried milk powder proved to contain a high content of bacteria, including large numbers of Staph. aureus, of a phage pattern often associated with food poisoning. The assumption was therefore made that these outbreaks were caused by staphylococcal enterotoxin.Because the food was often consumed within 3–4 hr. of reconstitution of the milk powder—before, in fact, the staphylococci had had time to grow—it is concluded that the poisoning must have been due mainly to pre-formed toxin.Consideration is given to the opportunities for the formation of toxin in a spray-drying plant, and reasons are brought forward for believing that it is formed mainly in the balance tank where the warm milk is kept, sometimes for several hours, before passing into the final drying chamber.The processing of the milk and the precautions for preventing contamination of the finished product are discussed.

The impact of spray drying outlet temperature on the particle morphology of mannitol

2011 ◽  
Vol 213 (1-3) ◽  
pp. 27-35 ◽  
Author(s):  
Stephan G. Maas ◽  
Gerhard Schaldach ◽  
Eva M. Littringer ◽  
Axel Mescher ◽  
Ulrich J. Griesser ◽  
...  
Keyword(s):  
Spray Drying ◽  
Particle Morphology ◽  
Outlet Temperature ◽  
The Impact

Refined palm oil fractions: Effect of skim milk powder and maltodextrin on emulsion properties and microencapsulation by spray drying

2021 ◽  
Author(s):  
K. Cevik ◽  
H. Yalcin
Keyword(s):  
Spray Drying ◽  
Palm Oil ◽  
Palm Olein ◽  
Milk Powder ◽  
Skim Milk ◽  
Palm Stearin ◽  
Skim Milk Powder ◽  
Solid Content ◽  
Coating Materials ◽  
Oil Fractions

Abstract The aim of this study was to investigate microencapsulation of palm oil fractions (palm olein (POL) and 90% palm olein+10% palm stearin (POS)) using skim milk powder (SMP) and maltodextrin (MD) by spray drying. Twenty-seven emulsions with POL were prepared to determine appropriate solid content (SC) and oil/coating material ratio (O/CM) of the emulsions to be fed into the spray dryer. Emulsion properties, such as viscosity and stability, were affected by SC and coating materials. The effects of coating materials used in microencapsulation of POL and POS were also tested by using different ratios of SMP and MD. The microencapsulation efficiency (69.28–84.97%), the microencapsulation yield (14.50–31.79%), and the peroxide value (4.12–7.07 meq O2/kg oil) of the powders were affected by the coating materials (P < 0.05).

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