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 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 Pantoea agglomerans Strain CPA-2 in a Spray-Drying Process

2002 ◽  
Vol 65 (1) ◽  
pp. 185-191 ◽  
Author(s):  
E. COSTA ◽  
N. TEIXIDÓ ◽  
J. USALL ◽  
E. FONS ◽  
V. GIMENO ◽  
...  
Keyword(s):  
Spray Drying ◽  
Dairy Products ◽  
Biocontrol Agent ◽  
Low Cost ◽  
Pantoea Agglomerans ◽  
Penicillium Expansum ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Drying Process ◽  
Drying Conditions

Spray drying could be a suitable method for preserving microorganisms, as it allows large quantities of cultures to be dried at low cost. The aims of this paper were to evaluate the effects of spray-drying conditions on survival of the biocontrol agent Pantoea agglomerans CPA-2, which has shown antifungal activity against Penicillium expansum and Penicillium digitatum on citrus fruits. Various compounds cited in the bibliography as carriers were tested in our spray drying, and some salts (MgSO4, K2SO4, and Na2CO3) and dairy products (lactoserum or nonfat skimmed milk [NFSM]) showed the best results in terms of recovered powder. Outlet temperature had more influence on the death of bacteria than inlet temperature. P. agglomerans was heat sensitive, and the activation energy was around 6 kcal/mol K when MgSO4 (10%) or NFSM (10%) were used as carriers and only 3 kcal/mol K when the combination of MgSO4 (10%) and NFSM (10%) was used. The highest powder recovery was obtained when NFSM was used as the rehydration medium. Although the percentage of powder recovery was not high (around 50%) and viability was low, the results suggest that with bigger spray dryers, we could expect a lower outlet temperature and probably an increased viability. Further research into spray-dryer design is needed in order to demonstrate this.

scholarly journals Effect of spray drying process parameters on Uncaria tomentosa (Willd. ex Schult.) DC. dried extracts

Revista Fitos ◽  
2020 ◽  
Vol 14 (4) ◽  
pp. 469-475
Author(s):  
Lucas Oliveira Rodrigues ◽  
Rachel Andrade de Faria ◽  
Marcos Martins Gouvêa ◽  
Carlos Augusto de Freitas Peregrino ◽  
Elizabeth Valverde Macedo ◽  
...  
Keyword(s):  
Spray Drying ◽  
Process Parameters ◽  
Inlet Temperature ◽  
Airflow Rate ◽  
Spray Nozzle ◽  
Drying Process ◽  
Process Yield ◽  
Uncaria Tomentosa ◽  
Acacia Gum ◽  
Higher Temperature

Uncaria tomentosa (Willd. ex Schult.) DC. (Cat's claw) is a plant member of the Rubiaceae family, from the Amazon region, and used in traditional medicine as raw material for phytomedicines indicated for arthritis and osteoarthritis. This study aimed to evaluate the spray drying process parameters on the properties of different extracts obtained from Uncaria tomentosa. A reduced 24-1 multifactorial design was applied to evaluate the importance of the equipment variables (pump speed, spray nozzle diameter, air inlet temperature, and atomization airflow rate) in the process. Maltodextrin and acacia gum were used as carriers in a 1:1 (m/m) ratio, considering the solid residue content of the liquid plant extract. Process yield, moisture, and hygroscopicity were evaluated as dependent variables. Higher atomization airflow rate led to higher process yield for powdered dried extracts with maltodextrin. Higher temperature led to lower moisture contents regarding powdered dried extracts with acacia gum. No variable, for any carrier, was considered significant for hygroscopicity. The best spray drying configuration for the desired characteristics (i.e. lower hygroscopicity and moisture) used the larger spray nozzle with a diameter of 1.2 mm and the higher temperature of 150 °C, with both carriers.

scholarly journals Physical Properties of Nonfat Dry Milk and Skim Milk Powder

2017 ◽  
Vol 12 (2) ◽  
pp. 149-154 ◽  
Author(s):  
A.K. Abdalla ◽  
K. Smith ◽  
J. Lucey
Keyword(s):  
Physical Properties ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Dry Milk ◽  
Nonfat Dry Milk

Oxidation of Cholesterol in Commercially Processed Cow's Milk

1987 ◽  
Vol 50 (10) ◽  
pp. 867-871 ◽  
Author(s):  
MAE Z. CLEVELAND ◽  
NATHOLYN D. HARRIS
Keyword(s):  
Skim Milk ◽  
Milk Lipid ◽  
Oxidized Cholesterol ◽  
Heated Milk ◽  
Whole Milk ◽  
Dry Milk ◽  
Liquid Milk ◽  
Milk Lipids ◽  
And Storage ◽  
Layer Chromatography

Pasteurized whole milk, ultra-high temperature heated milk, canned evaporated milk, skim milk and instant nonfat dry milk were analyzed for presence of oxidized cholesterol compounds. Effects of heating whole milk and storage of whole milk lipid extracts were also examined. Analytical thin-layer chromatography data indicate that cholesterol in liquid milk was stable during commercial pasteurization, sterilization and evaporation. However, instant non-fat dry milk contained 7-hydroxy-cholesterol. Heating whole milk for 12 h at 85°C did not produce oxysterols, but GC-MS analysis indicate that storage of whole milk lipids may have produced steroidal ketones.

Survival of Listeria monocytogenes in Simulated Milk Cooling Systems1

1988 ◽  
Vol 51 (3) ◽  
pp. 172-175 ◽  
Author(s):  
R. PETRAN ◽  
E. A. ZOTTOLA
Keyword(s):  
Listeria Monocytogenes ◽  
Propylene Glycol ◽  
Water Systems ◽  
Cooling Systems ◽  
Dry Milk ◽  
Sweet Water ◽  
Minimal Media ◽  
Nonfat Dry Milk

Survival of Listeria monocytogenes under conditions that might be found in milk cooling systems was studied. Sterile solutions of 0.1 and 0.01% peptone, 0.1 and 0.01% nonfat dry milk (NFDM), 30% propylene glycol, and 30% propylene glycol with 0.01 % NFDM were inoculated with 6000 L. monocytogenes Scott A/ml and were incubated at 4°C. The temperature was increased to 7°C when little growth was observed. At 7°C, populations approached 109 organisms/ml in NFDM and peptone. Growth was greater in the higher concentrations of each, and there was limited survival in the glycol media. Growth in minimal media, 0.01% peptone, 0.01% NFDM, 30% propylene glycol with 0.01% NFDM, and 1 % tryptic soy broth (TSB), was studied. These media were inoculated with 3500 L. monocytogenes Jalisco cheese/ml. At 4°C, more growth was observed in the NFDM than in the peptone, no survival was seen in the glycol media, and the most growth was observed in the TSB. Growth in sterile 10, 20, and 30% propylene glycol solutions (with 0.1 % NFDM) was studied by inoculation with 8800 L. monocytogenes Jalisco cheese/ml and incubation at 4°C. Growth in the 10% solution was observed. However, there was survival in the 20 and 30% solutions with no increase in numbers apparent over the time studied. Presence of L. monocytogenes in milk cooling systems may pose a hazard, especially in sweet water systems that might contain a small amount of milk.

Changes in Concentration of Aflatoxin M1 during Manufacture and Storage of Skim Milk Powder

2006 ◽  
Vol 69 (3) ◽  
pp. 682-685 ◽  
Author(s):  
ORGUN DEVECİ ◽  
EMEL SEZGİN
Keyword(s):  
Spray Drying ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Aflatoxin M1 ◽  
Weight Changes ◽  
Sample Weight ◽  
Powder Samples ◽  
And Storage ◽  
Different Levels

In this study, skim milk powder was produced from cow's milk contaminated artificially with aflatoxin M1 (AFM1) at two different levels, 1.5 and 3.5 μg/liter (ppb), and the effects of process stages on the AFM1 contents were investigated. Pasteurization, concentration, and spray drying caused losses of about 16, 40, and 68%, respectively, in AFM1 content of the milk contaminated with 1.5 μg/liter AFM1, and losses of 12, 35, and 59%, respectively, in the milk contaminated with 3.5 μg/liter AFM1. These losses were found to be statisticially significant at the level of P < 0.01. After 3- and 6-month storage periods, AFM1 content of the skim milk powder produced from milk with 1.5 μg/liter AFM1 decreased by 2 and 5%, respectively, whereas these rates were 2 and 4%, respectively, for the skim milk powders made from milk with 3.5 μg/liter AFM1 (after adjustment for sample weight). Changes in AFM1 content of milk powder samples were found statistically insignificant (P > 0.05 and P > 0.01) for 3- and 6-month storage periods.

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