Interactive Effects of Duration of Storage and Addition of Formaldehyde on Levels of Aflatoxin M1 in Milk

1988 ◽  
Vol 71 (2) ◽  
pp. 285-287 ◽  
Author(s):  
Susan K Heimbecher ◽  
Karen V Jorgensen ◽  
Ralph L Price
Keyword(s):  
Skim Milk ◽  
Raw Milk ◽  
Final Concentration ◽  
Interactive Effects ◽  
Aflatoxin M1 ◽  
Formaldehyde Concentration ◽  
Glass Containers ◽  
Whole Milk ◽  
Duration Of Storage ◽  
Spray Dried

Abstract Spray-dried skim milk, naturally contaminated with aflatoxin M„ was added to either raw or pasteurized whole milk to a final concentration of 1.1 Mg aflatoxin M,/L milk. Formalin (37% w/w) was added to the milk solutions to final concentrations of 0, 0.025, 0.05, and 0.1% formaldehyde. Samples were stored in the dark at 21°C in plastic and glass containers and were analyzed for aflatoxin M, at 0,1, 2, 3, and 4 weeks. This experiment was repeated using only raw milk and glass containers. Aflatoxin M, analyses were done at 0, 1, and 2 weeks. Aflatoxin M, losses increased over time and with increased formaldehyde concentration. With both experiments, aflatoxin M, levels after 2 weeks were less than 0.05 iigfL in samples containing 0.1% formaldehyde.

Distribution and Resistance to Pasteurization of Aflatoxin M1 in Naturally Contaminated Whole Milk, Cream and Skim Milk

1983 ◽  
Vol 46 (6) ◽  
pp. 530-532 ◽  
Author(s):  
DANA W. WISEMAN ◽  
RHONÁS. APPLEBAUM ◽  
ROBERT E. BRACKETT ◽  
ELMER H. MARTH
Keyword(s):  
Heat Treatment ◽  
Skim Milk ◽  
Aflatoxin M1 ◽  
Whole Milk

Milk, naturally contaminated with aflatoxin M1 (AFM1) was separated with a hand-operated separator. Distribution of AFM1 paralleled the partitioning of whole milk into cream and skim milk. Most of the whole milk was recovered as skim milk, which also contained most of the AFM1. Cream accounted for 5–15% of the amount of whole milk and had 2–14% of AFM1 that originally occurred in whole milk. Cream and skim milk were pasteurized at 64°C for 30 min, AFM1 was stable in both products given this heat treatment.

Fluorometric Determination of Alkaline Phosphatase in Fluid Dairy Products: Collaborative Study

1990 ◽  
Vol 73 (6) ◽  
pp. 842-849 ◽  
Author(s):  
Richard M Rocco
Keyword(s):  
Alkaline Phosphatase ◽  
Dairy Products ◽  
Collaborative Study ◽  
Skim Milk ◽  
Raw Milk ◽  
Chocolate Milk ◽  
Phenyl Phosphate ◽  
Whole Milk ◽  
Standard Deviations

Abstract Official methods for the measurement of alkaline phosphatase (ALP) in dairy products use either phenyl phosphate or phenolphthaleln monophosphate as substrate. Quantitation of results requires butanol extraction of the Indophenol (Scharer) or 3-h dialysis of the liberated phenolphthaleln (Rutgers). The Advanced Fluorophos® assay Is based on a self-indicating substrate which, when acted upon by ALP, loses a phosphate radical and becomes a highly fluorescent compound. The rate of fluorophore formation Is monitored for 3 mln In a fluorometer and the enzyme activity In mU/L Is calculated. Eight laboratories participated in a collaborative study to evaluate the Fluorophos® assay for determining ALP activity In whole milk, skim milk, chocolate milk, and cream (half and half). The comparative method was the AOAC quantitative phenyl phosphate method, 16.121-16.122 (14th Ed.). Mixed herd raw milk was added to pasteurized samples at 0.05, 0.1, and 0.2% (v/v). Method performance at 0.1% (v/v) added raw milk as measured by repeatability and reproducibility standard deviations (sr and sR) and relative standard deviations (RSDr and RSDR), respectively, were: whole milk, sr = 21.7%, sR = 34.6%, RSDr = 4.4%, RSDR = 7.0%; skim milk, sr = 19.2%, sR = 31.4%, RSDr = 3.8%, RSDR = 6.2%; chocolate milk, sr = 27.6%, sR = 45.8%, RSDr = 5.3%, RSDR = 8.8%. The method has been adopted official first action by AOAC for determination of alkaline phosphatase in whole milk, skim milk, and chocolate milk.

Fate of Organochlorine Pesticides During Processing of Milk into Dairy Products

1970 ◽  
Vol 53 (1) ◽  
pp. 127-139
Author(s):  
C F Li ◽  
R L Bradley ◽  
L H Schultz
Keyword(s):  
Dairy Products ◽  
Cheese Whey ◽  
Skim Milk ◽  
Cheddar Cheese ◽  
Bactericidal Action ◽  
Milk Products ◽  
Condensed Milk ◽  
Lactating Dairy Cows ◽  
Whole Milk ◽  
Spray Dried

Abstract Two lactating dairy cows per group were fed selected pesticides dissolved in organic solvents and mixed into a grain concentrate for a two week period. The reference pesticides used in this study were dieldrin; a mixture of heptachlor, DDT, and lindane; toxaphene; chlordane; endosulfan (Thiodan); and dicofol (Kelthane). The milk from these contaminated cows was collected and processed into the following dairy products: pasteurized whole milk, 30% cream, butter, spray-dried whole milk, condensed whole milk, sterilized condensed whole milk, and Cheddar cheese. The byproducts (skim milk, buttermilk, and Cheddar cheese whey) from manufacturing these products were also saved for subsequent analysis. The residues in these dairy products and byproducts were extracted, cleaned up, and analyzed by electron capture gas chromatography. The 30% cream, condensed milk, and pasteurized milk were analyzed at 0, 7, and 14 days and Cheddar cheese, spray-dried milk, butter, and sterilized condensed milk after storage for 0, 3, and 6 months. The results indicated that, in general, the pesticides used were very stable for ordinary dairy processing operations and remained essentially unchanged even after storage at refrigeration and room tempera-tures for 6 months. However, dieldrin, lindane, and chlordane showed a 27, 34, and 11% decrease, respectively, for spray-dried products and the concentration of dicofol showed a slight decrease in the sterilized condensed whole milk products, whereas the concentration of DDE extracted from the products stored 3 and 6 months was generally less than the amount extracted initially. In manufacturing Cheddar cheese, most of the pesticides showed some bacteriostatic or bactericidal action against starter microorganisms. Generally the pesticide residues were found in greater concentration (on a fat basis) in the skim milk, buttermilk, and whey than in products from which these were derived. This might be attributable to the affinity of the residues for the lipoprotein portion of the products. Concentrations of dieldrin and toxaphene increased slightly during storage of the milk and milk products, suggesting that a reorientation occurred.

Interactions between the bovine milk fat globule membrane and skim milk components on heating whole milk

1992 ◽  
Vol 59 (2) ◽  
pp. 187-195 ◽  
Author(s):  
Avis V. Houlihan ◽  
Philippa A. Goddard ◽  
Stephen M. Nottingham ◽  
Barry J. Kitchen ◽  
Colin J. Masters
Keyword(s):  
Milk Fat ◽  
Bovine Milk ◽  
Skim Milk ◽  
Milk Proteins ◽  
Raw Milk ◽  
Membrane Lipid ◽  
Milk Fat Globule Membrane ◽  
Whole Milk ◽  
Milk Fat Globule ◽  
Fat Globule

SummaryHeating raw milk at 80 °C for 2·5–20 min was found to result in compositional changes in the milk fat globule membrane (MFGM). The yield of protein material increased with the duration of heating, owing to incorporation of skim milk proteins, predominantly β-lactoglobulin, into the membrane. Lipid components of the MFGM were also affected, with losses of triacylglycerols on heating.

Preservation of raw milk by the addition of carbon dioxide

1982 ◽  
Vol 49 (3) ◽  
pp. 439-447 ◽  
Author(s):  
Joseph S. King ◽  
Leonard A. Mabbitt
Keyword(s):  
Carbon Dioxide ◽  
Storage Temperature ◽  
Skim Milk ◽  
Raw Milk ◽  
Lag Phase ◽  
Logarithmic Phase ◽  
Inhibitory Effects ◽  
Whole Milk ◽  
Pure Cultures ◽  
Per Se

SUMMARYThe effects of concentrations of 10–30 mM/1 of CO2on the growth of psychrotrophic milk spoilage organisms were examined, both in untreated whole milk and in pure cultures ofPseudomonas fluorescensgrowing in skim-milk and broth. Spoilage of refrigerated untreated whole milk was found to be inhibited by the addition of CO2and the effect was enhanced with increasing concentrations of CO2and decreasing storage temperature. Experiments with pure cultures ofPs. fluorescensshowed that the inhibitory effects of CO2were not due to increased acidity or to displacement of dissolved O2, but to the presence of CO2per sewhich induced an increase in the duration of the lag phase of growth and had only a small effect on the logarithmic phase.

Psychrotrophic Growth and Thermal Inactivation of Listeria monocytogenes as a Function of Milk Composition

1986 ◽  
Vol 49 (12) ◽  
pp. 994-998 ◽  
Author(s):  
CATHERINE W. DONNELLY ◽  
ELIZABETH H. BRIGGS
Keyword(s):  
Listeria Monocytogenes ◽  
Thermal Resistance ◽  
Thermal Inactivation ◽  
Skim Milk ◽  
Raw Milk ◽  
Milk Composition ◽  
Cellular Growth ◽  
Whole Milk ◽  
Serotype 1 ◽  
Serotype 4B

Listeria monocytogenes strains 19111, 19113, 19115, F5027 and F5069 were grown in 11% nonfat milk solids, skim milk and whole milk at 4, 10, 22, and 37°C to determine the influence of temperature and milk composition on growth and thermal resistance. Milk composition affected cellular growth. The psychrotrophic growth of L. monocytogenes serotype 4b strains was enhanced in whole milk when compared to skim milk or 11% NFMS. This enhancement of psychrotrophic growth was not observed for serotype 1 or 3 strains. The stimulatory effect of whole milk on serotype 4b L. monocytogenes strains was most dramatic at 10°C where cells increased from 7.9 × 10° to 5.8 × 106 CFU/ml within 48 h. Milk composition did not affect the thermal resistance of L. monocytogenes. All strains used in this study had a D62.7°C value of 1.0 min or less, therefore, pasteurization as defined by current FDA guidelines should eliminate this organism from raw milk with a large margin of safety. Post-pasteurization contamination of dairy products with L. monocytogenes must be eliminated since the psychrotrophic nature of this organism ensures survival and proliferation during refrigerated storage.

Effects of feeding formalin-treated skim milk to calves

1960 ◽  
Vol 2 (01) ◽  
pp. 33-36 ◽  
Author(s):  
T. R. Preston ◽  
E. Rattray ◽  
F. White
Keyword(s):  
Histological Examination ◽  
Alimentary Tract ◽  
Clinical Symptoms ◽  
Skim Milk ◽  
Final Concentration ◽  
Post Mortem ◽  
Severe Damage ◽  
Whole Milk

1. 2-week-old calves previously fed whole milk were changed abruptly o t skim milk which had been treated with formalin to give a final concentration of 0·1% of the preservative.2. Difficulty was experienced in accustoming the calves to drink such formalin-treated milk and scouring invariably occurred within two days of the changeover.3. Post-mortem and histological examination of calves fed formalin-treated skim milk showed severe damage to the alimentary tract compatible with clinical symptoms.4. None of the above findings was apparent in control calves fed untreated skim milk.

303. The production of rennet from living calves

1943 ◽  
Vol 13 (2) ◽  
pp. 145-161 ◽  
Author(s):  
N. J. Berridge ◽  
J. G. Davis ◽  
P. M. Kon ◽  
S. K. Kon ◽  
F. R. Spratling
Keyword(s):  
Vitamin D ◽  
Standard Deviation ◽  
Chloride Solution ◽  
Milk Powder ◽  
Skim Milk ◽  
Skim Milk Powder ◽  
Calcium Chloride Solution ◽  
Whole Milk ◽  
The Mean ◽  
Spray Dried

Abomasal juice containing rennin was obtained from living calves by means of an abomasal fistula as described by Fomin, in order to ascertain whether the process could be used as an alternative method of manufacturing rennet, should the present curtailed sources fail completely.The operation for fistula was performed on the calves at the age of about a fortnight by the technique of Phillipson & Innes. The animals received, during the three months for which the experiment lasted, an exclusive diet of whole milk, supplemented by minerals and vitamin D. Although only two calves were used, we feel that the results are nevertheless representative.Abomasal juice was obtained by allowing them to drink diluted whey and removing it through the fistula after about half an hour. The mean yield of rennin for each ‘perfusion’ from the first calf was 3120 units with a standard deviation of ± 1330. The corresponding figures for the second calf were 5680 and ± 2560 respectively. (One unit of rennin clots 10 ml. of substrate in 100 sec. The substrate is made by dissolving 12 g. spray-dried skim-milk powder in 100 ml. N/50 calcium chloride solution.)

Estimation of Aflatoxin M1 Levels in Some Dairy Products Manufactured from Raw Milk Experimentally Inoculated with Toxin

2019 ◽  
Vol 43 (1) ◽  
pp. 50-58
Author(s):  
H. S. Alnaemi
Keyword(s):  
Dairy Products ◽  
Raw Milk ◽  
Aflatoxin M1 ◽  
Consumer Health ◽  
Goat’S Milk ◽  
White Cheese ◽  
Elisa Technique ◽  
Permissible Levels ◽  
Goat's Milk

     Fate of AflatoxinM1 in soft white cheese and its by-product (whey) and in yogurt locally made from raw sheep's and goat's milk experimentally inoculated with 0.05 and 0.5 µg/l AflatoxinM1 were investigated using ELISA technique. Results reported that AflatoxinM1 was concentrated in cheese at levels significantly higher than that recorded in the raw milk that used for its processing, with a significant decrease in AflatoxinM1 levels in its by-product (whey) comparable to the raw milk used in manufacturing at both inoculated levels. Yogurt produced from raw sheep's milk at second inoculated level exerted AflatoxinM1concentration significantly lower than that present in the milk. Significant differences in AflatoxinM1distribution in cheese and whey produced from sheep's milk comparable to their counterparts produced from goat's milk were recorded. Finally, results revealed the efficacious role of the various dairy manufacturing processes in AflatoxinM1 distribution and the necessity to issue of local legislations concerning the maximum permissible limits for AflatoxinM1 in milk in order to stay within the universal permissible levels for AflatoxinM1 in dairy products to provide greater protection for consumer health. 

Sign in / Sign up

Export Citation Format

Share Document