Effect of carbon dioxide on improving the keeping quality of raw milk

1986 ◽  
Vol 39 (2) ◽  
pp. 62-64 ◽  
Author(s):  
M. A. RASHED ◽  
N. M. MEHANNA ◽  
A. S. MEHANNA
Keyword(s):  
Carbon Dioxide ◽  
Raw Milk ◽  
Keeping Quality

693. A rejection test for raw milk

1958 ◽  
Vol 25 (1) ◽  
pp. 32-51 ◽  
Author(s):  
Peggy B. Taylor ◽  
L. F. L. Clegg
Keyword(s):  
Lactic Acid ◽  
Ferric Chloride ◽  
Technical Assistance ◽  
Milk Proteins ◽  
Raw Milk ◽  
Ph Change ◽  
Yellow Colour ◽  
A Value ◽  
Keeping Quality

The determination of apparent lactic acid has been used as a basis for a rejection test for raw milk. The method consists of precipitation of milk proteins with barium chloride, sodium hydroxide and zinc sulphate, and the addition of ferric chloride to the filtrate to produce the yellow colour of ferric lactate. Lactic acid is not solely responsible for the production of the yellow colour, which, nevertheless, gives a good relationship with keeping quality of milk (measured as hours to the C.O.B. end-point at 22° C.) and the values have been expressed as ‘apparent lactic acid’.The relationship of winter and summer milks to keeping quality has been studied, and a value of 0·03% apparent lactic acid in milk is equivalent to an average keeping quality of 5¾ and 8½ hr. for winter and summer milks, respectively. A value of 0·03% is recommended as the earliest value of apparent lactic acid at which milk could be rejected.The apparent lactic acid in colostrum and late-lactation milk and in milk from cows suffering from mastitis has been determined, and only in late-lactation milk were the values found to be significantly higher than usual in fresh raw milk, and an inverse relationship between yield and apparent lactic acid is suggested.Permanent glass matching disks have been prepared for use in a Lovibond comparator. This permits the intensity of the yellow colour produced with 1% ferric chloride to be determined and the apparent lactic acid in milk estimated.Grateful acknowledgement is made to the management and staff of the Dairy Department of the Reading Co-operative Society and the Farmer's Clean Milk Dairy, Reading, and local milk producers for supplying samples for experiments; to the N.M.T.S. staff in Reading for help in finding suitable farmers, and to the Dairy Husbandry Department of the N.I.R.D. for information about and samples of abnormal and late-lactation milk. Our particular thanks are due Miss Marie Gruber for technical assistance, to Dr N. J. Berridge for the suggestion and help on the work on pH change as an indication of keeping quality (given in the appendix), and to Dr A. T. R. Mattick for the advice given in this work.

Keeping quality and raw-milk grading: I. Dye tests as measures of the keeping quality of milk

1950 ◽  
Vol 17 (2) ◽  
pp. 159-191 ◽  
Author(s):  
A. T. R. Mattick ◽  
A. Rowlands ◽  
H. Barkworth ◽  
Zena Hosking ◽  
O. Kempthorne
Keyword(s):  
Raw Milk ◽  
Keeping Quality ◽  
Quality Of Milk

The experiments analysed in this series of papers were undertaken as the result of a discussion on methods of measuring the keeping quality of milk, at a Conference of Advisory Bacteriologists of the Ministry of Agriculture and Fisheries.Owing to the disturbance and difficulty following the outbreak of war and the dislocation of handling and distribution, a serious decline in the keeping quality of raw-milk supplies was threatened.

THE KEEPING QUALITY OF DEHYDRATED MIXTURES OF EGG AND MILK

1946 ◽  
Vol 24f (1) ◽  
pp. 70-76 ◽  
Author(s):  
Jesse A. Pearce ◽  
W. A. Bryce ◽  
Joan Whittaker ◽  
H. Tessier
Keyword(s):  
Carbon Dioxide ◽  
Beneficial Effect ◽  
Milk Powder ◽  
Storage Life ◽  
Carbohydrate Content ◽  
Added Sugar ◽  
Fluorescence Measurements ◽  
Similar Protein ◽  
Keeping Quality

The storage life of a dehydrated mixture of egg and milk, when assessed by both palatability and fluorescence measurements, was shorter than the life of milk powder of similar protein, fat, and carbohydrate content. Increased quantities of egg in the mixture decreased the quality of the mixture, both initially and during 16 weeks' storage. These effects were noticeable at all temperatures studied between 40° and 140° F. but were most marked above 80° F. After 16 weeks at 80° F., material packed under carbon dioxide usually had better palatability than the air-packed products. The effect of added sugar was most noticeable at 120° and 140° F. Lactose had a slightly beneficial effect; sucrose was more effective.

DRIED WHOLE EGG POWDER: VI. EFFECT OF STORAGE TEMPERATURE AND GAS PACKING ON KEEPING QUALITY

1943 ◽  
Vol 21d (9) ◽  
pp. 271-276 ◽  
Author(s):  
W. Harold White ◽  
M. W. Thistle ◽  
Margaret Reid
Keyword(s):  
Carbon Dioxide ◽  
Beneficial Effect ◽  
Potassium Chloride ◽  
Storage Temperature ◽  
Keeping Quality ◽  
Egg Powder ◽  
Whole Egg

Dried whole egg powders were obtained from three different manufacturers and stored at temperatures ranging from 7.1° to 32.1 °C. for periods up to six months. Quality was assessed by determination of fluorescence and potassium chloride values. At 23.8 °C. the rate of deterioration was comparatively rapid; at 32.1 °C. it was markedly so. To maintain quality during storage and transport dried egg should be stored at a temperature of 15.6 °C. or lower.The effect on keeping quality of packing in nitrogen, carbon dioxide, in vacuo, or in the form of compressed tablets was studied. Carbon dioxide alone had beneficial effect.

462. The keeping quality of composite milk

1952 ◽  
Vol 19 (1) ◽  
pp. 63-71 ◽  
Author(s):  
J. Babad ◽  
A. Shenhav-Hetman
Keyword(s):  
Milk Powder ◽  
Skim Milk ◽  
Raw Milk ◽  
Skim Milk Powder ◽  
Keeping Quality ◽  
Better Than

The keeping quality of various mixtures, made up of raw milk and skim milk-powder in varying proportions, has been studied. It has been found that the keeping quality of unpasteurized samples containing milk powder was slightly better than that of raw milk. The keeping quality of the pasteurized mixtures was satisfactory during the time of storage for 40 hr. at 23 and 18° C. and for 60 hr. at 10° C.

scholarly journals Study on the Extension of Shelf-life by Activation of Inherent Lactoperoxidase System in Raw Cow Milk

2014 ◽  
Vol 7 ◽  
pp. 57-60
Author(s):  
Prashanta Pokhrel ◽  
Suman Kumar Lal Das
Keyword(s):  
Hydrogen Peroxide ◽  
Lactic Acid ◽  
Shelf Life ◽  
Room Temperature ◽  
Raw Milk ◽  
Potassium Thiocyanate ◽  
Cow Milk ◽  
Lactoperoxidase System ◽  
Keeping Quality

Effectiveness of lactoperoxidase in raw cow milk was studied to observe the increase in shelf-life. Lactoperoxidase system was activated within two hours after milking by the addition of hydrogen peroxide and potassium thiocyanate, then milk was kept at different conditions viz. refrigerated condition (5±2)°C, room temperature (25±3)°C and at (35±2)°C. The keeping quality of raw milk was determined by the acidity, which when reached 0.18 % as lactic acid, was considered spoiled. Results indicated that the lactoperoxidase system (LP-s) increased the shelf-life of raw cow milk kept at room temperature (25±3)°C and refrigeration temperature (5±2)°C significantly (p<0.05);however no significant increase in shelf-life was observed between the control and LP-s treated raw milk sample held at (35±2)°C. DOI: http://dx.doi.org/10.3126/jfstn.v7i0.10606   J. Food Sci. Technol. Nepal, Vol. 7 (57-60), 2012   

PRESERVATION OF EGGS: VII. EFFECT OF AGE OF EGG AND CARBON DIOXIDE CONTENT AT TIME OF OILING ON KEEPING QUALITY

1950 ◽  
Vol 28f (5) ◽  
pp. 118-127 ◽  
Author(s):  
N. E. Gibbons
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Content ◽  
Simple Method ◽  
Keeping Quality ◽  
Effect Of Age ◽  
Better Than

The quality of eggs oiled when one day old is maintained better than that of eggs oiled when 6 or 10 days old, the ages between which most commercial eggs are treated. If the pH of the albumen of the older eggs is lowered by exposure to carbon dioxide before oiling (a simple method of treating eggs with carbon dioxide is described), the keeping quality as measured by yolk index, albumen height, and percentage of thick albumen is improved. However, these differences are not apparent on candling, and on this basis the improvement does not justify the added cost of the gassing treatment.

DRIED WHOLE EGG POWDER: XVIII. THE KEEPING QUALITY OF ACIDULATED, GAS-PACKED POWDERS OF LOW MOISTURE CONTENT

1946 ◽  
Vol 24f (1) ◽  
pp. 39-46 ◽  
Author(s):  
Jesse A. Pearce ◽  
Margaret Reid ◽  
W. H. Cook
Keyword(s):  
Carbon Dioxide ◽  
Moisture Content ◽  
Potassium Chloride ◽  
Storage Life ◽  
Ph Measurements ◽  
Keeping Quality ◽  
Egg Powder ◽  
Subsequent Storage ◽  
Whole Egg

Acidification of liquid egg prior to drying did not improve subsequent storage life, although pH measurements showed that powder from untreated egg became acid more rapidly during storage. Reduction in the moisture content (total volatiles) from 4.7 to 3.0% doubled, and reduction from 4.7 to 1.7% tripled, the storage life of dried whole egg powder as assessed by fluorescence tests. The maximum storage life predicted for the low moisture powder by this test was only 36 wk. at 27 °C. and 5 wk. at 38 °C. Palatability tests suggested that the product was somewhat less perishable, as a powder of 1.7% moisture was considered fit for use as an egg dish after 64 wk. at 27 °C. Gas-packing low moisture powders in an atmosphere of carbon dioxide appeared to be slightly more effective as a means of retaining palatability than packing in an atmosphere of air or nitrogen, but was particularly effective in preventing loss of solubility (assessed by potassium chloride values) during storage.

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