173. The effect of commercial sterilization on the nutritive value of milk. III. Effect on the vitamin A and carotene content of milk

1938 ◽  
Vol 9 (1) ◽  
pp. 17-21 ◽  
Author(s):  
A. E. Gillam ◽  
K. M. Henry ◽  
S. K. Kon ◽  
P. White
Keyword(s):  
Heat Treatment ◽  
Vitamin A ◽  
Nutritive Value ◽  
Colorimetric Method ◽  
Raw Milk ◽  
Carotene Content ◽  
Lovibond Tintometer ◽  
Ether Extraction ◽  
Sterilized Milk

1. The vitamin A and carotene content of raw milk have been compared with that of milk from the same bulk after it had been commercially sterilized.2. For this purpose the fat was obtained by ether extraction from eleven samples of raw milk and from eleven corresponding samples of sterilized milk. As the sterilized milk had been previously homogenized it was not possible to churn it.3. The vitamin A and carotene content was estimated by colorimetric (Lovibond tintometer) and by spectrophotometric tests.3. The vitamin A and carotene content was estimated by colorimetric (Lovibond tintometer) and by spectrophotometric tests.4. The results showed that the efiect of the heat treatment was negligible, neither method demonstrating a loss in vitamin A, while for carotene only the colorimetric method indicated a loss of about 2 %.5. The vitamin A and carotene contents of sterilized milk were not decreased after storage for several weeks in a cool dark place.

216. The effect of churning on the vitamin A and carotene content of milk fat

1939 ◽  
Vol 10 (1) ◽  
pp. 114-117 ◽  
Author(s):  
K. M. Henry ◽  
S. K. Kon ◽  
A. E. Gillam ◽  
P. White
Keyword(s):  
Vitamin A ◽  
Milk Fat ◽  
Carotene Content ◽  
Lovibond Tintometer ◽  
Butter Fat ◽  
Ether Extraction

The vitamin A and carotene content of 14 samples of butter fat churned from milk in the usual way has been compared in spectrophotometric and Lovibond tintometer tests with figures similarly obtained for the ether-extracted fat from the same milks. On the assumption that there is no loss of either carotene or vitamin A in the course of the ether extraction, it has been found that some carotene is lost in churning but that vitamin A is not appreciably affected.

171. The effect of commercial sterilization on the nutritive value of milk. IIa. biological value and digestibility of the proteins (nitrogen) of milk

1938 ◽  
Vol 9 (1) ◽  
pp. 6-11 ◽  
Author(s):  
K. M. Henry ◽  
S. K. Kon
Keyword(s):  
Heat Treatment ◽  
Nutritive Value ◽  
Statistical Tests ◽  
Raw Milk ◽  
Biological Value ◽  
True Digestibility ◽  
The Difference ◽  
Sterilized Milk

1. The biological values and true digestibilities of the proteins of raw and commercially sterilized milks from the same bulk have been compared on rats by the method of Mitchell.2. For raw milk a biological value of 84·3 and a true digestibility of 96·4 were obtained, while the figures for sterilized milk were 79·1 and 95·3 respectively.3. Statistical tests showed that the difference in true digestibility was not significant but that the lowering of the biological value by about 6% could be ascribed to the effect of the heat treatment, the odds against chance factors being 625: 1.

170. The effect of commercial sterilization on the nutritive value of milk

1938 ◽  
Vol 9 (1) ◽  
pp. 1-5 ◽  
Author(s):  
S. K. Kon ◽  
K. M. Henry ◽  
E. W. Ikin ◽  
A. E. Gillam ◽  
P. White
Keyword(s):  
Heat Treatment ◽  
Nutritive Value ◽  
Legal Definition ◽  
Previous Communication ◽  
Nutritional Effects ◽  
Definition Of ◽  
Sterilized Milk

We have dealt in a previous communication (1) with the effects-of commercial pasteurization on the nutritive value of milk. We present here the results of an enquiry into the nutritional effects of the more drastic heat treatment to which milk is subjected during commercial sterilization. There is no legal definition of either sterilized milk or of the process of sterilization, but in commerce it is customary to apply the term to milk which has been heated to at least 212° F. for varying lengths of time.

The influence of pH and heat treatment on the colour and stability of ultra-high-temperature sterilized milk

1971 ◽  
Vol 38 (3) ◽  
pp. 393-401 ◽  
Author(s):  
J. G. Zadow
Keyword(s):  
Heat Treatment ◽  
Sodium Citrate ◽  
Whey Proteins ◽  
Raw Milk ◽  
Hydrogen Phosphate ◽  
Sediment Formation ◽  
Bacterial Action ◽  
Sterilized Milk ◽  
Influence Of Ph

SummaryWhen the pH of milk was varied within the range 7·1 to 6·3 by addition of acid or alkali or through bacterial action, the reflectance of the milk after subsequent ultra-heat-treatment (UHT) was at a maximum of about pH 6·70. Below this value the reflectance dropped rapidly with decrease in pH. The cause of this decrease was the development of increasing amounts of sediment in the product. At pH 6·4–6·5, at least 90% of the casein and 40% of the whey proteins had been precipitated. The addition of 0·1% sodium di-hydrogen phosphate or 0·1% sodium citrate to the raw milk prevented the formation of the sediment. The role of calcium appeared important as small additions of calcium chloride or EDTA altered the patterns of sediment formation and reflectance with changing pH. Addition of 0·3% EDTA prevented sediment formation as the pH dropped.

188. The effect of commercial sterilization on the nutritive value of milk. V. The effect of commercial sterilization on the vitamin C of milk

1938 ◽  
Vol 9 (2) ◽  
pp. 185-187 ◽  
Author(s):  
K. M. Henry ◽  
S. K. Kon
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Chemical Method ◽  
Nutritive Value ◽  
Raw Milk ◽  
Sterilized Milk

1. Fifteen samples of raw and fifteen samples of commercially sterilized milk from the same bulk were analysed for vitamin C by the chemical method (titration with dichlorophenol-indophenol).2. The raw milk contained on an average 1·83 mg./100 ml. of total (reduced and reversibly oxidized) ascorbic acid. The corresponding figure for sterilized milk was 1·03 mg./100 ml., a loss of 43% of the original value.3. Storage of the sterilized milk for a period of 4·6 weeks resulted in a further reduction equivalent to about 30%.

SOME OBSERVATIONS ON THE BACTERIOLOGICAL KEEPING QUALITY OF MILK PROCESSED BY HIGH TEMPERATURES WITH A 0.6 SECOND HOLDING TIME1 2

1963 ◽  
Vol 26 (10) ◽  
pp. 332-336 ◽  
Author(s):  
D. A. Evans ◽  
Eleanor L. Lachman ◽  
Warren Litsky
Keyword(s):  
Heat Treatment ◽  
Raw Milk ◽  
Plate Heat Exchanger ◽  
Plate Heat ◽  
Milk Samples ◽  
Whole Milk ◽  
Keeping Quality ◽  
Quality Of Milk ◽  
Sterilized Milk

Summary Raw milk was processed through a commercial sized plate heat exchanger at temperatures of 160 F through 260 F with a 0.6 sec hold. Milk samples were collected at increments of 10 F during processing and analyzed for psychrophilic, mesophilic and thermophilic counts initially and at weekly intervals thereafter. All samples were held at 40 F after processing. Results indicated that temperatures of processing at 160 F and 170 F were not sufficient to impart acceptable keeping qualities to whole milk held at 40 F for a period of one week. By comparison, processing temperatures of 180 F through 210 F with 0.6 sec hold appeared to impart to whole milk keeping qualities which were approximately comparable to those observed in milk pasteurized according to present standards. When heat treatment in the range of 220 F through 260 F were used, it was indicated that bacteriological keeping quality of the milk was improved to an extent far beyond that experienced with present day commercial pasteurization. There appeared to be somewhat of a tendency for higher count raw milk related to the level of population in the processed product although the magnitude of this relationship was not clearly defined in all cases. It was evident that this process did not produce “commercially sterilized” milk at the processing temperatures and holding time used.

190. The effect of commercial sterilization on the nutritive value of milk. VII. Conclusions

1938 ◽  
Vol 9 (2) ◽  
pp. 207-207 ◽  
Author(s):  
S. K. Kon
Keyword(s):  
Heat Treatment ◽  
Amino Acids ◽  
Nutritive Value ◽  
Essential Amino Acids ◽  
Limiting Factor ◽  
Vitamin B ◽  
Anaerobic Conditions ◽  
Biological Value ◽  
Sterilized Milk ◽  
Partial Destruction

The work carried out by us on the nutritive value of commercially sterilized milk shows definitely that certain factors are injured in the course of the heat treatment. The biological value of the proteins is slightly but unmistakably decreased, most probably because of the partial destruction of one or more essential amino-acids. Of the vitamins, vitamin C is the most markedly affected. It is decreased by half and, in view of the severity of the heat treatment, it is remarkable that the loss is not greater. The anaerobic conditions which exist during the application of the highest sterilizing temperatures may account for the survival of a part of this labile factor. Vitamin B1 also suffers serious loss, the destruction amounting to 30 % of the original value. Neither vitamin A and carotene nor vitamin B2 (flavin) are affected by the heat treatment. The fate of other components of milk was not studied by us, but experiments on rats on the effect of sterilization on the total nutritive value of milk indicates that vitamin B1 was the first limiting factor of sterilized milk.

Influence of thermal and other manufacturing stresses on retinol isomerization in milk and dairy products

1998 ◽  
Vol 65 (2) ◽  
pp. 253-260 ◽  
Author(s):  
GIANFRANCO PANFILI ◽  
PAMELA MANZI ◽  
LAURA PIZZOFERRATO
Keyword(s):  
Heat Treatment ◽  
Vitamin A ◽  
Thermal Processing ◽  
Dairy Products ◽  
Analytical Procedure ◽  
Fermented Milk ◽  
Thermal Conversion ◽  
Vitamin A Status ◽  
Sterilized Milk ◽  
Milk And Dairy Products

An analytical procedure, based upon HPLC, has been used to determine the degree of isomerization of retinol (vitamin A) in various dairy products. In raw milks, which are not subjected to thermal processing, there was no conversion of the predominant all-trans-isomers to cis-isomers in samples from various species. Pasteurized milks with mild heat treatment (high quality milk) had an average 13-cis[ratio ]all-trans ratio of 2·6%, while pasteurized milk treated for 15 s at temperatures ranging from 72 to 76°C had an average ratio of 6·4%. Milk subjected to more severe heat treatments had a higher degree of isomerization (UHT milk, 15·7%; sterilized milk, 33·5%), consistent with increased thermal conversion of the retinol isomers. In pasteurized and UHT cream, the increase in 13-cis-isomer was also a consequence of heat treatment (pasteurized cream, 3·0%; UHT cream, 14·4%). The presence of cis isomers in fermented milk suggests that fermentation processes, directly or indirectly, can induce cis–trans isomerization. In the cheeses analysed, the extent of retinol isomerization ranged from 7·6 to 35·0%. Our results confirm the importance of individual isomers in evaluating the vitamin A status of dairy products.

189. The effect of commercial sterilization on the nutritive value of milk. VI. Comparison of the total nutritive value of raw and commercially sterilized milks

1938 ◽  
Vol 9 (2) ◽  
pp. 188-206 ◽  
Author(s):  
K. M. Henry ◽  
E. W. Ikin ◽  
S. K. Kon
Keyword(s):  
Nutritive Value ◽  
Basal Diet ◽  
Raw Milk ◽  
Cane Sugar ◽  
Male Rats ◽  
Limiting Factor ◽  
Protein Energy ◽  
Preceding Experiment ◽  
The Difference ◽  
Sterilized Milk

1. The effect of commercial sterilization on the total nutritive value of milk was studied in five separate experiments.2. In the first experiment raw and sterilized milks supplemented with minerals were given in equal amounts to pairs of litter-mate male rats. No differences were found in the growth performance of the rats, but the rats on sterilized milk consumed it more readily than their mates on raw milk. This difference was statistically significant.3. Rats getting limited but equal amounts of milk in addition to a basal diet which supplied only protein, energy and minerals grew better on raw than on sterilized milk.4. When the basal diet contained in addition 5% brewer's yeast and the milk intakes were the same as in the previous experiment no difference was found between the two groups.5. Rats receiving raw milk to which 15 g. of cane sugar was added per 100 ml. grew better than rats receiving equal quantities of similarly treated sterilized milk.6. Rats given raw milk containing 30 g. per 100 ml. of sugar grew as well as the rats on sterilized milk in the preceding experiment, but rats receiving similarly treated sterilized milk took much less milk than the raw milk rats, grew very poorly and some of them developed symptoms of beri-beri.7. The difference between raw and sterilized milk is discussed and it is concluded that in these experiments on the total nutritive value of milk vitamin B1 was the first limiting factor of sterilized milk.

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