Tag Archives: vitamin A

1396–1406 T. Michlová, H. Dragounová, R. Seydlová and A. Hejtmánková
The hygienic and nutritional quality of milk from Saanen goats bred in the Moravian-Silesian region
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The hygienic and nutritional quality of milk from Saanen goats bred in the Moravian-Silesian region

T. Michlová¹*, H. Dragounová², R. Seydlová² and A. Hejtmánková¹

¹Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamýcká 129, CZ165 21, Prague, Czech Republic
²Dairy Research Institute Ltd, Ke dvoru 791/12A, CZ160 00, Prague, Czech Republic
*Correspondence: michlova@af.czu.cz

Abstract:

 The aim of the study was to monitor milk yield and the hygienic and nutritional quality of milk of Saanen goats in the Moravian-Silesian region in Czech Republic. Milk samples were collected once a month during the lactation period. The average milk yield in the standardized lactation was 1,100 liters. The somatic cell count in pool samples ranged from 470 x 103 to 696 x 103. The total microorganism count ranged from 3.6 x 103 to 1.4 x 105. The pathogen Staphylococcus aureus was proven no more than in 6.3%. The highest values of all main components of milk were achieved within a relatively short time after kidding (April 2015). The average content of fat was 3.64  0.52 g 100 ml-1, 3.17  0.16 g 100 ml-1 of protein, 2.60  0.06 g 100 ml-1 of casein, 4.56  0.24 g 100 ml-1 of lactose, and 12.02  0.80 g 100 ml-1 of solids. Average content of vitamin A was 0.27  0.14 mg kg-1 and average content of vitamin E was 0.60  0.34 mg kg-1. Content of vitamin E increased almost continuously during the lactation, and the content of vitamin A was significantly higher at the end of lactation. In lyophilized milk powder the average trace metal contents were 7.76  0.92 g kg-1 Ca, 1.62  0.26 g kg-1 Mg, 15.3  1.43 g kg-1 K, 789  111 mg kg-1 Na, 23.2  2.73 mg kg-1 Zn, and 0.85  0.55 mg kg-1 Cu. Contents of minerals varied during the lactation period, but no significant trends were observed.

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1002-1009 T. Michlová,, H. Dragounová and A. Hejtmánková
Stability of vitamin A and E in powdered cow’s milk in relation to different storage methods
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Stability of vitamin A and E in powdered cow’s milk in relation to different storage methods

T. Michlová¹,*, H. Dragounová² and A. Hejtmánková¹

¹Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamýcká 129, 165 21, Prague, Czech Republic 2Dairy Research Institute Ltd, Ke dvoru 791/12A, 160 00, Prague, Czech Republic *Correspondence: michlova@af.czu.cz

Abstract:

In this article, the influence of different ways of storage on the content of vitamin A and E in powdered cow´s milk was studied. The cow´s whole milk powder was taken directly from the manufacturer and stored for one year in 4 different ways – in the light at room temperature, in the dark at room temperature, in a refrigerator at 8°C and in a freezer at -20°C. The content of vitamins was measured 4 times during the first month and then once a month. The samples were stored for one year. Vitamins A and E were determined by HPLC using DAD and FLD detectors. Vitamin A was identified in all samples but only α-tocopherol (out of various forms of vitamin E) was detected in all samples. In all cases steeper decline of both vitamins in first 14 days of storage was identified. The highest losses of vitamin A and E in powdered milk occurred during storage in the light at room temperature. The value decreased by 91 resp. 95% of the original value.

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737-744 T. Michlová, Š. Horníčková, H. Dragounová and A. Hejtmánková
Quantitation of vitamins A and E in raw sheep milk during lactation period
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Quantitation of vitamins A and E in raw sheep milk during lactation period

T. Michlová¹, Š. Horníčková¹, H. Dragounová² and A. Hejtmánková

¹Department of Chemistry, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, the Czech Republic 2Dairy Research Institute Ltd, Prague, the Czech Republic

Abstract:

In this article, the influence of breed and lactation stage on vitamin A and E content in raw sheep milk was studied. The milk of the East Friesian, Romanov and Lacaune sheep breeds was included in the study. The samples were taken once a month throughout lactation. The total average content of vitamin A in raw milk of all sheep breeds during lactation was 0.76 ± 0.19 mg kg-1 of milk and the total average content of vitamin E was 2.86 ± 0.99 mg kg1 of milk. The content of vitamin A and E during lactation varied in respect to the breed type. The highest average content of vitamin A and E was detected in the Romanov sheep:1.01 ± 0.19 mg kg-1 of milk for vitamin A and 4.26 ± 1.90 mg kg-1 for vitamin E. The lowest average value of vitamin A was found in the milk of the East Friesian sheep (0.56 ± 0.10 mg kg-1). This milk showed also the lowest content of vitamin E 2.11 ± 0.53 mg kg-1. The highest content of vitamins was found in summer and at the end of lactation, which is in September, and the lowest values appeared in early lactation, which is in April.

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