Štěpánka Horníčková

Production of Benzoic Acid in Fermented Goat's and Sheep's Milk

Abstract The content of hippuric acid in raw goats and sheeps milk and the content of benzoic acid in model fermented milk drinks prepared using different cultures of bacteria of milk fermentation were determined. All fermented milk drinks contained benzoic acid in the range 5.0-78 mg kg-1. Higher quantity of benzoic acid in fermented sheeps milk drinks corresponded also to significantly higher quantity of hippuric acid in raw sheeps milk. No significant differences among used cultures of bacteria of dairy fermentation and the quantity of benzoic acid in fermented milk drinks were recorded. In addition, the quantity of benzoic acid in various commercial goats and sheeps cheeses produced directly in farms was analyzed. The contents of benzoic acid in cheeses ranged from 5.1 to 90 mg kg-1. No significant difference in the quantity of benzoic acid from goats and sheeps cheeses was found, whereas significant differences were registered in the quantity of benzoic acid in cheeses produced in individual farms.

Factors influencing the content of vitamins A and E in sheep and goat milk.

Michlova T., Dragounova H., Hornickova S., Hejtmankova A. (2015): Factors influencing the content of vitamins A and E in sheep and goat milk. Czech J. Food Sci., 33: 58-65. The content of lipophilic vitamins A and E was determined in samples of sheep and goat milk of different breeds com - ing from 9 farms in central, eastern, and southern Bohemia. Samples were collected throughout the period of lactation (from April to September). Vitamins A and E were determined by HPLC using DAD and FLD detectors. Vitamin A was determined in all samples but only α-tocopherol (out of various forms of vitamin E) was detected in all samples. The total average content of vitamins A and E in raw milk of all sheep breeds during lactation was 0.93 ± 0.07 and 2.93 ± 0.87 mg/kg, levels of these vitamins in goat milk were 0.79 ± 0.08 and 1.29 ± 0.35 mg/kg, respectively. The re - sults showed a significantly medium and strong correlation between the content of vitamin A and E and the content of fat ( R 2 = 0.57 and 0.75, respectively). The year did not have any statistically significant influence on the content of monitored vitamins. The content of both vitamins is dependent on the phase of lactation. The levels of vitamins A and E were significantly lower in the early phase and significantly higher in the late phase of lactation. The a mount of monitored vitamins slightly decreased during pasteurisation. A strong decrease in the content of both vitamins was observed during the first two weeks after milk storage in a freezing box at the temperature of -20°C (about 11-55%).