Agrarian Science and Food Technologies

Vovkohon A.Н., Candidate of Agricultural Sciences, Assistant Professor

Bila Tserkva National Agrarian University

The sour milk products are important for people in terms of their gerodietetic properties. The nutritive value of sour milk products depends on raw material quality (milk of big and small cattle) and the ferment. Namely it depends on the conglomerate of microorganisms or set up of enzymes in the ferment and their resistance to various factors of environment. The sour milk bacteria are not resistant to antimicrobial preparations. The antibiotics, which got into milk by different ways including as medical preparations, suppress and eliminate the living cells of sour milk ferment.

Every year more and more people consume sour milk products with streptosan ferment. The impact of antibiotics on the streptosan ferment cells has become of scientific interest.

The question of how the different doses of streptomycin sulfate in the cow milk influence the ability of streptosan ferment microorganisms to create a sour milk product remains not studied.

Therefore, the aim of this work was to investigate the impact of different doses of streptomycin sulfate in milk on the ability of streptosan ferment cells to sour it.

For the experiment, the pasteurized milk was used. The mass share of fat in milk was 3,2%, acidity was about 18,4˚Т.

For the experiment, there were prepared 17 groups of milk samples of 100,0 cm³ each. The milk souring was done by streptosan ferment. For streptosan ferment cells inactivation, an antimicrobial preparation streptomycin was chosen. Exactly 1,0 g of streptomycin sulfate was dissolved in 1440 ml of distilled water.

The milk samples of the control group contained no antibiotic. 0,1 cm³ streptomycin solution was added to the milk of experiment group I, which made 0,5 units/cm³ (table 1).

The milk samples of the experiment groups II, III and IV contained 1,0; 1,5 and 2,0 units respectively of streptomycin sulfate reactant in one cm³. The milk samples from experiment groups V, VI, VII and VIII contained 2,5; 3,0; 3,5 and 4,0 units respectively of antibiotic in one cm³. To the milk of the experiment samples IX, X and XI, a streptomycin solution was added in the amount of 0,9; 1,0 and 1,1 cm³ respectively.

In the experiment groups XII-XVI, the samples contained from 6,0 to 8,0 units of reactant (streptomycin sulfate) in one cm³.

The souring of milk samples with the ferment was carried out in a thermostat. The temperature for souring was maintained at about 36,0±0,5˚С. The souring lasted for 8 hours.

After 8 hours souring, the control samples of sour milk product (the milk contained no streptomycin) had a pleasant sour milk taste. The clot was thick and homogenous. After slight mixing, some separation of whey from the clot was observed. There were no other non-specific after-tastes of the products identified.

With the streptomycin content in one cm³ milk, the end product looked like a not formed, not thick clot of white color. The taste was the one of sour milk, however less expressed compared to the control sample. Adding antibiotic to the milk in amount of 1,0 units/cm³ had negative impact on the streptosan ferment compared to the control sample. The milk clot after souring was thin and did not meet the standards. The taste was of fable sour milk.

The 2,0 to 8,0 units/cm³ of antibiotic in milk gradually inactivated the ferment microorganisms so that the end product was similar to turned and not fresh milk.

The sour milk product produced without streptomycin had titrated acidity of 88,0˚Т. The     0,5 units/cm³ streptomycin in milk led to decrease of titrated acidity of end product by 14,7% compared to the control sample.

The milk with antibiotic content of 2,0 to 4,0 units/cm³ after souring by streptosan ferment had by 2,6-2,9 times less titrated acidity compared to the control.

Thus, the souring technology of the raw material by streptosan ferment is deflecting in the cow milk containing streptomycin sulfate concentration of 0,5 units/cm³. The above mentioned antibiotic in the raw material in the amount of 1,5 units/cm³ disables obtaining of sour milk product by means of streptosan ferment.

1. Passantino A. Ethical aspects for veterinarians regarding antimicrobial drug use in Italy. Int J Antimicrob Agents. 2007; 29:240–244. doi: 10.1016/j.ijantimicag.2006.09.023. 

2. Grave T, Greko C. et al. The usage of veterinary antibacterial drugs for mastitis in cattle in Norway and Sweden during 1990-1997. Prev Vet Med. 1999;42:45–55. doi: 10.1016/S0167-5877(99)00057-4.

3. Romanchuk, I.O., Hondar, O.P. & Moiseieva, L.O. (2016). Otsinka yakosti kyslomolochnoho produktu herodiietychnoho pryznachennia [Estimation of the quality of the sour-milk product of herdietic purpose]. Problemу starenyia y dolholetyia – Problems of aging and longevity. 25, Vol. 2. 269-27).

4. Kharchenko, N.V. & Anokhinoi, H.A. (2012). Diietolohiia [Dietology]. Kyiv: p. 526

5. Romanchuk, I.O., Rudakova, T.V., Andreus, S.M. & Moiseieva L.O. (2015). Kharchova tsinnist funktsionalnoho kyslomolochnoho produktu herodiietychnoho pryznachennia [Nutritional value of a functional dairy product of hereditary purpose]. Prodovolchi resursy – Food resources. Vol. 4. (pp. 23-25).

6. Mitchell, J.M., Griffiths, M.W., McEwen, S.A. et al. Antimicrobial drug residues in milk and meat: causes, concerns, prevalence, regulations, tests and test performance. J Food Protect. 1998;61:742-756.

7. Franklin A, Horn af Rantzien M, Obel N. et al. Concentrations of penicillin, streptomycin, and spiramycin in bovine udder tissue liquids. Am J Vet Res. 1986;47:804-807.

8. Tatarny`kova, N.A. & Maul`, O.G. (2014). Anty`by`oty`ky` v py`shhevyx produktax [Antibiotics in food]. Y`zvesty`ya Orenburgskogo gosudarstvennogo agrarnogo uny`versy`teta – News of the Orenburg State Agrarian University. (pp. 208-211]                   [in Russian].

9. Yohurty. Zahalni tekhnichni umovy [Yogurt General specifications]. (2004). DSTU 4343:2004. P. 10.

10. Milk and milk products. Titrimetric methods of acidity determination [Milk and dairy products. Titrimetric methods for determining acidity]. (1992). ГОСТ 3624-92. P. 8.