Determining the efficiency of cleaning a milk line made from different materials from contaminants

While moving along the milk-conducting systems in a milking machine, milk is in contact with the inner surface whose area exceeds 20 m2. That leads to the formation of protein-fat biofilms of contamination, which are a nutrient medium for the development of microorganisms. With insufficiently effective cleaning of these contaminants, in the periods between milking, the number of microflorae located in milk-conducting systems increases by tens of thousands of times. When cleaned with ineffective cleaning agents, mineral elements from milk are adsorbed on the surface of a protein-fat bio-film, which are subsequently compacted, changed, and converted into milk stone. In this case, the technical implementation of milk conducting systems is of critical importance. It has been established that a milk line made from any material is better cleaned with a hot washing solution than a cold one. Thus, with an increase in the temperature of a washing solution from 60 °C to 85 °C, the cleaning time of the milk line is reduced from 9.5 minutes to 1.5 minutes, or by 6 times. It was established that during the washing phase of a milk line there is a significant decrease in the temperature of the washing solution (≈30 %), which reduces the effectiveness of cleaning the parts of the system. Therefore, there is a need to maintain the solution temperature throughout the entire cleaning process. It is proved that the specific energy of adhesion of pollution in water is 2 times higher than that in a washing solution. With an increase in the temperature of the solution for every 10 °C, the decrease in the specific energy of pollution adhesion is on average 13 %. With an increase in the period after the end of milking before washing the milk line, the specific energy of its purification increases. The study reported here could lead improve the productivity of milking machines and the quality of the resulting product. That involves designing milking and dairy equipment from innovative materials.

Improvement of Raw Milk Cheese Hygiene through the Selection of Starter and Non-Starter Lactic Acid Bacteria: The Successful Case of PDO Pecorino Siciliano Cheese

This review article focuses on the technological aspects and microbiological critical points of pressed-cooked cheeses processed from raw ewe’s milk without the inoculation of starter cultures, in particular “Pecorino” cheese typology produced in Italy. After showing the composition of the biofilms adhering to the surface of the traditional dairy equipment (mainly wooden vat used to collect milk) and the microbiological characteristics of PDO Pecorino Siciliano cheese manufactured throughout Sicily, this cheese is taken as a case study to develop a strategy to improve its hygienic and safety characteristics. Basically, the natural lactic acid bacterial populations of fresh and ripened cheeses were characterized to select an autochthonous starter and non-starter cultures to stabilize the microbial community of PDO Pecorino Siciliano cheese. These bacteria were applied at a small scale level to prove their in situ efficacy, and finally introduced within the consortium for protection and promotion of this cheese to disseminate their performances to all dairy factories. The innovation in PDO Pecorino Siciliano cheese production was proven to be respectful of the traditional protocol, the final cheeses preserved their typicality, and the general cheese safety was improved. An overview of the future research prospects is also reported.

Research of acute toxicity and the effect of detergent-disinfectant “Argomol” on the culture of ciliates Tetrahymena pyriformis

Detergents and disinfectants for sanitation of milking equipment and dairy equipment must have a wide range of antimicrobial activity and provide a proper cleaning effect. At the same time, they must meet high standards of environmental safety and non-toxicity. The article presents data on the parameters of acute toxicity of the new detergent-disinfectant “Argomol”, based on lactic acid, “Katamine AB”, polyhexamethylene guanidine hydrochloride and colloidal silver solution, as well as the toxicity of the tool, which was determined using the express method of Tetrachymena pyriformis. The acute toxicity of the means and its working 0.5% solution in tentative and detailed experiments on white mice was determined and the median lethal dose (DL50) was determined by the method of G. Kerber. It was found that the DL50 of the means in white mice for intragastric administration when calculated by the method of G. Kerber is 4250 mg/kg body weight, and 0.5% of its solution — more than 11000 mg/kg body weight, i. e. according to SOU 85.2-37-736:2011 “Veterinary drugs. Determination of acute toxicity”, this indicates that the means belongs to the IV class of toxicity, which combines low-toxic substances. The results of research on the effect of the new detergent-disinfectant “Argomol” on the culture of ciliates Tetrahymena pyriformis are presented. It was found that the detergent-disinfectant “Argomol” in concentrations of 0.02–0.5% at exposures of 1–10 min did not show toxic effects on the ciliate Tetrahymena pyriformis. Toxicological studies on ciliates suggest that the detergent-disinfectant “Argomol”, when used in the recommended doses and exposures, can be used for sanitation of milking equipment and dairy equipment, as it is environmentally friendly and low-toxic.

RESIDUAL CONTENT OF VETERINARY PREPARATIONS IN MILK OF DIFFERENT COUNTRIES

In the context of the development of the dairy industry, and especially small farm enterprises, the issue of using of veterinary drugs and controlling their residual content in milk and dairy products is particularly acute. Veterinary drugs that require control of the residual content include: antibiotics, detergents and disinfectants; hormones, etc. the Main sources of their appearance in milk are: treatment of cows (antibiotics, hormones); feeding of animals (feed antibiotics); processing of milking and other dairy equipment to maintain sanitation and hygiene (detergents, disinfectants, neutralizers). The article presents a literary review of the regulatory documentation for controlling the content of antibacterial and hormonal drugs in milk in Russian Federation, as well as in European countries and the United States of America.

Formation of microbial biofilms on stainless steel with different surface roughness

The physical essence of the formation and influence of bacteria on the surface of technological equipment in the dairy industry is considered as an essential factor leading to contamination of dairy products and is a major hygienic problem. The ability of microorganisms on the surfaces of technological equipment to form biofilm forms and requirements for steel grade, relief, and its roughness were analysed. The effect of surface roughness on promoting or preventing adhesion and reproduction of biofilm forms of bacteria, which reduce the efficiency of sanitary processing of dairy equipment and thereby increase the microbial contamination of dairy products with shortened shelf life, is substantiated. Research about the process of bacterial adhesion to the surface of metals with different roughness depending on the size and shape is presented. It is found that on the surface of stainless steel with roughness 2.687 ±0.014 micron film formation process in Escherichia coli and Staphylococcus aureus are similar from 3 to 24 hours and does not depend on the size of the bacteria, and accordingly allows us to argue that rod-shaped and coccid bacteria attach freely in the hollows of the roughness are the beginning of the process of the first stage of biofilm formation. It is found that on the surface of stainless steel with roughness 0.95 ±0.092 micron film formation process in S. aureus is more intense than in E. coli. Thus, within 3 hours of incubation, the density of biofilms formed S. aureus was 1.2 times bigger than biofilms E. coli, by the next 15 hours of incubation formed biofilms S. aureus were, on average, 1.3 times denser. It is established that S. aureus due to its spherical shape is able to fit in the hollows of the roughness 0.95 ±0.092 μm and faster to adhere to the surface at the same time. E. coli, due to its rod-like shape, with such surface roughness, can adhere to the cavities only over its entire length. It is proved that by surface roughness 0.63 ±0.087 μm film intensity S. aureus was, on average, 1.4 times faster than E. coli, for roughness 0.16 ±0.018 micron film formation process took place equally for S. aureus and E. coli, but biofilms were lower in density than those formed on roughness 0.63 ±0.087 micron. Studies suggest that the use of equipment in the dairy industry with a roughness of less than 0.5 microns will reduce the attachment of microorganisms to the surface and reduce the contamination of dairy products.

Investigation of the minimum bactericidal concentration of acid detergent “Milkodez” on the test culture of microorganisms

The main task of the dairy industry is the production of raw milk, the quality of which depends on the degree of bacterial background of milk and is achieved only if the regular cleaning and disinfection of milking equipment, dairy equipment. Milk is a good nutrient for microorganisms. The safety of milk that is obtained in dairy complexes provides for acceptable standards in its composition of any chemical, physical or biological substances that pose a potential threat to human health. The largest share of the listed factors belongs to microbiological contamination. The purpose of the work was to investigate the minimum bactericidal concentration of the acid detergent “Milkodez” on the test culture of microorganisms: S. aureus ATCC 25923, E. coli 055K59 No. 3912/41, P. aeruginosa 27/99. The study found that the acid “Milkodez” has bactericidal activity on the S. aureus culture test at dilution of a disinfectant 1: 268.8 and less and an active substance concentration of 0.371% or more at exposure of 2 minutes, for breeding 1:376, 5 and less (concentration of the active substance 0.265% and more) at exposure of 5 minutes and at dilution 1:1466.3 and less and a concentration of 0.0691% or more for 15 minutes. Minimal bactericidal concentration of the acid “Milkodez” on the test of E. coli culture at an exposure of 2 minutes amounted to 0.134%, at an exposure of 5 minutes. – 0.0493% and 15 minutes – 0.0352%. When the concentration of the agent is 0.012856% or more and its dilution is 1:7778.4 and less, throughout all investigated time ranges, there is no growth of the test culture P. aeruginosa. The use of the product at a temperature of 70 ± 5 °C allowed to inhibit the golden staphylococci at the concentration of the solution of the drug 0.371% for 2 minutes of action and 0.265% and 0.0691% – respectively within 5 and 15 minutes. At the same time, at the temperature of the solution of the Milkodez solution 70 ± 5 °C, the death of the E. coli was observed at the concentration of the acidic substance 0.0352%, 0.0493% and 0.134%, respectively, for 2, 5 and 15 minutes. The increase in the temperature of the solution from 20 ± 5 °C to 70 ± 5 °C resulted in the death of P. aeruginosa bacteria at a concentration of 0.01285% in all time ranges.

STUDY OF THE INFLUENCE OF SAVINASE®EVITY16L ENZYME ON BIOFILMS FORMATION OF STAPHYLOCOCCUS AUREUS ON STAINLESS STEEL WITH DIFFERENT ROUGHNESS

Microbial films formation on the dairy equipment creates a serious problem, because they are difficult to eliminate by washing and disinfecting means that results in contaminating dairy products by microorganisms. The aim of the work was to study the influence of Savinase®Evity 16L proteolytic enzyme on the process of destructing biofilms, formed by Staphylococcus aureus on stainless steel with different surface roughness. It has been established, that surface roughness of stainless steel influences the process of Savinase®Evity 16L enzyme penetration in a hollow and prevents the destruction of the biofilm matrix, created by Staphylococcus aureus. It has been revealed, that after the influence of a proteolytic enzyme on Staphylococcus aureus biofilms, created on steel with roughness 0,16±0,018 mcm, the density decreased in 4,0 times (р≤0,05), comparing with a condition before processing. At roughness 0,63±0,087 mcm the density of formed biofilms decreased at the effect of Savinase®Evity 16L in 3,3times (р≤0,05) and the biofilm was characterized as a weak one. At the same time at stainless steel surfaces with roughness 2,68–0,95mcm, the density of biofilms decreased in 2,3–2,1times (р≤0,05), comparing with a condition before processing, and they were characterized as ones of the middle density. It has been also revealed, that the degradation intensity of biofilms under the influence of Savinase®Evity 16L enzyme at roughness 2,68–0,95 mcm was 1,7–1,9 times (р≤0,05) lower than at the surface with roughness 0,16±0,018 mcm. So, the revealed degradation features of a biofilm, created by Staphylococcus aureus at surfaces of stainless steel of different roughness at the influence of Savinase®Evity 16L proteolytic enzyme give a possibility to substantiate the addition of proteolytic enzymes to the composition of washing means for dairy production. It is also offered to process the surface to the roughness no more than 0,63 mcm for producing food steel for raising the effectiveness of biofilms destruction by enzymes and for the sanitary processing.

DETERMINAN KEGAGALAN ASI EKSKLUSIF PADA KOMUNITAS MADURA

Exclusive breastfeeding is the first intake that is very important for infants aged 0-6 months. Exclusive breastfeeding achievement in the Madurese community in the working area of ​​the outpatient Puskesmas Purun Kecil is 29%. This is due to several things including the habit of giving honey to babies, therefore in giving ASI exclusively is interrupted. This study aims to analyze the relationship between the habit of giving honey to infants aged 0-6, the support of biological mothers from the baby's mother, the support of mother-in-law from the mother's baby, the support of health officers, the working status of a mother, the knowledge of lactation management, the effort to use the independent exclusive breastfeeding, and the exclusive breastfeeding failure. This study uses a cross sectional design. The study sample was 162. The statistical test used was the Chi-square test (X2). The results showed that the determinants of exclusive breastfeeding failure in infants in Peniraman Village and Nusapati Village were the support of biological mothers from the baby's mother, mother-in-law's support of the baby's mother, health worker support, lactation management knowledge, efforts to use independent ASI dairy equipment.