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V Aleksieva

Publications and source records attributed to V Aleksieva.

17 recordsLinked to original sources
PubMed1985

[Microbiological research on processed cheese].

Microbiologic studies were carried out with a total of 136 batches of 8 assortments of softened cheese to establish the amount and composition of the microbial content of this product. It was found that the total count of mesophilic organisms of 72.8 per cent of the investigated batches reached up to 200 000/g. The content of hygiene-indicative organisms (coliforms and enterococci) was limited: 97 per cent of batches had a coli titer of 1 and over 1. The content of enterococci in 54.4 per cent of the investigated was below 100/g, and in 4.4 per cent it was over 100 000/g. No Salmonella bacteria and plasmacoagulase positive staphylococci in 25, resp., 10 g of the product were found. Contamination with sporeforming aerobic and anaerobic organisms in 72.1, resp., 91.9 per cent reached up to 1000, resp., 100 per gram of the product. The amount of proteolytic bacteria in 61.8 per cent of the batches was up to 1000/g, and in 8 per cent only--up to 100 000/g. The content of yeasts and moulds in 58.8, resp. 83.1 per cent of the batches was below 100/g.

Bacteria↗
PubMed1984

[Streptococci and staphylococci in raw cow's milk on the market].

Studied were a total of 649 batches of raw cow milk produced on 42 farms, and 1100 flushing samples taken from 370 containers for the presence of pathogenic streptococci and staphylococci. It was found that 26.5 per cent, resp., 18.03 per cent of the batches contained coagulase-positive staphylococci and pathogenic streptococci (in 8.94 per cent--Str. agalactiae, in 6.0 per cent--Str. uberis, and in 3.08 per cent--Str. dysgalactiae ). In 28.3 per cent of the batches there were both strepto - and staphylococci that had pathogenic character. The study of the flushing material showed that the cleaning of containers for shipping the milk from the farms to the dairy processing enterprises was effective--only 1.62 per cent of the cisterns were contaminated with pathogenic strepto - and staphylococci.

Animals↗
PubMed1984

[Microbiological studies of Mladost sour milk].

Studied were a total of 239 productional batches of Mladost sour milk to establish the occasional contamination with coliform bacteria. It was found that 97.9 per cent of the batches had coli titers of 0.1 and over 0.1, and 2.1 per cent of the batches--over 0.01. Fourteen productional experiments were carried out to ascertain the sources of contamination with coli forms, yeasts, and moulds. It was found that the productional starter used for this type of sour milk did not contain coliforms and moulds in 0.1 cm3 but in about 43 per cent of the batches it contained 20 to 470 cm3 yeasts. It was also established that both yeasts and moulds that have found their way to the product multiplied in it to a various extent, depending on the activity of the cultures and the temperature of storage. Some of the stored batches deteriorated in terms of their organoleptic indices. At 11,000 cm3 yeasts the deterioration becomes stronger following the cummulation of greater amounts of biomass.

Bulgaria↗
PubMed1983

[Microbiological studies of Eskimo ice cream].

Studied were a total of 86 batches of Eskimo ice-cream and 101 batches of 'cream' ice-cream. It was found that 83.6 per cent of the Eskimo batches were of 0.1 coliform titers and higher, and 16.3 per cent - of 0.01 coliform titers. The total microbial contamination of 86 per cent of the batches reached 50000 g, while that of 13.9 per cent reached 50000 to 180000/g. The colititer with 98 per cent of the batches of 'cream' ice-cream was 0.1 and more 0.1, and with 1.98 per cent only was it 0.01, while the microbial count with 96 per cent of these batches was up to 50000/g, and with 3.9 per cent it was from 50000 to 118000/g. Studied was the quality of the products used to obtain the Eskimo icing. The total microbial content of the surface layer varied from 200 to 46000/g, dropping up to 100-2100/g at storage. The fresh cow sweet cream butter had a colititer above 0.1 and did not contain yeasts and moulds per 0.01/gram of produce. During production, transportation, and storing of the produced frosting the microbial count rose 7 times, on an average, and the colititer dropped from 0.1 up to 0.001. The icing (frosting) used contributed to the rise of the microbial amount from 1.5 to 3.5 times and to the drop of the colititer of the final Eskimo product.

Animals↗
PubMed1983

[Enterococci and coliforms in yellow sheep cheese].

The developmental dynamic of enterococci and coliforms was followed up in the entire technologic process and the storage of kashkaval (yellow cheese of ewe milk) under the conditions of modern industrial production. It was found that during the whole industrial cycle up to the steam cooking of curd the amount of enterococci grew and reached its peak value in the cheddarized cheese curd (2.4--30 million per gram), increasing from 10 to 34 times as against its level in the initial milk used. The coliform bacteria also rose in number, and their amount reached maximum values of 10 to 120 mill/g in the processed and dipped curd, after which a slowly advancing reduction set in. Species of the Enterobacter (55.1%), Escherichia (14.1%), Citrobacter (19.2%), and Klebsiella (11.5%) genera were isolated. The steam cooking of cheddarized curd produced an unfavourable effect on enterococci (pasteurization effect of up to 98.3 to 99.9%) and a lethal effect on the coliforms. Enterococci that resisted steaming multiplied in kashkaval and reached their highest level--960 000 up to 39 mill/g--between the 30th and the 60th day of production after which their numbers dropped. Their amount in the ripened product varied from 95000 to 17.8 mill/g, and on the 240th following production--from below 100 to 1.6 mill/g. Coliform bacteria were not found in 0.1 g of the product mass during ripening and storage of kashkaval. Out of the 196 strains that were differentiated as enterococci 30.7 per cent of the fecalis subgroup, and 69.3 per cent--of the Sp. faecium-durans subgroup. After steaming 92.3 per cent of the strains were of the Str. faecium and Str. durans species.

Animals↗
PubMed1981

[Cases of clinical and subclinical mastitis due to "D" streptococci].

Cytologic and bacteriologic investigations were carried out with a total of 364 samples of cow milk and secretion from 11 farms taken from individual quarters of the udder that have reacted positively and strongly positively with the rapid mastitis test Bernburg. It was found that in 330 of the cases there were data of clinical and subclinical mastitis of varying etiology. In 43 of the cases the causative agent (as isolated in pure cultures) proved to be "D" streptococci, giving positive reaction as judged by Schermann's criteria--from 9 cases of clinical and 34 cases of subclinical mastitis. The cell count varied from 360 000 to more than 5 million per cub. cm. Detailed studies were carried out on the cultural and biochemical properties of 31 strains of "D" streptococci, 17 strains belonging to Str. faecalis var. zymogenes, 9 strains--to Str. faecalis var. faecalis, and 5 strains--to Str. faecalis var. liquefaciens.

Animals↗
PubMed1981

[Etiological study of mastitis in cows].

The rapid mastitis test was employed to study a total of 13 880 cows on 40 farms. Positive for mastitis proved 2384 udder quarters. Clinically manifested mastitis was established in 3.23 per cent of the cases, subclinical mastitis - in 58.14 per cent, carrier status - in 12.55 per cent, secretion disturbances - in 22.58 per cent, and normal proved 3.84 per cent. In the mastitis-positive cases pathogenic streptococci were isolated in 57.14 per cent of the quarters, staphylococci - in 20.77 per cent, Corynebacteria - in 9.09 per cent, and other bacteria - in 5.19 per cent. In the cases with subclinical mastitis staphylococci accounted for 40.93 per cent, streptococci - for 38.7 per cent, Corynebacteria - for 14.22 per cent, and other organisms - for 6.0 per cent. Most frequently encountered were the carriers of staphylococci - 46.8 per cent, followed by those of Corynebacteria - 26.4 per cent, and of streptococci - 20.73 per cent.

Animals↗
PubMed1981

[Quality of raw cow's milk].

Studies were carried out on a total of 1459 batches of raw cow milk intended for processing with regard to the standard indices--temperature, titratable acidity, and mechanical contamination. The same batches were also investigated in terms of total bacterial contamination and coliform count. It was found that the quality of milk was good. Only 21 per cent of the investigated samples did not correspond to the standard requirements because of insufficient cooling, 0.2 per cent of the samples showed higher acidity, and 1.4 per cent were with mechanical admixtures. The total microbial content of the investigated milk varied in 52 per cent of the samples from 0.1 to 1 x 10/7cm3. It was established that microbial contamination correlated strongly with the season. The coliform count in about 27 per cent of the samples was up to 1 x 10(4), and in about 42 per cent it was above 1 x 10(5)/cm3. Highest coliform numbers were noted during the warm months. There existed a correlation between the total bacterial contamination and the amount of coliforms, which was more clearly expressed in batches of high and low bacterial count.

Animals↗
PubMed1980

[Enterococcal and coliform content in white brine cheese].

The contamination with microorganisms (enterococci and coliforms) indicative of hygeinic status was studied in 98 samples of white brine cheese (33 samples of cow's milk cheese and 65 of ewe's milk cheese) prepared for sale. It was found that 22.4 per cent of the cheese samples do not contain enterococi in 0.01 g product but in 15.3 per cent their amount exceeds 100 000/g. No relationship was found between enterococci finding and cheese content of salt, titratable and active acidity. Cheese contamination with coliforms bacteria is limited--merely 3.1 per cent of the samples contain coliforms in quantity of 10--100/g. No difference was found in the contamination of cow's and ewe's milk white brine cheese with enterococci and coliforms. The enterococci microflora in white brine cheese and in the brine is represented predominantly by Str. faecium and Str. durans (91.3 per cent of the isolated strains). The coliforms are represented by E. coli, Enterob. aerogenes and Citrob. intermedium.

Animals↗
PubMed1979

[Development of enterococci and coli bacteria in Bulgarian yogurt].

The effect of lactic acid fermentation in Bulgarian yoghourt was studied by the development and decline of hygiene level indicating microorganisms--enterococci and coli-bacteriae. It was established that for the first 6 h after production of Bulgarian yoghourt, the quantity of enterococci (Str. faecalis, resp. Str. faecium) increases 5--6 times on the average, after the 12th hour it begins slowly to decrease and the number is reduced two times during storage for 7 days at 7--10 degrees C temperature of 6 days at 18--22 degrees C. The reduction in enterococci number is not fully correlated with the stage of lactic acid fermentation. Coli-bacteriae (E. coli) do not grow in number at the time the milk is turned into yoghourt. Their initial quantity diminishes along with the advance of the lactic acid process and after 24 h of milk storage at 18--22 degrees C or after 48 h at 7--10 degrees C they cannot be detected at all. The conclusion is drawn that enterococci are more suitable as hygiene level indicating microorganisms for hygienic evaluation of Bulgarian yoghourt, as compared to coli-bacteriae, due to their greater viability and longer survival in the product at the time of its production and during storage. It is recommended to perform the investigations on coli-forms not later than the 24th hour after yoghourt productions begins.

Dairy Products↗
PubMed1979

[Enterococci and coliforms in yellow sheep's milk cheese].

Ninety-two samples of sheep milk yellow cheese were investigated 30 and 180 days after its production. The content of enterococci varied within a wide range--from 100 to 1,9 million per g. In 14.28% of the samples more than 10 000 enterococci per g were found. No correlation between salt content, acidity and pH and number of enterococci in the yellow cheese samples studied as well as between quantity of enterococci, period of cheese ripening and storage and the organoleptic evaluation of the product's ripeness was established. In 100% of the samples studied coli titer was above 0.1. Of the 137 differentiated enterococci strains 67.1% belonged to the species Str. durans, while 32.8%--to Str. faecium.

Animals↗
PubMed1979

[Contamination of Bulgarian yogurt with yeasts and molds and the dynamics of their development in the product].

Twenty one complex production experiments aiming to establish the sources of Bulgarian yoghourt contamination with yeasts and moulds were carried out. It was established that they enter the product by way of unclean production lines and implements, by the fermenting agent, by the air in the fermentation premises. Their number in the ready product increases during storage. The extent of their increase is in relation with their initial number and with the type of yoghourt cooling and storage. At temperature 8-10 degrees C yeast numbers increase after 6-day storage from 1 500 to 4 000 times, while at temperature 18-25 degrees C even on the 3d day their number surpasses 1-15 millions per g. Moulds appear after 2-4 days of storage at 18-25 degrees C in quantities of 2000-13 000/g, while at 8-10 degrees C--after the 5th day and their number varies from 100 to 2 000/g. Defects in the organoleptic indices of yoghourt (acid-tart yeast taste and "rising") appear in case of accumulation of more than 500 000-1 million yeasts per g. In 3.5% of the 201 lots of yoghourt presented for sale on the market and investigated the presence of yeasts was established, while only one lot had moulds. Standards concerning the permissible yeast and mould content are presented, which guarantee longer periods of preservation time for Bulgarian yoghourt.

Bulgaria↗
PubMed1977

[Isolation and cold resistance of enterococci in ice cream].

Studies were a total of 85 samples of ice-cream assortments. It was found that the presence of enterococci was reduced--up to 21 per cent of the samples only had from 101 to 2000 microbial cells per cu. cm of the ice-cream mass. Enterococci of the fecal group predominated--81 per cent. The regime of thermal treatment applied to the ice-cream melange produced bactericidal effect on the Enterococcus microflora. After pasteurization, however, the product became contaminated with a secondary Enterococcus infection due to the improperly cleaned glassware and equipment. In freezing the ice-cream melange the amount of Enterococcus microflora dropped from 3.2 to 3.3 times. No changes in the microbial count were established after the deep-freezing storage of ice-cream for 24 months at -18 to -25 degrees C. The Enterococcus titer is suggested as an index in the hygiene evaluation of ice-cream.

Cold Temperature↗
PubMed1976

[Find of enterococci in sour cream and butter].

Studied was the enterococcus count in cream intended for the production of butter. It was found that in about 33 per cent of the cream samples the enterococcus titer varies within the 0.1+range, and in 66 per cent it is 0.01, up to and below 0.0001. It was likewise established that after the churning process is over and after the washing of the butter product more than 90 per cent of the enterococcus microflora has passed into the buttermilk and the waste water. The enterococcus count in the butter was found to be limited: 93 per cent of the butter samples have 0.1 and higher titers, and at least 7 per cent of them are with titers ranging from 0.01 up to 0.001. Prevailing are ususally the species of the fecalis group and in the first place Streptococcus faecalis var. liquefaciens. Suggested are standard norms concerning the admissible numbers of Enterococcus bacteria in butter. For example, superior quality butter should have a titer of 1, and first quality butter --0.1.

Animals↗