scholarly journals The dynamic of the number of coliform bacteria in white cheese

2011 ◽  
Vol 27 (3) ◽  
pp. 1091-1096
Author(s):  
J. Stojiljkovic ◽  
V. Kakurinov
Keyword(s):  
Raw Milk ◽  
Coliform Bacteria ◽  
Small Decrease ◽  
Cheese Making ◽  
Cheese Ripening ◽  
The Third ◽  
White Cheese ◽  
Number Of Microorganisms

The aim of this research is that the presence of coliform bacteria in cheese is characterized undesirable, because it can cause a variety of defects on quality of cheese. For this reason, it is very important for this bacteria to be destroyed or to prevent their appearance in a number during processing and during the cheese ripening in the brine. During the cheese making, in the milk prepared for making cheese the number of coliform bacteria shows a small decrease comparing with their number in the raw milk, which proves that the number of microorganisms is less after pasteurization. During the cheese ripening in the pickle the number of coliform bacteria has kept at 3.0 x 103 /g of cheese for the second repetition, but for the first and the third repetition they disappeared which avoided the danger of early blowing or appearance of any other defect.

scholarly journals Studying the Influence of Acoustic Cavitation and Avalanche-Streamer Discharge on the Quality of Raw Milk in Order to Achieve the Pasteurization Effect

2020 ◽  
Author(s):  
Olga Krasulya ◽  
Kseniya Kanina ◽  
Nikolay Zhizhin ◽  
Nataliya Shlenskaya ◽  
Alexandra Demid
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Acoustic Cavitation ◽  
Raw Milk ◽  
Coliform Bacteria ◽  
Streamer Discharge ◽  
Anaerobic Microorganisms ◽  
Number Of Microorganisms ◽  
Quality Of Milk

The article presents the results of the studies obtained in the investigation of the quality of milk processed with the use of physical methods of exposure - acoustic cavitation and avalanche-streamer discharge, in order to achieve a pasteurizing effect. It is shown that in the treatment of high-frequency ultrasonic oscillations (over 45 kHz) generated by an electric ultrasonic device of the submersible type of impulse action ”Activator-150”, the number of bacteria of the E. coli group decreased by almost 40%, which allows concluding that the chosen method of influence is effective for the destruction of sanitary and pathogenic (indicative) microflora in raw milk and achieve a certain pasteurization effect. Using low-frequency ultrasonic exposure (20-22 kHz) generated by the cavitation ultrasonic flow type reactor RKU, the raw milk indicators QMAFAnM (Quantity of Mesophilic Aerobic and Facultative Anaerobic Microorganisms) and number of Coliform bacteria did not change after processing, as well as physical and chemical indicators, apart from the indicators of particle fineness. It can be stated that low-frequency ultrasonic cavitation treatment is not effective in terms of achieving a pasteurizing effect. In order to achieve a pasteurization effect by applying avalanche-streamer treatment we assessed its effect on QMAFAnM - the microbiological background of milk. The use of avalanche-streamer discharge does not have the expectation effect on the total number of microorganisms in milk. It is advisable to use high-frequency acoustic cavitation for microbial biota inactivation and avalanche-streamer discharge to reduce spore bacteria contamination.

Assessment of swine, bovine and chicken pepsins as rennet substitutes for Cheddar cheese-making

1972 ◽  
Vol 39 (2) ◽  
pp. 261-273 ◽  
Author(s):  
Margaret L. Green
Keyword(s):  
Cheddar Cheese ◽  
Cheese Making ◽  
Stomach Mucosa ◽  
Milk Clotting ◽  
Cheese Ripening ◽  
Cheese Flavour ◽  
The Cost ◽  
Substrate Ph ◽  
Milk Clotting Activity

SummaryThree enzymes were assessed as rennet substitutes for cheese-making. The bovine and chicken pepsins used were relatively crude extracts of bovine stomach mucosa and chicken proventriculae respectively; the swine pepsin was a partially purified commercial product. The ratios of milk-clotting activity to general proteolytic activity were high for rennet and bovine pepsin and low for swine and chicken pepsins. Both bovine mucosa and chicken stomach gave low milk-clotting activities compared with calf stomach. For all the enzymes the chemical reactions causing milk clotting appeared to be the same. The milk-clotting activity showed a decrease with increase in substrate pH for all the enzymes, although they were all still active at pH 6·81.Duplicate cheeses were made from each of the swine, bovine and chicken pepsins, with rennet as a standard in each trial. The cheese-making process was similar with each enzyme, but differences appeared during ripening. The chicken-pepsin cheeses had poor body and weak Cheddar-cheese flavour, with many and intense off-flavours. The cheeses made with bovine and swine pepsins were only slightly inferior in quality and intensity of Cheddar-cheese flavour to the rennet cheeses. From a simulated cheese-making experiment it was concluded that 30–40 % of the added rennet, bovine pepsin and chicken pepsin was probably inactivated during the cheese-making process and that most or all of the swine pepsin was lost. These results provide an explanation for the variations observed in cheese ripening.It was concluded that chicken pepsin would not prove a suitable rennet substitute for making Cheddar cheese because of the quality of the cheese produced, and that bovine pepsin would not prove suitable because of the cost of preparing a suitable extract. Swine pepsin would appear to be suitable if the ripening time were to be lengthened or if another enzyme were to be added to assist ripening; it is cheaper than rennet and other rennet substitutes.

scholarly journals Study of the effect of high-frequency acoustic cavitation on the quality of raw milk and dairy products based on it

2019 ◽  
Vol 81 (3) ◽  
pp. 145-150
Author(s):  
K. A. Kanina ◽  
O. N. Krasulya ◽  
N. A. Zhizhin ◽  
E. S. Semenova
Keyword(s):  
High Frequency ◽  
Dairy Products ◽  
Raw Materials ◽  
Acoustic Cavitation ◽  
Raw Milk ◽  
Raw Material ◽  
Coliform Bacteria ◽  
Cow’S Milk ◽  
Cow's Milk

The article presents the results of studies obtained in the study of the quality of milk processed with the use of high-frequency acoustic cavitation and dairy products produced with its use. The research was carried out with the use of General scientific and special research methods in the laboratory of the Department of technology of storage and processing of animal products of the K. A. Timiryazev and in the accredited laboratory of technochemical control of the all-Russian research Institute of dairy industry. It is shown that the treatment of cow's milk-raw materials high-frequency ultrasonic vibrations (above 45 kHz), the generated electric ultrasonic device immersion type pulse impact ouzo "Activator-150", the number of bacteria of group of intestinal sticks (coliforms) decreased by almost 40%, which allows to make a conclusion about the appropriateness of the selected method of exposure for the destruction of microorganisms E. coli and coliform bacteria. Processed, using high-frequency acoustic cavitation, cow's milk was used for the production of brine cheese-cheese. It is shown that cheese cheese had a high nutritional value, which is due to the preservation of essential substances in the raw material (in particular, calcium, which in the production of cheese cheese precipitates if pasteurized milk is used), elastic consistency, safety of consumer characteristics - microbiological and physico-chemical.

scholarly journals Study on Physico-Chemical and Microbial Quality of Raw Milk Collected From Different Places of Assi Region in Varanasi City, Varanasi

2020 ◽  
Vol 39 (01) ◽  
Author(s):  
Pankaj Kumar Gupta ◽  
Dinesh Chandra Rai ◽  
Vinod Kumar Paswan ◽  
Rajendra Panta ◽  
Ashok Kumar Yadav
Keyword(s):  
Standard Procedure ◽  
Microbiological Quality ◽  
Raw Milk ◽  
Coliform Bacteria ◽  
Plate Count ◽  
Microbial Quality ◽  
Average Percentage ◽  
Physico Chemical ◽  
Two Samples

The present study was conducted to evaluate the physico-chemical characteristics including Adulteration and Microbiological quality of cow raw milk collected from four different places of ASSI region in Varanasi. Samples were analysed to know the chemical composition, the results showed that the statistically average percentage of Moisture (87.46), Fat (3.87), Protein (3.15), Lactose (4.42), Ash (.712), pH (6.43) and acidity (0.147). The keeping quality of milk was evaluated by Methylene Blue Reduction Test (MBRT). This phenomenon testified that milk sample 1 is fair quality and remained sample were found good and excellent. The microbiological conclusion confirmed the presence (less or more) of microbial load in all the raw milk samples. The highest level of microbial quality in standard plate count (SPC) was 19.1×106 cfu/ml. in sample 1 and in logarithm value is 7.28 cfu/ml at the same time, the highest coliform bacteria 2.3×102 in logarithm value is 2.36 was found in the sample 2. The adulterations in raw milk were checked by the standard procedure. In cow’s raw milk the different mixed adulterant were found in two samples contaminated with detergent and pulverized soap. Besides different hazardous chemical adulterant, raw milk from sample 1 was detected with presence of hydrogen peroxide and sample 2 was contaminated formalin whereas urea was present in sample 2 and 4. Milk adulteration is a global concern and social problem. Increased demand, growth in competition in dairy industry and financial gain makes some producers to adulterate the milk thereby decreasing milk quality.

scholarly journals Study About Pathogenic Bacteria Associated With Bovine

2004 ◽  
Vol 28 (1) ◽  
pp. 227-234
Author(s):  
Safana A. S. AL-Taan ◽  
Asmaa H. AL-Jobori ◽  
Anton S. AL-Bana.
Keyword(s):  
Bacillus Cereus ◽  
Pathogenic Bacteria ◽  
Raw Milk ◽  
Viable Count ◽  
Coliform Bacteria ◽  
Milk Samples ◽  
Different Types ◽  
High Level ◽  
Living Bacteria

Out of 100 raw milk samples collected from one hundred cows infected with mastitis, thirty three isolates of different types of pathogenic bacteria were isolated using different types of selective media.  On the basis of traditional bacteriological tests, these isolates were identified as the following: 13 isolates of Staphylococcus aureus, 9 isolates of B-haemolytic Streptococci, 6 isolates of Coliform bacteria, 4 isolates of Corynebacterium pyogenes, and only one isolate Bacillus cereus.  In addition to these isolates, a number of non-pathogenic bacteria were recovered during the isolation and they were considered as contaminants of milk such as S. epidermidis, C. bovis and B. subtilus.  The total number of living bacteria present in milk samples was measured and it was ranged from (1400 to 1800) bact./ml.  The isolates of pathogenic bacteria were tested for their sensitivity to different types of antibiotics and the results were: 100% of these isolates were sensitive to Gentamycin and Tetracycline, 11 (84.6%) isolates of S. aureus, 6(66.2%) isolates of B-hacmolytic Streptococci , 4(66.2%) isolates of Coliform bacteria and 3(75%)  es of C. pyogenes were sensitive to Ampicillin, Penicillin, Erythromycin and Cepholexin. While Bacillus cereus isolate was resistant to all these antibiotics.  As a result of this work, generally the bacteriological quality of this milk is acceptable due to the low number of viable count of bacteria in   milk and the isolates showed high level of sensitivity to the antibiotics used in this study.

Effect of Storage of Raw and Pasteurized Goats' Milk on Flavor Acceptability, Psychrotrophic Bacterial Count, and Content of Organic Acids

1985 ◽  
Vol 48 (2) ◽  
pp. 122-129 ◽  
Author(s):  
E. J. GUY ◽  
K. B. HICKS ◽  
J. F. FLANAGAN ◽  
T. A. FOGLIA ◽  
V. H. HOLSINGER
Keyword(s):  
Organic Acids ◽  
Cold Storage ◽  
Hplc Analysis ◽  
Bacterial Count ◽  
Raw Milk ◽  
Flavor Quality ◽  
High Count ◽  
The Third ◽  
Hedonic Scale

Pasteurization of raw goats' milk either at 63°C for 30 min or 72°C for 15 s within 1 d of milking ensures a better tasting product both initially and during storage at 4.5°C for 6 weeks than if the raw milk is aged for several days at 4.5°C before being pasteurized. Pasteurized milks processed from high-count raw milks aged 1 to 2 weeks had lower acceptability ratings (on a 9-point hedonic scale), which decreased further in cold storage and were independent of bacterial increases in the log phase of growth. Pasteurized milks processed from raw milk 7 or more days old were subject to rapid increases in bacterial numbers in storage if they were trace-contaminated during pasteurization even though initial counts were <100 psychrotrophs/ml. For all raw and pasteurized milks, three peaks were consistently observed from an HPLC analysis designed to monitor some organic acids. Two of the components decreased and the third appeared and increased during storage. Disappearance of one component coincided with appearance of another. These compounds may be associated with loss of flavor quality of the milk since in some instances these changes significantly correlated with the decrease in hedonic ratings of the stored milks.

scholarly journals Biochemical changes during ripening of cheeses in an animal skin

2020 ◽  
Vol 70 (4) ◽  
pp. 225-241
Author(s):  
Milna Tudor Kalit ◽  
Samir Kalit ◽  
Ilhan Gün ◽  
Ante Rako ◽  
Tihana Lojbl
Keyword(s):  
Chemical Properties ◽  
Consumer Preference ◽  
Raw Milk ◽  
Biochemical Changes ◽  
Negative Consequences ◽  
Cheese Ripening ◽  
Physico Chemical ◽  
Manufacturing Procedure ◽  
Animal Skin

A few types of cheeses ripened in an animal skin sack are produced around the world: Sir iz mišine (Croatia), Sir iz mijeha (Bosnia and Herzegovina and Montenegro), Tulum and Divle Cave (Turkey), Bouhezza (Algeria) and Darfiyeh (Lebanon). Pronounced and piquant taste, flavour and aroma of these cheeses originate from intensive lipolysis and proteolysis as a result of specific anaerobic conditions inside the skin sack, autochthonous microorganisms from raw milk and skin, as well as their manufacturing procedure. The specific and complex biochemical changes that occur during ripening of cheeses in animal skin sacks have become of great interest to researchers, and numerous studies have been conducted over the last decade. Therefore, the aim of this paper is to review the specificities of proteolytic and lipolytic changes that occur during ripening of cheese in the animal skin sack, which cause the characteristic volatile compounds profile. Moreover, the manufacturing procedures and physico-chemical properties of cheeses is shown due to their relationship with biochemical reactions during cheese ripening. As biochemical changes during ripening directly influence sensory attributes of cheese, which determine consumer preference, this review could provide practical data for cheesemakers to prevent negative consequences of overly intensive biochemical changes during cheese ripening, and so improve the quality of this kind of cheeses.

scholarly journals Quality of cows’ milk from organic and conventional farming 

2014 ◽  
Vol 32 (No. 4) ◽  
pp. 398-405 ◽  
Author(s):  
L. Kouřimská ◽  
V. Legarová ◽  
Z. Panovská ◽  
J. Pánek
Keyword(s):  
Freezing Point ◽  
Farming Systems ◽  
Preference Test ◽  
Raw Milk ◽  
Coliform Bacteria ◽  
Conventional Farming ◽  
Milk Samples ◽  
Whole Milk ◽  
Organic And Conventional Farming

The results of chemical and microbial analyses of raw milk samples coming from organic and conventional farming systems were statistically compared. The samples were analysed during a twelve-month period (June–May). A total of 2206 samples were collected of which 528 were organic. After raw milk was processed, sensory hedonic quality of 171 pairs of organic and conventional non-standardised pasteurised whole milk samples were evaluated using the pair comparison preference test. Four parameters in raw milk, free fatty acids, urea content, somatic cell count and coliform bacteria count, showed no significant differences between the two types of production. Significantly higher contents of protein, casein, lactose, and non-fat solids were detected in conventional milk, which also had a significantly lower freezing point. On the contrary, significantly higher contents of total mesophilic bacteria count and a higher percentage of samples with positive coliform bacteria count were found in organic milk samples. Sensory analysis of pasteurised milk showed no significant hedonic difference between organic and conventional samples.

scholarly journals THE SIZE OF THE FARM AND ITS INFLUENCE AT CLEANLINESS OF THE COWS AND MILK HYGIENE

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
A. Marić ◽  
B. Važić ◽  
Maja Regoda ◽  
M. Erbez
Keyword(s):  
Dairy Cows ◽  
Somatic Cells ◽  
Raw Milk ◽  
Surrounding Area ◽  
Hygienic Quality ◽  
Number Of Microorganisms ◽  
Milk Hygiene ◽  
Physical Comfort ◽  
Quality Of Milk

For animals the sense of physical comfort is necessary (physical comfort). When animals feel physically comfortable, it means that every part of their bodies is in harmony with the surrounding area. Therefore, the farms are usually build in accordance with the number of cattle that will be hold in designed facilities, which provide a higher degree of cows cleanliness. Cleanliness of cows is important in order to produce hygienically clean milk and to achieve the cattle welfare of dairy cows too. Cleanliness of animals mostly depends on what kind of object they are placed in. Hygienically proper milk includes the number of microorganisms up to 100,000 / ml and the number of somatic cells to 400,000 / ml, which are regulated by the "Regulations on quality of fresh raw milk." For this research farms are divided into three groups according to the number of cows. The first group included the number of cows from 1 to 9, the second group included 10 to 19, and a third group 20 or more cows. The aim of this paper is to examine whether there is an influence of the size of farms (number of cows) on the subjective cow cleanliness and hygienic quality of milk.

scholarly journals Study About Pathogenic Bacteria Associated With Bovine Mastitis

2004 ◽  
Vol 28 (1) ◽  
pp. 227-234
Author(s):  
Safana A. S. AL-Taan ◽  
Asmaa H. AL-Jobori ◽  
Anton S. AL-Bana.
Keyword(s):  
Bacillus Cereus ◽  
Pathogenic Bacteria ◽  
Bovine Mastitis ◽  
Raw Milk ◽  
Viable Count ◽  
Coliform Bacteria ◽  
Milk Samples ◽  
Different Types ◽  
High Level

Out of 100 raw milk samples collected from one hundred cows infected with mastitis, thirty three isolates of different types of pathogenic bacteria were isolated using different types of selective media.  On the basis of traditional bacteriological tests, these isolates were identified as the following: 13 isolates of Staphylococcus aureus, 9 isolates of B-haemolytic Streptococci, 6 isolates of Coliform bacteria, 4 isolates of Corynebacterium pyogenes, and only one isolate Bacillus cereus.  In addition to these isolates, a number of non-pathogenic bacteria were recovered during the isolation and they were considered as contaminants of milk such as S. epidermidis, C. bovis and B. subtilus.  The total number of living bacteria present in milk samples was measured and it was ranged from (1400 to 1800) bact./ml.  The isolates of pathogenic bacteria were tested for their sensitivity to different types of antibiotics and the results were: 100% of these isolates were sensitive to Gentamycin and Tetracycline, 11 (84.6%) isolates of S. aureus, 6(66.2%) isolates of B-hacmolytic Streptococci , 4(66.2%) isolates of Coliform bacteria and 3(75%)  es of C. pyogenes were sensitive to Ampicillin, Penicillin, Erythromycin and Cepholexin. While Bacillus cereus isolate was resistant to all these antibiotics.  As a result of this work, generally the bacteriological quality of this milk is acceptable due to the low number of viable count of bacteria in  milk and the isolates showed high level of sensitivity to the antibiotics used in this study.

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