scholarly journals Effect of acidification of raw milk on psychrotrophic microrganims.

2013 ◽  
Vol 2 (2) ◽  
Author(s):  
Marianne Ayumi Shirai ◽  
Maria Lucia Masson
Keyword(s):  
Dairy Products ◽  
Inhibitory Action ◽  
Raw Milk ◽  
Psychrotrophic Bacteria ◽  
Milk Samples ◽  
Ph Reduction ◽  
Quality Of Milk ◽  
Micro Organisms ◽  
Milk And Dairy Products

<p>The contamination of raw milk with psychrotrophic micro-organisms has become a concern because they are able to multiply at refrigeration temperatures and produce heat resistant enzymes that affect the quality of milk and dairy products. The objective of this study was to evaluate the effect of acidification with CO<sub>2</sub> and HCl on mesophilic and psychrotrophic bacteria present in raw milk during cold storage. Raw milk samples were acidified with CO<sub>2</sub> and HCl 1N until pH 6,0 and stored at 5 &deg;C for 10 days. The results showed an average reduction of 1 logarithmic cycle in the growth of psychrotrophic and mesophilic microorganisms in samples treated with CO<sub>2</sub>. Acidification with HCl showed no effect, indicating that inhibitory action was due to CO<sub>2</sub> not by pH reduction.</p><p>&nbsp;</p><p>DOI: http://dx.doi.org/10.14685/rebrapa.v2i2.68</p>

scholarly journals Microbiological, chemical, physical, and proteolytic activities of raw milk after thermal processing

2018 ◽  
Vol 70 (5) ◽  
pp. 1625-1632 ◽  
Author(s):  
H.S. Milaneze ◽  
L.S. Silva ◽  
L.B.M. Kottwitz ◽  
M.A. Zambom ◽  
L.M. Fonseca ◽  
...  
Keyword(s):  
Life Quality ◽  
Raw Milk ◽  
Progressive Increase ◽  
Milk Composition ◽  
Production Chain ◽  
Psychrotrophic Bacteria ◽  
Milk Samples ◽  
Quality Of Milk ◽  
Staphylococcus Spp

ABSTRACT The aim was to evaluate the microbiological, chemical- physical, and shelf-life quality of milk samples after pasteurization (HTST) for 10 days or ultra-high temperature (UHT) treatment for 120 days. Raw milk counts of mesophilic aerobic microorganisms, Staphylococcus spp. and thermotolerant coliforms before HTST and UHT processing were 6.73 and 7.77; 2.84 and 4.30, and 4.68 and 4.37log10, respectively. Pseudomonas spp. were found in raw milk samples. No presence of any other microorganisms studied was detected and no microbial inhibitor was found. Processed samples met microbiological legal requirements. However, aerobic mesophilic counts for HTST pasteurized milk samples stored for 5 and 10 days increased to values comparable to those in raw milk. Composition chemical- physical of all samples were within legal limits. These results demonstrate that, although HTST and UHT processed milk comply with the microbiological standards required by Brazilian law, high microbial counts in raw milk are an issue, possibly due to failures in the early stages of the production chain. Increase in casein macropeptide (CMP), probably because of proteases psychrotrophic bacteria. It is concluded that the quality of raw milk directly influences the progressive increase of the CMP values.

Improved Methods for Quality Assessment of Raw Milk

1988 ◽  
Vol 51 (12) ◽  
pp. 955-957 ◽  
Author(s):  
J. RUSSELL BISHOP ◽  
JIA-YING JUAN
Keyword(s):  
Raw Milk ◽  
Plate Method ◽  
Fresh Sample ◽  
Psychrotrophic Bacteria ◽  
Milk Samples ◽  
Bacterial Enumeration ◽  
Quality Of Milk ◽  
Improved Methods ◽  
Medium Culture

Raw milk samples (203) were obtained from locations throughout Virginia for the purpose of evaluating the presently available techniques, used as is or modified, for enumeration of psychrotrophic bacteria as indicators of the actual quality of milk. Each of the samples was split into two sub-samples, one being tested by various bacterial enumeration methods on the fresh sample, and the other subjected to a preliminary incubation of 13°C or 21°C for 18 h prior to bacterial enumeration. Agar pour plates and Petrifilm dry medium culture plates were both used. Results indicated that the Petrifilm technique was not significantly different from agar pour plate methods as evidenced by correlation values, mean log differences, slopes, and Y-intercepts. The Petrifilm method for the modified (rapid) Psychrotrophic Bacteria Count (mPBC) produced similar overall results (0.96, −0.283, 1.016, −0.340, respectively) to the pour plate method (0.94, 0.272, 0.865, 0.684, respectively) when compared to the standard PBC, and enumeration of colonies on the Petrifilm plates was easier due to the incorporated TTC. A modified Preliminary Incubation Count (mPIC) yielded results not significantly different from those of the PIC (0.94, 0.044, 0.991, 0.169, respectively), and was conducted in less time - 2 d vs. 3 d.

scholarly journals The influence of chlorella suspension on the quality of milk and its processing products

2020 ◽  
Vol 222 ◽  
pp. 02021
Author(s):  
Raisat Akhmedkhanova ◽  
Zaidin Dzhambulatov ◽  
Zemfira Gadzhaeva ◽  
Gadji Shabanov ◽  
Samira Alieva
Keyword(s):  
Amino Acids ◽  
Chemical Composition ◽  
Dairy Products ◽  
Nutritional Value ◽  
Milk Samples ◽  
Lactating Cows ◽  
Quality Of Milk ◽  
Almost All ◽  
Milk And Dairy Products

This job is devoted to the production of dairy products enriched with iodine, which accumulates naturally when chlorella (Chlorella vulgaris) suspension is introduced into the diet of lactating cows. It was found that as a result of the introduction into the diet of lactating Holstein cows during the winter stall period at the rate of 1 and 1.5 liters of chlorella suspension per head per day, the content of protein, fat and iodine in milk, as well as in macro and microelements, and almost all amino acids they are superior compare to milk samples from the experimental groups. Milk and dairy products made from cows’ milk that have been fed with chlorella suspension have increased nutritional value, improved properties and a well-balanced chemical composition.

Proteinase and phospholipase activities and development at different temperatures of yeasts isolated from bovine milk

2011 ◽  
Vol 78 (4) ◽  
pp. 385-390 ◽  
Author(s):  
Priscilla A Melville ◽  
Nilson R Benites ◽  
Monica Ruz-Peres ◽  
Eugenio Yokoya
Keyword(s):  
Dairy Products ◽  
Room Temperature ◽  
Bovine Milk ◽  
Raw Milk ◽  
Pathogenic Potential ◽  
Proteinase Production ◽  
Different Temperatures ◽  
Quality Of Milk ◽  
Means Of Transmission

The presence of yeasts in milk may cause physical and chemical changes limiting the durability and compromising the quality of the product. Moreover, milk and dairy products contaminated by yeasts may be a potential means of transmission of these microorganisms to man and animals causing several kinds of infections. This study aimed to determine whether different species of yeasts isolated from bovine raw milk had the ability to develop at 37°C and/or under refrigeration temperature. Proteinase and phospholipase activities resulting from these yeasts were also monitored at different temperatures. Five genera of yeasts (Aureobasidium sp., Candida spp., Geotrichum spp., Trichosporon spp. and Rhodotorula spp.) isolated from bovine raw milk samples were evaluated. All strains showed one or a combination of characteristics: growth at 37°C (99·09% of the strains), psychrotrophic behaviour (50·9%), proteinase production (16·81% of the strains at 37°C and 4·09% under refrigeration) and phospholipase production (36·36% of the isolates at 37°C and 10·9% under refrigeration), and all these factors may compromise the quality of the product. Proteinase production was similar for strains incubated at 37°C (16·81% of the isolates) and room temperature (17·27%) but there was less amount of phospholipase-producing strains at room temperature (15·45% of the isolates were positive) when compared with incubation at 37°C (36·36%). Enzymes production at 37°C by yeasts isolated from milk confirmed their pathogenic potential. The refrigeration temperature was found to be most efficient to inhibit enzymes production and consequently ensure better quality of milk. The viability of yeasts and the activity of their enzymes at different temperatures are worrying because this can compromise the quality of dairy products at all stages of production and/or storage, and represent a risk to the consumer.

scholarly journals The Occurrence of Aflatoxin M1 in Milk, soft cheese and yoghurt in Baghdad Province by Using ELISA Test

2014 ◽  
Vol 38 (2) ◽  
pp. 9-16
Author(s):  
Najim Hadi Najim
Keyword(s):  
Dairy Products ◽  
Raw Milk ◽  
Elisa Test ◽  
Mean Value ◽  
Aflatoxin M1 ◽  
Contamination Level ◽  
Milk Samples ◽  
White Cheese ◽  
The Mean ◽  
Milk And Dairy Products

     Milk and dairy products are fundamental components in the human diet and may be the principle way for entrance of Aflatoxin M1 (AFM1) in to the human body. All milk and dairy products samples were tested for the occurrence of AFM1 by the competitive ELISA technique. Out of 32 bovine raw milk samples that were collected from eight villages around Baghdad province, 32 samples (100 %) were contaminated with AFM1 ranging from 0.15 to 86.96ng/kg with mean value of 42.37±26.07 ng/kg, of which 17 samples were contaminated with concentrations < 50 ng/kg and 15 samples exceeded the maximum acceptable level of AFM1 in milk (50 ng/kg) imposed by the European legislation. The raw milk samples belonged to animals fed with composite and stored fodder as in Althahab Alabiadh, Radhwaniya and Fadhaliya villages had higher significantly AFM1 concentrations over all the other five villages (Grazing feed). All 32 (100%) locally produced soft white cheese samples analyzed were contaminated with AFM1 ranging from 31.84 to 89.44 ng/kg with the mean value of 59.92±17.03 ng/kg. Out of 32 locally produced yoghurt samples analyzed, 32 samples (100%) were contaminated with AFM1 ranging from 0.16 to 42.74 ng/kg with the mean value of 16.92±11.55 ng/kg. Thirty samples (100%) of the examined 30 imported UHT milk samples that were collected from different commercial companies in the province of Baghdad presented significantly  high contamination level with AFM1 that were found to range from 0.18 to 85.66 ng/kg.

Milk productivity of cows, quality of milk and dairy products when using natural feed additive

2020 ◽  
pp. 13-21
Author(s):  
Yu. A. Karmatskikh ◽  
N. M. Kostomakhin
Keyword(s):  
Milk Production ◽  
Dairy Products ◽  
Feed Additive ◽  
Control Group ◽  
Black And White ◽  
Mineral Additive ◽  
Quality Of Milk ◽  
Experimental Group ◽  
Milk And Dairy Products

The organization of feeding of highly productive cows is one of the most difficult tasks in dairy cattle breeding. The purpose of the work was to study the influence of natural mineral additive on the productivity, composition and some technological qualities of milk of cows of Black-and-White breed of Ural type. Research and production experiment has been carried out in CJSC “Glinki” in the Ketovsky district in the Kurgan region on Black-and-White cows. The influence of bentonite additive in the ration of highly productive cows during the period of increasing the milk yield on the composition and technological quality of milk and dairy products has been determined. In general, for the first 100 days of lactation the cows of the experimental group have produced by 191 kg more natural fat milk or 8,4 %, compared to the control group. In terms of 4 % milk from animals of the experimental group has been got by 233 kg or 9,3 % more than of the control group. The yield of milk fat in the experimental group was by 10,44 kg or 12,9 % more than the control group. The difference in milk protein yield for 100 days of lactation was 7,34 kg or 9,8 %. The economic indicators (prime-cost, profitability) of milk production when feeding the mineral additive bentonite to cows have been calculated. With an increase in the total cost of obtaining milk from cows of the experimental group, caused by higher milk yields and the purchase of bentonite, the revenue from the sale of milk from this group was by 7,83 thousand rubles or 8,4 % more. As a result, milk production from animals of the experimental group was by 3,44 % more efficient. It has been found that the inclusion of bentonite in the composition of concentrated feed in the amount of 400 g/head/day allowed to reduce their expenditure, as well as EFU and digestible protein, which ultimately provided a higher level of profitability of milk production.

Rapid Detection of Psychrotrophic Bacteria In Manufacturing Grade Raw Milks

1991 ◽  
Vol 54 (11) ◽  
pp. 861-867 ◽  
Author(s):  
S. R. TATINI ◽  
P. MEKALA ◽  
A. EL-HABAZ ◽  
M. W. GRIFFITHS
Keyword(s):  
Rapid Detection ◽  
Bacterial Count ◽  
Raw Milk ◽  
Plate Count ◽  
Psychrotrophic Bacteria ◽  
Milk Samples ◽  
Microscopic Count ◽  
Direct Epifluorescent Filter Technique ◽  
Native Microflora

Methods to rapidly assess the bacteriological quality of raw milk were investigated. Whereas direct microscopic count, modified psychrotrophic plate count, and direct epifluorescent filter technique (DEFT) did not correlate well with initial psychrotrophic bacterial count of raw milk, improvements were obtained after preincubation of the milk samples. The best preincubation conditions were identified as 30°C for 6 h, 21°C for 10 h, 13°C for 15 h, 13°C for 20 h, or 7°C for 37 h. The “square root” equation was applied to the data, and a model was produced for predicting growth of the native microflora of raw milk. Using this equation, a DEFT count after preincubation of the milk at 21°C for 10 h could accurately predict the initial psychrotroph count and the count after storage of the milk at 6°C for 48 h.

scholarly journals Dairy farming: Integration into Europe

2005 ◽  
Vol 21 (1-2) ◽  
pp. 123-132
Author(s):  
Miomir Jovanovic ◽  
Bogdan Bulatovic ◽  
Aleksandra Despotovic
Keyword(s):  
Dairy Products ◽  
Dairy Farming ◽  
International Economy ◽  
The European Union ◽  
Milk Processing ◽  
Increasing Trend ◽  
The Republic ◽  
Quality Of Milk ◽  
Milk And Dairy Products

Because of the increasing trend in globalization in dairy farming resulting in joining and taking over some companies with the aim of rationalization of production and realizing greater market participation, it seems quite real to expect such a trend to appear in our country as well. After the process of privatization had been realized a significant part of Montenegrin economy fell into the hands of private owners. In such conditions it can be expected that efficiency and competitiveness of some producers of milk and dairy products in the Republic of Montenegro will be increased, since in previous period this industry was characterized by insufficient exploitation of already existing capacities for milk processing while the quality of milk was considerably under the standards prescribed by the European Union. Depending on the dynamics of entering Montenegro into international economy the national dairy industry must be ready to face the challenge which will certainly be imposed on it. The object of this paper was to try to find the answers to the two questions. First where we are now and where we will be in the next five years in order to improve the competitive potential of domestic dairy farming.

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