scholarly journals ATP-Bioluminescence as a method to evaluated microbiological quality of UHT milk

2014 ◽  
Vol 66 (6) ◽  
pp. 1909-1916 ◽  
Author(s):  
A.F. Cunha ◽  
A.D. Lage ◽  
M.M. Pereira e Araújo ◽  
C.F. Abreu ◽  
A.R. Tassinari ◽  
...  

New approaches are needed to quickly indicate possible contamination of UHT milk, among them the technique of ATP-Bioluminescence. Therefore, the aim of this study was to compare the results of culture methods with the results of ATP-Bioluminescence technique of 102 UHT whole milk samples incubated at 48, 72, and 168 hours. UHT milk samples were analyzed for the presence of mesophilic and psychrotrophic aerobic microorganisms using Plate Count Agar (PCA), Brain-Heart Infusion (BHI) media and PetrifilmTM Aerobic Count (AC) plates. The ATP-Bioluminescence technique was applied through the Microbial Luminescent Screening (MLS) system. Significant correlations were found between counts of aerobic mesophilic microorganisms on PCA, PetrifilmTM AC, BHI and results of ATP bioluminescence technique (P≤0.05). The ATP-Bioluminescence technique had higher correlation with counting method in PCA than BHI media. At lower pass/fail limits of Relative Light Units (60, 50, 45 and 40 RLU), the number of samples identified as positive increased and statistically agreed with aerobic mesophilic microorganism counts (P>0.05). For the dairy industry, the ATP-Bioluminescence technique may become an important tool that assists the official methods to quickly monitor the microbiological quality of UHT milk though this will likely require a threshold below 150 RLU.

2019 ◽  
Vol 7 (1) ◽  
pp. 161-168 ◽  
Author(s):  
AVIJIT BANIK ◽  
MARUF ABONY ◽  
SUVAMOY DATTA ◽  
SYEDA TASNEEM TOWHID

The objective of this research was to assess the microbiological quality of ready-to-eat food available in Dhaka city, Bangladesh, and check the risk factors associated with ingestion of ready-to-eat food from popular public places. This study was conducted in the Center of Excellence in the Department of Microbiology, Primeasia University, Dhaka, Bangladesh from August 2016 to February 2017. Forty-five samples belonging to 18 categories were collected aseptically in triplicates in pre-sterilized zip-lock bags or sterile bottles from Banani area from local street vendors. Samples were transported to and analysed in the Laboratory of Department of Microbiology, Primeasia University according to standard food analysis methods. Total viable count (TVC) and Total coliform count (TCC) were determined by using plate count agar (PCA) andMacConkey agar plates respectively. Antibiogram of the isolated strains was conducted with commercial antibiotics according to the Kirby-Bauer disc diffusion method on Mueller-Hinton agar medium. Identification of the coliforms together with antibiotic-resistance profile showed Escherichia coli, Enterobactersakazaki, Citrobacterfreundii and Salmonella typhimurium were present in various foods. E. coli and S.typhimurium showed increased sensitivity against Ampicillin 10 mg and Sulfamethoxazole 25 mg. The occurrence of antibiotic-resistance potential pathogens in ready-to-eat food poses a considerable health risk to consumers. Public awareness and timely assessment of food safety are needed to avoid the risks of food-borne infection and intoxication from ready-to-eat food.


2006 ◽  
Vol 69 (10) ◽  
pp. 2534-2538 ◽  
Author(s):  
FUR-CHI CHEN ◽  
SANDRIA L. GODWIN

The feasibility of using an ATP bioluminescence assay for assessing microbial contamination of home refrigerators was evaluated and compared with the standard culture methods. Samples of refrigerator surfaces were collected from 123 households by swabbing an area of 100 cm2 on three locations in the refrigerator with premoisturized sterile swabs. Microbial contaminations were determined by aerobic plate count (APC; incubated at 35°C for 48 h) and psychrotrophic plate count (PPC; incubated at 7°C for 10 days) on plate count agar. The results were compared to the readings from the microbial ATP (mATP) bioluminescence assay. The correlation coefficient (r) between mATP and PPC (r = 0.851) was slightly higher than that between mATP and APC (r = 0.823). Our results indicated a potential discrepancy in the population of mesophilic and psychrotrophic bacteria in the refrigerator samples. Nevertheless, mATP appeared to be a reliable indication of the average of APC and PPC (r = 0.895). The mATP bioluminescence assay would provide a rapid and convenient test for researchers in field studies to assess microbial contamination in refrigerators.


2019 ◽  
Vol 8 (1) ◽  
pp. 1-6
Author(s):  
Jubaida Binte Jamal ◽  
Sharmin Akter ◽  
Md Aftab Uddin

The present study was undertaken to determine the microbiological quality of pasteurized milk, UHT milk and flavoured milk samples collected from different locations in Dhaka, Bangladesh. Twenty pasteurized milk samples, fifteen UHT milk samples and fifteen flavoured milk samples of different brand were collected and different batch were analyzed for enumerating the total viable bacterial count (TVBC), total coliform count (TCC) and physiochemical tests (sensory test, alcohol test, acidity test, fat test, CLR test, SNF). The range of TVBC and pasteurized milk samples was between 2.3×102 cfu/ml to 4.69×103 cfu/ml. TVBC range of flavoured milk samples was between 5.0×101 cfu/ml to 1.8×102 and no TVBC was detected for any of the UHT milk samples. No TVBC was found for flavoured milk samples of company-8 (UHT). Because it was processed with ultra high temperature, slightly lower than that recommended by BSTI (not exceeding 20,000 cfu/ml). Coliform bacteria were present only for pasteurized milk samples in one brand, though the count was under acceptable range according to BSTI recommendation (<10/ml coliform in pasteurized milk). Physiochemical tests are also very important to detect the quality of milk samples. Acidity range should not exceed 0.14, for this study fat range should be minimum 3.5% and SNF should be minimum 8%. In this study, for pasteurized milk samples acidity range was between 0.14-0.16, fat range was between 3.5-3.9% and SNF was between the ranges of 8-9.784%. For UHT milk samples acidity range was between 0.13-0.16, fat range was between 3.5-3.8% and SNF was between 8.034-9.012. All the results of sensory and physiochemical tests for pasteurized and UHT milk samples were satisfactory. So, UHT processed milk and flavoured milk can be considered as safe for consumption within the mentioned expiry date without heat treatment. Stamford Journal of Microbiology, Vol.8(1) 2018: 1-6


Domiati cheese is the most popular brand of cheese ripened in brine in the Middle East in terms of consumed quantities. This study was performed to investigate the impact of the microbiological quality of the used raw materials, the applied traditional processing techniques and ripening period on the quality and safety of the produced cheese. Three hundred random composite samples were collected from three factories at Fayoum Governorate, Egypt. Collected samples represent twenty-five each of: raw milk, table salt, calf rennet, microbial rennet, water, environmental air, whey, fresh cheese, ripened cheese & swabs from: worker hands; cheese molds and utensils; tanks. All samples were examined microbiologically for Standard Plate Count (SPC), coliforms count, Staphylococcus aureus (S. aureus) count, total yeast & mould count, presence of E. coli, Salmonellae and Listeria monocytogenes (L. monocytogenes). The mean value of SPC, coliforms, S. aureus and total yeast & mould counts ranged from (79×102 CFU/m3 for air to 13×108 CFU/g for fresh cheese), (7×102 MPN/ cm2 for tank swabs to 80×106 MPN/ml for raw milk), (9×102 CFU/g for salt to 69×106 CFU/g for fresh cheese) and (2×102 CFU/cm2 for hand swabs to 60×104 CFU/g for fresh cheese), respectively. Whereas, E. coli, Salmonella and L. monocytogenes failed to be detected in all examined samples. There were significant differences in all determined microbiological parameters (p ≤0.05) between fresh and ripened cheese which may be attributed to different adverse conditions such as water activity, pH, salt content and temperature carried out to improve the quality of the product.


2016 ◽  
Vol 44 (3) ◽  
pp. 132-136
Author(s):  
MY Arafat ◽  
R Habib ◽  
MSR Siddiki ◽  
MF Imam

This experiment was conducted to evaluate the quality of existing ultra-high temperature (UHT) treated milk available in two selected town markets of Bangladesh. A total of 27 UHT milk samples from three different brands–Pran Dairy (A), Aarong Dairy (B) and Farm Fresh (C) were collected from local markets at Mymensingh and Gazipur districts during the period of 1stSeptember to 29th November, 2014. Parameters studied in this experiment were organoleptic (flavour, consistency, colour and appearance), physic-chemical (specific gravity, acidity, total solids, solids-not-fat, fat, protein, lactose, and ash) and microbiological (Total Viable Count and Coliform Count). All the samples were similar in respect of color, flavor, taste and texture, and no significant difference was observed. However, significant differences were revealed (p<0.05) in case of specific gravity, acidity, total solids, solids-not-fat, and protein content. On the other hand, insignificant differences were found (p>0.05) in case of fat, lactose, and ash content. Total Viable Count and Coliform count were found to be nil in all the milk samples. Milk samples of Farm Fresh UHT milk were superior to other brands of UHT Milk in terms of contents of total solids (119.23±0.57 g/kg),fat (34.97±0.35g/kg), lactose (43.23±0.51g/kg), and ash (7.00±0.26g/kg). Though there were some fluctuations in all the parameters studied, all the milk samples conformed to the standard values for UHT milk, and in general all of the UHT milk samples studied in this experiment was of good quality.Bang. J. Anim. Sci. 2015. 44 (3):132-136


1993 ◽  
Vol 56 (4) ◽  
pp. 336-337 ◽  
Author(s):  
JOSEP SERRA BONVEHI ◽  
ROSSEND ESCOLÁ JORDÁ

The number of mesophilic aerobic colonies was determined in 72 samples of mono- and multifloral honey from various sources by the plate count and the membrane filter methods. The presence of motile colonies made the plate counts unreliable. The microorganism producing these colonies was identified as Bacillus alvei. Colony counts could only be carried out in 27 of the samples when using the plate count method, while with the membrane filter method the number of colonies was counted in all the samples.


1984 ◽  
Vol 47 (3) ◽  
pp. 177-181 ◽  
Author(s):  
T. G. REHBERGER ◽  
L. A. WILSON ◽  
B. A. GLATZ

A study was done to investigate the microbiological quality of commercial tofu available in local retail outlets. A sampling method was first developed to obtain accurate and representative microbial counts of individual pieces of tofu. Plate count determination of total aerobic organisms, psychrotrophs, coliforms, sporeformers, yeasts and molds, and staphylococci were made on 60 tofu samples (representing three lots each of four different brands) obtained within 24 h after delivery to the retail store. In addition, for two brands that provided manufacturer's pull dates, the same microbial counts were obtained for samples stored in the laboratory at 10°C until the pull date. Of the tofu sampled immediately after purchase, 83% of the lots tested had total counts greater than 106 colony-forming units (CFU)/g and psychrotrophic counts greater than 104 CFU/g. In addition, 67% of the lots tested had confirmed coliform counts greater than 103 CFU/g. Very low levels (less than 10 CFU/g) of all other microbial groups tested for were found in the majority of lots. Samples held until the manufacturer's pull date contained higher total and psychrotrophic counts but lower or stable counts of other organisms compared with samples tested immediately after purchase. To improve the microbiological quality of tofu, processors need to reduce initial loads by improving sanitation and processing techniques, and retailers should provide more consistent and colder refrigerated storage.


2011 ◽  
Vol 74 (10) ◽  
pp. 1762-1768 ◽  
Author(s):  
MOUNA BOULARES ◽  
LOBNA MEJRI ◽  
MNASSER HASSOUNA

Eighty samples of fresh fish were collected in Tunisia and analyzed for microbial load. Quality and hygienic safety of the meat and intestines of wild and aquacultured fresh fish were determined. The mesophilic aerobic plate count and populations of psychrotrophic lactic acid bacteria (LAB) and other psychrotrophic bacteria ranged from 5.67 to 7.29, 4.51 to 6, and 5.07 to 6.21 log CFU/g, respectively. For all microbiological determinations, bacterial counts were lower in meat than in the intestines of fresh fish. For all samples lower microbial populations were found in most of the wild fish than in the aquacultured fish. No isolates of the pathogenic genera Salmonella and Listeria were detected in any sample. Among the 160 strains of biopreservative psychrotrophic LAB and the 150 strains of spoilage psychrotrophic gram-negative bacteria identified by biochemical and molecular methods, Lactobacillus (six species) and Pseudomonas (six species) predominated. Lactococcus, Leuconostoc, Carnobacterium (C. piscicola and C. divergens), Aeromonas, and Photobacterium were the most common genera, and Lactococcus lactis, Lactobacillus plantarum, Pseudomonas fluorescens, and Aeromonas hydrophila were the most common species. These findings indicate that the microbiological quality of fresh fish in Tunisia can be preserved by controlling pathogenic and psychrotrophic bacteria.


2008 ◽  
Vol 13 (4) ◽  
pp. 327 ◽  
Author(s):  
M. KOIVULA ◽  
H-R. KYMÄLÄINEN ◽  
L. VANNE

Linseed (Linum usitatissimum L.) and fi bre hemp (Cannabis sativa L.) can be used as raw materials in various applications. In this study, microbiological quality and meteorological measurements were made during the growing seasons and harvesting periods of 2001 and 2002. The microbiological analyses were carried out with Hygicult® TPC and Y&F dipslides, and with a surface spreading method using Plate Count and Potato Dextrose agars. During the growing season of 2001 the conditions were mostly humid, whereas the growing season of 2002 was rather dry and warmer than that of 2001. The lack of water during the growing season of 2002 affected the growth of the plants. In the case of both hemp and fl ax, the mould and bacterial contents (cfu gdw-1) increased markedly at the end of the growing season of 2001. During the growing season of 2002 the increase in mould and bacterial contents was noticeable but more constant throughout the whole growing season. At the end of the growing seasons, the mould and bacteria contents were higher in 2001 than in 2002. The genera of moulds identifi ed included Cladosporium, Fusarium, Penicillium, Mucor and Alternaria. The microbiological safety should be controlled during the whole production chain, beginning with the cultivation and harvesting periods.;


1980 ◽  
Vol 43 (5) ◽  
pp. 385-389 ◽  
Author(s):  
C. JANE WYATT ◽  
V. GUY

A sanitation profile scoring form for evaluating sanitation in retail food stores was designed. The profile was tested in 10 Oregon retail markets to evaluate its ability to reflect sanitary conditions. At the time of inspection, samples of meat processed in-store were purchased for microbiological analysis to explore the feasibility of bacterial quality as a measurement of sanitary conditions. Microbiological tests performed included total aerobic plate count (A PC), coliform, Escherichia coli, Staphylococcus aureus, Clostridium perfringens, and Salmonella. Certain deficiencies were noted in the profile designed; however, it provides a means for objective, uniform measurement of sanitary conditions. Data show no correlation exists between microbiological quality of products processed in the store and total store profile sanitary conditions. Fifty percent of the products sampled exceeded bacterial load guidelines currently enforced in Oregon. These “high” counts appear to be directly related to poor temperature control.


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