Microbiological Quality Analysis Research Articles

Comparison of Microbiological and Physicochemical Quality of Tap and Dispenser Water from Different Mid-Range Restaurants of Dhaka City, Bangladesh

Dhaka is the most populous city in Bangladesh and the tenth-largest metropolitan in the world with about twelve million inhabitants. Most people of Dhaka have low or middle ranged incomes and frequently use roadside mid range restaurants to take their meals and drinking water. Water quality is a significant health concern in Bangladesh and is a probable source of many water borne diseases and outbreaks. Tap water and dispenser water samples were collected from ten roadside restaurants. These samples were analyzed for pH, salinity, conductivity, TDS (total dissolved solid) for physicochemical quality analysis while total coliform, faecal coliform and total heterotrophic bacterial counts were determined for microbiological quality analysis. All the samples conformed to the WHO standards of TDS, salinity and conductivity. Except for 20% of the tap water samples, pH of all the samples was found to be satisfactory. The heterotrophic plate count was in a range of 8.0 x 101 cfu/ml to 9.3 x 105 cfu/ml from tap water sample and 6.5 x 101 cfu/ml to TNTC from dispenser water samples. Only 10% of the tap water samples and 30% of the dispenser water samples complied with the WHO stipulated limit of total heterotrophic count (100 cfu/ml). In terms of total coliforms, all the tap water samples and 20% of the dispenser water samples were found to be contaminated, whereas 50% of both the tap water and dispenser water samples were contaminated with faecal coliforms, indicating possible faecal contamination and presence of pathogenic bacteria. By comparing coliform/faecal coliform count on tap and dispenser water it was found that dispenser water is safer than tap water.Bangladesh J Microbiol, Volume 31, Number 1-2,June-Dec 2014, pp 69-72

Microbiological quality analysis of raw, pasteurized, UHT milk samples collected from different locations in Bangladesh

Present study attempted to determine the microbiological quality of raw, pasteurized and UHT (Ultra High Temperature-processed) milk samples collected from different locations in Bangladesh. A total of 46 samples were studied including 22 raw milk samples from the local dairy markets and 24 different brands of pasteurized and ultrahigh temperature (UHT) treated milk manufactured in different beverage industries. The samples were examined for determining the total viable bacterial count (TVBC) and total coliform count (TCC). Results revealed that the raw milk samples were substandard in terms of TVBC and TCC. The range of TVBC and TCC in raw milk samples was 5.2×108 to 1.3×107 cfu/ml and 4.2×104 to 1.0×104 cfu/ml, respectively. On the contrary, the quality of pasteurized and UHT-treated milks was excellent. The TVBC range in pasteurized milk samples was from 1.8×103 to 1.1×102 cfu/ml, slightly lower than that recommended by the Bangladesh Standards and Testing Institution (BSTI). Interestingly sample numbers P-6, P-10 and P-12 of pasteurized milk samples had no growth at all both in terms of TVBC and TCC and none of the UHT processed milk contained any bacteria. So from the consumer point of view, both types of processed milk can be considered safe for consumption within the mentioned expiry date. DOI: http://dx.doi.org/10.3329/sjm.v4i1.22753 Stamford Journal of Microbiology, Vol.4(1) 2014: 5-8

Quantitative Analysis of Fish Microbiological Quality Using Electronic Tongue Coupled with Nonlinear Pattern Recognition Algorithms

AbstractThe objective of this study was to establish quantitative evaluation models for fish microbiological quality analysis based on electronic tongue technique coupled with nonlinear pattern recognition algorithms. Crucian carp stored at 4C were used. A commercial electronic tongue system was employed. The total viable counts (TVCs) of fish samples were measured by the classical microbiological plating method. Partial least square regression, support vector regression (SVR) and back propagation neural network (BP‐NN) were applied comparatively to predict TVC values. The multivariate regression models were evaluated by the root mean square error of prediction (RMSEP) and the correlation coefficient in prediction set (Rpre). Results revealed that the performance of BP‐NN model was superior to that of PLS model and SVR model. The RMSEP and Rpre of the BP‐NN model for TVC prediction were 0.211 ln colony‐forming unit (cfu)/g and 0.993, respectively. This study showed that electronic tongue together with BP‐NN model could be a reliable technique for the detection of fish microbiological quality.Practical ApplicationsFish is a highly perishable commodity after harvesting and postmortem as a consequence of microbial breakdown mechanisms. Total viable count (TVC) method is the most widely used microbiological indicator for the evaluation of fish microbiological quality. However, the conventional analytical methods for the determination of TVC are cumbersome and time wasting. This work provides a practical and efficient way for rapid, accurate and convenient determination of TVC in fish using electronic tongue combined with regression algorithms to address these limitations.

Microbiological Control of UHT Sterilized Milk and Milk Products and Effects on Consumers' Health in Western Algeria

The present study focused on the analysis of microbiological quality of various milk samples such as ultra-high temperature sterilized milk (UHT), melted cheese and yoghurt, obtained from dairy product factories in western Algeria. Hazards identification and development of a quality management standard for these subsidiaries evidenced that the sanitary quality was satisfactory. The result revealed detection of faecal origin contamination ‘total and fecal coliforms’ in both the yoghurt product and sample of melted cheese where the average content was(1.29±6.72-0.14±0.56 x 103cfu/g) and (0.14±0.6-0.022±0.275 x 103cfu/g) respectively. It is indicative that all samples were free from Staphylococcus aureus and Salmonella sp. The study demonstrated that prerequisite programs (PRP) will prevent the occurrence of microbiological hazards origin, which confirms the fact that hygiene measures are the best safety assurance. The hazard analysis of the production process of yoghurt and cheese allowed us to find out their causes, adoption of preventive measures for certain sensitive stages where hazards can be eliminated or reduced at acceptable levels, the determination of critical control points (CCP)and operational prerequisite programs ‘PRPo’, implementing critical limits, and monitoring plans. DOI: http://dx.doi.org/10.3329/mh.v3i1.19777 Microbes and Health, June 2014. 3(1): 21-24