Treated Cow Milk Quality Analysis in High-Temperature Short Time (HTST) Thermal Treatment using F-Value and Methylene Blue Reduction Test (MBRT)

This study was conducted to evaluate raw and pasteurized cow milk regarding physical properties, microbiological quality, and lethality value ofMycobacterium Paratuberculosis(MAP)at different temperature and time combinations of the pasteurization process.Cow milk samples were pasteurized at high-temperature (70°C, 75°C, and 81°C) and short-time (15s and 25s) high temperature and short time (HTST) combinations. Raw and pasteurized (HTST) cow milk was analyzed, while commercial cow milk that undergo proses (HTST) was used as control. High-temperature short time (HTST) pasteurization showed a significant effect on the colour of raw and pasteurized cow milk (p<0.05) at every temperature. In addition, cow milk also indicated an increase in lightness and yellowness after HTST pasteurization.The microbiological quality of raw, pasteurized, and commercial cow milk is evaluated using the Methylene Blue Reduction (MBRT) test, a common, rapid, simple, and inexpensive method for microbiological quality evaluation.The MBRT on raw milk samples revealed that it was of poor quality. On the other hand, all pasteurized samples were good quality, and the commercial sample was excellent.Based on the evaluated F-values, the most suitable temperature and time combinationsin this study was 70°C and 25s.

Express-Method for Determination of the Oxidizing Capacity of Activated Sludge and Its Biofilms in Pulp and Paper Mill

Microbial dehydrogenase activity can help to determine the oxidizing capacity of activated sludge. Here we propose an innovative and automated express-method based on rapid determination of dehydrogenase activity. The measurement is based on the rate of methylene blue reduction by living microbial cells in suspension. A single analysis takes 10 min. The method was adapted for biofilms immobilized on the floating carriers of industrial bioreactors and the kinetics of biological oxidation by activated sludge and biofilms was compared. New parameters were proposed to characterize the biological oxidation under low oxygen levels. The obtained make it possible to quickly determine the dehydrogenase activity of activated sludge and biofilms and promptly monitor the effectiveness of industrial biological wastewater treatment.

COMPOSITION AND QUALITY OF FRESH COW MILK OFFERED FOR SALE IN PARTS OF PLATEAU STATE OF NIGERIA.

The gross composition and quality of fresh cow milk purchased from Fulani milk vendors in three locations of Plateau State were investigated. Milk quality was assessed by the methylene blue reduction test while bacterial contamination was by the agar plate count and the direct microscopic count. The mean contents of total solids, butterfat, protein and ash of a total of 100 samples from Barkin Ladi, Jos and Bukuru markets were 12.45, 4.77, 3.90, 0.92; 12.85, 4.50, 3.68, 0.93; and 12.41, 5.26, 3.72, 0.91% respectively. The proximate constituents did not differ significantly between locations. The methylene blue test indicated that only 23.5% of the sample were of good quality while 41.2 and 35.3% were rated fair and poor respectively. No sample merited excellent rating. The agar plate count showed a range of 1.97 x 106 for Bukuru to 2.54 x 106 cells/ml for Jos market. The direct microscopic count showed the highest mean bacteria value for Barkin Ladi samples. The high bacterial counts as observed were probably indicative of poor milking hygiene and handling. It is suggested that such milk should be properly pasteurized before consumption and delivered/marketed early at source to reduce the time for microbial multiplication.

Computer vision based Comparative Studies on the Physicochemical Analysis and Bacterial Biota in Different Milk Samples

Milk is a complete food with high nutritional value. Milk is an important culture medium for the growth and reproduction of microorganisms. This study focuses on the samples collected from the different milk distribution areas in MaduranthagamTaluk, South India. Fifty pasteurized milk samples of ten different brands were collected and physicochemical, microbiological analysis were carried out in both raw milk and pasteurized milk samples. The milk samples were subjected to physicochemical analysis such as Fat content, Clearance, Lactometric Reading, Clot on Boiling Test, Solid Non Fat and Acidity were calculated. The milk sample were also subjected to the chemical analysis for the Nitrogen content, crude protein content, Lactose content, ash content were also calculated Methylene blue reduction test has been used to test quality of the milk samples. These findings may be helpful to monitor the quality of the milk products in the market. It can provide an interest in examine the organic and inorganic content in milk. It is reported that all samples added with urea and few samples have sulphate. Raw milk showed inferior quality, processed milk have Low load of bacterial population.

The extended methylene blue reduction test and milk quality

Introduction. This study aimed to evaluate the quality of milk produced by six cattlemen’s associations in small, isolated farming communities of Carchi, Ecuador. It involved a herd of 814 cows and lasted eight consecutive months. Another aim was to propose a suitable methodology for milk quality evaluation. Study objects and methods. All milk samples were analyzed for total solids, protein, fat, acidity, density, total bacterial count (TBC) and somatic cell count (SCC). Each sample was subjected to an extended qualitative methylene blue reduction test (MBRTe) for which 10 mL of milk, with 0.5 mL of methylene blue, was incubated at 37°C for 24 h. Results and discussion. As a result, we obtained the following types of clots: MBRTe-I (homogeneous solid/liquid clot), MBRTe-II (lumpy clot), MBRTe-III (gaseous clot) and MBRTe-IV (lumpy + gaseous clot). The study showed significant differences in the quality of milk between different associations, suggesting that some of them did not comply with good practices of milking, handling and storage of fresh milk. The quality of milk was classified as good in one association, as regular in another association, and as low in four associations. The MBRTe classified 37% of the samples as MBRTe-I, 18% as MBRTe-II, 14% as MBRTe-III and 12% as MBRTe-IV. Of the MBRTe-I samples, 95% showed the TBC and SCC values of first quality milk. The MBRTe-II had the TBC values of first quality milk, but exceeded the SCC, while the MBRTe-III had good SCC values, but exceeded the TBC. Finally, the MBRTe-IV samples exceeded the permissible levels of both TBC and SCC. Conclusion. It was proved that the MBRTe can help milk producers evaluate the quality of milk and alert them to the possible presence of mastitis in the herd. The MBRTe is a reliable and cheap method that is quick and easy to perform.

Prevalence of latent acidotic stress in dairy cows in the Şanliurfa region

This study aimed to determine the incidence of latent acidotic stress (LAS), which is an important problem in dairy cow breeding in Turkey, to investigate net acid-base excretion in urine, and to provide veterinary doctors with information about the early diagnosis and treatment of LAS. Two study groups were formed according to the rumen fluid pH values: LAS group (19 cows) with 5.2 < pH < 6.0 (19 cows) and healthy group (81 cows) with 6.0 < pH < 7.2. Blood, urine and ruminal fluid samples were taken after a general clinical examination of the animals. The physical properties of the rumen fluid, methylene blue reduction time, total infusoria number, and volatile fatty acid (VFA) amounts were determined. In addition, examinations of blood gases, urine pH, and net acid-base excretion (NABE) were performed. The general physical examination did not reaveal any statistically significant difference in the body temperature between the LAS group (n = 19) and the control group (n = 81) (p = 0.614), but a significant increase in the heartbeat, respiratory frequency, and the number of rumen movements was observed in the LAS group (p = 0.001). The following findings were observed in the rumen fluid from cows of the LAS group: decreased methylene blue reduction time (p = 0.001), decreased pH (p = 0.001) and infusoria density (p = 0.001), increased sedimentation time (p = 0.001) and total VFA amount (p = 0.001), no flotation. Compared with the healthy cows, the LAS group showed decreased blood pH (p = 0.001) and oxygen pressure (pO2) (p = 0.001), increased carbon dioxide pressure (pCO2), base excess (BE) and bicarbonate (HCO3) values (p = 0.001), and decreased urine pH (p = 0.001) and net acid-base excretion (p = 0.001) values. The incidence of latent acidotic stress in dairy cows in the Sanliurfa region was determined as 19%. In addition, it was concluded that net acid-base excretion values in urine can be used as an auxiliary parameter in the diagnosis of LAS and can be easily applied in the field.

Selective synthesis of visible light active γ-bismuth molybdate nanoparticles for efficient photocatalytic degradation of methylene blue, reduction of 4-nitrophenol, and antimicrobial activity

In this study, we have reported selective synthesis of γ-Bi2M2O6 NPs under different pH conditions for photocatalytic degradation of methylene blue (MB), reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) and antimicrobial activities.