Higher Plate Counts Research Articles

Influence Marination Length Using Evaporated Roselle (Hibiscus sabdariffa Linn) Extract on Microbiological Quality of Beef Se'i

Experiment was conducted to determine the influence of marination length using evaporated roselle extract (Hibiscus sabdariffa Linn) on microbiological aspects of beef se’i. The completly randomized design (CRD) with 4 treatments 4 replicates was applied in this experiment. Those treatments were P0 marination length of 12 hours without roselle extract; P1 marination length 6 hours with 5% roselle extract; P2 marination length 12 hours with 5% roselle extract, and P3 marination length 18 hours with 5% roselle extract. The parameters measured were pH, moisture, water activity and total plate count. Data compilled were analyzed using variance analysis and Duncan’s multiple range test. The result of analysis showed that pH and moisture of beef se’i significantly affected by marination length using evaporated roselle extract (P<0.05) but no significant (P>0.05) on water activity and total plate count. It was concluded that beef se’i produced through the marination process with different lengths of time (6, 12 and 18 hours) using evaporated rosela extract, showed characteristics of decreased pH, increased water content with high water activity and total plate count tended to decrease. The best marination length of this study was 12 hours using rosela extract.

Microencapsulation of Bifidobacterium lactis and Lactobacillus plantarum within a Novel Polysaccharide-Based Core-Shell Formulation: Improving Probiotic Viability and Mucoadhesion.

Probiotics health benefits are hampered by long-term storage, gastrointestinal transit, and lack of adequate colonization within the colon. To this end, we have designed a core-shell structure that features an acid resistant core formulation with low water activity composed of alginate, hydroxypropyl methyl cellulose, and gellan gum (AHG) and a mucoadhesive shell made from chemically modified carboxymethyl chitosan with polyethylenimine (PEI-CMC). The structure of the core-shell microparticles was examined using scanning electron microscopy, and rheological measurements confirmed the improved ionic interactions between the core and the shell using the PEI-modified CMC. Simulated release from core-shell microparticles using polystyrene beads showed preferential release under intestinal conditions. PEI-CMC coating yielded improvements in mucoadhesion that was consistent with a positive shift in surface charge of the particles. Ex vivo studies using Bifidobacterium lactis probiotic bacteria demonstrated a 1.1 × 105-fold improvement in bacterial viability with encapsulation under storage conditions of high humidity and temperature (30 °C). When exposed to simulated gastric fluid, encapsulation increased the probiotic viability by 3.0 × 102-fold. In vivo studies utilizing bioluminescent Lactobacillus plantarum in mice revealed that encapsulation extended the duration of the signal within the gut and resulted in higher plate counts in suspensions isolated from the cecum. Conversely, we observed an abrupt loss of signal in the gut of the free probiotic. In conclusion, this core-shell system is suitable for improving probiotic shelf life and maximizing delivery to and retention by the colon.

Total plate count and Salmonella spp. in de-boned milkfish (Chanos chanos) in Palu City, Indonesia

High total plate count (TPC) and the presence of Salmonella spp. in food products can cause health problems for consumers. De-boned milkfish products are popular with consumers in Palu City, Central Sulawesi, Indonesia, but there is a lack of data on their safety. Therefore, this study aimed to investigate TPC levels and detect contamination by Salmonella spp. in these products. Samples of fresh and processed milkfish were collected from two de-boned milkfish processing sites: the Technical Implementation Unit for the Application of Fishery Product Quality Control (TIU-AQFP) and the Melona Micro, Small and Medium Enterprise (MSME) Group in Palu City. Microbiological assays included counting the number of bacterial colonies (TPC) as well as the isolation and identification of Salmonella spp. through biochemical tests. The study applied a completely randomized factorial design with three replicates per site and per product (12 experimental units). De-boning had a significant (P0.05) effect on TPC (1.26×103 to 2.20×103 CFU/g for de-boned milkfish compared to 4.28×103 to 2.94×104 CFU/g for fresh unprocessed milkfish). However, the types of bacteria identified in fresh and de-boned milkfish, including Klebsiella, Enterobacter and Citrobacter, were present at non-pathogenic levels. No Salmonella spp. contamination was found in the test samples. These results indicate that de-boned milkfish products from the TIU-AQFP and Melona MSME Group in Palu City are safe and suitable for human consumption.Keywords:Bone-free milkfishBacterial contaminationPathogen assayFish processingFood safety

Stagnation arising through intermittent usage is associated with increased viable but non culturable Legionella and amoeba hosts in a hospital water system.

Hospital water systems are a significant source of Legionella, resulting in the potentially fatal Legionnaires' disease. One of the biggest challenges for Legionella management within these systems is that under unfavorable conditions Legionella transforms itself into a viable but non culturable (VBNC) state that cannot be detected using the standard methods. This study used a novel method (flow cytometry-cell sorting and qPCR [VFC+qPCR] assay) concurrently with the standard detection methods to examine the effect of temporary water stagnation, on Legionella spp. and microbial communities present in a hospital water system. Water samples were also analyzed for amoebae using culture and Vermamoeba vermiformis and Acanthamoeba specific qPCR. The water temperature, number and duration of water flow events for the hand basins and showers sampled was measured using the Enware Smart Flow® monitoring system. qPCR analysis demonstrated that 21.8% samples were positive for Legionella spp., 21% for L. pneumophila, 40.9% for V. vermiformis and 4.2% for Acanthamoeba. All samples that were Legionella spp. positive using qPCR (22%) were also positive for VBNC Legionella spp.; however, only 2.5% of samples were positive for culturable Legionella spp. 18.1% of the samples were positive for free-living amoebae (FLA) using culture. All samples positive for Legionella spp. were also positive for FLA. Samples with a high heterotrophic plate count (HPC ≥ 5 × 103 CFU/L) were also significantly associated with high concentrations of Legionella spp. DNA, VBNC Legionella spp./L. pneumophila (p < 0.01) and V. vermiformis (p < 0.05). Temporary water stagnation arising through intermittent usage (< 2 hours of usage per month) significantly (p < 0.01) increased the amount of Legionella spp. DNA, VBNC Legionella spp./L. pneumophila, and V. vermiformis; however, it did not significantly impact the HPC load. In contrast to stagnation, no relationship was observed between the microbes and water temperature. In conclusion, Legionella spp. (DNA and VBNC) was associated with V. vermiformis, heterotrophic bacteria, and stagnation occurring through intermittent usage. This is the first study to monitor VBNC Legionella spp. within a hospital water system. The high percentage of false negative Legionella spp. results provided by the culture method supports the use of either qPCR or VFC+qPCR to monitor Legionella spp. contamination within hospital water systems.

Effects of Simulated Gastrointestinal Conditions on Combined Potentially Probiotic Limosilactobacillus fermentum 296, Quercetin, and/or Resveratrol as Bioactive Components of Novel Nutraceuticals.

This study evaluated the effects of simulated gastrointestinal conditions (SGIC) on combined potentially probiotic Limosilactobacillus fermentum 296 (~ 10 log CFU/mL), quercetin (QUE, 160mg), and/or resveratrol (RES, 150mg) as the bioactive components of novel nutraceuticals. Four different nutraceuticals were evaluated during exposure to SGIC and analyzed the plate counts and physiological status of L. fermentum 296, contents and bioaccessibility of QUE and RES, and antioxidant capacity. Nutraceuticals with QUE and RES had the highest plate counts (4.94 ± 0.32 log CFU/mL) and sizes of live cell subpopulations (28.40 ± 0.28%) of L. fermentum 296 after SGIC exposure. An index of injured cells (Gmean index, arbitrary unit defined as above 0.5) indicated that part of L. fermentum 296 cells could be entered the viable but nonculturable state when the nutraceuticals were exposed to gastric and intestinal conditions while maintaining vitality. The nutraceuticals maintained high contents (QUE ~ 29.17 ± 0.62 and RES ~ 23.05mg/100g) and bioaccessibility (QUE ~ 41.0 ± 0.09% and RES ~ 67.4 ± 0.17%) of QUE and RES, as well as high antioxidant capacity (ABTS assay ~ 88.18 ± 1.16% and DPPH assay 75.54 ± 0.65%) during SGIC exposure, which could be linked to the protective effects on L. fermentum 296 cells. The developed nutraceuticals could cross along the gastrointestinal tract with high concentrations of functioning potentially probiotic cells and bioavailable phenolic compounds to exert their beneficial impacts on consumer health, being an innovative strategy for the co-ingestion of these bioactive components.

Preparation of an anion stationary phase modified by quaternary ammoniated allyl glycidyl ether

制备了一种季铵化烯丙基缩水甘油醚(allyl glycidyl ether, AGE)改性聚合物基质的阴离子固定相应用于离子色谱系统。它是利用AGE与水解的聚甲基丙烯酸缩水甘油酯-二乙烯基苯(poly(glycidylmethacrylate-divinylbenzene, GMA-DVB)微球表面残留双键通过表面自由基共聚,再通过N,N-二甲基乙醇胺(一种叔胺)进行开环反应制备得到的。通过考察有机叔胺类型、微球水解、单体和引发剂用量、反应温度和时间对7种阴离子分离性能的影响,优化了制备条件。采用扫描电镜、元素分析对所得阴离子固定相进行了表征。结果表明,采用预先水解的GMA-DVB微球(水解过程中微球表面丰富的环氧基团转化为羟基)相对于直接采用GMA-DVB微球有助于降低固定相的交换容量和微球自身的非离子吸附作用;通过淋洗液浓度和目标离子保留因子的拟合结果证实了该固定相保留机理为典型的离子交换作用。使用碳酸根淋洗液,在优化的色谱条件下,该固定相可在13 min内实现常见7种无机阴离子的基线分离,并表现出较高的柱效(Cl-理论塔板数为49000块/m)。该色谱柱实用性通过分析自来水实际样品进行了验证。

Monolithic columns with incorporated titanium dioxide nanoparticles for hydrophilic interaction liquid chromatography

This research article presents the preparation and characterisation of monolithic columns with incorporated titanium dioxide nanoparticles (TDNPs) and their subsequent use in hydrophilic interaction liquid chromatography (HILIC) of small relatively polar solutes. The monolithic support was based on the in situ polymerisation of glyceryl monomethacrylate (GMM) and ethylene glycol dimethacrylate (EDMA) yielding the poly(GMM-co-EDMA) monolith for the incorporation of TDNPs. The poly(GMM-co-EDMA) functioned as a ‘true support’ for TDNPs’ ‘stationary phases’ as manifested by TDNPs being the major contributor to solute retention, column selectivity and separation efficiencies. In other words, monolithic columns with ‘TDNPs stationary phases’ were achieved with the understanding that the contribution of the monolith proper to the solute© retention was at its minimum. The TDNPs were subjected to probe tip high-power sonication at an output power of 10 W for 20 minutes with the aim of better dispersing the incorporated TDNPs into the monoliths under investigation. In fact, high-power sonication yielded columns with a relatively higher plate count (~3-fold increase) when compared to low-power sonication. Overall, the prepared TDNPs stationary phases proved useful in HILIC of small polar solutes including dimethyl formamide, formamide, thiourea, nucleobases and nucleosides.

A weak cation exchanger by encapsulating silica with maleic anhydride-modified polyvinyl alcohol.

A novel weak cation exchanger is described by encapsulating silica with a (or multiple) layer(s) of maleic anhydride-modified polyvinyl alcohol coating(s). The preparation method is facile and fast, which is simply performed by dipping silica particles into maleic anhydride-modified polyvinyl alcohol solution as-synthesized, then filtering and curing thermally, and finally generating a thin coating onto silica particles. Multiple layers of maleic anhydride-modified polyvinyl alcohol coatings can be generated by repeating above steps, offering an easy way to manipulate the capacity. The obtained weak cation exchanger demonstrated high separation efficiency and good selectivity toward common inorganic cations, for example, high plate count of 81000 per meter was obtained for NH4 + . Simultaneous separation of alkali and alkaline earth metals could be achieved within 14 min under isocratic conditions.

Microbiological profile of fresh goat milk: Impact of goat farmer practices in “Taruna Mukti” goat farmer group, Sragen, Central Java

Goat milk is susceptible to be contaminated by many microorganisms including microbial pathogens responsible for causing diseases. Various contaminations come from every stage of goat milk produce including feeding, milking, and milk treatments. The aim of this study was to assess the practice of dairy goat farmer and evaluate the microbiological profile of raw goat milk in dairy goat farmer group. The study showed that row milk had high total plate count (7, 8x106 CFU/ml). Thus, Coliform and E. coli were detected in the samples of fresh goat milk. Overall, it can be seen that fresh goat milk was relatively poor hygienic quality and was not conformed to the Indonesian Nasional Standard.

Influence of connection tubing in modern size exclusion chromatography and its impact on the characterization of mAbs

The goal of the study was to evaluate the impact of connection tubing in modern size exclusion chromatography (SEC), since it may strongly impact the apparent column efficiency, as the compounds are not retained in SEC. For this purpose, a reference SEC column of 150×4.6mm, 1.8μm was considered, and various proteins were tested as model compounds. Different tube geometries (lengths and internal diameters) and materials (stainless steel and PEEK) were evaluated in a systematic way. Large proteins always showed larger tube dispersion vs. small molecules, especially when the residence time in the tube was long (at low flow rate). This confirms the need to drastically reduce the tube volume (using the shortest and narrowest connector tubing) to attain the full benefits of UHPSEC columns. In addition, PEEK tubing were found to be more appropriate than stainless steel tubing, since adsorption of proteins was less pronounced, and higher plate count can be obtained. Finally, after a careful system optimization, up to 40% increase of apparent column efficiency can be achieved compared to a regular UHPLC system, when using a 150×4.6mm UHPSEC columns packed with sub–3μm particles.

Microbiological, chemical and sensory spoilage analysis of raw Atlantic cod (Gadus morhua) stored under modified atmospheres

During fish spoilage, microbial metabolism leads to the production of volatile organic compounds (VOCs), characteristic off-odors and eventual consumer rejection. The aim of the present study was to contribute to the development of intelligent packaging technologies by identifying and quantifying VOCs that indicate spoilage of raw Atlantic cod (Gadus morhua) under atmospheres (%v/v CO2/O2/N2) 60/40/0, 60/5/35 and air. Spoilage was examined by microbiological, chemical and sensory analyses over storage time at 4 or 8 °C. Selected-ion flow-tube mass spectrometry (SIFT-MS) was used for quantifying selected VOCs and amplicon sequencing of the 16S rRNA gene was used for the characterization of the cod microbiota. OTUs classified within the Photobacterium genus increased in relative abundance over time under all storage conditions, suggesting that Photobacterium contributed to spoilage and VOC production. The onset of exponential VOC concentration increase and sensory rejection occurred at high total plate counts (7–7.5 log). Monitoring of early spoilage thus calls for sensitivity for low VOC concentrations.

Effects of different coagulants on the physico-chemical, microbial and sensory properties of Wara, a Nigerian soft soy-cheese

Nigerian soft cheese often referred to as wara was produced from soya bean milk using coagulants from lime, alum and steep water. Effects of these coagulants on the yield, proximate composition, functional properties, microbial loads and sensory properties were evaluated. The result revealed that different coagulants used had no significant (p ≥ 0.05) effect on yield of the cheeses. The result for the proximate composition shows that, different coagulants used influenced all the proximate parameters except the protein content. Similarly, coagulants used significantly affected the water absorption capacity, oil absorption capacity, foam capacity and gelation capacity. However, the bulk density was not significantly (p ≥ 0.05) affected. Steep water coagulated cheese had the highest total plate count. The result for sensory properties shows that, lime gave the best cheese in terms of general acceptability. Cheese produced from steep water as a coagulant gave the best proximate attributes, however, its high total plate count calls for concern.Key words: local cheese, proximate, microbial, sensory and functional

Surveillance of Vittaforma corneae in hot springs by a small-volume procedure

Vittaforma corneae is an obligate intracellular fungus and can cause human ocular microsporidiosis. Although accumulating reports of V. corneae causing keratoconjunctivitis in both healthy and immunocompromised persons have been published, little is known about the organism's occurrence in aquatic environments. Limitations in detection sensitivity have meant a large sampling volume is required to detect the pathogen up to now, which is problematic. A recent study in Taiwan has shown that some individuals suffering from microsporidial keratitis (MK) were infected after exposure to the pathogen at a hot spring. As a consequence of this, a survey and analysis of environmental V. corneae present in hot springs became an urgent need. In this study, sixty water samples from six hot spring recreation areas around Taiwan were analyzed. One liter of water from each sample site was filtered to harvest the fungi. The positive samples were detected using a modified nested PCR approach followed by sequencing using specific SSU rRNA gene primer pairs for V. corneae. In total fifteen V. corneae-like isolates were identified (25.0% of sites). Among them, six isolates, which were collected from recreational areas B, C and D, were highly similar to known V. corneae keratitis strains from Taiwan and other countries. Furthermore, five isolates, which were collected from recreation areas A, C, E and F, were very similar to Vittaforma-like diarrhea strains isolated in Portugal. Cold spring water tubs and public foot bath pools had the highest detection rate (50%), suggesting that hot springs might be contaminated via untreated water sources. Comparing the detection rate across different regions of Taiwan, Taitung, which is in the east of the island, gave the highest positive rate (37.5%). Statistical analysis showed that outdoor/soil exposure and a high heterotrophic plate count (HPC) were risk factors for the occurrence of V. corneae. Our findings provide empirical evidence supporting the need for proper control and regulations at hot spring recreational waters in order to avoid health risks from this pathogen. Finally, we have developed a small volume procedure for detecting V. corneae in water samples and this has proved to be very useful.

Qualidade do leite cru ovino armazenado sob refrigeração

The dairy sheep industry is recent in Brazil and the production is concentrated in mountainous regions, such as Serra Gaucha. Ovine milk has a higher solids content compared to bovine milk, thus with higher yield in cheese production. Sheep milk production undergoes seasonal variations and it could be stored until a sufficient quantity is available for processing. The objective of this study was to evaluate microbiological and physicochemical parameters in ovine milk from six different producers under refrigerated storage. Milk was analyzed during seven days, including standard plate count, psychrotrophic bacteria, total and fecal coliforms, Staphylococcus sp. and S. aureus, titratable acidity, pH, water activity, and protein content. The results showed high microbial counts and standard plate counts above those established by legislation for most samples. Psychrotrophic, total and fecal coliforms counts were increased during this period. Titratable acidity increased over the days, while protein content decreased. Samples of milk producer B presented the lowest microbial counts among all tested. Cold storage becomes a short-term alternative when there is a decrease in sheep milk production for dairy processing. Storage period of refrigerated milk must not exceed two days due to deterioration.

Phospholipid bilayer affinities and solvation characteristics by electrokinetic chromatography with a nanodisc pseudostationary phase.

Phospholipid bilayer nanodiscs composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine and synthetic maleic acid-styrene copolymer belts have been introduced as a pseudostationary phase (PSP) in electrokinetic chromatography and demonstrated good performance. The nanodiscs provide a suitable migration range and high theoretical plate counts. Using this nanodisc pseudostationary phase, the affinity of the bilayer structure for probe solutes was determined and characterized. Good correlation is observed between retention factors and octanol water partition coefficients for particular categories of solutes, but the general correlation is weak primarily because the nanodiscs show stronger affinity than octanol for hydrogen bond donors. This suggests that a more appropriate application of this technology is to measure and characterize interactions between solutes and lipid bilayers directly. Linear solvation energy relationship analysis of the nanodisc-solute interactions in this study demonstrates that the nanodiscs provide a solvation environment with low cohesivity and weak hydrogen bond donating ability, and provide relatively strong hydrogen bond acceptor strength.

Viscoelastic behavior and physico-chemical characteristics of heated swai-fish (Pangasius hypophthalmus) based emulsion containing fermented soybeans

Various proportions of fermented soybeans i.e. thua nao and rice-koji miso were added into the swai-fish emulsion to improve the health potential of the products. Accordingly, the physico-chemical, microbiological properties and sensory attributes of the fish-based emulsions as well as the main ingredients were determined. The results showed that fatty acid profile of the swai-fish fillet consisted mainly of saturated and monounsaturated fatty acids, while isoflavone profiles of the fermented soybeans illustrated that thua nao contained more aglycones than rice-koji miso. For physical properties, the profiles of storage and loss moduli, creep parameters and gel strength depicted that samples added thua nao gave rise to stronger gel structure than those added rice-koji miso or the whole fish emulsion. Microbiological examination indicated that the fish emulsion with thua nao addition showed high total plate or spore counts.

Correlation between Milk Yield, Somatic Cell Count and Milk Quality in Dairy Farming

This study investigated between milk yield and Somatic Cell Count, sampled from 3 different dairy enterprises. Chemical and microbiological parameters analyzed for the relation with milk yield. Milk samples have been collected from 10 dairy cows, two times per month during 1 year period. Bacteriological analyzes have been employed for milks. Milk yield data for each cow have been recorded in every sampling day. Depending on the logistic regretion analyses on the data collected from all enterprises; high total plate count and E.coli counts have negative effects on milk yield, but has been found significally important (p<0.05) only for the data of E.coli. counts. In group 1; somatic cell count and E.coli counts have negative effect on milk yield and only the data of E.coli has been found statistically important (p<0.05). In group 2; only the data related negative effect of E.coli counts on milk yield has been found as statistically important (p<0.05). The third group, total plate count has negative effect on milk yield. Regarding to the chemical analyses of fat in milk, non-fat dry matter, density and protein values have been detected in the enterprises 1, 2 and 3 as 2.88, 3.56, 4.34; 7.91, 7.83, 8.12; 1026.4, 1025.8, 1026; 3.04, 2.96, 3.07, respectively. According to the correlation analyses applied between milk yield and fat in milk, non fat-dry matter, protein and density in milk in all enterprises; there were significant correlation between non-fat dry matter and milk yield in enterprise 2 (p<0.05) and density and milk yield in enterprise 3 (p<0.01).

Necessity and Effect of Combating Legionella pneumophila in Municipal Shower Systems

The objective was to obtain research-based, holistic knowledge about necessity and effect of practiced measures against L. pneumophila in municipal shower systems in Stavanger, Norway. The effects of hot water treatment and membrane-filtering were investigated and compared to no intervention at all. The studies were done under real-world conditions. Additionally, a surveillance pilot study of municipal showers in Stavanger was performed. The validity of high total plate count (TPC) as an indication of L. pneumophila was evaluated. A simplified method, named “dripping method”, for detection and quantification of L. pneumophila was developed. The sensitivity of the dripping method is 5 colony-forming units of L. pneumophila/ml. The transference of L. pneumophila from shower water to aerosols was studied. Interviews and observational studies among the stakeholders were done in order to identify patterns of communication and behavior in a Legionella risk perspective. No substantial effects of the measures against L. pneumophila were demonstrated, except for a distally placed membrane filter. No significant positive correlation between TPC and L. pneumophila concentrations were found. L. pneumophila serogroup 2–14 was demonstrated in 21% of the 29 buildings tested in the surveillance pilot. Relatively few cells of L. pneumophila were transferred from shower water to aerosols. Anxiety appeared as the major driving force in the risk governance of Legionella. In conclusion, the risk of acquiring Legionnaires' disease from municipal shower systems is evaluated as low and uncertain. By eliminating ineffective approaches, targeted Legionella risk governance can be practiced. Risk management by surveillance is evaluated as appropriate.

Risk factors associated with bulk tank standard plate count, bulk tank coliform count, and the presence of Staphylococcus aureus on organic and conventional dairy farms in the United States

The purpose of this study was to assess the association of bulk tank milk standard plate counts, bulk tank coliform counts (CC), and the presence of Staphylococcus aureus in bulk tank milk with various management and farm characteristics on organic and conventional dairy farms throughout New York, Wisconsin, and Oregon. Data from size-matched organic farms (n=192), conventional nongrazing farms (n=64), and conventional grazing farms (n=36) were collected at a single visit for each farm. Of the 292 farms visited, 290 bulk tank milk samples were collected. Statistical models were created using data from all herds in the study, as well as exclusively for the organic subset of herds. Because of incomplete data, 267 of 290 herds were analyzed for total herd modeling, and 173 of 190 organic herds were analyzed for the organic herd modeling. Overall, more bulk tanks from organic farms had Staph. aureus cultured from them (62% of organic herds, 42% conventional nongrazing herds, and 43% of conventional grazing herds), whereas fewer organic herds had a high CC, defined as ≥50cfu/mL, than conventional farms in the study. A high standard plate count (×1,000cfu/mL) was associated with decreased body condition score of adult cows and decreased milk production in both models. Several variables were significant only in the model created using all herds or only in organic herds. The presence of Staph. aureus in the bulk tank milk was associated with fewer people treating mastitis, increased age of housing, and a higher percentage of cows with 3 or fewer teats in both the organic and total herd models. The Staph. aureus total herd model also showed a relationship with fewer first-lactation animals, higher hock scores, and less use of automatic takeoffs at milking. High bulk tank CC was related to feeding a total mixed ration and using natural service in nonlactating heifers in both models. Overall, attentive management and use of outside resources were useful with regard to CC on organic farms. In all models except the organic CC model, we observed an association with the average reported somatic cell count from 3 mo before the herd visit, indicating that many of the regularly tested milk quality parameters are interconnected. In conclusion, we found that conventional and organic farms are similar in regard to overall herd management, but each grazing system faces unique challenges when managing milk quality.

RP-HPLC method for simultaneous determination of atenolol and indapamide in pharmaceutical dosage forms, human blood and milk

A simple, sensitive and precise high performance liquid chromatographic method for the analysis of atenolol and indapamide with UV detection at 231 nm, has been developed, validated and used for the determination of these compounds in pharmaceutical dosage forms, in human blood and in human milk. The compounds were well separated on a Hypersil BDS C 18 reversed-phase column with mobile phase consisting of, pH = 3.5, 0.01 M potassium dihydrogen orthophosphate buffer-acetonitrile (60:40; v:v) at a flow rate of 1.0 mL/min. The method showed good linearity in the range of 5-30 µg/mL for atenolol and 0.25-1.50 µg/mL for indapamide. Both the drugs were eluted within 5 minutes and give sharp peak with high theoretical plate count and low tailing factor. The reaction time for atenolol and indapamide was found to be 2.29 and 3.83 min, respectively. The validation was carried according to International Conference on Harmonisation (ICH) guidelines. In linearity curve correlation coefficients for atenolol and indapamide were found to be 0.9995 and 0.9991, respectively. The percent recovery was 99.81-100.02 for atenolol and indapamide indicating accuracy and reliability of method. So the method can be used for estimation of these drugs in tablet dosage form, human blood and milk.