Combination Of Sodium Dodecyl Sulfate Research Articles

Study on an all-in-one foaming agent with corrosion inhibition for air foam flooding

Abstract Foam has been widely used in drilling, well washing, and oil driving during the development of oil and gas fields. Although air foams have been successfully employed as an enhanced oil medium, the oxygen they contain can seriously corrode piping systems, which can have a negative influence on output. This work used a combination of sodium dodecyl sulfate (SDS), dodecyl aminopropyl betaine (LAB), sodium dodecylbenzene sulfonate (SDBS), and cosurfactants to solve the problem above. The corrosion inhibitor hydrazine hydrate (N₂H₄·H₂O) was added as corrosion inhibitor. The foaming (air)-corrosion inhibitor all-in-one (SLN) was obtained with the formulation of SDS: LAB: N₂H₄·H₂O = 8:2:4. The foam volume of 0.7 % SLN was measured to be 515 mL at room temperature with a half-life of 4.1 min using the stirring method. The initial foam height of this all-in-one agent was measured to be 15.6 cm at 30 °C using the Roche foaming method. The foam height was still maintained at 15.5 cm after 20 min with a foam height retention of 99.2 %. The foam height retention rate was 50.0 % at 70 °C. Moreover, the formulation had good salt resistance to common inorganic salts in oilfield water. It should be emphasized that the SLN all-in-one agent has strong corrosion inhibition performance, and the corrosion inhibition rate can reach up to 96.9 %. The surface tension of this SLN all-in-one agent was reduced to 27.8 mN m−1 at a concentration of 0.1 %. It indicated that the all-in-one agent might increase the stability of the foam by decreasing the surface tension, thus improving the persistence of the foam and the effect of the repelling oil.

Investigating the surfactant antagonism with the Open Source Reconstructed Epidermis (OS-Rep) model

Under the current EU chemicals legislation, in vitro test methods became the preferred methods to identify and classify the skin irritation potential of chemicals and mixtures. Among these, especially in vitro skin models are widely used. For surfactants, a well-known group of typically irritating chemicals, it is a long-standing experience that the irritation potential of a mixture of surfactants is typically lower than the irritation potential of the single surfactants, an effect usually described as surfactant antagonism. In order to evaluate if this effect can be observed in skin model systems as well, the irritation potential of the surfactants and of their mixtures was determined in the Open Source Reconstructed Epidermis (OS-REp) models. Combinations of sodium dodecyl sulfate or linear alkylbenzene sulfonate with cocoamidopropyl betain and alkyl polyglycosid, respectively, resulted in a clear decrease of the irritation potential compared to the irritation exerted by the single surfactants. The effect appeared to be primarily driven by the mixture's lower ability to damage the skin model's barrier, as shown by a reduced fluorescein permeation.

Recellularization of Acellular Xeno Kidney Scaffold: An In Vivo Method to Generate Bioartificial Kidney.

A significant hurdle for kidney tissue engineering is reproducing the complex three-dimensional structure of the kidney. In our study, a stepwise approach of generating a reproducible Xeno kidney scaffold from a goat kidney is described, which can be implanted and recellularized by host cells. We have proposed a combination of sodium dodecyl sulfate and Triton-X-100-based protocol to generate a reproducible Xeno kidney scaffold, which was then analyzed by histology, DNA quantification, SEM, and renal angiography. Further, a small portion from the cortico-medullar region of the acellular scaffold was implanted in the rat's kidney subcapsular pocket for a period of 1 month, to check the recruitment of host cells into the scaffold. Post implantation, the extracellular matrix of the scaffold was well preserved and it did not induce any damage or inflammation in the native kidney. Implantation of the Xeno scaffold resulted in apparent early vascularization which helped in the recruitment of the host cells, which was characterized by histology, immunohistochemistry, and scanning electron microscopy. Implanted Xeno scaffold showed AQP-1, Nephrin, α-SMA, and VEGF expression in proximal tubules and renal glomerulus. Importantly, Ki-67 and WTAP-expressing cells were also observed near proximal tubules suggesting a high level of proliferation in the scaffold. Thus, showing the potential of Xeno kidney development that can be recellularized by the host cell to engineer into a functional kidney.

Decontamination of Salmonella Typhimurium and Listeria monocytogenes on Food-Related Surfaces by a Combination of Sodium Dodecyl Sulfate, Lactic Acid, or Citric Acid Under Different Temperatures

Background: Salmonella Typhimurium and Listeria monocytogenes are among the most important foodborne pathogens, and new methods to remove them from surfaces are useful. The aim of this study was to investigate the bactericidal effect of a combination of sodium dodecyl sulfate (SDS) and some food matrix-related factors such as temperature, salinity, acidity, and exposure time on L. monocytogenes and S. Typhimurium in suspension and on different food industry related surfaces. Methods: The bacterial strains were treated with different concentrations of SDS, citric acid, lactic acid, and NaCl at different temperatures at various times. At least one concentration was selected that caused one or less log reduction in the viability of each bacterium, and the combination treatments were examined in this regard. The best combination was then selected, and its bactericidal effect on the bacteria tested was evaluated on ceramic, stainless steel, and plastic surfaces. Results: The results showed that the sensitivity of the bacteria studied to different disinfectants was different. L. monocytogenes was highly sensitive to SDS, while S. Typhimurium was relatively resistant to SDS. Both bacteria were more sensitive to lactic acid than to citric acid, and the bactericidal effects of the disinfectants were enhanced in the combined treatments at 45º C compared to 35º C treatments. The addition of NaCl to the SDS solution resulted in a strong reduction in the bactericidal effect of SDS. The selected disinfectant removed bacterial biofilms from stainless steel surfaces in a shorter time than ceramic and plastic surfaces. Conclusion: The preparation of combined solutions using SDS and an organic acid at an appropriate concentration and temperature could be useful for removing or reducing bacterial biofilms. Therefore, the combination of SDS and the lactic acid at 45° C can effectively remove pathogenic bacteria from various surfaces.

Cardiac-derived extracellular matrix: A decellularization protocol for heart regeneration.

Extracellular matrix (ECM) is a fundamental component of the heart, guiding vital cellular processes during organ homeostasis. Most cardiovascular diseases lead to a remarkable remodeling of the ECM, accompanied by the formation of a fibrotic tissue that heavily compromises the heart function. Effective therapies for managing fibrosis and promoting physiological ECM repair are not yet available. The production of a decellularized extracellular matrix (d-ECM) serving as a three-dimensional and bioactive scaffold able to modulate cellular behavior and activities is considered crucial to achieve a successful regeneration. The protocol represents a step-by-step method to obtain a decellularized cardiac matrix through the combination of sodium dodecyl sulphate (SDS) and Triton X-100. Briefly, cardiac samples obtained from left ventricles of explanted, pathological human hearts were dissected and washed to remove residual body fluids. Samples were then snap-frozen and sliced by a cryostat into 350 μm thick sections. The sections obtained were decellularized using a solution containing 1% Triton X-100 and 1% SDS in combination, for 24 hours, until observing the color change from brownish-red to translucent-white. As a result, the protocol shows efficiency in preserving ECM architecture and protein composition during the whole process, suggesting that it is worthwhile, highly reproducible and produces a well- preserved decellularized extracellular matrix from cardiac samples. Notwithstanding, some limitations need to be addressed, such as the risk for microbial contamination and the unpredictable trend of the protocol when applied to decellularize samples other than myocardium, vessels, or skin. These issues require antibiotics mixture supplement during the procedure followed by UV sterilization, and appropriate adjustments for a tissue-specific utilization, respectively. The protocol is intended to produce a cardiac d-ECM for cell settlement, representing the ideal scaffold for tissue engineering purposes.

Development and validation of eco-friendly micellar organic solvent-free HPLC method for the simultaneous determination of some antihypertensive combinations

To minimize the environmental impacts of using organic solvent without affecting the chromatographic performance, alternatives had to be utilized to decrease such pollution. Combination of sodium dodecyl sulfate (SDS) with polyoxyethylene-23-lauryl ether (Brij-35) could be incorporated as a green alternative for using organic solvents as mobile phases in HPLC separation systems. In this research, a micellar organic solvent-free HPLC method have be established for determination of five antihypertensive drugs, namely, captopril (CPT), hydrochlorothiazide (HCT), indapamide (IND), valsartan (VAL) and carvedilol (CAR). The most favorable conditions were validated using mobile phase consists of 0.1 mol/L SDS, 0.03 mol/L Brij-35, adjusted at pH 2.8 using ortho-phosphoric acid on symmetry C18 column and detection at 210 nm. The flow rate was sudden increased from 1.2 to 1.5 mL/min after two minutes and the total separation run time was nine minutes. The method was successfully applied to determine four different combinations of the analytes in bulk and their pharmaceutical dosage forms. Method validation was done according to International Conference of Harmonization guidelines. At linearity range of 5–100 µg/mL for CPT, HCT and CAR, 8 – 160 µg/mL for VAL, and 2 – 40 µg/mL for IND, high accuracy results were found. Moreover, the coefficient of the variation of the points of the calibration curve being below 2% indicating precise method. The LLOQ was (4.88 μg/mL) for CPT, (4.89 μg/mL) for HCT and CAR, (7.91 μg/mL) for VAL, and (1.81 μg/mL) for IND. The method’s greenness was determined with the help of an eco-scale scoring method, Green Analytical Procedure Index, and Analytical Greenness Calculator and the proposed method was found to be an excellent green methodology.

Optimization of proteomics sample preparation for identification of host and bacterial proteins in mouse feces.

Bottom-up proteomics is a powerful method for the functional characterization of mouse gut microbiota. To date, most of the bottom-up proteomics studies of the mouse gut rely on limited amounts of fecal samples. With mass-limited samples, the performance of such analyses is highly dependent on the protein extraction protocols and contaminant removal strategies. Here, protein extraction protocols (using different lysis buffers) and contaminant removal strategies (using different types of filters and beads) were systematically evaluated to maximize quantitative reproducibility and the number of identified proteins. Overall, our results recommend a protein extraction method using a combination of sodium dodecyl sulfate (SDS) and urea in Tris-HCl to yield the greatest number of protein identifications. These conditions led to an increase in the number of proteins identified from gram-positive bacteria, such as Firmicutes and Actinobacteria, which is a challenging task. Our analysis further confirmed these conditions led to the extraction of non-abundant bacterial phyla such as Proteobacteria. In addition, we found that, when coupled to our optimized extraction method, suspension trap (S-Trap) outperforms other contaminant removal methods by providing the most reproducible method while producing the greatest number of protein identifications. Overall, our optimized sample preparation workflow is straightforward and fast, and requires minimal sample handling. Furthermore, our approach does not require high amounts of fecal samples, a vital consideration in proteomics studies where mice produce smaller amounts of feces due to a particular physiological condition. Our final method provides efficient digestion of mouse fecal material, is reproducible, and leads to high proteomic coverage for both host and microbiome proteins.

Survival of Salmonella Typhimurium and Escherichia coliO157:H7 on blueberries and impacts on berry quality during 12 weeks of frozen storage after washing with combinations of sodium dodecyl sulfate and organic acids or hydrogen peroxide

AbstractSalmonella spp. and Escherichia coli are well tolerant of freezing. This study was to investigate survival of the foodborne pathogens during storage at −18 ± 2°C for 12 weeks on blueberries after washing with: 500 ppm acetic acid plus 5,000 ppm sodium dodecyl sulfate (SDS) (AA/SDS), 20 ppm peroxyacetic acid plus 5,000 ppm SDS (PPA/SDS), or 200 ppm hydrogen peroxide plus 5,000 ppm SDS (H2O2/SDS), when compared with findings from no wash, or wash with water, 80 ppm PPA or 200 ppm chlorinated water. Following a 60 s contact with one of the three new solutions, the treatments showed 3.3–3.9 log10 CFU/g reductions in Salmonella Typhimurium and E. coli O157:H7 counts. After 2 weeks of frozen storage, 3.9–4.2 log10 CFU/g reductions of Salmonella and E. coli were observed. After 12 weeks of frozen storage, Salmonella and E. coli survivors were below detection limits (0.39 log10 CFU/g) in berries washed with new solutions. The frozen storage had a significant impact (p < .05) on microbial counts of both treated and nontreated blueberries. Although none of these washings decreased the total phenolic and anthocyanins contents and apparent quality at time 0, frozen storage caused significant damage on the texture of both treated and nontreated blueberries. Interestingly, no significant decrease in the total phenolic, anthocyanins content, and apparent quality was observed during the 12‐week frozen storage. The counts of total bacteria, yeasts, and molds decreased throughout storage for treated and untreated berries. This demonstrates that the three wash solutions enhance the safety of frozen berries.

Decellularization for the Preparation of Highly Preserved Human Acellular Skin Matrix for Regenerative Medicine.

Extracellular matrix (ECM) provides biophysical and biochemical stimuli to support self-renewal, proliferation, survival, and differentiation of surrounding cells due to its content of diverse bioactive molecules. Due to these characteristics, the ECM has been recently considered a promising candidate for the creation of biological scaffolds to boost tissue regeneration. Emerging studies have demonstrated that decellularized human tissues could resemble the native ECM in their structural and biochemical profiles, preserving the three-dimensional (3D) architecture and the content of fundamental biological molecules. Hence, decellularized ECM can be employed to promote tissue remodeling, repair, and functional reconstruction of many organs. Selecting the appropriate decellularization procedure is crucial to obtain acellular tissues that retain the characteristics of the ideal microenvironment for cells. The protocol described here provides a detailed step-by-step description of the decellularization method to obtain a reproducible and effective cell-free biological ECM. Skin fragments from patients undergoing plastic surgery were scaled down and decellularized using a combination of sodium dodecylsulfate (SDS), Triton X-100, and antibiotics. To promote the regular and homogeneous transport of the solution through the samples, they were enclosed in embedding cassettes to ensure protection from mechanical insults. After the decellularization procedure, the snow-white color of skin fragments indicated complete and successful decellularization. Additionally, decellularized samples showed an intact and well-preserved architecture. The results suggest that the proposed decellularization method was effective, fast, and reproducible and protected samples from architectural damages.

Microcapsule synthesis and evaluation on fatigue and healing of microcapsule-based asphalt by the entropy and TOPSIS method

ABSTRACT Encapsulation is a promising approach to enhance the self-healing ability of asphalt materials. In this study, microcapsules encapsulated waste engine oil was synthesised to improve the self-healing ability of asphalt. The factors affecting the synthesis of microcapsules, especially emulsification and core shell ratio, were investigated through a micro-observation. Dynamic mechanical properties of microcapsule-based asphalts were analysed. Fatigue and healing properties of asphalt binder were evaluated using the entropy and TOPSIS method. Results showed that a combination of sodium dodecyl sulphate and Span-60 showed better emulsification and the optimised dosage of emulsifier was 1.5 wt%. Increasing emulsifying speed, or decreasing core shell ratio, improved encapsulation efficiency. Addition of microcapsules decreased the asphalt stiffness at low frequency and the fatigue resistance of microcapsule-based asphalt went through relatively large decay when microcapsule addition exceeded 4 wt%. Three healing indexes increased with the addition of microcapsules. By entropy weight and the Technique for Order Preference by Similarity to an Ideal Solution analysis, healing index relating to fatigue life shows a larger entropy weight than others and asphalt with 2 wt% microcapsules perform better with respect to fatigue and healing properties.

Determination of six drugs used for treatment of common cold by micellar liquid chromatography.

The use of organic solvents as eluants in RP-HPLC has an important role to decrease retention time and improve peak shape; however, it has high environmental impacts. Their production and disposal represent economic and biohazard problems. So, alternatives had to be introduced and studied to minimize such pollution. Combination of sodium dodecyl sulfate (SDS) together with polyoxyethylene-23-lauryl ether (Brij-35) was studied as an alternative to the presence of organic solvents on the separation performance of six active pharmaceutical ingredients. Response surface methodology was applied to testthe impact of three independent variables; concentrations of SDS and Brij-35, as well as, pH of the mobile phase; on retention, peak symmetry, and resolution of the analytes using a rotatable central composite design. Significant variables were determined and the suggested models for predicting retention and resolution parameters were significant. Meanwhile, the common cold is the most abundant disease treated with over-the-counter (OTC) medications worldwide. In 2015, the USA recorded $9.56 billion total sales of OTC cold and cough medicaments alone, with average individual patient expenditure of $338. The worldwide sales and generics of common cold and cough products keep growing annually. The six active pharmaceutical molecules under study, namely, paracetamol, guaifenesin, pseudoephedrine, ibuprofen, chlorpheniramine, and dextromethorphan, are widely used in common cold products. The predicted optimum conditions were validated using mobile phase consisting of 93.6 mM SDS, 32.0 mM Brij-35, and 10.0 mM sodium dihydrogen phosphate, adjusted at pH 5.2, column temperature 35° C, and detection at 215-nm wavelength. The method was successfully applied to determine 12 different combination formulae of the analytes in their pharmaceutical products and was assessed for greenness on two novel metrics. A thorough comparison to previously reported methods was included and methods were assessed against greenness metrics Green Analytical Procedure Index and Analytical Greenness Metric to demonstrate superiority.

Mechanistic study of drag reduction in turbulent pipeline flow over anionic polymer and surfactant mixtures

The mixed aqueous solutions of anionic surfactant sodium dodecyl sulfate with polymer polyacrylamide of various kinds, i.e., cationic, anionic, nonionic, and zwitterion, were firstly tested to study their synergistic effect on drag reduction performance. The optimal combination of sodium dodecyl sulfate with anionic polyacrylamide was confirmed due to their strong hydrophobic interaction and electrostatic repulsion caused by the same charge. The surface tension, conductivity, and viscosity of pure surfactant solution and mixed solutions at different surfactant concentrations with anionic polymer of certain concentration were tested, and their drag reduction behavior in pipe flow was also investigated experimentally. It turns out that drag reduction performance acquired from the combination of anionic surfactant and anionic polyacrylamide is better than either of the single additive, especially under high shear rate. For the mixtures, the degree of drag reduction is strongly dependent on the concentration of SDS and more pronounced in the high Reynolds number range. The best drag reduction performance is obtained for the SDS concentration around the polymer saturation point. Our work should be of value for the drag reduction in the application such as shale gas fracturing and various fluid transports.

The reduction of Salmonella on chicken skin by the combination of sodium dodecyl sulfate with antimicrobial chemicals and coating wax microemulsions

Chickens with high populations of various microorganisms arrive at processing facilities. Salmonella species are one of the important foodborne pathogens commonly found in poultry products. Various intervention strategies are implemented during poultry processing to reduce microorganisms in the products, including pre-scald bird brushes, multi-stage scalding, antimicrobial applications, etc. In this study, the effects of adding sodium dodecyl sulfate (SDS) to chlorine (Cl) and peracetic acid (PAA) against Salmonella were investigated. In addition, the efficacy of wax coating the skin to reduce Salmonella attachment was studied. Skin samples were collected following the 4 different methods of (1) euthanized-dry hand-de-feathered carcasses, (2) carcasses rinsed in tap water and mechanically de-feathered, (3) carcasses soft scalded and mechanically de-feathered, and (4) from carcasses hard scalded and mechanically de-feathered. It was shown that 0.5% SDS was able to reduce Salmonella both loosely (34, 28, 42, and 13%, respectively) and firmly (29, 39, 32, and 53%, respectively) attached in the 0.005% Cl-treated samples, but did not increase antimicrobial efficacy of 0.2% PAA. Moreover, carnauba wax coating significantly (P ≤ 0.05) reduced Salmonella attachment on all 4 types of chicken skins, 1.57, 0.71, 0.74, and 0.84 log cfu/sample on dry hand de-feathered, tap water rinsed, soft-scalded and hard-scalded chicken skins, respectively. Beeswax coating did not affect Salmonella attachment regardless of types of chicken skins. Overall, the addition of SDS improved antimicrobial activity of Cl, but not for PAA. Moreover, carnauba wax coating was an effective intervention to reduce Salmonella on chicken skin.

Development of an Eco-friendly HPLC method for the simultaneous determination of three benzodiazepines using green mobile phase

The analysis of the class of benzodiazepines (BDZs) is of a great importance on the levels of forensic, clinical and pharmaceutical uses. The study is focusing on the separation of three BDZs which are diazepam, clonazepam, and bromazepam using a green micellar mobile phase. It was found that the non-ionic surfactant Brij-35 can replace the organic solvent, as it decreases the retention time significantly and contributes to environmentally friendly or Eco-friendly separation procedures. The study was achieved on monolithic C18 column. Combination of sodium dodecyl sulphate (SDS): polyoxyethylene(23)lauryl ether (Brij-35) in a ratio of 50:50% v/v, was used as a mobile phase. The UV detection was set at 240 nm at a flow rate of 1.0 mL/min. The separation of diazepam, clonazepam and bromazepam was achieved in less than ten minutes even though there is no organic modifier in the mobile phase. A detailed study for the chromatographic parameters in this micellar system is carried out, in addition to a comparison with that achieved with other systems containing a single surfactant with low percent of organic modifier or other traditional mobile phase systems. Additionally, assessment of the greenness of the method is carried out using analytical eco-scale and the developed micellar HPLC method was proved to be an excellent green method for the analysis of the three drugs.

Highly fluorinated polymers with sulfonate, sulfamide and N,N-diethylamino groups for the capillary electromigration separation of proteins and steroid hormones.

Highly fluorinated polymers are promising materials in separation methods due to their combination of high chemical and thermally stability, hydro- and oleophobicity, and weak intermolecular forces. However, application of these polymers in chromatography is limited because of their low solubility in aqueous-organic solvents. In our research, the highly fluorinated water soluble polymers with -SO3- N(Et)4+ , -SO2 NH2 , and -N(Et)2 terminal groups were synthesized and applied as additives to the background electrolyte for the separation of steroid hormones and proteins by capillary electromigration methods. It is shown that highly fluorinated polymers can be used both as pseudo-stationary phases in electrokinetic chromatography for high separation efficiency (N∼200×103 ) and selectivity (α∼1.1) of uncharged analytes (e.g., steroid hormones), and as dynamic modifiers of fused silica capillary walls. The highest separation efficiency (N∼1×106 ) and selectivity (α∼1.3) of steroid hormones was achieved by combination of sodium dodecyl sulfate and fluoropolymer with sulfonate groups in background electrolyte with pH 2. Dynamic wall coatings based on fluoropolymer with -SO2 NH2 (which are easier and faster to create and wash off) exhibit significantly higher separation efficiency and selectivity compared to capillary electrochromatography on capillary columns based on polymethacrylate polymers.

Metal-free synthesis of polysubstituted pyrroles using surfactants in aqueous medium

An efficient and metal-free method has been developed for the synthesis of polysubstituted pyrrole derivatives with combination of sodium dodecyl sulphate (SDS) and Triton X-100 surfactants using water as a solvent at room temperature in 2–6 h and under microwave conditions (10 min) with good to excellent yields.

Combination of Sodium Dodecylsulfate and 2,2′-Bipyridine for Hundred Fold Rate Enhancement of Chromium(VI) Oxidation of Malonic Acid at Room Temperature: A Greener Approach

Chromic acid oxidation of malonic acid in aqueous media has been investigated spectrophotometrically at 303 K. The product glyoxylic acid has been characterized by 13C-NMR and FTIR spectroscopy. Three representative N-heteroaromatic nitrogen base promoters, 2-picolinic acid, 2,2′-bipyridine (bpy) and 1,10-phenanthroline, in combination with the anionic surfactant sodium dodecylsulfate (SDS) enhanced the rate of the oxidation reaction compared to the unpromoted reaction. 2,2′-Bipyridine produced the maximum rate enhancement of the three promoters used. The mechanism of the reaction has been proposed with the help of kinetic results and spectroscopic studies. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. The SDS and bpy combination is suitable for malonic acid oxidation.

Enhanced inactivation of Salmonella Typhimurium from blueberries by combinations of sodium dodecyl sulfate with organic acids or hydrogen peroxide

Increasing consumption of raw blueberries has led to the need for improved food safety in the berry fruit industry. This study was undertaken to evaluate an enhanced Salmonella inactivation on blueberries by washing with sodium dodecyl sulfate (SDS) in combination with one of common antimicrobial agents (chlorine, lactic acid, acetic acid, citric acid and hydrogen peroxide). In addition, the impacts of most effective treatments on apparent quality, total phenolic, anthocyanin content, mold and yeast, and Salmonella survivors during the storage of blueberries were also determined. Maximum reductions of Salmonella after washing with 0.5mg/ml acetic acid plus 5000ppm SDS and 200ppm hydrogen peroxide containing 5000ppm SDS were 4.0 and 4.2log10CFU/g, respectively. Addition of SDS enhanced Salmonella inactivation of the acetic acid or hydrogen peroxide solutions. These treatments showed similar Salmonella reductions with 200ppm chlorine (P>0.05). None of these washings decreased the total phenolic, anthocyanin content and apparent quality. Following the two effective antimicrobial washes, 0.5mg/ml acetic acid plus 5000ppm SDS and 200ppm hydrogen peroxide containing 5000ppm SDS, populations of Salmonella on blueberries remained constant throughout the 3-day storage with no appreciable growth. Both treatments decreased counts of yeasts and molds throughout the storage. Therefore, the use of 0.5mg/ml acetic acid plus 5000ppm SDS, 200ppm hydrogen peroxide in combination with 5000ppm SDS may have practical potential as an alternative to the use of chlorine-based washing solution for blueberries.

Extraction of Piperine from Piper Nigrum (Black Pepper) by Aqueous Solutions of Surfactant and Surfactant + Hydrotrope Mixtures

The effect of combining butyl benzene sulfonate as hydrotrope with a surfactant in aqueous solutions is investigated for isolation of piperine, an alkaloid, from black pepper. The standard free energy change associated with piperine solubilization in the aqueous solutions of surfactant and hydrotrope individually and in their mixtures is determined from the solubility of piperine in these solutions. A combination of sodium dodecyl sulfate (SDS) and the hydrotrope gives increased percentage extraction of piperine as compared to the hydrotrope alone. The piperine purity recovered from aqueous solutions was higher as compared to the purity of piperine recovered using organic solvents. The piperine crystallized from aqueous solutions of surfactants and hydrotrope also showed cleaner surfaces and uniform structures with sharp edges, unlike the particles crystallized from organic solvents.

Chemical cleaning of ultrafiltration membranes in the milk industry

Ultrafiltration (UF) is one of the membrane processes has the most applications in dairy industries such as milk dehydration and whey concentration. Fouling of UF membranes in the milk industry is mostly due to precipitation of microorganisms, proteins, fats and minerals on the membrane surfaces. Thus, chemical cleaning of the membranes is essential. Results from investigations on a polysulfone UF membrane fouled by precipitation of milk components are presented. The effect of different cleaning agents on recovery of the fouled membrane was studied. Results showed that a combination of sodium dodecyl sulfate, EDTA and sodium hydroxide could be used as a cleaning material to reach an optimum recovery of the membrane used for milk dehydration. It seems that the results obtained on an experimental scale can be applied to an industrial scale, and the method is able to overcome fouling on any scale.