Treatment of wastewaters from the olive mill industry by sonication

BACKGROUND: In this study, the effects of additives (manganese (III) oxide (Mn₃O₄), Cu⁺², Fe⁰ and potassium iodate (KIO₃)) and radical scavengers (sodium carbonate (Na₂CO₃), perfluorohexane (C₆F₁₄) and t‐buthyl alcohol (C₄H₁₀O)) on the dephenolization, decolorization, dearomatization and detoxification of olive mill wastewater (OMW) by sonication were investigated because wastewaters from this industry are not removed effectively. RESULTS: The maximum COD, color, total phenol and total aromatic amines (TAAs) removal efficiencies were 63, 82, 78 and 71%, respectively, at 60 °C with sonication only. The TAAs and phenol yields were increased to 96 and 97% with 6 mg L^?1 KIO₃ and 3 mg L^?1 Fe⁰ while color removal reached 97% with 6 mg L^?1 C₆F_14. The total annual cost with sonication only was 665 € m^?3 year^?1 while the cost slightly increased (666€ m³ year^?1) with C₆F₁₄. The maximum acute toxicity removals were 97‐98% in Daphnia magna and Vibrio fischeri The Microtox acute toxicity test was more sensitive than the Daphnia magna to the OMW samples. CONCLUSION: COD, color, total phenol, TAAs and toxicity in an OMW were removed efficiently and cost‐effectively by sonication. © 2012 Society of Chemical Industry     

Risk assessment of staphylococcal poisoning due to consumption of informally-marketed milk and home-made yoghurt in Debre Zeit, Ethiopia

The objectives of the study were twofold: to prove that participatory risk assessment can be applied to informally-marketed foods, and to assess the risk of staphylococcal poisoning through consumption of raw milk and home-made yoghurt in Debre Zeit, Ethiopia. Rapid urban appraisals were combined with conventional interviews to identify and quantify formal and informal milk value chains and to collect information on consumers' food preparation and consumption behavior. Milk was sampled in 170 dairy farms and 5 milk collection centers and microbiological tests were conducted. Published data on milk fermentation in Ethiopia was combined with a growth model of Staphylococcus aureus to develop a stochastic risk model. The annual incidence rate of staphylococcal poisoning was estimated to be 20.0 (90% CI: 13.9-26.9) per 1000 people. When the effect of fermentation was removed from the model, the annual incidence rate increased to 315.8 (90% CI: 224.3-422.9) per 1000 people, showing the importance of traditional food preparation methods in risk mitigation; traditional milk fermentation reduced the risk by 93.7%. Improving the safety of milk and dairy products could be achieved through supporting appropriate traditional food preparation and consumption where an industrial risk mitigation system is not feasible. Participatory risk assessment was shown to be applicable to informal food value chain.     

Frequency and antimicrobial resistance of Salmonella serotypes on beef carcasses at small abattoirs in Jalisco State, Mexico

The prevalence and antimicrobial resistance of Salmonella serotypes on beef carcasses from four small abattoirs in Jalisco State, Mexico, were investigated during a 10-month period. Following U.S. Department of Agriculture Food Safety and Inspection Service protocols, Salmonella was isolated from 78 (15.4%) beef carcasses (n = 505) after the final carcass water wash. Isolation frequency differed by establishment (P < 0.05) and was higher (P < 0.05) during the wet season (May through September) for all establishments. Thirteen Salmonella serotypes and four serogroups (partially serotyped isolates) were identified. The most prevalent were Salmonella enterica Give (24.4%), Salmonella Typhimurium (17.9%), and Salmonella Group B (14.1%). Antimicrobial susceptibility was tested against 11 drugs, and results indicated that 46.2% of the isolates were resistant to tetracycline, 42.3% were resistant to streptomycin, 23.1% were resistant to chloramphenicol, 21.8% were resistant to trimethoprim-sulfamethoxazole, and 19.2% were resistant to gentamicin. No resistance to ceftriaxone or ciprofloxacin was observed, and 33% of the isolates were resistant to three or more antimicrobials. Although Salmonella Give was the most prevalent serotype, 95% of the isolates of this serotype were susceptible to all antimicrobials tested. Antimicrobial resistance was more common in Salmonella Typhimurium, and 93% (13 of 14) of the isolates of this serotype were resistant to at least five antimicrobials. The frequency of multidrug-resistant Salmonella isolates differed among establishments (P < 0.05) and may be related to the origin of the cattle presented for harvesting. These findings highlight the need for control measures to reduce Salmonella prevalence on beef carcasses in small abattoirs in Mexico and for strategies to ensure the cautious use of antimicrobials in animal production to prevent and control the spread of antimicrobial-resistant foodborne pathogens.     

Effect of reagent type on the acetylation of barley and maize starches

The objective of this work was to study the effect of reagent type on properties of acetylated barley starch (BS) and maize starch (MS) after modification with acetic anhydride (AA) and vinyl acetate (VA) at similar molar concentration for mole of glucose of both reagents. Degree of substitution (DS), morphological characteristics and granule size distribution, gelatinization and retrogradation, pasting properties, and X‐ray diffraction pattern were evaluated. Acetylation disturbs the short and long range order, and the effect was higher with AA than VA, and for BS than MS. This is due to the higher DS determined in AA–BS. In the pasting profile, acetylated starch showed the maximum peak viscosity at lower temperature, this effect was strongest for BS and anhydride acetic‐acetylation. Differential scanning calorimetry showed decrease in gelatinization parameters in acetylated starches (temperatures and enthalpy), and retrogradation was suppressed by acetylation. This effect was stronger in starches acetylated with AA despite their higher DS. This pattern can be explained from the occurrence of surface effects in acetylation with AA.     

Ligand-based virtual screening, parallel solution-phase and microwave-assisted synthesis as tools to identify and synthesize new inhibitors of mycobacterium tuberculosis

In an attempt to identify new inhibitors of the growth of Mycobacterium tuberculosis (MTB), the causative agent of tuberculosis, a procedure for the generation, design, and screening of a ligand-based virtual library was applied. This used both an in silico protocol centered on a recursive partitioning (RP) model described herein, and a pharmacophoric model for antitubercular agents previously generated by our research group. Two candidates emerged from databases of commercially available compounds, both characterized by a minimum inhibitory concentration (MIC) of 25 microg mL(-1). Based on these compounds, two series of derivatives were synthesized by both parallel solution-phase and microwave-assisted synthesis, leading to enhanced antimycobacterial activity. During both the design and synthesis, attention was focused on the efficient allocation of available resources with the aim of reducing the overall costs associated with calculation and synthesis.     

Assembly of ligand-stripped nanocrystals into precisely controlled mesoporous architectures

The properties of mesoporous materials hinge on control of their composition, pore dimensions, wall thickness, and the size and shape of the crystallite building units. We create ordered mesoporous materials in which all of these parameters are independently controlled. Different sizes (from 4.5 to 8 nm) and shapes (spheres and rods) of ligand-stripped nanocrystals are assembled using the same structure-directing block copolymers, which contain a tethering domain designed to adsorb to their naked surfaces. Material compositions range from metal oxides (Sn-doped In(2)O(3) or ITO, CeO(2), TiO(2)) to metal fluorides (Yb,Er-doped NaYF(4)) and metals (FePt). The incorporation of new types of nanocrystals into mesoporous architectures can lead to enhanced performance. For example, TiO(2) nanorod-based materials withstand >1000 electrochemical cycles without significant degradation.     

Carotenoid composition of kale as influenced by maturity,season and minimal processing

The principal carotenoids of kale were identified by chemical reactions, high‐performance liquid chromatography/mass spectrometry and high‐performance liquid chromatography/photodiode array detection and were quantified by the last technique. In kale taken from conventional farms, the β‐carotene and lutein contents were significantly higher in the mature leaves, violaxanthin was at an unusually high level in the young leaves, and neoxanthin had practically the same concentration at both stages of maturity. In samples taken from an organic farm, the carotenoid contents were essentially the same in the young and the mature leaves. Except for β‐carotene, which did not differ with season, the carotenoid concentrations of marketed minimally processed kale were found to be significantly higher in the summer than in the winter, reflecting seasonal rather than processing effects. In minimally processed kale monitored during 5 days of storage at 7–9 °C, β‐carotene, lutein, violaxanthin and neoxanthin were reduced by 14, 27, 20 and 31% respectively. Thus minimal processing, seasonal and maturity factors were found to have an influence on the carotenoid content of kale. Copyright © 2004 Society of Chemical Industry     

Tackling 4G challenges with "TACT" - Design and optimization of 4G radio receivers with a transceiver architecture comparison tool (TACT)

Current integration trends imposed by the market are pushing toward the software radio paradigm. 4G radio receivers, where different wireless standards converge, make RF engineers face harder and harder challenges. Electronic design automation (EDA) tools play an increasing role in the design and verification of wireless system. This article presents a transceiver architecture comparison tool (TACT) which is a hierarchical, user-friendly, Matlab-based tool. It automates the design-space exploration procedure for 4G (fourth generation) wireless receivers. An example that considers a multistandard wideband code division multiple access (WCDMA)/wireless local area network (WLAN) receiver was also presented to illustrate the capabilities of TACT