Survey of seed oils for use as diesel fuels

Fifty-one out of 364 plant seeds being surveyed had fatty acid contents greater than 15% (dry weight), and their methyl esters had cetane indices higher than 50. Rambutan seed was an exception, with a lipid content of only 14.7%, but a high cetane index (67.1); thus, it was included in this report. Twenty seed oil methyl esters had cetane indices greater than 60. Three seed oils from the Sapindaceae family not only had high cetane indices but also contained long-chain fatty acids of 20 carbon atoms. Gross heats of combustion of the fatty acid methyl esters were slightly higher than those of neat oil, ranging from 38.2 to 40.8 j/g, whereas the heating values of the oils ranged from 37.4 to 40.5 j/g. Thus, these plant seed oils have great potential for development as diesel fuel or diesel fuel extender.     

Utilization of rice hull ash as a support material for immobilization of Candida cylindracea lipase

Rice hull ash was heated in a muffle furnace at 700°C for 2 h and metallic oxides were leached with 10% sulfuric acid. The acid-activated ash was then examined for immobilization of Candida cylindracea lipase. Immobilization was carried out by direct addition of the enzyme solution to the activated ash suspended in hexane. The immobilized lipase retained 30% of its hydrolytic activity, but thermal stability was greatly increased. Half-lives of the immobilized enzyme at 50, 60, and 70°C were 45, 17, and 4 min, respectively. Optimal pH of the immobilized enzyme was 7.2. The apparent K_m and V_max for olive oil were 41 mM and 99.5 μmol/h-mg solid, respectively.     

Gas Chromatographic Separation and Identification of Jacaric and Punicic 2-Ethyl-1-Hexyl Esters

The present study demonstrates the separation of a critical pair of conjugated linolenic acid (CLN) isomers—jacaric acid (JA; c8, t10, c12-18:3) and punicic acid (PA; c9, t11, c13-18:3)—on a 60-m conventional Supelcowax 10 column. The alkyl esters of different alcohols (C₁–C₈) of JA and PA were prepared and analyzed isothermally at 220, 230 and 240 °C. The adequacy of their separation was determined from the separation factors (α) and peak resolutions (R _s). Acceptable resolution (R _s = 1.01) of JA and PA was obtained with their 2-ethyl-1-hexyl ester derivatives at a column temperature of 230 °C. In addition, the Gibbs energy of transfer from solution to gas of the three double bonds \((\Delta_{\text{sln}}^{\text{g}} G_{\text{u}}\)) could be used to describe the interactions of the double bond with the stationary phase. Characterization of 2-ethyl-1-hexyl esters of Jacaranda mimosifolia seed oil at 230 °C demonstrates that the oil contains JA and α- and β-calendic acid as a CLN without the presence of PA. The results suggested that JA could be resolved from PA on a 60-m Supelcowax 10 column as the ethyl hexyl ester.     

Effects of barium zirconium titanate on the properties of β-tricalcium phosphate bioceramics

In the present work, a new composite between β-tricalcium phosphate (a bioceramic material) and barium zirconium titanate (a ferroelectric material) were fabricated. Beta-tricalcium phosphate (β-TCP) powder was synthesized from egg shells while barium zirconium titanate powder was synthesized from metal oxide powders. The composites were fabricated by a solid-state reaction method. Effects of barium zirconium titanate on many properties of the composites were investigated. Barium zirconium titanate additive improves the electrical properties of the composites such as dielectric, ferroelectric and piezoelectric properties. Furthermore, the mechanical properties, such as hardness are improved by the additive. In-vitro bioactivity test suggests that β-tricalcium phosphate has a higher apatite forming ability as compared to the BZT. The obtained results indicate that the composites are a promising biomaterial candidate.     

Partial characterisation of bacteriocins produced by lactic acid bacteria isolated from Thai fermented meat and fish products

Lactic acid bacteria (LAB) from Thai fermented meat and fish products were isolated. From a total of 93 samples, 152 isolates of lactic acid bacteria were obtained. Antimicrobial activity screening was performed using the agar spot test and the agar well diffusion method. Of the six isolates which produced antimicrobial activities against Weissella confusa N31, only isolate N23 was identified as Weissella cibaria (GenBank accession number AB494716.1) with 99% similarity by 16S rDNA sequence analyses. Complete inactivation of antimicrobial activity produced by W. cibaria N23 was observed after treatment of the bacteriocins with trypsin, actinase, protease XIII, ficin, trypsin from porcine pancreas, α-chymotrypsin and pepsin. In addition, the inhibitory activities were not affected by the addition of catalase. Taken together, these results confirmed that the inhibitory compounds produced by this strain were proteinaceous in nature and possessed typical characteristics of bacteriocins. The highest yield of bacteriocin produced by W. cibaria N23 was recorded at 20 h. The bacteriocin N23 remained stable after 2 h of incubation at pH values between 2.0 and 8.0, and also for 15 min at 121 °C. The bacteriocin produced by W. cibaria N23 was found to have a narrow antibacterial spectrum, being able to inhibit only W. confusa N31. In addition, bacteriocin N23 did not adhere to the surface of the producer cells. The results produced from this study will contribute to the existing body of knowledge and enhance the databases of bacteriocin-producing Weissella.     

Mapping inland lake water quality across the Lower Peninsula of Michigan using Landsat TM imagery

The number, size, and distribution of inland freshwater lakes present a challenge for traditional water-quality assessment due to the time, cost, and logistical constraints of field sampling and laboratory analyses. To overcome this challenge, Landsat imagery has been used as an effective tool to assess basic water-quality indicators, such as Secchi depth (SD), over a large region or to map more advanced lake attributes, such as cyanobacteria, for a single waterbody. The overarching objective of this research application was to evaluate Landsat Thematic Mapper (TM) for mapping nine water-quality metrics over a large region and to identify hot spots of potential risk. The second objective was to evaluate the addition of landscape pattern metrics to test potential improvements in mapping lake attributes and to understand drivers of lake water quality in this region. Field-level in situ water-quality measurements were collected across diverse lakes (n = 42) within the Lower Peninsula of Michigan. A multicriteria statistical approach was executed to map lake water quality that considered variable importance, model complexity, and uncertainty. Overall, band ratio radiance models performed well (R² = 0.65–0.81) for mapping SD, chlorophyll-a, green biovolume, total phosphorus (TP), and total nitrogen (TN) with weaker (R² = 0.37) ability to map total suspended solids (TSS) and cyanobacteria levels. In this application, Landsat TM and pattern metrics showed poor ability to accurately map non-purgable organic carbon (NPOC) and diatom biovolume, likely due to a combination of gaps in temporal overpass and field sampling and lack of signal sensitivity within broad spectral channels of Landsat TM. The composition and configuration of croplands, urban, and wetland patches across the landscape were found to be moderate predictors of lake water quality that can complement lake remote-sensing data. Of the 4071 lakes, over 4 ha in the Lower Peninsula, approximately two-thirds, were identified as mesotrophic (n = 2715). This application highlights how an operational tool might support lake decision-making or assessment protocols to identify hot spots of potential risk.     

Isoniazid proliposome powders for inhalation-preparation, characterization and cell culture studies

The aims of this study were to develop proliposome powders containing isoniazid (INH) in a dry powder aerosol form. INH-proliposome powders were prepared by a spray drying method. Proliposome physicochemical properties were determined using cascade impactor, X-ray diffraction and differential scanning calorimetry. The toxicity of proliposomes to respiratory-associated cell lines and its potential to provoke immunological responses from alveolar macrophages (AM) were determined. Free INH and INH-proliposome bioactivities were tested in vitro and in AM infected with Mycobacterium bovis (M. bovis). Aerosolization properties of INH-proliposome powders at 60 L/min, the powders showed mass median aerodynamic diameters of 2.99-4.92 μm, with fine particle fractions (aerosolized particles less than 4.4 μm) of 15-35%. Encapsulation of INH was 18-30%. Proliposome formulations containing INH to mannitol ratios of 4:6 and 6:4 exhibited the greatest overlapping peak between the drug and mannitol. INH-proliposomes were evidently nontoxic to respiratory-associated cells, and did not activate AM to produce inflammatory mediators-including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and nitric oxide-at a toxic level. The efficacy of INH-proliposome against AM infected with M. bovis was significantly higher than that of free INH (p < 0.05). INH-proliposomes are potential candidates for an alternative tuberculosis treatment.     

A facile nonenzymatic electrochemical sensor based on copper oxide nanoparticles deposited on activated carbon for the highly sensitive detection of methyl parathion

Journal of Applied Electrochemistry - A facile and novel nonenzymatic electrochemical sensor for the detection of methyl parathion (MP) was developed using a glassy carbon electrode modified by...     

Reducing Oil Losses in Alkali Refining

Neutralization is an important step in the chemical refining of edible oils. Free fatty acids (FFA) are generally removed in neutralization as sodium soaps but neutral oil is also entrapped in the emulsion and removed with the soap during centrifugation. Thus, alkali neutralization causes a major loss of neutral oil in the chemical refining of edible oils. The effects of demulsifiers (NaCl, KCl, Na₂SO₄ and tannic acid) on reducing alkali refining losses of refined palm, soybean, and sunflower oils (used as model oils) incorporated with FFA from rice bran oil were investigated. Adding small amounts of demulsifiers to the alkali neutralization step significantly reduced neutral oil loss of these model oils. All demulsifiers except for tannic acid had similar effects on refining losses in all oil model systems. The optimum demulsifier content was 1.0 % (w/w of oil).     

Oxidative Modification and Poor Protective Activity of HDL on LDL Oxidation in Thalassemia

Oxidative modification of low-density lipoprotein (LDL) has been reported in thalassemia, which is a consequence of oxidative stress. However, the levels of oxidized high-density lipoprotein (HDL) in thalassemia have not been evaluated and it is unclear whether HDL oxidation may be linked to LDL oxidation. In this study, the levels of total cholesterol, iron, protein, conjugated diene (CD), lipid hydroperoxide (LOOH), and thiobarbituric acid reactive substances (TBARs) were determined in HDL from healthy volunteers and patients with β-thalassemia intermedia with hemoglobin E (β-thal/Hb E). The protective activity of thalassemic HDL on LDL oxidation was also investigated. The iron content of HDL₂ and HDL₃ from β-thal/HbE patients was higher while the cholesterol content was lower than those in healthy volunteers. Thalassemic HDL₂ and HDL₃ had increased levels of lipid peroxidation markers i.e., conjugated diene, LOOH, and TBARs. Thalassemic HDL had lower peroxidase activity than control HDL and was unable to protect LDL from oxidation induced by CuSO₄. Our findings highlight the oxidative modification and poor protective activity of thalassemic HDL on LDL oxidation which may contribute to cardiovascular complications in thalassemia.