Hexane Washing Research Articles

Environmental and cost analysis for polyhydroxyalkanoate production from glycerol byproduct: A case study from integrated soap and biodiesel plants

This work focuses on the sustainable integrated production of bioplastic, also known as Polyhydroxyalkanoate (PHA). Glycerol by-product generates from soap production and biodiesel production plant were utilized as the feedstock to overcome the current drawbacks in PHA production. Different purities of glycerol (i.e,16 wt%, 40 wt% and 60 wt%) were undergone pretreatment steps such as acidification, filtration, evaporation, hexane washing, methanol recovery and ion exchange to obtain 98 wt% of glycerol prior to PHA production. Capital of equipment purchase was estimated by using correlation and graphical method. It was found that, cost of chemical purchase for pretreatment has a high impact on the overall economy of the production. Economic feasibility of all proposed process routes was assessed by calculating the Payback period. Lastly, environmental impact of each pretreatment method was assessed by conducting an LCA by setting the annual target of 750,000 kg as the functional unit. Global warming potential, acidification potential and ecotoxicity of freshwater were chosen as the impact categories in this process. It was found that route 4 with feedstock purity of 60 wt% CG and pretreatment steps of methanol recovery, neutralization, centrifugation, water evaporation and distillation was found to be the most economically and environmentally sustainable among the assessed process routes.

Simultaneous determination of protoporphyrin IX and magnesium protoporphyrin IX in Arabidopsis thaliana and Camellia sinensis using UPLC-MS/MS

BackgroundsInsertion of Mg2+ into protoporphyrin IX (PPIX) to produce magnesium-protoporphyrin IX (Mg-PPIX) was the first step toward chlorophyll biosynthesis, which not only imparts plants green pigmentation but underpins photosynthesis. Plants that blocked the conversion of PPIX to Mg-PPIX displayed yellowish or albino-lethal phenotypes. However, the lack of systematic study of the detection method and the metabolic difference between species have caused the research on chloroplast retrograde signaling controversial for a long time.ResultsAn advanced and sensitive UPLC-MS/MS strategy for determining PPIX and Mg-PPIX was established in two metabolic different plants, Arabidopsis thaliana (Columbia-0) and Camellia sinensis var. sinensis. Two metabolites could be extracted by 80% acetone (v/v) and 20% 0.1 M NH4OH (v/v) without hexane washing. Since the Mg-PPIX could be substantially de-metalized into PPIX in acidic conditions, analysis was carried out by UPLC-MS/MS with 0.1% ammonia (v/v) and 0.1% ammonium acetonitrile (v/v) as mobile phases using negative ion multiple reaction monitoring modes. Interestingly, it could be easier to monitor these two compounds in dehydrated samples rather than in fresh samples. Validation was performed in spiked samples and mean recoveries ranged from 70.5 to 916%, and the intra-day and inter-day variations were less than 7.5 and 10.9%, respectively. The limit of detection was 0.01 mg·kg− 1 and the limit of quantification was 0.05 mg·kg− 1. The contents of PPIX (1.67 ± 0.12 mg·kg− 1) and Mg-PPIX (3.37 ± 0.10 mg·kg− 1) in tea were significantly higher than in Arabidopsis (PPIX: 0.05 ± 0.02 mg·kg− 1; Mg-PPIX: 0.08 ± 0.01 mg·kg− 1) and they were only detected in the leaf.ConclusionsOur study establishes a universal and reliable method for determining PPIX and Mg-PPIX in two plants using UPLC-MS/MS. This procedure will facilitate studying chlorophyll metabolism and natural chlorophyll production.

Identification and Bioassays of Sex-Specific Compounds From a Nuisance Net-Spinning Caddisfly Smicridea fasciatella (Trichoptera: Hydropsychidae).

Municipalities in Arizona and Nevada along the Colorado River are subject to seasonal mass emergences of a nuisance net-spinning caddisfly, Smicridea fasciatella McLachlan (Trichoptera: Hydropsychidae). Here, we describe the characterization and field testing of S. fasciatella extracts to evaluate their potential as lures in baited traps. Solvent extracts of external (i.e., full body-cuticular hydrocarbon, abdominal hexane washes) and internal (i.e., crushed abdomen) parts of adult S. fasciatella were prepared from both sexes, and analyzed by coupled gas chromatography-mass spectrometry (GCMS). Several sex-specific compounds were identified, including (6Z,9Z)-6,9-nonadecadiene and (3Z,6Z,9Z)-3,6,9-nonadecatriene from males, and 2-undecanone, 2-tridecanone, and a heptadecene isomer from females. Extracts from both sexes were also analyzed by coupled gas chromatography-electroantennographic detection (EAD) using antennae of males for detection. Antennae of males weakly responded to 2-undecanone and 2-tridecanone, and to their corresponding alcohols, 2-undecanol and 2-tridecanol, which were included in field tests. Extracts of adult males did not elicit a response from male antennae, suggesting that males do not produce aggregation pheromones attractive to other males. The synchronized, dense populations of lekking males and other possible mating signals (e.g., visual recognition) may have contributed to the minimal attraction seen to test lures deployed in PHEROCON 1C traps. Overall, our results suggest that for this species, attractant pheromones have minimal or no role in bringing the sexes together for mating.

Characterization of Diarrhetic Shellfish Toxins in the Mizuhopecten yessoensis (Scallop) Midgut Gland by High-Performance Liquid Chromatography – Tandem Mass Spectrometry (HPLC-MS/MS)

Liquid chromatography – tandem mass spectrometry (LC-MS/MS) is routinely applied for the determination of toxins associated with diarrhetic shellfish poisoning (DSP) as a part of the Japanese official method. For scallops, not only the edible part but also the midgut gland may be used for analysis. In this study, the matrix effects in the LC-MS/MS-based determination of okadaic acid (OA) and dinophysistoxin-1 (DTX1) in the scallop midgut gland were evaluated to assess the impact on the accuracy of the results. The analyzed sample in an interlaboratory comparison study was subjected to the Japanese official method. The solutions obtained with and without a cleanup process (combination of hexane washing and solid-phase extraction using a C18 cartridge) were diluted to varying ratios and used for evaluation. For all prepared solutions, the ionization of OA and DTX1 was enhanced compared to the samples in methanol; the cleanup process did not sufficiently reduce the matrix effects. Although the dilution of the sample solution reduced the matrix effect, the improvement was limited. Another pretreatment technique is necessary for the accurate determination of DSP-associated toxins in this matrix.

Accurate quantification of TiO2 nanoparticles in commercial sunscreens using standard materials and orthogonal particle sizing methods for verification

The implementation and enforcement of product labeling obligation as required, for example, by the cosmetic product regulation, needs simple and precise validated analytical methods. This also applies to the analysis of nanoparticles in products such as cosmetics. However, the provision of such methods is often hampered by inaccurate sizing due to unwanted nanoparticle changes, interference of matrix components with sizing and interactions between nanoparticles and analytical instrumentation. It is, therefore, necessary to develop appropriate sample preparation methods that preserve NP properties and reduce or remove matrix compounds that interfere with sizing. Further, accurate particle size analysis of samples containing unknown and possibly multiple nanoparticulate constituents is needed. In this study, we evaluated three sample preparation methods to identify and quantify TiO2 nanoparticles in sunscreens. Specifically, we used a combination of ultracentrifugation and hexane washing, thermal destruction of the matrix, and surfactant assisted particle extraction. The method accuracy was assessed by two internal reference samples: pristine TiO2 nanoparticles (NM104) and similar TiO2 nanoparticles dispersed in a sunscreen matrix. The PSDs were determined using an asymmetrical flow field-flow fractionation hyphenated with multi-angle light scattering and inductively coupled plasma-mass spectroscopy. Particle sizing was based on size calibration of the particle retention time in the AF4. Computation of radius of gyration from MALS data was used as an orthogonal particle sizing approach to verify ideal elution and particle size data from the AF4 calibration. Among the three tested sample preparation methods surfactant assisted particle extraction revealed TiO2 nanoparticle recoveries of above 90% and no increase in particle size due to sample preparation was observed. Finally, the sample preparation methods were applied to two commercial sunscreen samples revealing the existence of TiO2-NP < 100 nm. Conclusively, the surfactant assisted particle extraction method can provide valid data for TiO2-NPs in sunscreen and possibly for cosmetic samples of similar matrix.

Assay of Endogenous 3,5-diiodo-L-thyronine (3,5-T2) and 3,3'-diiodo-L-thyronine (3,3'-T2) in Human Serum: A Feasibility Study.

3,5-diiodo-L-thyronine (3,5-T2) is an endogenous derivative of thyroid hormone with potential metabolic effects. It has been detected in human blood by immunological methods, but a reliable assay based on mass spectrometry (MS), which is now regarded as the gold standard in clinical chemistry, is not available yet. Therefore, we aimed at developing a novel ad-hoc optimized method to quantitate 3,5-T2 and its isomers by MS in human serum. Serum samples were obtained from 28 healthy subjects. Two ml of serum were deproteinized with acetonitrile and then subjected to an optimized solid phase extraction-based procedure. To lower background noise, the samples were furtherly cleaned by hexane washing and acetonitrile precipitation of residual proteins. 3,5-T2 and its isomers 3,3′-T2 and 3′,5′-T2 were then analyzed by HPLC coupled to tandem MS. Accuracy and precision for T2 assay were 88–104% and 95–97%, respectively. Recovery and matrix effect averaged 78% and +8%, respectively. 3,5-T2 was detected in all samples and its concentration averaged (mean ± SEM) 41 ± 5 pg/ml, i.e., 78 ± 9 pmol/l. In the same samples the concentration of 3,3′-T2 averaged 133±15 pg/ml, i.e., 253±29 pmol/l, while 3′,5′-T2 was not detected. 3,5-T2 concentration was significantly related to 3,3′-T2 concentration (r = 0.540, P < 0.01), while no significant correlation was observed with either T3 or T4 in a subset of patients in which these hormones were assayed. In conclusion, our method is able to quantify 3,5-T2 and 3,3′-T2 in human serum. Their concentrations lie in the subnanomolar range, and a significant correlation was detected between these two metabolites in healthy individuals.

Use of an Argentine Ant, Linepithema humile, Semiochemical to Deliver an Acute Toxicant

The Argentine ant, Linepithema humile, is an invasive nuisance, agricultural, and ecological pest from South America. In the United States, its primary distribution is in California and the Southeast. The structural pest control industry responds to property owner complaints when this ant’s populations become problematic and a persistent nuisance. Actions taken to control Argentine ants in the urban and suburban environment are typically complaint-driven, and often involve the application of insecticide sprays applied to the outdoor environment by professional pest managers. In California, and elsewhere, spray treatments of various residual insecticides by property owners and pest management professionals has resulted in significant runoff and in subsequent surface water contamination. As a result, an immediate need exists to develop alternative methods of ant control targeted at reducing environmental contamination. The purpose of this study was to investigate the potential for the development of an alternative method of toxicant delivery focused on the Argentine ant’s behavior modifying cuticular chemistry. In short, methanol and hexane washes of Argentine ant pupae applied to paper dummies were handled significantly more by worker ants than the paper dummies that did not contain the solvent extracts. Additionally, paper wicks soaked in a methylene chloride wash from Argentine ant cadavers, air dried, and then treated with fipronil, were removed by worker ants and placed on a midden pile at the same rate (≈86% to 99% removal at 1 h) as untreated and fipronil-treated ant cadavers. The paper wicks that did not contain the methylene chloride extract were ignored by the worker ants. After three days, the mortality of the ants exposed to the fipronil-treated wicks or the ant cadavers were dose-related. In conclusion, our study suggests that there is potential for the use of ant semiochemicals for the delivery of acute toxicants.

Extraction-based recovery of RDX from obsolete Composition B

Abstract Recovery of explosives from obsolete ammunition has been considered an eco-friendly alternative to conventional dumping or detonation disposal methods Composition B, made of 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and paraffin wax, has been used as the main explosive filling in various munitions. It was selected as a model explosive for this study. TNT was extracted from Composition B by exploiting the different solubilities of TNT and RDX in acetonitrile. After removing paraffin wax by hexane washing, RDX was recovered from unused Composition B with a purity higher than 99% and a yield of 84%.

Pentacyclic triterpenes responsible for photoprotection of Corema album (L.) D.Don white berries

Screening-based photoprotection is a first-line defence of plants against potentially harmful solar radiation. In the Iberian Peninsula, most natural fleshy fruits are red, purple or black, although there do exist a few plants that naturally present white fruit, such as Corema album (L.) D.Don (Ericaceae). This is a wild shrub of Atlantic coastal areas, which presents white fleshy fruit that ripens throughout the summer. We analysed the reflectance of fully ripened fruit in the field, and laboratory (before and after hexane washing and pericarp removal). The aqueous and ethyl acetate extract was successively obtained from the crushed fruit and submitted to column chromatography on Silicagel. The fractions were analysed through gas chromatography/mass spectrometry, and two compounds were separated and identified as oleanolic and ursolic acids. The reflectance measurements were taken with the UniSpec-SC Spectral Analysis System. The fruit in the field and laboratory exhibited elevated UV reflectance. The ethyl acetate extract, fractions, and isolated compounds showed high reflectance in UV, which indicated that these triterpene acids could be responsible for reflectance in natural berries. Ursolic and oleanolic acids can play a photoprotective role in berries of Corema album. In sunny environments white fruit can be more visible to dispersers.

Toxicity of Mexican native plant extracts against larvae of Aedes aegypti (Diptera: Culicidae)

ABSTRACT Objective To evaluate five indigenous Mexican plants [ Hippocratea excelsa , Hippocratea celastroides , Argemone mexicana ( A. mexicana ), Tagetes lucida , and Pseudosmodingium perniciosum ( P. perniciosum )] toxicity against the fourth instar larvae of the dengue primary vector, Aedes aegypti ( A. aegypti ). Methods Each plant part was treated successively with hexane, ethyl acetate, acetone, and methanol to extract potential active components of the plants against the dengue vector. Results There was a range of toxicity at 24 or 48 h post-exposure for the different plant parts and organic solvent used (LC 50 values ranged between 20 and 890 μg/mL). Extracts from seeds of A. mexicana (hexane washing with methanol and acetone) and stem-bark of P. perniciosum (hexane) showed highest toxicity to Ae. aegypti larvae at 48 h post-exposure (LC 50 values were 80, 50, and 20 μg/mL, respectively), thus making them potential candidates as biolarvicides. Efforts are on-going to characterize the bioactive components of the extracts, through chromatography, for their use as biological tools for the control of the primary dengue vector. Conclusions A. mexicana and P. perniciosum are good candidates to combat the dengue vector, Ae. aegypti , as they were highly toxic to the larvae.

Hydrogen and oxygen stable isotope analysis of pollen collected from honey

Analyses of stable isotope ratios of pollen present within complex matrices may be useful in sample provenance or climate change applications. We developed a method for separating pollen from honey and preparing pollen for hydrogen and oxygen stable isotope ratio analysis. The method combined several treatments: ethanol dilution to separate pollen; hexane washing to remove wax; and acetolysis to digest all but the external layer of pollen granules. There were large isotopic effects associated with treatments but effects were consistent between replicate applications of the method. We used the method to separate pollen from 45 honey samples from across the United States. Pollen δ2H and δ18O isotope values were significantly positively correlated (P < 0.05), but there was little variation in δ2H values explained by δ18O values (r2 = 0.17). Pollen δ2H values were significantly correlated with δ2H values of precipitation predicted for hive locations (P < 0.05, r2 = 0.24), but there was no significant correlation between pollen and precipitation δ18O values (P = 0.34, r2 = 0.03). These results suggest hydrogen and oxygen stable isotope analysis of pollen may not be as useful as analysis of liquid honey or beeswax in investigating provenance.

Differences in cuticular lipid composition of the antennae of Helicoverpa zea, Heliothis virescens, and Manduca sexta

Analyses of the hexane washes of antennae, forelegs and whole bodies of Helicoverpa zea, Heliothis virescens, and Manduca sexta revealed notable differences in the components of the cuticular coatings of each species. Most striking were the differences between the cuticular coatings of male and female antennae of both H. zea and H. virescens. Novel esters of short-chain acids (C2–C4) and long-chain secondary alcohols (C25–C32) were identified in the hexane washes of the male antenna and forelegs of H. zea and H. virescens. These compounds were found in only small amounts or were completely absent on the female antennae of both species. In H. zea, butyrates of 7- and 8-pentacosanol and 8- and 9-heptacosanol were found, whereas, in the foreleg extracts of H. virescens, acetates and propionates were detected in addition to butyrates. While cholesterol is a major component of antennal washes (10–15%), only traces were found in the foreleg extracts. Although the composition of the cuticular coating of M. sexta differed greatly from that of the other two species, the extractable coatings of the antennae of male and female M. sexta were nearly identical.

Sunflower‐Oil Wax Reduction by Seed Solvent Washing

AbstractWax distribution in sunflower seeds was determined by capillary‐gas chromatography, as well as both the wax composition in sunflower oils obtained from washed seeds and the wax composition in the solvent extracts. The dehulling efficiency was evaluated by using a laboratory centrifugal process. The washing effect on hull morphology and on wax distribution was observed by scanning‐electron microscopy. Washing preferentially removed the crystallized fraction, hexane being the most effective solvent. Short contact times (20 s) at 25–40 °C were sufficient to extract the insoluble waxes by hexane washing. The extracted material consisted of C40–C54 waxes with higher percentages of extracted C44, C46 and C48. These are superficially in the hull of sunflower seed presenting a non‐uniform distribution as observed by microscopy. Solvent washing with pre‐heating of the seeds caused a decrease in sample moisture content, which reduced dehulling ability. Ethanol‐washed seeds were the easiest to dehull, but higher production of fines was also observed. Solvent washing improves both the dehulling‐seed ability increment and the recovery of sunflower waxes as a by‐product for commercial use.

Generalization of Courtship Learning in Drosophila Is Mediated by cis-Vaccenyl Acetate

Reproductive behavior in Drosophila has both stereotyped and plastic components that are driven by age- and sex-specific chemical cues. Males who unsuccessfully court virgin females subsequently avoid females that are of the same age as the trainer. In contrast, males trained with mature mated females associate volatile appetitive and aversive pheromonal cues and learn to suppress courtship of all females. Here we show that the volatile aversive pheromone that leads to generalized learning with mated females is (Z)-11-octadecenyl acetate (cis-vaccenyl acetate, cVA). cVA is a major component of the male cuticular hydrocarbon profile, but it is not found on virgin females. During copulation, cVA is transferred to the female in ejaculate along with sperm and peptides that decrease her sexual receptivity. When males sense cVA (either synthetic or from mated female or male extracts) in the context of female pheromone, they develop a generalized suppression of courtship. The effects of cVA on initial courtship of virgin females can be blocked by expression of tetanus toxin in Or65a, but not Or67d neurons, demonstrating that the aversive effects of this pheromone are mediated by a specific class of olfactory neuron. These findings suggest that transfer of cVA to females during mating may be part of the male's strategy to suppress reproduction by competing males.

Isolation and Enzymatic Digestion of Body Complex of Soybean Seed

The body complex of the soybean seed (BCSS) was isolated from the single cells (27.2%) by a sequential procedure of autoclaving with water, cellulase digestion for the primary cell wall, pectinase digestion for the secondary cell wall, and defatting with hexane washing. Its characteristics were then investigated. The defatted BCSS (DBCSS) consisted of protein (76.5%) and mannose-rich carbohydrates (3.2%). Screening of the food-processing protease for the digestion of DBCSS was carried out, and a kind of alkaline protease was selected. The inner protein of DBCSS was easily extracted with 0.1 M sodium carbonate buffer, pH 10, and the insoluble shell of the body complex (SDBCSS) was left. SDBCSS consisted of hydrophobic amino acid-rich protein. SDBCSS was easily digested by the selected alkaline protease. SDBCSS was dissolved by boiling with sodium dodecyl sulfate-mercaptoethanol, and it was found to consist of a protein of approximately 3 kDa. The high enzymatic digestion including the selected protease for soybean seed and defatted soybean meal was carried out; both were extracted and digested with a yield of >99.5%. The final indigestible residue was found as paired hexagonal and filamentous organs of the soybean cells.

Boll Weevil (Coleoptera: Curculionidae) Bait Sticks: Toxicity and Malathion Content

Assays of malathion content and toxicity to boll weevil, Anthonomus grandis grandis Boheman, were conducted on boll weevil bait sticks, now marketed as Boll Weevil Attract and Control Tubes (BWACTs; Plato Industries, Houston, TX). In general, the longer BWACTs were in the field, the lower the mortality of weevils that were exposed to them. Bioassays of weevil mortality correlated with hexane washes of BWACT surfaces showed highly variable mortality when surface malathion fell below ≈20 ng per 1 μl of hexane, but consistently high mortality (≥90%) when surface malathion was above 30 ng per 1 μl of hexane. A linear equation was calculated to predict mortality as a function of malathion on a BWACT surface. Although mortality was related to surface amounts of malathion, it was unrelated to the total amount of malathion present in BWACTs. Similarly, surface malathion was unrelated to the total amount present in BWACTs. As with mortality, amount of surface malathion declined with time, but total malathion did not decline with time. Boll weevils placed on fresh BWACTs tended to accumulate more malathion and died in greater numbers as time spent on fresh tubes increased, but not as time spent on tubes aged in the field (for 5 mo total) increased. Weevils that landed on tubes after a short flight died in approximately the same numbers as those that were placed on tubes using proper methodology. The amount of malathion expected to cause 90% mortality of boll weevils subjected to proper methodology was 47% higher than for a less stringent methodology (34.3 versus 23.4 ng), which demonstrates the importance of strictly adhering to proper methodology; nevertheless, chemical assay of malathion on the BWACT surface proved to be a more consistent measure of BWACT toxicity than bioassay, and it should replace the bioassay.

Boll weevil (Coleoptera: Curculionidae) bait sticks: toxicity and malathion content.

Assays of malathion content and toxicity to boll weevil, Anthonomus grandis grandis Bohemian, were conducted on boll weevil bait sticks, now marketed as Boll Weevil Attract and Control Tubes (BWACTs; Plato Industries, Houston, TX). In general, the longer BWACTs were in the field, the lower the mortality of weevils that were exposed to them. Bioassays of weevil mortality correlated with hexane washes of BWACT surfaces showed highly variable mortality when surface malathion fell below approximately 20 ng per 1 microl of hexane, but consistently high mortality (> or = 90%) when surface malathion was above 30 ng per 1 microl of hexane. A linear equation was calculated to predict mortality as a function of malathion on a BWACT surface. Although mortality was related to surface amounts of malathion, it was unrelated to the total amount of malathion present in BWACTs. Similarly, surface malathion was unrelated to the total amount present in BWACTs. As with mortality, amount of surface malathion declined with time, but total malathion did not decline with time. Boll weevils placed on fresh BWACTs tended to accumulate more malathion and died in greater numbers as time spent on fresh tubes increased, but not as time spent on tubes aged in the field (for 5 mo total) increased. Weevils that landed on tubes after a short flight died in approximately the same numbers as those that were placed on tubes using proper methodology. The amount of malathion expected to cause 90% mortality of boll weevils subjected to proper methodology was 47% higher than for a less stringent methodology (34.3 versus 23.4 ng), which demonstrates the importance of strictly adhering to proper methodology; nevertheless, chemical assay of malathion on the BWACT surface proved to be a more consistent measure of BWACT toxicity than bioassay, and it should replace the bioassay.

Some Changes in Potato Chips During Frying Observed by Confocal Laser Scanning Microscopy (CLSM)

Confocal laser scanning microscopy (CLSM) was used in fluorescence mode for oil and cell wall detection, and in reflective mode to observe the surface morphology of potato chips. Oil distribution in chips fried at 170°C in oil mixed with the thermoresistant probe Nile Red was studied as the crust developed during frying. Oil was trapped only in intercellular spaces for short frying times while at longer times it was strongly linked to the developed crust microstructure (not only in intercellular spaces but also over some cells) and not easily extractable by hexane washing. Chips infiltrated with a solution of the dye Congo Red (CR) before frying revealed drastic changes in cell walls but no signs of rupture during frying at the magnification used in this research (20X). Topographical data acquired by CLSM in reflective mode confirmed that several cells are broken during the cutting operation. Image representation of the reconstructed surface of a fried chip (170°C, 3 min) allowed observe oil location in potato surface after frying.

Wax composition of sunflower seed oils

AbstractWaxes are natural components of sunflower oils, consisting mainly of esters of FA with fatty alcohols, that are partially removed in the winterization process during oil refining. The wax composition of sunflower seed as well as the influence of processing on the oil wax concentration was studied using capillary GLC. Sunflower oils obtained by solvent extraction from whole seed, dehulled seed, and seed hulls were analyzed and compared with commercial crude and refined oils. The main components of crude sunflower oil waxes were esters having carbon atom numbers between 36 and 48, with a high concentration in the C40−C42 fraction. Extracted oils showed higher concentrations of waxes than those obtained by pressing, especially in the higher M.W. fraction, but the wax content was not affected significantly by water degumming. The hull contribution to the sunflower oil wax content was higher than 40 wt%, resulting in 75 wt % in the crystallized fraction. The oil wax content could be reduced appreciably by hexane washing or partial dehulling of the seed. Waxes in dewaxed and refined sunflower oils were mainly constituted by esters containing fewer than 42 carbon atoms, indicating that these were mostly soluble and remained in the oil after processing.

Cattle and Amblyomma variegatum Odors Used in Host Habitat and Host Finding by the Tick Parasitoid, Ixodiphagus hookeri

The response of mated naive Ixodiphagus hookeri females to cattle and Amblyomma variegatum nymphal odors was tested in a Y-tube olfactometer. I. hookeri females were attracted to cattle urine, dung, and odors from tick-free feeding sites of A. variegatum nymphs on cattle, e.g., dewlaps, front heels, and hind heels. Tick-free scrotal odors did not attract the parasitoids. Furthermore, odors from off-host unfed and fed A. variegatum nymphs did not attract the parasitoids, despite an increase in the number of the nymphs to amplify any odor signal. A blend of odors from feeding on-host nymphs and cattle scrota attracted the parasitoids. In T-tube bioassays, I. hookeri females were attracted to hexane washes and fecal extracts of A. variegatum nymphs.