Validation of an immunoassay method for the determination of traces of carbaryl in vegetable and fruit extracts by liquid chromatography with photodiode array and mass spectrometric detection

A competitive enzyme-linked immunosorbent assay (ELISA) method for carbaryl quantitation in crop extracts was validated by liquid chromatography (LC) with diode array detection (DAD). For this purpose, six crops (banana, carrot, green bean, orange, peach and potato) were chosen for recovery and reproducibility studies. The general sample preparation included extraction with methanol followed by liquid-liquid partitioning and clean-up on Celite-charcoal adsorbent column of the vegetable extracts. ELISA samples consisted of a diluted LC extract in assay phosphate buffer (pH 7.5). The potential effect of methanol in these samples was evaluated. It was observed that a maximum content of 10% methanol present in the assay buffer could be tolerated without expressive losses in the ELISA performance. Under these conditions, a IC50 similar to 1.48 mu g l(-1) was obtained. A minimum matrix effect with a 1:50 dilution of the methanolic extracts in assay buffer was noticed, except for green bean samples that inhibited completely the assay. For the vegetable extracts, the ELISA sensitivities varied from 3.9 to 5.7 mu g l(-1), and good recoveries (82-96%) with R.S.D.s ranging from 5.7 to 12.1% were found. An excellent correlation between the LC-DAD and ELISA techniques was obtained. The confirmation of the carbaryl in less concentrated samples was achieved by LC-mass spectrometry interfaced with atmospheric pressure chemical ionisation. The [M + H](+)= 202 and [M + H-57](+)=145 ions, equivalent to the protonated molecular and l-naphthol ions, respectively, were used to carbaryl identification in these samples. (C) 1998 Elsevier B.V. B.V. All rights reserved.

Evaluation of the thermal diffusivity of vegetable oils during frying by Thermal Lens Spectrometry

In this work we report on the use of the Thermal Lens method to verify the evolution of the thermal diffusivity of sunflower and soybean vegetable oils utilized in preparation of twenty five snacks portions. Our results show that the thermal diffusivity for sunflower oil does not change between 1 and 25 portions of fried snacks. By another hand, the soybean thermal diffusivity exhibits a little decrease for higher portion of fried snacks, indicating that for this oil the triglyceride level is reduced as a degradation process.

Analysis of biodiesel and frying vegetable oils by means of FTIR photoacoustic spectroscopy

Fourier Transform Infrared Photoacoustic Spectroscopy was used to determine the mid-infrared vibrational modes of biodiesel and vegetable oils. Our results indicate that this method can contribute significantly to the biodiesel wash process during the sample preparation. Besides, by analyzing the spectra of vegetable oils used to fry snacks we could to monitor the degradation in function of the fried time.

Toothbrushing with vegetable oil: a clinical and laboratorial analysis.

The dentifrices currently available in the marketplace contain many anticariogenic substances, fluoride and abrasives aimed to better clean the dental surface, remove dental plaque, improve salivary flow and its buffer capacity and reduce colonies of bacteria such as S. mutans, the causative agent of dental caries. The objective of this study was to evaluate the possibility of adequately removing dental plaque using an experimental almond oil dentifrice (Titoil) with no abrasives or antiplaque agents. This study was carried out with 80 volunteers, all of them 18-year-old recruits from the military training school of Araçatuba -- SP. Saliva sampling and dental plaque disclosing were undertaken both before and after 28 days of toothbrushing with a low abrasive dentifrice (Group 1: 40 volunteers) or with Titoil (Group 2: 40 volunteers). Statistical analysis of the results revealed that the experimental dentifrice (Titoil) did not interfere with salivary flow and reduced dental plaque more than the low abrasive dentifrice, improved the salivary buffer capacity and decreased salivary S. mutans (Caritest-SM) as much as regular dentifrices. It was concluded that if the dental industry replaces abrasive by vegetable oil in dentifrices, these will be more effective in maintaining oral health and will cause less dental abrasion.

In vitro evaluation of the abrasiveness of a commercial low-abrasive dentifrice and an experimental dentifrice containing vegetable oil

Toothpastes usually contain detergents, humectants, water colorant, fluoride and thickeners (e.g. silica). Tooth wear has a multi-factorial etilology and the use of abrasive dentifrices is related to abrasion of dental tissues during toothbrushing. This study evaluated in vitro the abrasiveness of a commercial silica gel low-abrasive dentrifice compared to an experimental dentifrice containing vegetable (almond) oil. Distilled water served as a control group. Acrylic specimens (8 per group) were submitted to simulated toothbrushing with slurries of the commercial dentifrice experimental dentifrice, almond oil and water in an automatic brushing machine programmed to 30,000 brush strokes for each specimen which is equivalent to 2 years of manual toothbrushing. Thereafter, surface roughness (Ra) of the specimens was analyzed with a Surfcorder SE 1700 profilometer. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. There was no statistically significant differences (p>0.05) in the surface roughness after brushing with water almond oil experimental dentifrice. The commercial dentifrice produced rougher surfaces compared to the control and abrasive free products (p<0.05). Further studies are necessary in confirm the potential benefits of using vegetable oil in toothpaste as an alternative in abrasives in an attempt to minimize the tooth wear caused by toothbrushing.

Performance of different genotypes of vegetable soybeans in Jaboticabal-SP

The study was conducted in the field, in the experimental area of the Section of Crop Production and Aromatic Medicinal Plants, belonging to the Faculty of Agricultural and Veterinary Sciences, Jaboticabal Campus-SP. The aim of the study was to assess the performance of seven genotypes of vegetable soybeans in Jaboticabal-SP. The experiment was carried out in a complete randomized block design with seven treatments (genotypes) and four replications. The genotypes examined were: CNPSOI, JLM003, JLM010, JLM018, JLM019, JLM024 and BRS216. The seeds were obtained from EMBRAPA-Soja and EMBRAPA- Hortaliças, and planted in Styrofoam trays with 128 cells containing Plantmax Hortaliças® as substrate. Transplanting occurred 10 d after seeding when the seedlings showed 2 or 3 definitive leaves and about 12 cm in height, demonstrating that the soil had been properly prepared according to the recommendations for this crop. Pests and diseases were adequately controlled in the event of their occurrence in the experimental area and in accordance with technical recommendations for the chemical products utilized. Collections were carried out based on the maturation of the pods, according to the scale of Fehr and Caviness (1977) adapted by Costa and Marchezan (1982), when the pods reached the reproductive stage R6. The parameters determined were mean precocity, height of the first pod, mean number of pods per plant, mean number of seeds per pod, fresh weight of 100 seeds and total yield of immature grains. Based on the results obtained, the genotypes JLM003 and JLM010 were found to be most indicated for growing vegetable soybeans, because of their capacity to produce immature grains of 1090 and 848 g·m-2, respectively, and fresh weights for 100 seeds of 62.20 and 68.19 g, respectively.

Influence of vegetable oil in the viscosity of biodiesel-a review

Viscosity is a measure fluid resistance to flowing, affecting the fuel spray in the combustion chamber and, by this way, thus the formation of carbon deposits. The analysis of the influence of vegetable oil viscosity in biodiesel seems appropriate, because biodiesel viscosity is a function of vegetable oil. The increase of the fuel viscosity, promoted by biodiesel, has a major impact on the dynamics of jet fuel, increasing its speed and distance of penetration, obtaining therefore an increase in the amount of turbulent movement of the jet and thus an increase in the rate of preparation of the mixture, air-fuel, when adding biodiesel to diesel oil. The negative effect of this higher fuel viscosity is the increase of the wear of the train of gears, cam shaft, and valve push rod of all the injection pumps due to the higher pressure of injection. The viscosity of biodiesel is influenced by the size of its molecule and by the increase of molecule insaturations, is directly related with its origin vegetable oil or fat. This study is a review of the influence of vegetable oils in viscosity of biodiesel. Copyright © 2008 SAE International.

Associação do padrão de ingestão lípidica com a qualidade da dieta, resistência insulínica e homocisteinemia em adultos

Objectives: To evaluate the association between the consumption of different dietary fats with the quality of the diet, insulin resistance, and hyperhomocysteinemia in adults. Methods: Cross-sectional study conducted with 624 overweight subjects (73.7% females). Assessments of food intake (24h food recall and health eating index-HEI), anthropometry, and biochemical assays of fasting glucose, insulin (HOMA-IR and β calculus) and homocysteinemia were performed. Results: The low quality of diet was associated with the vegetable oil at 3rd quintile (≥1.5-2.0 servings) showed risk 2.9 times and cholesterol at quintiles 2nd, 3rd, and 4th was 2.0 times. HOMA-IR was higher at 5th quintile of saturated fat (≥10,7% - total caloric value) with risk of 60% and hyperhomocysteinemia the vegetable oil at 3rd quintile (>1.5-2.0 servings) with risk of 12.0 times and 5th (≥3.5 servings) 7.1 times. However, significance disappeared when adjusted for anthropometric variables. Conclusion: Dietary fats were associated with the harm diet quality, insulin resistance, and hyperhomocysteinemia. However, associations are dependant of demographic variables, dietetic, and nutritional state. © 2011 CELOM.