ABSTRACT
The aim of this study was to investigate how the combination of extraction parameters, such as extraction temperature seeds preheating and screw rotation speed, influenced the yield and chemical quality of tobacco seed oil (TSO). For its peculiar properties, TSO can be used for several purposes, as raw material in the manufacturing of soap, paints, resins, lubricants, biofuels and also as edible oil. TSO was obtained using a mechanical screw press and the quality of the oil was evaluated by monitoring the free fatty acids (FFA), the peroxide value (PV), the spectroscopic indices K232, K270 and ΔK and the fatty acid composition. The maximum extraction yield, expressed as percent of oil mechanically extracted respect to the oil content in the seeds, determined by solvent extraction, was obtained with the combination of the highest extraction temperature, the slowest screw rotation speed and seeds preheating. Under these conditions yield was 80.28 ± 0.33% (w/w), 25% higher than the lowest yield obtained among investigated conditions. The extraction temperature and seed preheating showed a significant effect on FFA, on spectroscopic indices K232, K270 and ΔK values. The average values of these parameters slightly increased rising the temperature and in presence of preheating, the screw rotation speed did not affect the chemical characteristic tested. In the extraction conditions investigated no significant changes in PV and fatty acids composition of oil were observed.
ABSTRACT
The non-invasive urea breath test can demonstrate the presence of Helicobacter pylori infection with the same accuracy as invasive methods (histology, rapid urease test, culture), but with less distress and inconvenience to the patient. It is evident that this test can and should substitute invasive methods in patients with uncomplicated duodenal ulcer, in those with non-ulcer dyspepsia and in all who have gastrointestinal disorders that do not require endoscopic examination. The urea breath test has a primary role for determining the success of eradication therapy. It is ideal for short- and long-term follow-up, particularly in the case of duodenal ulcer, which is strictly related to the presence of Helicobacter pylori. In serious disease, when endoscopic examination is mandatory, such as complicated ulcer or mucose associated lymphoid tissue lymphoma, the urea breath test can still improve the diagnostic accuracy of Helicobacter pylori infection as it does not imply sampling error, to which biopsy is subject.
