Phytochemical Analysis and Antimicrobial Properties of Eucalyptus torelliana Oils

Normal oil and Essential oil from fresh leaves of Eucalyptus torelliana (F. Muell) were extracted using solvent (Soxhlet) and steam distillation extraction methods respectively. The leaves were screened for the presence of secondary metabolites and the extracted oils for their antimicrobial potentials. The phytochemical screening revealed the presence of Phytates (27.81 mg/g) Phytic acids (7.833mg/g) Oxalates (3.061mg/g) Tannins (2.457mg/g) Phenols (30.00%) Flavonoids (2.948%) Saponins (3.166%) and Alkaloids (2.84%). In addition to this the leaves were found to contain anthraquinone. The two oils extracted from the leaves of Eucalyptus torelliana were studied for their antimicrobial activity against the following isolated microorganisms: Xanthomonas axonopodis, Shigella dysenterine, Pseudomonas solanecearium, Streptococcus faecales, Staphylococcus aureus, Salmonella enterica, Erwinia carotovora, Salmonella typhi. The oils were found to inhibit all the microorganism isolates. The zone of inhibition exhibited by the extracts on the tested microorganism was between 22-6mm. The oil extracts compared favourably with Ampiclox used as a standard control. The results obtained from this study reveals that the oils extracted from Eucalyptus torelliana has antibacterial activities against enteric pathogens and the oil may be potential source of new antimicrobials against enteric organisms.Keywords- Enteric microorganisms, essential oil, Eucalyptus torelliana, secondary metabolites, solvent extraction

Mathematical Model for the Removal of Essential Oil Constituents during Steam Distillation Extraction

Steam distillation is the conventional means by which oils are extracted in the flavour and fragrance industry. A mathematical model for the steam distillation extraction (SDE) of air-dried Ocimum basilicum (basil) leaves has been developed and tested using a small-scale pilot plant. The model predicts the removal of oil components from the plant matrix and subsequent transfer to the steam. It also accounts for the diffusional transfer of components within the leaf and the simultaneous convective transfer into the vapour phase while also respecting the individual components’ volatilities. It has been applied vertically on an element-by-element basis through the bed for a mixture of major and minor components. The proposed SDE model appears to be a good match between predicted values and the experimental data. The model predicts a faster initial extraction rate for components such as α-pinene and α-terpinene, possibly due to preferential extraction of light, volatile components present in larger quantities.

Study on the Different Method of Extraction of Star Anise Oil

The three reagents of anhydrous ethanol, petroleum ether and ethyl acetate were selected by soxlet extraction, steam distillation and ultrasonic extraction to extract the star anise oil from the fine anise powder. Three kinds of methods for extracting star anise oil were studied on different pattern organic solvent. The result of the different volume fractions of ethanol is that the highest extraction rate is 99.7% ethanol. It can be seen that the extraction rate are: ethanol > petroleum ether > acetic acid ethyl ester. The different methods of extracting the star anise oil shows that the extraction rate are: soxhlet extraction method > ultrasonic extraction method > steam distillation extraction method. In summary, it can be seen by soxhlet extraction method and the best solvent is 99.7% ethanol.

The influence of roasting conditions on volatile flavour compounds in raw and roasted cashew kernels (Anacadium ocidentale) grown in Nigeria

The use of inappropriate temperature-time combinations during the roasting of nuts could lead to quality defects, such as burnt taste, short shelf-life, rancidity, and poor flavour. In this study, cashew kernels were roasted in a forced airflow-drying oven for 20, 40,and 60 min at 100, 120, 140, and 160°C. The productswere evaluated for volatile flavour compounds and the sensory evaluation of the roasted cashew kernelsat different roasting conditions. The volatile fraction was isolated using the combined steam distillation–extraction procedure and identified by gas chromatography–flame-ionization detection (GC-FID). The consumer acceptability test was carried out by 100 panellists using nine point hedonic scales to assess preferences for like or dislike, colour, taste, texture, flavour,and overall acceptability. It was found that there were significant differences in flavour compounds between the different conditions of roasting. Twenty-nine volatile compounds were identified in both fresh and roasted cashew kernelscomprising five main classes,which consist of 12 hydrocarbons, eight aldehydes, four ketones, three alcohols,and one acid. The volatile compounds(mg/100g) ranged from 5.03x10-2to 1.20 (2-butanone), 7.46x10-6to 1.85 (hexanal), 8.91x10-6to 1.94 (acetone), 6.74x10-1to 2.24 (benzaldehyde). The amount of generated volatile compounds increased astheroasting temperature and time increased. The consumer acceptability test revealed that samples roasted for 40 or 60 min at 140°C produced the most acceptable product in terms of all the measured attributes. The study showed that the roasting conditions produced acceptable cashew kernelsof desirable colour and superior flavour quality that enhance direct and commercial utilization.