Biological effects of essential oils - A review

A positive temperature coefficient is the term which has been used to indicate that an increase in solubility occurs as the temperature is raised, whereas a negative coefficient indicates a decrease in solubility with rise in temperature.

Effect of Temperature

2.2. New Approaches 707 2.2.1. Optical Sensor Systems 707 2.2.2. Mass Spectrometry 708 2.2.3. Ion Mobility Spectrometry 708 2.2.4. Gas Chromatography 709 2.2.5. Infrared Spectroscopy 709 2.2.6. Use of Substance-Class-Specific Sensors 709 2.3. Combined Technologies 710 3. Companies 710 4. Application Areas 710 4.1. Food and Beverage 712 4.2. Environmental Monitoring 715 4.3. Disease Diagnosis 716 5. Research and Development Trends 718 5.1. Sample Handling 719 5.2. Filters and Analyte Gas Separation 719 5.3. Data Evaluation 720 6. Conclusion 721 7. References 722

/pdf/electronic-nose-current-status-and-future-trends-475b22mugv.pdf

Electronic nose: current status and future trends.

Über die Adsorption in Lösungen

Mycotoxins: occurrence, toxicology, and exposure assessment.

Inhibitory effect of cinnamon, clove, lemongrass, oregano and palmarose essential oils on growth and fumonisin B1 production by Fusarium proliferatum in maize grain.

Aims: To investigate the volatile fractions of 16 essential oils for activity against the more common fungi causing spoilage of bakery products, Eurotium amstelodami, E. herbariorum, E. repens, E. rubrum, Aspergillus flavus, A. niger and Penicillium corylophilum.

Methods and Results: The study applied 50 μl of pure essential oils in a sterilized filter paper, were carried out at pH 6 and at different water activity levels (0·80–0·90). First, a wheat flour based agar medium was used, where cinnamon leaf, clove, bay, lemongrass and thyme essential oils where found to totally inhibit all microorganisms tested. These five essential oils were then tested in sponge cake analogues, but the antifungal activity detected was much more limited.

Conclusion: Five essential oils showed potential antifungal capacity against all species tested, over a wide range of water availability. Their activity, however, seems to be substrate-dependent. More research is needed to make them work in real bakery products, as in the preliminary study limited effectiveness was found.

Significance and Impact of the Study: The potential of the cinnamon leaf, clove, bay, lemongrass and thyme essential oils against species belonging to Eurotium, Aspergillus and Penicillium genus has been demonstrated.

Antifungal activity of volatile compounds generated by essential oils against fungi commonly causing deterioration of bakery products.

The effects of water activity (aw, 0.994-0.90 identical to 0.4-14.0 (-)MPa water potential), temperature (4-45 degrees C), and pH (3.6, 5.5, 7.0), and their interactions on growth of isolates of Fusarium moniliforme and Fusarium proliferatum were determined in vitro on a maize extract agar medium. Growth of two isolates of F. moniliforme and four isolates of F. proliferatum were significantly influenced by water activity regardless of solute type used (NaCl, glycerol, or glucose). However, at steady-state aw levels, growth was optimum at 0.994-0.98 aw and reduced significantly at 0.92 aw. Further detailed studies with one isolate of F. moniliforme (25N) and two isolates of F. proliferatum (73N, 131N) showed that growth occurred over the range of 0.994-0.90 aw in the temperature range 20-35 degrees C with slight differences between species. Growth did occur at 4 degrees C and 0.994-0.96 aw, but no growth was recorded at 40 and 45 degrees C regardless of aw. Profiles of aw x temperature relations for growth of these two species were constructed from these data for the first time. Optimum pH and temperature for growth was 5.5 and 25 degrees C for both isolates of F. proliferatum, and pH 7.0 and 30 degrees C for the isolate of F. moniliforme. However, for the latter isolate at < 0.98 aw, optimum pH and temperature for growth changed. The effects of pH, temperature, and aw for single, two-way and three-way interactions were all found to be statistically significant for these three isolates. The ecological significance of this information for understanding these important fumonisin-producing fungi is discussed.

Sonia Marín

Papers

Mycotoxins: occurrence, toxicology, and exposure assessment.

Inhibitory effect of cinnamon, clove, lemongrass, oregano and palmarose essential oils on growth and fumonisin B1 production by Fusarium proliferatum in maize grain.

Antifungal activity of volatile compounds generated by essential oils against fungi commonly causing deterioration of bakery products.

Water activity, temperature, and pH effects on growth of Fusarium moniliforme and Fusarium proliferatum isolates from maize

Predicting mycotoxins in foods: A review