Marco Poiana

Antimicrobial Effect of Some Essential Oils

Abstract Commercially available oils of lavender (Lavandula angustifolia Mill.), lemon-balm (Melissa officinalis L.), juniper berry (Juniperus communis L.), lemon verbena (Lippia citriodora Kunth), rosemary (Rosmarinus officinalis L.) and cypress (Cupressus sempervirens L.) were evaluated for their antimicrobial activity. Analyses of the oils by GC-FID and GC/MS revealed that the major constituents of these oils were linalool (23.1%) and linalyl acetate (23.1%) in lavender, citronellal (23.8%) and geranial (11.6%) in lemon-balm, α-pinene (29.2%) in juniper berry, neral (36.2%) and geranial (41.9%) in lemon verbena, 1,8-cineole (24.4%) and camphor (17.1%) in rosemary, α-pinene (31.1%) and δ-3-carene (18.6%) in cypress oil. The antimicrobial activity of the essential oils was evaluated on survival and growth of some microorganisms potentially dangerous to the safety of foods (Escherichia coli, Staphylococcus aureus, Listeria innocua). The antimicrobial tests were carried out both in solid and in liquid media. E. coli was the most sensitive organism among the tested ones to the inhibition effect of the oils.

Supercritical carbon dioxide extraction of bergamot peels. Extraction kinetics of oil and its components

Bergamot flavedo (Citrus bergamia Risso) was extracted by supercritical carbon dioxide (SC-CO 2 ) at three different conditions: 80 bar of pressure at 40°C of temperature, 90 bar at 50°C, 100 bar at 60°C. The density value was similar for every experiment and was limited between 282 and 288 g/dm 3 . The extractions were performed on fresh and dried minced peels. The extraction curves showed two phases of the process. The first part had a constant oil concentration in the SC-CO 2 procedure, with the slope of the line influenced by the temperature. The second extraction part showed that the concentration of the oil in the solvent is limited by diffusion and the oil yield has a small increase during the extraction. The asymptotic value was reached at ms:m0 ratio of 12-14 (ms:kg of CO 2 utilized; m0:kg of matrix charged). In addition, the composition of the extracts changed during the process. Therefore, in the first period a high concentration of hydrocarbon monoterpene was observed; after an appropriate extraction time, the composition of the volatile fraction was similar to that typical bergamot essential oil. Bergaptene content in the samples was also quantified and increase of its percentage during the extraction was observed. The bergaptene solubility was influenced by the water content of the matrix, so a higher percentage of this compound was found in extracts obtained from fresh bergamot peels.

Apricot melanoidins prevent oxidative endothelial cell death by counteracting mitochondrial oxidation and membrane depolarization

The cardiovascular benefits associated with diets rich in fruit and vegetables are thought to be due to phytochemicals contained in fresh plant material. However, whether processed plant foods provide the same benefits as unprocessed ones is an open question. Melanoidins from heat-processed apricots were isolated and their presence confirmed by colorimetric analysis and browning index. Oxidative injury of endothelial cells (ECs) is the key step for the onset and progression of cardiovascular diseases (CVD), therefore the potential protective effect of apricot melanoidins on hydrogen peroxide-induced oxidative mitochondrial damage and cell death was explored in human ECs. The redox state of cytoplasmic and mitochondrial compartments was detected by using the redox-sensitive, fluorescent protein (roGFP), while the mitochondrial membrane potential (MMP) was assessed with the fluorescent dye, JC-1. ECs exposure to hydrogen peroxide, dose-dependently induced mitochondrial and cytoplasmic oxidation. Additionally detected hydrogen peroxide-induced phenomena were MMP dissipation and ECs death. Pretreatment of ECs with apricot melanoidins, significantly counteracted and ultimately abolished hydrogen peroxide-induced intracellular oxidation, mitochondrial depolarization and cell death. In this regard, our current results clearly indicate that melanoidins derived from heat-processed apricots, protect human ECs against oxidative stress.

A Comparison between the Chemical Composition of the Oil, Solvent Extract and Supercritical Carbon Dioxide Extract of Citrus medica cv. Diamante

Abstract Citrus medica L. cv. Diamante collected in Calabria (Italy) was extracted by different technologies. The traditional hydrodistillation and solvent methods were compared to the supercritical carbon dioxide extraction (SCF-CO2) performed at two fluid densities: the lowest at 250 g/dm3 and the highest at 875 g/dm3. The effect of the drying process on the peels was studied, and the oil loss was found to be low. The solubility power of CO2 (related to its density) was observed. An enrichment of the less-volatile components like sesquiterpenes, heterocyclic compounds and waxes was quantified in the SCF-CO2 extracts. The monoterpene hydrocarbons were about 95% in the hydrodistillates and in the pentane extract, but these components decreased in the SCF-extracts to a value lower than 85%. The sesquiterpenes were about 0.62% in the hydrodistillates and 1.40% in the pentane extract, but high quantities were found in the SCF-CO2 extracts: 5.64% in the extraction performed at low CO2 density and 12.09% at hi...

Effect of Some Essential Oils as Natural Food Preservatives on Commercial Grated Carrots

Abstract In the present work, the effects of lemon verbena (Lippia citriodora), cypress (Cupressus sempervirens) and lemon-balm (Melissa offcinalis) essential oils against the growth of three microorganisms (potentially dangerous to the safety of foods) were evaluated. The three oils were chosen and tested on grated carrots inoculated with bacteria and stored at 8°C until 8 days to simulate the market sale. The most resistant of the three strains against all the tested oils was Escherichia coli, while Listeria strain was the most easily influenced. An important interaction was revealed with the packaging type: oxygen diffusion greatly influenced the bacteria survival at the end of the experiment.

Supercritical carbon dioxide separation of bergamot essential oil by a countercurrent process

The efficiency of separation of bergamot essential oil, performed by a countercurrent column filled with Raschig rings and using supercritical carbon dioxide as partition solvent, is affected by various parameters. In the experiments explained in this work, the direct effect of CO2 density was shown and the ratio between the amount of oil loaded to on the column and the amount of CO2 used were discussed. The conditions that produced extracts with a similar volatile fraction composition of starting material and with a high yield (more than 80% of recovery) were those with a low feed:solvent ratio; the lowest bergaptene content was obtained at low CO2 density or at high feed:solvent ratio. A good result was observed at a CO2 density of 206 g/dm3 (8 MPa of pressure and a temperature gradient of 46–50–54 °C) and a feed:solvent ratio of 9.4–9.6; in this separation, a yield of 74–77% and a bergaptene content lower than 0.01% was measured. Copyright

Alcoholic extracts composition from lemon fruits of the Amalfi-Sorrento peninsula

Abstract The composition of alcoholic extracts of lemons coming from the Amalfi and Sorrento areas were studied, namely samplings of the cultivars “Sfusato di Amalfi” and “Limone di Sorrento.” Lemons were taken monthly from six orchards in the Amalfi area and eight orchards in the Sorrento area. Lemon peels were submitted to alcoholic infusion similar to that used for the production of the “limoncello” drink. The extracts were analyzed by GC/MS and the volatile fractions were characterized. The compositions observed were similar to those reported for cold-pressed lemon essential oils, hydroalcoholic extracts and commercial “limoncello” drinks. The evolution during the season has underlined defined courses for some classes of components. The carbonyl-to-oxygenated compound ratio, alcohols-to-oxygenated compounds ratio and esters-to-oxygenated compounds ratio are indices of favoring quality. These showed a similar trend for both lemon types. In comparison to other lemon productions a higher amount of minor classes of components were exhibited.

Characterization of monovarietal olive oils obtained from mills of Calabria region (Southern Italy)

The qualitative characteristics of four monovarietal olive oils produced in Calabria region (Southern Italy) were evaluated. The aim of this work was to evidence the differences on chemical parameters due to variety and to growing environment. Results demonstrated a large variability in qualitative indexes according to the variety. Most of the Grossa di Gerace oils sampled in Ionian Southern coast revealed a high total acidity (percentage upper 0.8% of oleic acid). Fatty acid composition showed some varietal characters: in Grossa di Gerace oils possessed a low content of oleic acid and many Carolea oils showed a heptadecenoic acid level higher than 0.3% as European Rules requires for the extra virgin olive oil category. Carolea cultivar is widely grown in different sites of Calabria and so it is influenced by the different climatic conditions: the obtained oils strongly differed according to the production area.

Packaging and Storage of Olive Oil

Storage is a very important step of any food, including olive oil. In fact, olive oil shelf life can be influenced by different factors, from olive quality to processing technologies, however, the selection of proper storage conditions, including packaging, can be of great importance. The Mediterranean diet is recommended as food model for the prevention of various chronic-degenerative pathologies (cardiac diseases, cancer etc.) and olive oil is surely the cornerstone of this type of nutrition with fruits, vegetables, legumes and fish. Its peculiar nutritional characteristics depend on the presence of antioxidant components and monounsaturated fatty acids that are predominant on unsaturated ones, with positive results in the increase of HDL (High-Density Lipoproteins) and reduction of LDL (LowDensity Lipoproteins) oxidation.

Shelf-life of Almond Pastry Cookies with Different Types of Packaging and Levels of Temperature

Almond pastries are typical cookies of the south of Italy. Introduction of new packaging for this kind of cookies requires shelf-life assessments. This study, related to different types of packaging under various storage conditions of time and temperature, identifies critical parameters, as color and texture, to track during storage studies and to extend the shelf-life. The cookies were packed in three different ways and stored at two different temperatures. The pastries were separately stored: (1) in polyvinylchloride film; (2) in aluminum foil (ALL); (3) with modified atmosphere (MAP) in plastic vessels sealed into a polyamide/ polyethylene film; and (4) in vessels without any polymeric film. The storage temperatures were 20 and 30 °C. Evolution of texture, water activity, dry matter and color was assessed. Texture was evaluated by a texture analyzer with a puncturing test. Indices for hardening were the area under the curve (N × mm) up to 10 mm of distance, and the maximum force (N) corresponding to the crust fracture. The best results were obtained with ALL packaging and MAP condition, and above all, in all the trials a temperature of 30 °C reduced the crust hardness.