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Application of a novel “zeolite catalyst–solvent” system for the sustainable one-step synthesis of the terpenoid manoyl oxide, the potential precursor of forskolin and ambrox. Manoyl oxide high-yield and large-scale production over a zeolite catalyst has been infeasible so far, while this system results in 90% yields at 135 °C and atmospheric pressure. Substrate-controlled methodology is used to achieve selectivity. Solvent-driven catalysis is shown, as the activation energy barrier decreases in the presence of appropriate solvents, being 62.7 and 93.46 kJmol−1 for a glyme-type solvent and dodecane, respectively. Finally, catalyst acidity is key parameter for the process. Graphic Abstract

The influence of air–calcination (500oC for 2h) on the physicochemical properties of natural mordenite and mordenite activated by aqueous solutions of several acids, has been studied through various methods. Calcination does not affect the crystal structure of the samples and their fibrous and pores morphology. In contrast, it causes a drastic decrease in the high Bronsted acidity of the acidactivated samples, which was tentatively attributed to the partial destruction of the very strong Al– (OH)–Si acid sites. The influence of calcination on the texture is different depending on the acidic solution used for mordenite activation. The high specific surface area and the moderate acidity obtained after calcination of the sample activated by HCl render this material quite attractive support for the development of nickel supported catalysts for green diesel production.

Eight samples of activated montmorillonite were prepared by treating natural montmorillonite with HCl and HNO3 aqueous solutions in order to investigate the influence of several treatment parameters on its physicochemical characteristics and its catalytic activity for limonene transformation to high added value products (isomers and p-cymene). The samples were characterized using various techniques (SEM-EDS, TEM/HRTEM, XRD, ATR-FTIR, nitrogen adsorption-desorption isotherms, microelectrophoresis and determination of equilibrium pH) and evaluated in the transformation of limonene to isomers and p-cymene utilizing atmospheric oxygen as a green oxidant. The acid treatment, even under mild conditions, caused the removal of the sodium and calcium ions from the interlayer regions of the triple layers without disturbing the crystal structure of the triple layers, the plate-like morphology of the mineral at nanoscale and the pore morphology as well. Only the treatment under the hardest conditions (6 M HCl for 2 h) caused the transformation of plate-like particle morphology into granular one and the pore morphology from slit like-pores developed between plate-like particles into internal voids of irregular shape and broad pore size distributions. In contrast, the acid treatment brings about the reorganization/dislocation of the triple layers inside a plate-shaped particle causing the development of small mesopores, mainly in the range of 3–3.5 nm, and consequently the increase in the specific surface from 62 to 155 m2/g. In parallel, the removal of the sodium and calcium ions/phases brings about the development of negatively charged surface sites. These are transformed into Bronsted acid sites by adsorbing hydronium ions (H3O+). The above sites are catalytically active in the transformation of the limonene into intermediate isomers and undesired “polymers”. The intermediate isomers are transforming into p-cymene and additional “polymers” through a catalyst-free mechanism, in the presence of atmospheric oxygen acting as a green oxidant. The drastic decrease of the amount of the undesired “polymers” ( The low reaction temperature (100 °C), the use of limonene as a renewable reactant, the use of natural montmorillonite as a natural catalyst and the use of atmospheric oxygen as a green oxidant render the proposed process actually green.

Triggered by the development of lactic acid bacteria (LAB) during the production of Scotch whisky, this study examined the influence of yeast and LAB inoculation on whisky flavor. Four new spirits were produced using the same process. LAB were added as a form of a Greek yogurt's live culture. In each category (barley and rye), one sample was fermented with Greek yogurt while the other was fermented without it. The spirits were matured and analyzed at five different points. Results from gas chromatography-mass spectrometry (GC-MS) analysis showed basic volatile compounds, along with some important extra compounds with yogurt culture. The most obvious differences were observed in the concentration of butanoic acid, a characteristic acid in spirits undergoing lactic acid fermentation: to identify esters such as ethyl butanoate, ethyl isobutanoate, isoamyl butanoate, and 2-phenylethyl butanoate, they are not typical compounds in whisky.

Olive leaves (OLL) are reported as a source of valuable antioxidants and as an agricultural by-product/waste. Thus, a twofold objective with multi-level cost and environmental benefits arises for a “green” standalone extraction technology. This study evaluates the OLL waste valorization through maximizing OLL extracts polyphenol concentration utilizing an emerging “green” non-thermal technology, Pulsed Electric Field (PEF). It also provides further insight into the PEF assistance span for static solid-liquid extraction of OLL by choosing and fine-tuning important PEF parameters such as the extraction chamber geometry, electric field strength, pulse duration, pulse period (and frequency), and extraction duration. The produced extracts were evaluated via comparison amongst them and against extracts obtained without the application of PEF. The Folin-Ciocalteu method, high-performance liquid chromatography, and differential scanning calorimetry were used to determine the extraction efficiency. The optimal PEF contribution on the total polyphenols extractability (38% increase with a 117% increase for specific metabolites) was presented for rectangular extraction chamber, 25% v/v ethanol:water solvent, pulse duration (tpulse) 2 μs, electric field strength (E) 0.85 kV cm−1, 100 μs period (Τ), and 15 min extraction duration (textraction), ascertaining a significant dependence of PEF assisting extraction performance to the parameters chosen.

The current study evaluates the Pulsed Electric Field (PEF) technique for the extraction of polyphenols from the plants Rosa canina, Calendulaofficinalis and Castanea sativa. These plants are traditionally used both for the preparation of therapeutic decoctions and the aromatization of beverages (alcoholic or not). Pulses of 10 μs duration were used to apply electric field intensities ranging from 1.2 to 2.0 kV cm−1. The period of the phenomenon was set to 1 ms, with a total extraction time of 20 min. The total polyphenol content as well as the identified polyphenolic compounds of the extracts were determined for monitoring and evaluation. To estimate the PEF effect, control extracts were prepared using the same process as PEF extracts but without the application of electric field. For all the three plant materials studied, the PEF technique appeared to be successful in increasing polyphenols extraction. The application of a moderate to high electric field, up to 1.4 kV cm−1, resulted in increased total and individual polyphenols recovery, reaching 63.79% and 84%, respectively, in the case of Rosa canina fruits.

Olive leaves (OLL), an agricultural waste by-product, are considered a significant bioresource of polyphenols, known as bioactive compounds. This study evaluates the pulsed electric field (PEF) technique for the extraction of polyphenols from OLL. The study parameters included a series of “green” solvents (ethanol, water as well as mixtures of them at a 25% step gradient) and different input values for the pulse duration of PEF. The phytochemical extraction degree was evaluated using total phenol concentration (Folin–Ciocalteu method) and high-performance liquid chromatography (HPLC) analyses, while the antioxidant activity was assessed using differential scanning calorimetry (DSC). The results obtained from the PEF extracts were compared with those of the extracts produced without the PEF application. The highest PEF effect was observed for aqueous ethanol, 25% v/v, using a pulse duration of 10 μs. The increase in the total polyphenols reached 31.85%, while the increase in the specific metabolites reached 265.67%. The recovery in polyphenols was found to depend on the solvent, the pulse duration of treatment and the structure of the metabolites extracted.

To fine tune the production of phenolic aromas in beer, a pulsed electric field (PEF) was applied to beer wort, which was enriched with flax seeds. The choice of flax seeds as a source of FA is based on its high content of ferulic precursors and their intrinsic nutritional value. PEF was applied to ground flax seeds, with and without beta glycosidase. Fermentation was carried out with Saccharomyces and non-Saccharomyces yeast strains. Moreover, 4-vinylguaiacol (4-VG), a flavor highly active derived from volatile phenol, was produced by decarboxylation of ferulic acid (FA), or its precursor and flavor-inactive (4-hydroxy-3-methoxycinnamic acid). All yeast strains could metabolize FA into 4-VG, using the pure compound in the synthetic medium or in flax seeds, with the best quantity produced by Saccharomyces cerevisiae as a precursor. The method yields 4-VG production efficiencies up to 120% (mgL−1). Experimental treatment conditions were conducted with E= 1 kV/cm, total time treatment 15 min (peak time ti = 1 μs, pause time tp = 1 ms, Total pulses 9003). Treatment efficacy is independent of the fermentation yeast.

This paper investigates the process of extracting hop pellets (hops) utilizing the pulsed electric field (PEF) technique and the contrasting effects of the technique between two distinct hop varieties (one bitter and one aromatic). The effect of PEF on the extraction was evaluated by measuring the concentration of α-acids and β-acids (humulones and lupulones). Regarding the aromatic character, the hop’s volatile caryophyllene, humulene and β-myrcene were analyzed both with and without employing the PEF treatment. In order to analyze the acids and the volatile fraction, the analytical method of UV–vis spectrophotometry was applied followed by gas chromatography coupled with mass spectrometry. For the second technique, the extracts were previously purified through a Graphitized Carbon Black syringe for Solid Phase Extraction. The results revealed that PEF had a positive impact on the alpha acids of bitter hops by increasing the extraction rate of these acids by 20%, while the volatiles demonstrated an increase of 5.6 and 7.4% for humulene and caryophyllene, respectively. Concerning the aromatic variety of hops, the PEF treatment appeared to have no noteworthy effects.

Natural mordenite originated from volcanic soils in Greek islands was treated with aqueous solutions of various acids (CH3COOH, H2SO4, HCl, HNO3). The samples were characterized by the joint use of N2-physisorption, X-ray Diffraction, Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Transmission Electron Microscopy, ζ-Potential, and Equilibrium pH and evaluated for the transformation of limonene into p-cymene under air and N2 atmosphere. The influence of reaction temperature and time on catalytic performance of the most promising sample (activated by HCl) was also examined. The acid treatment brings about the removal of cations (mainly sodium cations) located inside the framework channels and in the inter-fiber mesopores without disturbing mordenite framework. The emptying of micropores and mesopores increases drastically the BET specific surface area which is mainly due to micropores. The samples studied exhibit fibrous morphology with fibers (10–100 nm) separated by slit-like mesopores. The emptying of micropores and mesopores unmasks negatively charged surface sites. These are transformed into surface acidic sites by adsorbing H+/H3O+ ions. The changes in the texture and acidity are converting the catalytically inactive natural mordenite into very active catalysts for the transformation of limonene into p-cymene. The increase in the conversion of limonene and the yield of p-cymene over the activated samples are following trends similar to that followed by the BET specific surface area. The catalytic performance is maximized over the sample resulted by the treatment of the original mordenite with hydrogen chloride solution. A quite high yield of p-cymene (65%) is obtained over this sample at 140 °C, limonene to catalyst ratio equal to 15 and reaction time equal to 7 h. A two-step mechanism established previously over sulfuric acid activated natural mordenite catalysts for transformation of limonene to p-cymene is followed regardless of the kind of acid used for activation of this clay.

Natural mordenite originated from volcanic soils in Greek islands was treated with sulfuric acid aqueous solutions of different concentrations and solid mass/solution volumes. The samples were characterized using various techniques (N2-physisorption, XRD, ATR-FTIR, SEM-EDS, TEM, Microelectrophoresis, Equilibrium pH) and tested in the transformation of limonene into p-cymene in the presence of atmospheric air at various temperatures and reaction times. The acid treatment is causing the removal of sodium oxide located inside the framework micropores and the small inter-fiber mesopores. This, in turn, increases drastically the BET specific surface area and unmasks negatively charged surface sites which are transformed into acid sites by adsorbing H+/H2O+ ions. The relatively low extent removal of Al3+ ions does not disturb the framework of natural mordenite nor its fibrous morphology. The development of micropores and small mesopores surface area and surface acid sites are transforming the catalytically inactive natural mordenite into very active catalysts. The increase in the conversion and the yield of p-cymene follows the increase in the BET specific surface area. A novel mechanism was experimentally established involving a catalytic step followed by a non catalytic one. The first step involves adsorption of limonene on acid sites via the exocyclic double bond to form the more stable tertiary carbenium ion from which terpinolenes, terpinenes and “polymeric species” are formed. The “transition state shape selectivity” manifested by the catalysts studied does not allow the formation of intermediate disproportionation products. In the second step, catalyst-free aromatization and “polymerization” of terpinolenes and terpinenes were found to occur. The aromatization was proposed to proceed by abstraction of an allylic hydrogen resulting to free radical (R ) followed by combination with O2 and radical chain propagation to yield allylic peroxides ([ROO ]) which by elimination of (HOO ) lead to the production of p-cymene. Moreover, high molecular weight compounds may be formed as radicals are combined to alkyl and peroxyl dimmers that may be polymerized. The experimental parameters concerning the acid treatment and reaction conditions were optimized for maximizing the amount of the produced p-cymene keeping as low as possible the amount of the produced polymeric species.

Fruits and vegetables are major sources of antioxidants. These are substances that remove free-radical intermediates by being oxidized themselves and delay or inhibit other oxidation reactions. Recent studies make clear that an antioxidant-rich diet acts as a health protecting factor. The antioxidant that was used in this study was 2,5-dimethyl-4-hydroxy-3(2H)-furanone (HDMF). Two frying methods (with and without antioxidant) were used: the first one with no replenishment of oil and the second one with frequent replenishment of oil. As it was proved by the induction period, using the Rancimat method, HDMF increased the resistance against oxidation not only of the frying oils but also of the oil that was absorbed by the chips. The results were in line with those of croissants when they were baked with or without HDMF. Taste panel test confirmed those results as panelists showed a clear preference for those products that were protected against oxidation by HDMF.

This study describes the identification of cyclic dipeptides known as diketopiperazines in red, white and sparkling wines from Greek market. Diketopiperazines have been isolated from bottled wines after liquid–liquid extraction and identified using gas chromatography coupled with mass spectrometry. Cyclo (Leu–Leu), cyclo (Leu–Pro), cyclo (Phe–Pro), cyclo (Leu–Phe), cyclo (Val–Phe) and cyclo (Ala–Phe) were the six diketopiperazines that were identified in bottled wines made from local and international plant varieties. The varieties tested were agiorgitiko, malagouzia, xinomauro, roditis, muscat, athiri, mandilari, vidiano, cabernet sauvignon, syrah and merlot. The cyclo (Leu–Pro) was identified in eighteen bottled wines while the cyclo (Phe–Pro), cyclo (Leu–Phe), cyclo (Leu–Leu), cyclo (Ala–Phe) and cyclo (Val–Phe) were identified in a small number of samples. The analysis of some wine samples showed that the values of cyclo (Leu–Pro) ranged from 0.1 to 1 mg/L. These cyclic dipeptides have biologi...

The present study aimed to evaluate the pulsed electric field (PEF)-assisted extraction of phytochemicals from Salvia officinalis L. leaves. The study parameters included a PEF pulse duration of 10 or 100 μs for 30 min, using different “green” extraction solvents: pure ethanol, pure water, and their mixtures at 25, 50, and 75% v/v concentrations. The resulting extracts were evaluated against reference extracts obtained without PEF. For estimation of the extraction efficiency, the content in total polyphenols, individual polyphenols, and volatile compounds, as well as the resistance to oxidation, were determined. The optimal PEF contribution on the total and individual polyphenols, rosmarinic acid, extractability (up to 73.2% and 403.1% increase, respectively) was obtained by 25% v/v aqueous ethanol solvent using a pulse duration of 100 μs. PEF was proven to also affect the final concentration and composition of volatile compounds of the extracts obtained.

This paper investigates the process of extracting hop pellets (hops) utilizing the pulsed electric field (PEF) technique and the contrasting effects of the technique between two distinct hop varieties (one bitter and one aromatic). The effect of PEF on the extraction was evaluated by measuring the concentration of α-acids and β-acids (humulones and lupulones). Regarding the aromatic character, the hop’s volatile caryophyllene, humulene and β-myrcene were analyzed both with and without employing the PEF treatment. In order to analyze the acids and the volatile fraction, the analytical method of UV–vis spectrophotometry was applied followed by gas chromatography coupled with mass spectrometry. For the second technique, the extracts were previously purified through a Graphitized Carbon Black syringe for Solid Phase Extraction. The results revealed that PEF had a positive impact on the alpha acids of bitter hops by increasing the extraction rate of these acids by 20%, while the volatiles demonstrated an increase of 5.6 and 7.4% for humulene and caryophyllene, respectively. Concerning the aromatic variety of hops, the PEF treatment appeared to have no noteworthy effects.

Traditional Greek yogurt-based salad Tzatziki is one of the most popular ready-to-eat deli salads in Greece. The objective of this study was to estimate the microbial stability of Tzatziki, with and without chemical preservatives, using a rapid method. Determination of the microbial count was carried out using the bioluminescence method (ATP) and traditional microbiological analysis, plate-counting method (CFU) in various batches of the final product of Tzatziki. The results showed that the Tzatziki salad without preservatives initially gave higher relative light units (RLU) values (79,532) than the same salad with preservatives (43,198) because the potassium sorbate and the sodium benzoate, used in recipe, appeared to suspend the action of microorganisms. After incubation in two different substrates, MacConkey and Sabouraud, the Tzatziki salad without preservatives gave higher RLU values (9,488 and 16,176, respectively) than the salad with preservatives (12,780 and 12,005, respectively). In the two selective substrates, differences appeared between the two methods of microbial count (RLU and CFU). While RLU values were roughly at the same level, the CFU values presented significant differences ( p < 0.05). It was also shown that there was a strong correlation ( R 2 = 0.93-0.95) between bacterial counts estimated by traditional CFU and ATP methods. As expected, the dominant microbial population in Tzatziki was Lactobacillus spp., originated from yogurt. Coliforms and yeasts were not able to survive in this environment. Generally, according to the results, Greek traditional Tzatziki salad was a microbial stable product and the bioluminescence method could be a rapid method to determine its microbial state.

The scope of this work was to determine the possibility of the application of the pulsed electric field (PEF) technique to the production of extracts from Moringa oleifera plant material (freeze-dried leaves). Various PEF conditions (pulse duration&mdash, PD, and pulse interval&mdash, PI) were tested. A field strength of 7 kV/cm was used. The total phenols in the extracts were evaluated by the Folin&ndash, Ciocalteu method and the antioxidant activity was evaluated by the radical scavenging activity (DPPH&bull, ), ferric reducing antioxidant power (FRAP) and Rancimat methods. The results were compared with those of the extracts obtained using other extraction techniques, namely microwave-assisted and ultrasound-assisted extractions, simple boiling water extraction, and plain maceration with water (as the control). The highest extraction of total phenols was achieved by the PEF procedure using 40 min treatment at a PD of 20 msec and a PI of 100 &mu, sec. Additionally, all methods for the determination of the antioxidant activity showed that the activity of the extracts was proportional to the total phenol content. Concerning the PEF procedure, a low pulse duration with a high pulse interval is proposed in order to achieve higher extraction efficiency.

Biocompatible colloidal dispersions of the micro- and nanoemulsion type based on lemon oil terpenes, polysorbates, water, and glycerol were used for the formulation of pyrethrins, botanical insecticides derived from the white pyrethrum daisy, Tanacetum cinerariifolium. The proposed formulation is based on pyrethrin-containing water-in-oil (W/O) microemulsions that could be diluted in one step with an aqueous phase to obtain kinetically stable oil-in-water (O/W) nanoemulsions. Structural characteristics of the micro- and nanoemulsions were evaluated by electron paramagnetic resonance (EPR) spectroscopy, dynamic light scattering (DLS), small angle X-ray scattering (SAXS), and electrical conductivity. Dynamic properties of the surfactant monolayer as evidenced by EPR measurements were affected by the water content, the surfactant, and also the presence of the biocide. DLS and SAXS experiments of the nanoemulsions indicated the existence of two populations of oil droplets dispersed in the aqueous phase, globular droplets of 36-37 nm in diameter, and also larger droplets with diameters150 nm. All of the applied techniques for structural determination revealed the participation of the biocide in the nanostructure. The insecticidal effect of the encapsulated natural pyrethrin was evaluated in laboratory bioassays upon a target-insect pest, the cotton aphid Aphis gossypii Glover (Hemiptera: Aphididae) in eggplant, and was found to be increased compared to the commercial pyrethrin formulation.

A method is being proposed in order to discriminate bottled wines of different varieties when no other information is known. The advantages of the method consist in the fact that anyone who wants to certify the variety, which is written on the label or the area of origin, can use such a technique to achieve the conformity. Additionally, the method can be easily applied by laboratories equipped with a GC. The differentiation has been achieved by using only seven of the total extracted volatiles, mainly higher alcohols and higher alcohol esters, namely 3-methyl-1-butanol, 2,3-butanediol, ethyl lactate, 3-methyl-1-butyl acetate, 2-phenylethanol, phenyl ethyl acetate and p-hydroxy phenyl ethanol. These key compounds are not relevant to a single variety. The proposed method does not take into account variables such as the year of vintage and fermentation procedures (agitation, temperature).

An improved method for the discrimination of oils and fats is being proposed. The method is based on the principal component analysis and discrimination analysis of the results obtained by determination of the mole percentage of total fatty acids (fatty acid methyl esters analysis by GC) and regiospecific distribution of the same fatty acids in positions 1 and 3 of triglycerides (using a regiospecific lipase and analysis by GC of the produced butyl esters). Various samples (pure olive oils, various seed oils, mixtures of pure olive oils with seed oils, commercially available foods containing animal fats and/or vegetable oils and, finally, local pure olive oils from different areas of Greece) were subjected to two transesterification treatments. It was proved that the proposed method has a global discriminating ability of identifying (at a level of 5%) olive oil adulteration with various seed oils, discriminating animal fats from vegetable oils and animal fat adulteration with seed oils and, finally, discriminating olive oils on the basis of their geographical origin, in a small area like south Greece. Additionally, the introduced method includes a complete database (as a demonstration tool, mainly for olive oil) in order to be used by any concerned laboratory.

The insecticidal activity of a new nano-formulated natural pyrethrin was examined on the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), and the predators Coccinella septempunctata L. (Coleoptera: Coccinellidae) and Macrolophus pygmaeus Rambur (Hemiptera: Miridae), in respect with the nano-scale potential to create more effective and environmentally responsible pesticides. Pyrethrin was nano-formulated in two water-in-oil micro-emulsions based on safe biocompatible materials, i.e., lemon oil terpenes as dispersant, polysorbates as stabilizers, and mixtures of water with glycerol as the dispersed aqueous phase. Laboratory bioassays showed a superior insecticidal effect of the pyrethrin micro-emulsions compared to two commercial suspension concentrates of natural pyrethrins against the aphid. The nano-formulated pyrethrins were harmless, in terms of caused mortality and survival time, to L3 larvae and four-instar nymphs of the predators C. septempunctata and M. pygmaeus, respectively. We expect that these results can contribute to the application of nano-technology in optimization of pesticide formulation, with further opportunities in the development of effective plant protection products compatible with integrated pest management practices.

This work was dedicated to reporting the full chemical and physical characterisation of Crambe abyssinica Hochst. seed oil. The oil from the seeds was extracted using n-hexane. The seeds contain about 30 % oil. Density, refractive index, colour, smoke point, viscosity, acidity, saponification value, iodine value, fatty acid methyl esters, the relative position of fatty acids in C1 and C3 carbon glycerol, sterols, tocopherols, peroxide value, \( \mathop E\nolimits_{{1{\text{cm}}}}^{1\,\% } \) at 232 nm, and the susceptibility to oxidation measured by the Rancimat method were determined. The oil was found to contain high levels of unsaturated fatty acids, especially C22:1 (63.77 %). The dominant saturated acid was C22:0 (2.14 %). The oil was also found to contain high levels of β-sitosterol (51.93 %), campestanol (21.98 %), and brassicasterol (12.35 %). α-, γ-, and δ-Tocopherols were detected up to levels of 7.67, 125.04, and 3.99 mg/kg, respectively. The induction period (at 110 °C and 20 l/h) of the oil was 8.83 h. The relative position of fatty acids in C1 and C3 position was as follows: linoleic 0.45 %, oleic 8.84 %, and erucic 90.72 %. The thermal profile of the oil presented a single peak at −20.94 °C.

Red wine from the Greek grape cultivar Aghiorghitiko, was aged in stainless steel with and without wood chips toasted to different degrees (heavily, medium, lightly) and in a 225L American standard oak barrel for 32 days. Headspace concentrations of four wood-derived congeners (furfural, guaiacol, cis and trans oak lactones) were determined over this period after which the wines were bottled, stored and subjected to sensory descriptive analyses. Of the 36 attributes for appearance, aroma and oral characters, 14 were significant in univariate analyses and differentiated wines in a multivariate (principal component analysis) product space explaining 72% variance in two factors. Wines from medium toast wood chips scored highest for woody, vegetative and smoky aromas and flavours but also for bitter taste and astringent mouthfeel and after 14 days had the highest headspace concentrations of furfural and cis oak lactone. Wood-related notes were ranked from heavily and lightly toasted chips, barrel and steel control.

Green, unripe olives were subjected to post-harvest treatment under a CO2 atmosphere for a period of 12 days. The total polyphenol (TP), total flavonoid (TFd) and total anthocyanin (TA) contents, along with the antioxidant and sensory characteristics, were continuously monitored during the treatment on a 24 h-interval basis, in order to identify possible changes in the quality of olives related mainly to changes in the polyphenolic contents. The storage of olives under CO2 atmosphere resulted in pronounced increases in TP and TF contents, mainly within the first 3-5 days, but TA exhibited a different pattern of evolution. Furthermore, storage under CO2 contributed to flavour appearance with the development of fruity/floral notes, and reduced bitterness. The in vitro antioxidant properties of the CO2-treated sample showed notable increases compared with the sample stored under regular atmospheric conditions. It was concluded that storage of olives under a CO2 atmosphere resulted in the appearance of desired sensory attributes, by decreasing bitterness and developing aroma and colour, and the functional (antioxidant) properties were improved. This approach may be used as an alternative, chemical-free means of table olive debittering.

Comparative sensory evaluation of wines produced by immobilized cells of Uvaferme 299 on dried raisin berries and free cells using the Saint Denis grape variety and of commercial Greek products (‘Biblia Chora’ rose wine produced from the Syrah grape variety, ‘Palivos’ and ‘Strofilia’ rose wines both produced from the Agiorgitiko grape variety) was carried out. Sensory evaluation was conducted twice by 11 tasters previously trained and a method for panel validation was proposed. Subsequently, the wines were evaluated for their aroma intension, aroma complexity, aroma elegance and overall quality. Duncan's multiple range test clearly showed that there were statistically significant differences between wines produced using different grape varieties and fermentation conditions. Linear regression analysis of the results was performed in order to investigate which sensory parameter had a significant effect on the overall quality and it revealed that only aroma elegance affected significantly the overall quality. Wine produced by immobilized cells scored a statistically higher value for its overall quality than the wine produced by free cells. Finally, discriminant sensory evaluation revealed a gooseberry, cherry, mint aroma for ‘Biblia Chora’ wine and a citrus, rose aroma for ‘Strofilia’ and ‘Palivos’ wines. Wines produced using immobilized and free cells were characterized by a fruity, banana-like aroma, and a herbaceous note was predominant. Copyright © 2005 Society of Chemical Industry

Due to the market introduction of genetically modified organisms (GMOs) in crops, foods, and ingredients, legislation worldwide came face to face with the question of the use and labeling requirements on GMO crops and their derivatives. In this review, protein- and DNA-based methods, such as enzyme-linked immunosorbent assay, western blots, and qualitative and quantitative polymerase chain reaction PCR (Q-PCR) are reviewed. Qualitative detection methods for genetically modified (GM) sequences in foods have evolved rapidly during the past years. The sensitivity of these systems is extremely high, even for processed foodstuffs. However, the availability of quantitative detection methods for GMO analysis is an important prerequisite for the introduction of threshold limits for GMOs in food. The recently introduced labeling threshold for GMOs in food ingredients by the European Union has forced official food control laboratories to apply quantitative PCR methods. Taking the precision of quantitative ...

Wine treated with oak chips was analysed for its contents of furfural, vanillin, guaiacol, oak lactone, eugenol and syringaldehyde. These wood-originated volatiles were released into the wine and their levels were measured by gas chromatography, at different time intervals, for fourteen days. The amounts measured were compared to those found in barrel-aged wine. Statistical analysis of the data indicates that syringaldehyde, primarily, and then vanillin, guaiacol and furfural can be used to discriminate artificially aged from barrel-aged wine. Two different sizes of oak chips were used for this study.

The effect of using a rosemary extract on the stability of oil used for frying potato chips has been evaluated. Sliced potatoes were fried intermittently in soybean oil containing a natural extract from rosemary. The conditions used for frying were 185°C for 90 s. Two separate experiments, with and without replenishment of oil, were carried out. Oil samples were taken each day, not only from the frying pans but also by extraction with hexane from the chips. Changes in the induction period of the oil samples (Rancimat method) were determined. The induction period decreased as frying progressed. The reduction in the induction period was higher in the oil free of rosemary extract, and the chips were much darker in color. The oil containing the extract showed greater antioxidant activity, and reduced darkening and rancidity of the oil. Potato chips fried in the oil with added rosemary extract were more acceptable than chips fried in oil containing no extract until the last frying. The free radical scavenging activity of rosemary extract in comparison to other natural antioxidants was also determined by the reduction of O2.- in a hypoxanthine/xanthine oxidase system.

Principal component analysis (PCA) has been used to establish a new method for the detection of olive oil adulteration. The data set, composed of values obtained from the determination of the mole percentage of total FA and their regiospecific distribution in positions 1 and 3 in TG of oils (pure or mixtures) by GC analysis, was subjected to PCA. 3-D scatter plots showed clearly that it is possible to distinguish the pure oils from the mixtures. Moreover it is possible to discriminate the different types of seed oil used for the adulteration.

Pulsed electric fields (PEF) is a non-thermal processing technology that uses instantaneous, pulses of high voltage for a short period in the range of milliseconds to microseconds; the application of high intensity electric field on toasted wood chips leads to a quick diffusion of extractable molecules. Currently most PEF studies, in the field of oenology, have been focusing on the application of PEF as a pretreatment of grape musts by examining the microbial inactivation and the enhancement of polyphenol extraction. In this study a post-treatment of wine is introduced as method to enhance the wood flavor in the wine with a green noninvasive technology. Major phenolic aldehydes that have been identified as the characteristic compounds of oak volatile compounds were selected as markers and were analyzed instrumentally to compare the influence of PEF processing to non-treated samples. PEF treated samples brought about higher concentrations of the examined oak compounds in the samples treated with PEF, which may explain the advantages of its application. The modulation of the intensity of the electric field and the period of pulses influenced the concentrations of the volatile phenols that were leached out. Differences found between the assayed treatments indicate that PEF application could be a potential practice for a rapid extraction of volatile compounds from oak.

Kyoho cultivar is a hybrid of V. vinifera and V. labrusca and is one of the major varieties cultivate in South Korea. Kyoho grapes are characterized for their intense grape flavor and sour attributes. Korean climatic conditions are different from worldwide wine producing countries. The summer season is hot and dominated by heavy rains. Wines from Kyoho grapes are distinct for their intense grape flavor and the key odors that characterize the wines are aromas of caramel and strawberry notes. The past few years efforts are put to improve the quality and to advance the potential of the domestic wines. The objective of the present study is to provide insight to the main aromatic compounds that form the aroma profile of Kyoho wines. For this aim, Gas Chromatography was coupled with Mass Spectrometry for the separation and identification of the compounds. Analysis allowed to identify the volatile compounds that form the aroma of the wine and to detect the key odors of its characteristic aroma. (2,5-dimethyl-4-hydroxy-3(2H)-furanone) Furaneol® , which is associated with caramel-like flavor, was one of the compounds that were detected along with ((3R)-hydroxy-4,4-dimethyloxolan-2-one) pantolactone.

Cyclopropane-1,1-dicarboxylic acid (CDA) and trans-2-phenylcyclopropane-1-carboxylic acid (PCCA) are the main representatives of a group of compounds that are structural analogues of 1-aminocyclopropane-1-carboxylic acid (ACC) and have been proved to have an inhibitory effect on the wound ethylene produced by Lycopersicum esculentum fruit discs. During the experiments, that were carried out in this work the inhibition pattern of PCCA and CDA were studied when tested on partially purified apple ACO and their Ki values were determined. A mechanistic proposal was given, in order to explain the kinetic behaviour of the inhibitors. The common feature of these molecules is their cyclopropane ring, with different substitutes mainly at the positions C1 and C2. Two other compounds with similar structure where also tested as inhibitors, in order to clarify the relationship between structure and activity. These compounds are: 2-methyl cyclopropanecarboxylic acid (MCA), and cyclopropanecarboxylic acid (CCA).

Inhibition of wound-ethylene by eight structural analogues of 1-aminocyclopropane-1-carboxylic acid (ACC) studied seperately was investigated in unripe tomato fruit discs (Lycopersicum esculentum). The compounds tested were: trans-2-phenylcyclopropane-1-carboxylic acid (PCCA), cyclopropane-1,1-dicarboxylic acid (CDA), cyclopropylamine (CPA), cyclopropyl methyl ketone (CMK), chrysanthemyl alcohol (CHRA), 2-methyl cyclopropanecarboxylic acid (MCA), cyclopropanecarboxylic acid (CCA), 2-methyl-cyclopropane-methanol (2-MCM). The level of inhibition was a function of treatment concentration and time. Differential inhibition induced by the tested compounds was related to their structure.

A direct injection-HPLC method, based on existing methods, slightly modified, was used to analyse commercially available wines in the Greek market for their trans -resveratrol content. Red wines produced from French, or French and Greek cultivars were found to have relatively higher amounts of trans -resveratrol compared with those produced exclusively from native Vitis vinifera cultivars. However, the wines produced from the original Greek Vitis vinifera cultivars, Kotsifali and Mantilaria , appeared to contain important amounts of trans -resveratrol. White wines were found to have markedly lower concentrations of this stilbene in comparison with red wines.

Volatiles of whole red grapes were isolated by using head-space technique. The grape prior to analysis were exposed for a period of 10 days under carbon dioxide atmosphere. This technique is currently used by wine-makers before the grapes are crushed and is called «carbonic maceration». The chemical composition of total volatiles was compared to this of control sample obtained from the same variety of grapes and stored for the same time period under normal atmosphere conditions. The composition of the amino acids and anthocyans, before and after carbon dioxide treatment, was also investigated

Dwarf plants derived from tissue cultures of Pelargonium capitatum, gave an essential oil of quite different composition from that produced by normal plants. This difference persisted for as long as the plant demonstrated the effect of the growth retardant. The chemical composition of the essential oil derived from ‘growth-retarded plants’ is presented.

Olives (Olea europaea cv. Chondrolia) were stored under a CO2 atmosphere immediately after harvesting for a period of 12 days. Samples obtained at 24-h intervals were analyzed by HPLC to identify components that may reflect changes in the biochemical behavior of the tissue. Four substances were shown to undergo significant fluctuations during storage, while their evolution was found to be different in olives stored under CO2 from those stored under regular atmospheric conditions (control). On the basis of data provided by liquid chromatography−electrospray ionization mass spectrometry, these substances were tentatively identified as hydroxytyrosol glucoside, demethylated ligstroside aglycone, ibotalactone A methyl ester, and verbascoside. The data are discussed in relation to the effect of postharvest treatments of olives for purposes of manipulating their polyphenolic content and plausible development of novel debittering processes. Keywords: Antioxidants; liquid chromatography−mass spectrometry; hydroxy...