The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Gerhard Spiteller - One of the best experts on this subject based on the ideXlab platform.
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identification of sinapyl alcohol derivatives in sicilian Lemon oil citrus limon l burm f
Journal of Essential Oil Research, 1992Co-Authors: Herta Ziegler, Gerhard SpitellerAbstract:ABSTRACT 3-(3′, 4′, 5′-Trimethoxyphenyl)- propanyl acetate and propionate, as well as 3-(3′, 4′, 5′-trimethoxyphenyl)-2-propenyl acetate and propionate were identified in a low volatile fraction isolated from cold-pressed Sicilian Lemon oil. The propionates are hitherto unknown natural products; the acetates have not been reported so far as constituents of Lemon oil. The structures of these four obviously related compounds were deduced from spectroscopic data and confirmed by synthesis.
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coumarins and psoralens from sicilian Lemon oil citrus limon l burm f
Flavour and Fragrance Journal, 1992Co-Authors: Herta Ziegler, Gerhard SpitellerAbstract:The coumarin fraction of cold-pressed Sicilian Lemon oils (Citrus limon (L.) Burm. f.) was investigated by HPLC, MS, GC-MS and NMR. Twenty-nine structurally different compounds were identified. Eleven of these were previously unknown as constituents of Lemon oil. 5-(2′,3′-Dihydroxy-3′-methylbutyloxy)-7-methoxycoumarin, 5-(2′,3′-epoxy-3′-methylbutyloxy)-7-methoxycoumarin, 8-(7′,8′-epoxygeranyloxy)psoralen as well as 5-(3′-methylbut-2′-enyloxy)-8-(2′,3′-dihydroxy-3′-methylbutyloxy)psoralen are hitherto unknown natural products. Moreover, a new derivatization method for the investigation of allyloxycoumarins, based on mild hydrogenation, is presented.
David Julian Mcclements - One of the best experts on this subject based on the ideXlab platform.
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food grade microemulsions and nanoemulsions role of oil phase composition on formation and stability
Food Hydrocolloids, 2012Co-Authors: David Julian McclementsAbstract:Abstract Lemon oil is widely used as a flavoring component in beverages, foods, cosmetics, and household products. Lemon oil comes in a variety of chemical compositions depending on its biological origin, extraction methods, and purification procedures. At present, there is a relatively poor understanding of the influence of Lemon oil composition on its functional properties. In this study, we examined the influence of Lemon oil fold (1×, 3×, 5× and 10×) on the formation and properties of oil-in-water microemulsions and nanoemulsions. The concentration of both polar (high water solubility and low log P ) and non-polar (low-water solubility and high log P ) components increased with increasing oil fold. The nature of the colloid dispersions formed was established using an emulsion titration method that involved titrating Lemon oil droplets into a surfactant micelle solution (1% Tween 80). Oil fold affected the rate and extent of solubilization, as well as the stability of Lemon oil droplets to growth. The maximum amount of Lemon oil that could be solubilized within the micelles increased with increasing oil fold, as did the stability of Lemon oil droplets to growth. The results were interpreted in terms of the ability of different Lemon oil molecules to be incorporated within water or surfactant micelles, and the influence of Lemon oil polarity on Ostwald ripening. This study provides valuable information about the relationship between Lemon oil composition and its performance in colloidal delivery systems suitable for use in the food and beverage industries.
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impact of Lemon oil composition on formation and stability of model food and beverage emulsions
Food Chemistry, 2012Co-Authors: David Julian McclementsAbstract:Abstract Lemon oil is a complex organic compound isolated from citrus peel, which is commonly used as a flavouring agent in beverages, foods, cosmetics, and household products. We have studied the influence of Lemon oil fold (1×, 3×, 5× and 10×) on the formation and properties of oil-in-water emulsions. Initially, the composition, molecular characteristics, and physicochemical properties of the four Lemon oils were established. The main constituents in single-fold Lemon oil were monoterpenes (>90%), whereas the major constituents in 10-fold Lemon oil were monoterpenes (≈35%), sesquiterpenes (≈14%) and oxygenates (≈33%). The density, interfacial tension, viscosity, and refractive index of the Lemon oils increased as the oil fold increased ( i.e ., 1× i.e ., diffusion of Lemon oil molecules from small to large droplets. The highest fold oil (10×) was stable to droplet growth, which was attributed to the presence of an appreciable fraction of constituents with very low water-solubility that inhibited droplet growth through a compositional ripening effect. This study provides important information about the relationship between Lemon oil composition and its performance in emulsions suitable for use in food and beverage products.
Herta Ziegler - One of the best experts on this subject based on the ideXlab platform.
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identification of sinapyl alcohol derivatives in sicilian Lemon oil citrus limon l burm f
Journal of Essential Oil Research, 1992Co-Authors: Herta Ziegler, Gerhard SpitellerAbstract:ABSTRACT 3-(3′, 4′, 5′-Trimethoxyphenyl)- propanyl acetate and propionate, as well as 3-(3′, 4′, 5′-trimethoxyphenyl)-2-propenyl acetate and propionate were identified in a low volatile fraction isolated from cold-pressed Sicilian Lemon oil. The propionates are hitherto unknown natural products; the acetates have not been reported so far as constituents of Lemon oil. The structures of these four obviously related compounds were deduced from spectroscopic data and confirmed by synthesis.
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coumarins and psoralens from sicilian Lemon oil citrus limon l burm f
Flavour and Fragrance Journal, 1992Co-Authors: Herta Ziegler, Gerhard SpitellerAbstract:The coumarin fraction of cold-pressed Sicilian Lemon oils (Citrus limon (L.) Burm. f.) was investigated by HPLC, MS, GC-MS and NMR. Twenty-nine structurally different compounds were identified. Eleven of these were previously unknown as constituents of Lemon oil. 5-(2′,3′-Dihydroxy-3′-methylbutyloxy)-7-methoxycoumarin, 5-(2′,3′-epoxy-3′-methylbutyloxy)-7-methoxycoumarin, 8-(7′,8′-epoxygeranyloxy)psoralen as well as 5-(3′-methylbut-2′-enyloxy)-8-(2′,3′-dihydroxy-3′-methylbutyloxy)psoralen are hitherto unknown natural products. Moreover, a new derivatization method for the investigation of allyloxycoumarins, based on mild hydrogenation, is presented.
Daniel Valero - One of the best experts on this subject based on the ideXlab platform.
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the essential oils thymol and carvacrol applied in the packing lines avoid Lemon spoilage and maintain quality during storage
Food Control, 2014Co-Authors: S Castillo, C O Perezalfonso, D Martinezromero, Maria Serrano, Fabian Guillen, Daniel ValeroAbstract:The objective of this paper was to study the effect of essential oils (EOs) thymol and carvacrol applied in citrus packing lines in combination with commercial wax on microbial spoilage, Lemon decay and quality parameters during postharvest storage and compared with control (tap water), wax and wax + imazalil as positive control. Results showed that the treatment with wax + EOs was able to reduce yeast and mould and total aerobe counts on Lemon surface and decayed Lemons after 8 weeks of storage, the efficacy being similar to that obtained from wax + imazalil treatment. In addition, Lemons coated with EOs or imazalil showed similar quality attributes (weight loss, softening and colour) retention compared with control or waxed fruits.
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the effects of essential oils carvacrol and thymol on growth of penicillium digitatum and p italicum involved in Lemon decay
International Journal of Food Microbiology, 2012Co-Authors: C O Perezalfonso, D Martinezromero, P J Zapata, Maria Serrano, Daniel Valero, S CastilloAbstract:Abstract In this work the antifungal efficacy of thymol, carvacrol and the mixture of both pure essential oils has been proved against Penicillium digitatum and Penicillium italicum, by using in vitro (liquid media, PDA plates and disk growth) and in vivo (Lemon) tests. Results indicated that both essential oils were effective in inhibiting fungal growth in all in vitro tests, with the highest efficacy displayed by thymol. In addition, the application of wax with thymol and carvacrol to Lemons inoculated with P. digitatum demonstrated the reduction of decay (expressed as percentage of infected fruit surface) in a concentration dependent manner, as well as reduced respiration rate, ethylene production and total acidity losses. Thus, the application of these essential oils together with wax in the citrus packing lines could be considered as good alternatives to reduce the use of synthetic fungicides.
Fernando E Prado - One of the best experts on this subject based on the ideXlab platform.
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effects of low uv b doses on the accumulation of uv b absorbing compounds and total phenolics and carbohydrate metabolism in the peel of harvested Lemons
Environmental and Experimental Botany, 2011Co-Authors: Roque Interdonato, Mariana Rosa, Cecilia B Nieva, J G Gonzalez, Mirna Hilal, Fernando E PradoAbstract:Abstract This paper examined the peel (albedo and flavedo) of postharvest Lemon fruits after UV-B exposure in order to analyze relationships between soluble carbohydrate metabolism and secondary metabolite accumulation. Lemons ( Citrus limon , cv. Limoneira 8A) were harvested in winter months (June to August), treated with 0.43 W m −2 (22 kJ m −2 d −1 UV-BBE) of UV-B radiation during 0 (control), 0.5, 1.0, 2.0, 3.0, and 5.0 min, and then stored at 25 °C for 24 h. Peel samples from irradiated areas were obtained with a razor blade and frozen in liquid nitrogen until use for measurements. Data obtained showed that 2 and 3 min of UV-B exposure effectively increased the level of UV-B absorbing compounds and total phenolics in flavedo without causing visual alterations of the peel colour as compared with non-irradiated Lemons. By contrast, there were no significant changes in albedo secondary metabolite accumulation. The amount of secondary metabolites was depending upon UV-B time–dose. Exposure over 3.0 min did not further improve the accumulation of UV-B absorbing and phenolic compounds. Soluble sugars (sucrose, glucose and fructose) also accumulated in the Lemon peel after UV-B exposure, but the distribution patterns were different. After 3 min time–dose, sucrose and hexoses increased in flavedo, whereas in albedo only increased the sucrose and glucose. This effect was related to UVB-induced changes in the activity of sucrose-hydrolyzing and sucrose-synthesizing enzymes: soluble and cell-bound invertase, sucrose synthase (SS) and sucrose phosphate synthase (SPS). Data indicate that Lemon peel retains the capacity to modify the enzyme activity of sucrose metabolism in response to UV-B exposure. Our results also suggest that the exposure of postharvest Lemons to low supplemental UV-B doses produces changes in the carbon allocation of peel tissues including synthesis, but probably not only limited to them, of UV-B absorbing and phenolic compounds.
