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Peel Oil (peel + oil)
Selected AbstractsMonoterpene biosynthesis in lemon (Citrus limon)FEBS JOURNAL, Issue 13 2002cDNA isolation, functional analysis of four monoterpene synthases Citrus limon possesses a high content and large variety of monoterpenoids, especially in the glands of the fruit flavedo. The genes responsible for the production of these monoterpenes have never been isolated. By applying a random sequencing approach to a cDNA library from mRNA isolated from the peel of young developing fruit, four monoterpene synthase cDNAs were isolated that appear to be new members of the previously reported tpsb family. Based on sequence homology and phylogenetic analysis, these sequences cluster in two separate groups. All four cDNAs could be functionally expressed in Escherichia coli after removal of their plastid targeting signals. The main products of the enzymes in assays with geranyl diphosphate as substrate were (+)-limonene (two cDNAs) (,)-,-pinene and ,-terpinene. All enzymes exhibited a pH optimum around 7; addition of Mn2+ as bivalent metal ion cofactor resulted in higher activity than Mg2+, with an optimum concentration of 0.6 mm. Km values ranged from 0.7 to 3.1 µm. The four enzymes account for the production of 10 out of the 17 monoterpene skeletons commonly observed in lemon peel oil, corresponding to more than 90% of the main components present. [source] Characterization of the major odorants found in the peel oil of Citrus reticulata Blanco cv. Clementine using gas chromatography,olfactometryFLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2003Mary G. Chisholm Abstract Gas chromatography,olfactometry (GC,O), gas chromatography,mass spectrometry (GC,MS) and preparative column chromatography were used to identify the key odorants present in laboratory-extracted clementine oil from Spain. Almost 50 odorants were identi,ed using GC,O, many of which were unsaturated aldehydes with high odour spectrum values (OSV). , - and , -sinensal, trans -4,5-epoxy-(E)-2-decanal, (E,Z)-2,6-dodecadienal and linalool were found to dominate clementine oil aroma. Enrichment of the oxygenates using preparative column chromatography provided further identi,cation of a total of 50 aldehydes, not all of which were present in the oil at concentrations high enough to produce a response using GC,O. Aldehydes contributed approximately 80% of the total aroma of clementine oil. New odorants not previously reported in clementine oil include many unsaturated aldehydes, trans -4,5-epoxy-(E)-2-decenal, trans -4,5-epoxy-(E)-2-dodecenal, 4-hydroxy-2,5-dimethyl-3(2H)-furanone (furaneol), 3-hydroxy-4,5-dimethyl-3(2H)-furanone (sotolon) and 1,8-cineole. No single odorant emerged as being characteristic of clementine oil aroma. Copyright © 2003 John Wiley & Sons, Ltd. [source] Effect of caking and stickiness on the retention of spray-dried encapsulated orange peel oilJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2003César I Beristain Abstract Flavour microcapsules containing amorphous carbohydrate as wall material can undergo changes such as crystallisation, clumping, sticking and caking during handling and storage. Such physical changes may lead to the release of entrapped flavours. The objective of this study was to investigate the effect of storage temperature and water activity on caking, stickiness and glass transition temperatures and to evaluate the relative degree of protection provided to orange peel oil entrapped in mesquite (Prosopis juliflora) gum by spray drying. The powders were stored at water activities (aw) ranging from 0.108 to 0.972 at 25 and 35 °C. The surface caking temperature (Tsc) and advance caking temperature (Tac) were determined by the modified ampoule and sealed glass tube methods respectively. The glass transition temperature was determined by differential scanning calorimetry. Changes in the amount of encapsulated oil were determined by Clevenger hydrodistillation. As expected, both Tsc and Tac decreased with increasing storage aw. Above aw 0.628 the powders caked and collapsed during storage at 35 °C. Below aw 0.628 the capsules were not damaged and high retention levels (above 90%) were obtained. Increasing aw in the range 0.743,0.972 caused progressive dissolution of the wall polymer, and the retention level dropped sharply. The volatiles are protected and retained by mesquite gum as long as the capsule structure remains intact. Copyright © 2003 Society of Chemical Industry [source] Chemical variability of peel and leaf oils of mandarinsFLAVOUR AND FRAGRANCE JOURNAL, Issue 2 2006Anne-Laure Fanciullino Abstract Peel and leaf oils of 35 mandarin cultivars, belonging to five different species, were obtained from fruits and leaves collected on mandarin-trees kept at the same pedoclimatic and cultural conditions. Their chemical composition was investigated by capillary GC, GC,MS and 13C-NMR and the results were submitted to a statistical analysis. Two major chemotypes, limonene and limonene/, -terpinene, were distinguished for peel oils, while five chemotypes, linalool, sabinene/linalool, , -pinene/linalool, , -terpinene and methyl N-methylanthranilate, were observed for leaf oils. The results were compared with those already reported by our groups. Copyright © 2005 John Wiley & Sons, Ltd. [source] Volatile constituents of Vietnamese pummelo, orange, tangerine and lime peel oilsFLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2002N. T. Minh Tu Abstract The compositions of Vietnamese pummelo (Citrus grandis Osbeck), orange (C. sinensis Osbeck), tangerine (C. reticulata Blanco var. tangerine) and lime (C. limonia Osbeck) peel oil samples have been investigated by GC and GC,MS. The essential oils were extracted by the cold-pressing method. Hydrocarbons, followed by aldehydes and alcohols, were the most abundant compounds in all four kinds of samples. Their percentages, respectively, were >98.7%, >97.6%, >98.6% and >95.4% in hydrocarbons; >0.3%, 0.4%, >0.3% and 1.1% in total aldehydes; 0.2%, 0.5%, 0.4% and 0.7% in alcohols. In Vietnamese pummelo oil, ,-terpinene was not detected, while terpinolene was detected in small amounts and nootkatone only at a level of <0.05%. Orange oil composition was comparable to that of other sweet orange oils. ,-3-Carene was detected at a level of 0.1%. Tangerine oil is easily distinguished from other citrus oils by its content of various aliphatic aldehydes. Lime oil presented a very different composition from the other oils studied. Its limonene content was substantially lower than that of pummelo, orange and tangerine oils, whereas ,-terpinene, ,-pinene and ,-pinene occurred in higher proportions, moreover, the sesquiterpene hydrocarbon fraction of this oil is qualitatively more complex and quantitatively more abundant than in the other oils. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||