Mandarin Leaf Research Articles

Chemical Diversity of Citrus Leaf Essential Oils.

The essential oils from leaves of 20 commercial citrus accessions maintained by the University of California, Riverside Givaudan Citrus Variety Collection and selected on the basis of their odor profile were analyzed by GCMS/FID. The main components were quantified while the semi-quantitative percentage composition data was compiled with data from other publications for sample visualization, classification and comparison with leaf oils from other citrus accessions. Some compositional clusters aligned closely with the taxonomic clades of sweet orange, bitter orange, and C. hystrix while other clades like the mandarins and lemons showed distinct chemical sub-groups. Characteristic compounds for the clusters included linalyl acetate and linalool (bitter orange leaf), sabinene (sweet orange leaf), methyl N-methyl anthranilate (mandarin leaf), γ-terpinene (yuzu leaf), citronellal (C. hystrix), limonene, citronellal and citral (lemons and citrons). A chemometric approach combined with t-SNE cluster plots can be more informative than taxonomic assignments when considering flavor and fragrance characteristics.

Evaluation of Antioxidant activity and Phenolic contents of Kinnow mandarin leaf extracts

Kinnow mandarin is a major citrus fruit crop in India. This study was designed to evaluate Total Phenol content (TPC), Total Flavonoid content (TFC) and antioxidant activity of vegetative and fruit associated leaves extracts of Kinnow at three different times of the year. The results revealed variation in all three parameters chosen: total phenol, flavonoid content as well as antioxidant capacity between vegetative and fruit associated leaves and during different time periods of the study.The TPC and TFC were highest for fruit associated leaf phase II (9.49 ± 0.075 GAE /g dw and 7.74 ± 0.125 QE mg /g dw respectively) whereas antioxidant activity 31.49 ± 0.025 mg AA/g dw was highest for fruit associated leaves phase I extracts. The TPC,TFC and DPPH free radical scavenging activity among the leaf extracts of Kinnow indicated that some non- phenolic components also contributed to the total antioxidant activity in Kinnow leaves extracts examined in the present investigation. To the best of our information, this is the first experiment presenting comprehensive data on TPC, TFC and antioxidant activity for Kinnow leaf extracts. The study further envisaged that the Kinnow leaves may be important sources of antioxidant for food and pharmaceutical industries.

A Green Valorisation Approach Using Microwaves and Supercritical CO2 for High-Added Value Ingredients from Mandarin (Citrus deliciosa Tenore) Leaf Waste

The present study aims to increase the efficiency of a resource from waste to health by valorisation of it through cleaner, eco-friendly and less energy-consuming technical processes such as microwave-asissted (MAE) and supercritical fluid (SFE) extractions. On the other hand, optimization of the processes have been applied utilizing multivariate statistic technique such as Response surface Methodology (RSM) in order to consider any possible interaction between variables with less number of experiments as well as to model a response affected by several variables. The outcome of the present study indicates that the optimum conditions for MAE were 275 W of microwave power together with 2 g mandarin leaf for 45 s; regarding SFE, 50 °C, 200 bar and 0.39 mL/min was found as the optimal condition to obtain the maximum yields of each dependent variable such as total phenolic material (TPM) and total flavonoid material (TFM), respectively. Additionally, antioxidant activity values measured by several methods such as cupric ion reducing antioxidant capacity (CUPRAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) were correlated positively with both TPM and TFM in the leaf extracts. Furthermore, scanning electron microscope (SEM) images indicated cell wall disruption in all the treatement groups compared to untreated samples.

English

  The volatile flavor components of flower, leaf, peel and juice of ‘Page’ mandarin were investigated in this study. Flower components were extracted by using ultrasound (US) water bath apparatus and then eluted by n-pentane : diethylether (1:2) solvent. Leaf flavor components were extracted by using water distillation method and then eluted by using n-hexane solvent. Juice flavor components were extracted by using poly dimethyl siloxane membranes (PDMS) and then eluted by pentane : dichloromethane (2:1). Peel flavor components were extracted by using cold-press and then eluted by using n-hexane. Then, they were all analyzed by GC-FID and GC-MS.  37 flower components,  53 leaf components,  54 peel components and 47 juice components including: aldehydes, alcohols, esters, ketones, monoterpenes, sesquiterpenes and other components were identified and quantified. The major flavor components were linalool, limonene, sabinene, α-pinene, β-myrcene, δ-3-carene, terpinene-4-ol and α-terpineol. The flower oil showed the highest content of aldehydes and alcohols. Since the aldehyde content of citrus oil is considered as one of the most important indicators of high quality, organ apparently has a profound influence on P ge mandarin oil quality.   Key words: ‘Page’ mandarin flower, ‘Page’ mandarin leaf, ‘Page’ mandarin peel, ‘Page’ mandarin juice, flavor components, ultrasound, water-distillation, pervaporation, cold-press.

The effects of rootstock on the volatile flavor components of page mandarin (( Citrus reticulata var dancy × Citrus paradisi var dancan) × Citrus clemantina ) flower and leaf

The effects of rootstock on the volatile flavor components of page mandarin flower and leaf were investigated in this study. Flower flavor components were extracted by using ultrasound(US) water bath apparatus and eluted by n-pentane: diethylether(1:2) solvent and then analyzed by GC-FID and GC-MS. Leaf flavor components were extracted by using water distillation method and eluted by using n-hexane solvent and then analyzed by GC-FID and GC-MS. Fifty-two flower components and, sixty-nine leaf components including: aldehydes, alcohols, esters, ketones, monoterpenes, sesquiterpenes and other components were identified and quantified. The major flavor components were linalool, limonene, ocimene, -pinene, sabinene and myrcene. The flower and leaf oil from plants grown on Swingle Citrumelo and Yuzu showed the highest content of aldehydes. Since the aldehyde content of citrus oil is considered one of the more important indicators of high quality, rootstock apparently has a profound influence on Page mandarin flower and leaf oil quality. Key words: Page mandarin flower, page mandarin leaf, flavor components, rootstock, ultrasound, water-distillation

LEAF MINERAL COMPOSITION OF ‘NOVA’, ‘ROBINSON’ AND ‘FREMONT’ MANDARIN CULTIVARS ON DIFFERENT ROOTSTOCKS

Rootstock selection has a critical importance for mineral nutrition of budded cultivars. This study was conducted at the experimental farm of Mustafa Kemal University, Dörtyol, Turkey. The aim of this study was to investigate the effect of sour orange, Troyer and Carrizo citrange rootstocks on the leaf nutrient contents of ‘Nova’, ‘Robinson’, and ‘Fremont’ mandarin cultivars in the 2004 and 2005 growing seasons. Carrizo citrange was examined for nitrogen (N), potassium (K), magnesium (Mg), sodium (Na), and manganese (Mn); Troyer citrange for iron (Fe); and sour orange for calcium (Ca) and zinc (Zn) were superior on the others. Nitrogen, phosphorus (P) and Mg levels of mandarin leaf budded on sour orange were under or just above the deficiency threshold. Potassium, Mn, and Zn content of ‘Robinson’; P, Ca and Fe content of ‘Fremont’; and Cu content of ‘Nova’ were statistically higher. Therefore, it can be concluded that Carrizo rootstock may be suggested for the region and regions with similar ecological conditions.

Constituents of the Distilled Essential Oils of Citrus reticulata and C. paradisi from Nigeria

Hydrodistilled essential oils from the fruit of Citrus paradisi Macfad. (Rutaceae), and fruit peel and leaf of Citrus reticulata L. occurring in Nigeria, were studied by GC and GC/MS on two separate columns. All oils yielded predominantly comparable amounts of monoterpene hydrocarbons (81.0–98.0%). Limonene was the main constituent in mandarin (67.0%) and grapefruit (94.2%) peel oils, while γ-terpinene (53.0%) and linalool (16.1%) were the chief constituents of mandarin leaf oil. Marked differences existed in the composition of the major and minor constituents of tangerine oils. Aliphatic aldehydes and alcohols were also detected in all oils.

Predominant Expression of Diploid Mandarin Leaf Proteome in Two Citrus Mandarin-Derived Somatic Allotetraploid Hybrids

Fusion of citrus diploid parental protoplasts generates allotetraploid hybrids which do not retain their parental traits with regard to leaf aroma compound biosynthesis. The aim of this study was thus to examine hybrid leaf proteomes in comparison with their parents. Leaf soluble proteins from two citrus allotetraploid hybrids (mandarin + lime and mandarin + kumquat) and their diploid parents (mandarin, lime, and kumquat) were submitted to 2-D gel electrophoresis. Leaf proteome maps of the tetraploid hybrids were compared with those of their parents on the basis of the presence/absence of spots and of their spot relative volumes. The two allotetraploid hybrid maps were found closer to that of their mandarin parent than to those of their nonmandarin parents in terms of the presence/absence of spots as well as at a quantitative level. This approach has to be related to the already observed dominance of mandarin in allotetraploids with regard to volatile compound biosynthesis in leaves.

Composition of Turkish Mandarin and Bergamot Leaf Oils

Mandarin (Citrus reticulata Blanco) and bergamot (Citrus bergamia Risso et Poit.) leaf oils were obtained from mandarin and bergamot leaves by steam distillation. The oils were analyzed by high-resolution gas chromatography (HRGC) and high-resolution gas chromatography/mass spectrometry (HRGC/MS). In total, 42 and 50 components were identifed in mandarin and bergamot leaf oils, respectively. Mandarin leaf oil showed a high content of monoter-pene hydrocarbons (62.6%), with sabinene (42.5%) and γ-terpinene (3.8%) being the major components. Bergamot leaf oil was characterized by a higher content of oxygenated compounds (90.4%), of which linalyl acetate (49.6%) and linalool (22.4%) were the major ones. It contained lower amounts of monoterpene hydrocarbons (8.1%) than the mandarin leaf oil.

Illumination-Independent Reflectance Information Acquirement for Leaf Water Potential Measurement on the Example of Satsuma Mandarin

Mandarin fruit sugar content can be increased when subjecting the satsuma mandarin tree (Citrus unshiu MARC. var. satsuma) to moderate water stress by mulching during the period of active sugar accumulation, thereby fruit quality improvement can be realized. In the frame of the precision agriculture production system, a non-destructive measuring method development became necessary based on remote sensing, field spectroscopy and image analysis, to be able to measure the degree of water stress. Large amount of visual information have been recorded at ground level, in near infrared, red and green channels by a false color digital camcorder designed specially for remote sensing applications. A method have been found to be able to calculate the absolute reflection of mandarin leaf surface by comparing leaf reflectance with known reference target reflectance, thereby established the basis of further studies in this topic. Leaf absolute reflection can be measured reliably, under variable natural illumination at field conditions. Functional correlation can be searched between visual information and leaf water potential measured by PMS pressure chamber.

On-line HPLC--HRGC--MS for the Analysis of Natural Complex Mixtures

A fully automated high–performance liquid chromatographic–high-resolution gas chromatographic-mass spectrometric system (ion-trap detection) is used for the analysis of hydrocarbon and oxygenated fractions of bitter orange, sweet orange, lemon, and mandarin leaf oils. The fractions are isolated by liquid chromatography and separated by gas chromatography. Component identification is by mass spectrometry (ITD). The qualitative and quantitative composition of the oils is discussed. Addition of or contamination by sweet orange, lemon, and mandarin leaf oils to bitter orange oil is detectable because of qualitative and quantitative differences.

Early physiological responses associated with race-specific recognition in soybean leaf tissue and cell suspensions treated with Pseudomonas syringae pv. glycinea

Pseudomonas syringae pv. glycinea race 4 ( Psgr4) induces a compatible reaction on soybean cv. Mandarin leaves while race 6 ( Psgr6) induces an incompatible hypersensitive response (HR). A single Psgr6 avirulence gene, avrA, when transformed into Psgr4, causes the resultant Psgr4(pAVRA) to induce a HR on Mandarin leaves. Mandarin leaf discs and suspension cells were inoculated and monitored for the K + H + and active oxygen responses, two early physiological events believed to be associated with recognition of HR-causing bacteria. Mandarin leaf discs exhibited a strong K + H + response following infiltration with either Psgr6 or Psgr4(pAVRA) but not Psgr4. Suspension cells derived from Mandarin hypocotyls reacted similarly when tested for the K + H + response to the Psg isolates. Luminol-dependent chemiluminescence (LDC) assays with suspension cells revealed active oxygen production concomitant with the K + H + response for both Psgr6- and Psgr4(pAVRA)-treated cells, but no such response was observed for Psgr4-treated cells. The data indicate that the K + H + and active oxygen responses are tightly correlated with recognition of the Psgr6 avrA gene or its products by Mandarin soybean leaves and suspension cells.