A comparison of pericarp anatomy and antioxidant responses after mandarin (Citrus reticulata Blanco) and orange (Citrus sinensis Osbeck) fruits sunburned

Full-scale experiments in forced-air precoolers for citrus fruit: Impact of packaging design and fruit size on cooling rate and heterogeneity

Different patterns of allergen recognition in children allergic to orange

Exploring the phytochemical content and the antioxidant potential of Citrus fruits grown in Cyprus

Essential oils from citrus cultivars are widely used in food, cosmetic, and pharmaceutical industries, and they have been extensively studied in the last decades. This study investigates the antioxidant activities of essential oils from 21 citrus cultivars and the active antioxidant constituents of the oils. Essential oils are extracted from the peels of citrus cultivars via hydrodistillation, and their chemical compositions are analyzed by gas-chromatography-mass-spectroscopy. The antioxidant activities of the citrus cultivars are determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and ferric-reducing antioxidant potential (FRAP) assays. Based on the results, the major constituent of the oils is d-limonene (50.88-97.19%). The essential oil from Citrus junos shows the highest phenolic content (360.04 ± 24.75 mg GAE/100 g), followed by that from Citrus × latifolia (339.42 ± 31.14 mg GAE/100 g), [(Citrus unshiu × Citrus sinensis) × Citrus reticulata] × Citrus reticulata (327.05 ± 14.29 mg GAE/100 g), and [(Citrus unshiu × Citrus sinensis) × Citrus reticulata] × Citrus reticulata (322.92 ± 21.43 mg GAE/100 g). The essential oil from [(Citrus unshiu × Citrus sinensis) × Citrus reticulata] × Citrus reticulata shows the highest DPPH and ABTS radical scavenging activity, with an EC50 of 86.17 ± 4.87 and 0.16 ± 0.06 mg/mL, respectively. The essential oil from Citrus reticulata and [(Citrus unshiu × Citrus sinensis) × Citrus reticulata] × Citrus reticulata shows the highest ferric-reducing activities (2302.55 ± 237.26 and 2213.12 ± 35.54 mg/100 g, respectively). These results indicate that the essential oil from [(Citrus unshiu × Citrus sinensis) × Citrus reticulata] × Citrus reticulata has a higher antioxidation effect than that from other cultivars. By comparing the chemical compositions of the essential oils, 12 compounds are selected as the major contributors to the antioxidant activities of the oils, and α-phellandrene and α-terpinene are the most active constituents of the oils.

Citrus fruits, in particular the genus Citrus, are very rich in antioxidants which have beneficial effects on human health. The objective of this study was to evaluate the phenolic content and the antioxidant activity of the ethanolic extracts from orange (Citrus sinensis L.) and mandarin (Citrus reticulata L.) fruits. The quantitative estimation of the total phenolic content in the two extracts revealed their richness in these compounds. The results obtained showed that the polyphenols content were 159.66 ± 2.62 mg GAE / g of dry extract and 127.33 ± 2.32 mg GAE / g of dry extract for C. sinensis and C. reticulata, respectively.The quantification of flavonoids content showed that the ethanolic extracts of C. sinensis and C. reticulata contained 0.85 ± 0.01 mg QE / g of dry extract and 0.876 ± 0.073 mg QE / g of dry extract, respectively. Whereas, the tannins contents were 46.32 ± 1.02 mg TAE / g of dry extract for C. sinensis and 47.65 ± 1.36 mg TAE / g of dry extract for C. reticulata. In vitro antioxidant activity was evaluated using two tests: the reducing power and the hydroxyl radical scavenger test. The evaluation of the two extracts by the ferric iron reducing power test showed an EC50 value of 0.882 ± 0.037 mg / ml for C. sinensis extract and an EC50 of 1.085 ± 0.068 mg / ml for C. reticulata extract. In addition, C. sinensis and C. reticulata showed good hydroxyl radical scavenging effect with IC50 values of 0.303 ± 0.026 mg /ml and 0.572 ± 0.100 mg / ml for C. sinensis and C. reticulata, respectively. These results suggested that these fruit extracts could be good sources of phenolic compounds and ingredients with high antioxidant potential.
 Keywords: Citrus sinensis, Citrus reticulata, Polyphenols, Flavonoids, Tannins, Antioxidant activity.

Experiment was conducted at the Biological Sciences Laboratory of Benue State University, Makurdi, Nigeria to determine the efficacy of bio-based extracts (Aloe vera and Gum arabic) on shelf-life and quality of sweet orange. Healthy orange fruits of two varieties (Valencia and Washington) used in the trial were picked at harvest maturity. The experimental design was a 2 x 4 factorial combination, fitted in a completely randomized design and replicated three times. The treatments consisted of two varieties of sweet orange and four extracts regimes (Aloe vera, Gum arabic, Aloe vera+Gum arabic and Control). The orange fruits were treated by dipping in extracts the various treatments until they were completely coated while the control fruits were not treated. The treated fruits and control were stored at ambient conditions of light and temperature for four weeks. Percentage weight loss, total soluble solids, fruit firmness, Vitamin C/Ascorbic acid content, pH, titratable acidity, decay percentage (DP %), marketability and shelf life of the fruits were recorded. The data were subjected to Analysis of Variance (ANOVA) using GENSTAT statistical package, and mean separation was done using Fisher’s Least Significant Difference (F-LSD) at 5% level of probability. Percent weight loss, fruit firmness, % decay and fruit marketability were significantly higher (P≤0.05) in Valencia compared with Washington. Fruits treated with Gum Arabic had significantly lower % weight loss and % decay compared with the control (P≤0.05). Fruit firmness was significantly higher (P≤0.05) in fruits treated with Gum Arabic + Aloe Vera while marketability was significantly higher in Aloe Vera treated fruits. All the treated fruits had significantly higher (P≤0.05) shelf life compared with the control. With respect to nutritional values, TSS was significantly higher (P≤0.05) in Valencia compared with Washington while Vitamin C and pH were significantly higher (P≤0.05) in Washington compared with Valencia. The TSS was significantly higher (P≤0.05) in Aloe Vera and Aloe Vera + Gum Arabic treated fruits compared with the control. The Vitamin C content of fruits treated with Gum Arabic was significantly (P≤0.05) higher followed by Aloe Vera + Gum Arabic compared with the control. All the treated fruits had significantly higher pH while TA was significantly lower (P≤0.05) compared with the control. Percent weight loss was positively and significantly correlated with % decay while marketability, shelf life, TSS, and TA were negatively and significantly correlated. The botanicals tested are environmentally friendly, cost-effective, easy to produce and also safe for consumers. The bio-based extracts of Aloe vera and Gum Arabic are recommended in the storage of flesh sweet orange fruits.

The province of West Sumatera in Indonesia prioritizes three types of fruit: orange, mangosteen, and banana in its production every year. Orange fruit be one of the people favorite fruits because rich in vitamin C, good taste and affordable prices. There are various ways of storing orange fruit, some are stored in the refrigerator and some in room temperature, eaten directly or stored for several days. Based on that reasons research on vitamin C content in orange fruit based on temperature and storage time has been conducted. The objective of this research was to determine the effects of temperature (refrigeration temperature/8oC and room temperature/30oC) and storage time (1, 3 and 7 days) on vitamin C content in orange fruit. The orange fruit were squeezed, filtered and diluted 100 times. All prepared solution of orange fruit has been measured with uv-visible spectrophotometer at wavelength of maximum absorbance264 nm. The results revealed that is a decreased vitamin C content in orange fruit based on temperature and storage time. Where orange fruit are stored at room temperature decreased faster more than orange fruit that stored in refrigeration temperature and orange fruit with storage time 7 days have decreased more than orange fruit that stored for 3 days or 1 day. In conclusion is vitamin C content decreases accelerate with higher storage temperature and longer storage time.

Carotenoids are the pigments responsible for the coloration of the peel and pulp of Citrus fruits. Light is one of the major environmental factors influencing coloration and carotenoid content and composition of fleshy fruits and therefore their commercial and nutritional quality. Agronomical observations indicate that citrus fruits exposed to sunlight develop a brighter peel coloration than shaded fruit inside the tree canopy. In the present study, the effect of light deprivation on carotenoid profile, and in the expression of genes of carotenoid metabolism and their precursors have been analyzed in fruits of Clemenules mandarin (Citrus clementine) and Navelina orange (Citrus sinensis). Fruit shading accelerated peel degreening, chlorophyll degradation, and reduced chloroplastic-type carotenoids. Time-course shading experiments revealed that the stage of fruit ripening appears to be determinant for the effect of darkness in carotenoid biosynthesis. Fruit shading produced a down-regulation of the expression of key carotenoids biosynthetic genes (PSY, PDS, ZDS1, LCY2a, LCY2b, and CHX). However, expression of MEP pathway genes (DXS, HDR1, and GGPPS1) and the carotenoid cleavage dioxygenase, CCD4b1, responsible of the formation of the apocarotenoid β-citraurin, were not substantially affected by dark-grown conditions. The content of abscisic acid (ABA), an end product of the carotenoid pathway, was not affected by the light regime, suggesting that effect of shading on the precursor’s pool is not sufficient to impair ABA synthesis. A moderate increase in total carotenoid and in the expression of biosynthetic genes was observed in mature dark-grown mandarin and orange fruits. Collectively, results suggest that light stimulates carotenoid biosynthesis in the peel of citrus fruits but a light-independent regulation may also operate.

Huanglongbing (HLB) is one of the world’s worst diseases of citrus trees. The research was conducted to characterize positive citrus samples of two local varieties, ‘Kinnow’ mandarin (Citrus reticulata Blanco) and ‘Mosambi’ orange (C. sinensis (L.) Osbeck), based on morphological, physical and biochemical characters. Physical and biochemical parameters of greening infected and healthy samples of both the cultivars were significantly different. Citrus fruits were lopsided and half to full green in the HLB infected trees compared to healthy. The HLB infected leaves samples were small and narrow. Fruit diameter, leaf area, and juice weight of HLB infected samples were significantly less than healthy samples. The rind thickness of infected fruits (70% and 80%) was significantly higher than healthy ones (20% and 30%). Starch content of leaves from mandarin (5.54 μg mL-1) and orange (6.12 μg mL-1) were significantly higher in HLB infected plants, while juice percentage of HLB infected fruit samples was lesser in mandarin and orange (22.73%, and 14.70%, respectively) than healthy fruits (38.22% and 31.30%, respectively). Acidity was significantly increased in juice of HLB infected mandarin and orange fruits (0.57%, and 0.53%, respectively). Similarly, there was significant reduction in biochemical parameters; total sugars in mandarin and orange (5.16% and 4.79%), total soluble solids (8.54% and 8.28%), total chlorophyll (13.50 and 14.92 mg mL-1) and ascorbic acid (34.28% and 34.12%) in HLB infected samples of both cultivars. This study determined differences of physical and biochemical parameters of two local citrus varieties, commonly cultivated in the Asian region.

Orange fruit who be the superior commodity is known as a fruit who rich of its vitamin C. One kind of orange who really liked by the society is Mandarin Orange (Citrus reticulata) that comes from China. The aims of this research were to know the effect of ethanol and chloroform solvent ratio to the characteristic of the natural colorant from Mandarin orange peel extract and determine the best ethanol and chloroform solvent ratio which produced Mandarin orange peel extract as natural colorant. Experimental design in this research used Randomized Block Design by using the comparison of ethanol and chloroform solvents that consist of 6 levels, there are: ethanol : chloroform (0:10); ethanol : chloroform (2:8); ethanol : chloroform (4:6); ethanol : chloroform (6:4); ethanol : chloroform (8:2); ethanol : chloroform (10:0). The treatment was repeated as many as 3 repetitions then obtained 18 units of the experiment. The data were analyzed by variance and if the treatment had a effect on the variable then continued with Duncan test. The result showed that ethanol and chloroform solvent ratio had significant effect on the yield, the total carotenoids content, the level of brightness (L*), the level of redness (a*), the level of yellowness (b*) of Mandarin orange peel extract. Based on the results of index effectiveness test used five expert, the ethanol and chloroform solvent ratio of 0 :10 produced the best characteristic of Mandarin orange peel extract with the yield 4.83 ± 0.22f (%), the total carotenoids content 3.56 ± 0.20a (%), the level of brightness (L*) 31.34 ± 0.63d, the level of redness (a*) 28.39 ± 0.69a, and the level of yellowness (b*) 34.52 ± 0.18a.
 Keywords : Citrus reticulata, extraction, ethanol, chloroform, natural colorant

Thiabendazole residue loading in dip, drench and wax coating applications to control green mould and chilling injury on citrus fruit

A description is provided for Hendersonula toruloidea . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On a wide range of hosts including Acacia spp., Agave sisalana, Ananas comosus, Arachis hypogaea, Citrus spp., Dioscorea spp., Ficus carica, Furcraea spp., Hevea brasiliensis, Ipomoea batatas, Juglans regia, Juglans hindsii, Malus pumila, Mangifera indica, Manihot utilissima, Melia azedarach, Morus alba, Musa spp., Liriodendron bipinnatifidum, Pithecolobium dulce, Plumeria acutifolia, Populus alba, Prunus spp., Psidium guajava, Sansevieria spp., Solanum tuberosum, Trifolium alexandrinum, Trigonella spp., Vitis vinifera (Browne, 1968 and Herb. IMI). Also pathogenic to man (Gentles & Evans, 1970). DISEASE: On plants : Causing branch wilt of fig, grapevine and walnut; dieback of apple, grapefruit, mulberry, stone fruit and walnut; canker of grapefruit, mandarin orange and mulberry; gummosis of apple, fig, grapefruit, mandarin orange, poplar and walnut; fruit rot of Cavendish banana and orange (on inoculation); associated with a rot of potato tubers ( Solanum tuberosum ) in U.K. following inoculation with roots of potato naturally infected with Phoma exigua (Herb. IMI) and a storage rot of yam ( Dioscorea spp.) in Nigeria (45, 3254). On man : The fungus has been isolated in U.K. from infections of feet and/or toe-nails of former residents of the tropics (Gentles & Evans, 1970). GEOGRAPHICAL DISTRIBUTION: Africa (Ghana, Guinea, Nigeria, Rhodesia, Sierra Leone, Sudan, Tanzania), Asia (Cyprus, India, Iraq, Malaysia, Pakistan); North America (U.S.A. : California); Central America and the West Indies (Jamaica); Europe (U.K.). TRANSMISSION: By wind-borne spores. A wound parasite of fig (43, 2007), grapefruit (34: 365), grapevine (46, 2590), mulberry (35: 647) and of banana and orange fruit (43, 1716). Germinating conidia penetrate walnut branches only through breaks in the periderm (43, 884u) especially cracks caused by sun scorch (35: 495; 44, 1757b). Hail damage also predisposes fig to branch wilt (43, 2007).

Calyx browning and internal quality loss are major physiological causes for the loss of quality in citrus fruit during storage. While the symptoms of calyx senescence are only superficial, it can affect the appearance and consumer acceptability of citrus fruit. In this study, continuous ethylene exposure at different storage temperatures was investigated to assess their effect on calyx senescence and internal qualities in ‘Afourer’ mandarin and Navel orange fruit during storage. ‘Afourer’ mandarin fruit were stored at ≤0.001 (equivalent to ethylene-free air), 0.01, 0.1 and 1 µL L−1 of ethylene at either 5, 10 or 20 °C, whilst in a parallel experiment, Navel oranges were exposed to ≤0.001, 0.1 and 1 µL L−1 ethylene at either 1 or 10 °C. Changes in external and internal postharvest quality parameters were assessed for up to 8 weeks for ‘Afourer’ mandarins and 10 weeks for Navel oranges. At all storage temperatures, high levels of ethylene were found to increase the level of calyx senescence, weight loss, loss of fruit firmness and respiration rates. Also, there were significant effects of ethylene and storage temperatures on total soluble solids (TSS) content, titratable acidity (TA), and ethanol accumulation in both citrus species. Continuous exposure to high ethylene also significantly reduced vitamin C and ferric reducing antioxidant power (FRAP) in ‘Afourer’ mandarins after 8 weeks of storage. Overall, ethylene treatments had a significant effect on both the external and internal qualities of the fruit during storage. The relationship between ethylene concentrations and storage temperatures demonstrate that lowering atmospheric ethylene levels at reduced storage temperatures maintain fruit quality during long term storage.

The citrus red mite, Panonychus citri (McGregor, 1916), is considered a very important pest in most citrus-growing countries. The developmental periods, reproduction rates, and population growth parameters of P. citri were evaluated using the fruit peel under experimental conditions (25 ± 1 °C, 50 ± 5% RH and 14:10 h photoperiod) on five Citrus species: Mexican lime (C. ×aurantiifolia (Christm.) Swingle), grapefruit (C. ×paradisi Macfad.), sweet orange (C. ×sinensis (L.) Osbeck), mandarin (C. reticulata Blanco), and tangelo fruit (C. ×tangelo J.W. Ingram & H.E. Moore). The developmental period of the immature stages of P. citri averaged 26.64, 25.93 and 25.75 d for sweet orange, mandarin, and tangelo fruit, respectively. The adult stage was not achieved in Mexican lime and grapefruit. Immature survival was less than 50% in mandarin and tangelo fruit, in contrast, in sweet orange it was 57%. On average, oviposition was 3.55, 4.95 and 5.00 eggs female-1, on sweet orange, mandarin, and tangelo fruit, respectively. The intrinsic natural growth rate (rm), net reproduction rate (R0), generation time (T), and finite growth rate (λ) of P. citri showed significant differences among the tested species (p < 0.05). The rm and R0 values were 0.005 and 1.209 for sweet orange, 0.026 and 2.474 for mandarin and 0.020 and 2.000 for tangelo fruit. The results indicated that mandarin was the most suitable species for the P. citri population growth, whereas sweet orange was less suitable to proliferate. These differences are important in the integrated management of P. citri on citrus.

Citrus is one of the most popular and widely grown fruit crops in the world. However, the bioactivity of only certain species of citrus cultivars is studied. In this study, the effects of essential oils from 21 citrus cultivars on melanogenesis were investigated in an effort to identify active anti-melanogenesis constituents. The essential oils from the peels of 21 citrus cultivars obtained by hydro-distillation were analyzed using gas chromatography-mass spectrometry. Mouse melanoma B16BL6 cells were used in all assays conducted in this study. The tyrosinase activity and melanin content were determined using the lysate of α-Melanocyte-stimulated B16BL6 cells. In addition, the melanogenic gene expression was determined by quantitative reverse transcription-polymerase chain reaction. Overall, the essential oils of (Citrus unshiu X Citrus sinensis) X Citrus reticulata, Citrus reticulata, and ((Citrus unshiu X Citrus sinensis) X Citrus reticulata) X Citrus reticulata provided the best bioactivity and comprised five distinct constituents compared to other essential oils such as limonene, farnesene, β-elemene, terpinen-4-ol, and sabinene. The anti-melanogenesis activities of the five individual compounds were evaluated. Among the five essential oils, β-elemene, farnesene, and limonene showed dominating properties. The experimental results indicated that (Citrus unshiu X Citrus sinensis) X Citrus reticulata, Citrus reticulata, and ((Citrus unshiu X Citrus sinensis) X Citrus reticulata) X Citrus reticulara are potential candidates with anti-melanogenesis activity for use as cosmetics and pharmaceutical agents against skin hyperpigmentation.