• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.510-518
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• 1989

Most of orange peels are disposed from orange juice manufacturing process. Thus, our purpose is to utilize these orange peels as fermentation substrate. We have investigated culture conditions and factors influencing citric acid production by an isolated strain, Asp. niger. Citric acid production was much higher in semisolid culture than in submerged culture and the particle size of ground orange peels was favored at 20 mesh in semisolid culture. The optimal pH and temperature were 4.5-5.0 and 3$0^{\circ}C$ respectively and the temperature cycling at 35$^{\circ}C$ for 20 hrs durig exponential phase, 1$0^{\circ}C$ for 4 hrs and 3$0^{\circ}C$ during stationary phase showed higher citric acid production than did at fixed temperature, 3$0^{\circ}C$. The addition of NH$_4$NO$_3$0.2%, MgSO$_4$7$H_2O$ 0.1%, methanol 2.5%, ethanol 1.5%, to culture medium promoted citric acid production but the addition of trace metal ions as nutrients had not effect on the acid production in orange peel medium. Under the optimal culture conditions, maximum yield of citric acid was 80.4% in solid medium. Almost of all original components of citrus peel was consumed by Asp. niger during fermentation.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.356-363
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• 2022

To investigate the functional activity of different citrus fruit peels, antioxidant compounds in 70% ethanol extracts of mandarin, lemon, orange, and grapefruit peel powders were identified, and antioxidant and antibacterial activities were quantitated. Mandarin peel contained the highest content of total phenolic compounds and total flavonoid substances (21.46±0.12 mg GAE/g and 11.57±0.05 mg RE/g, respectively). The total phenolic compound content of the three other citrus fruits was 14.16±0.18-18.44±0.07, and their total flavonoid content was 5.51±0.10-7.46±0.09 mg RE/g. DPPH radical scavenging activity was the highest in lemon peel (87.64±0.21%), and mandarin peel displayed the best antioxidant activity with respective ABTS radical scavenging activity and FRAP measurements of 43.20±0.61% and 78.82±1.06 mM TE/g. Grapefruit peel antimicrobial activity increased with treatment time, and was the most potent among the four tested citrus species, inhibiting Staphylococcus aureus by about 4.05 log cycle. These findings demonstrate that mandarin and grapefruit peel can be used to prevent oxidation, improve food storage capabilities, and potentially preserve food quality.

• Preventive Nutrition and Food Science
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• v.7 no.4
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• pp.411-416
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• 2002

The effects of electrodialysis (ED) alone or ED plus ultrafiltration (UF) on deacidification of mandarin orange juice were studied by using a commercial ED stack with ion exchange membranes. ED processing, reduced the total acidity of the juices by 30% (0.6~0.7% as total acidity) after 50 min and by about 60~70% (0.23~0.4% as total acidity) after 100 min, as compared to the control juice. However, the acidity reduction after 50 min of ED was determined to be suitable, when considering total acidity (0.6~0.7%, w/w) and current efficiency. There was no color change in the juices following ED, and the pH and Brix were only slightly decreased. Furthermore, ascorbic acid and citric acid concentrations showed only minor decreases, and amino-N, free sugar, and flavonoid contents remained almost unchanged. Therefore, we concluded that the nutritional integrity of the juice was maintained. ED combined with UF may be effective, not only in preventing membrane fouling, but also in preserving the nutrients, such as ascorbic acid, in citrus juice.

• Horticultural Science & Technology
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• v.19 no.2
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• pp.149-152
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• 2001

Leaf chlorophyll fluorescence capable to estimate $CO_2$ assimilation was compared among three citrus rookstocks: trifoliate orange (Poncitrus trifoliate L.), 'Flying Dragon' (Poncitrus trifoliate L. var. monstrosa) and citromelo (Poncitrus trifoliate L.${\times}$Citrus paradisi), as well as among satsuma mandarin (Citrus unshiu cv. Nichinan No.1) grafted on the 3 rootstocks. Citromelo, the most vigorous rootstock; and 'trifoliate orange'; the most common cultivar and moderate rootstocks gave the same potential and actual quantum yields, whereas 'Flying Dragon' (very dwarf) had lower values due to a higher Fo and Fs for fluorescence obtained from dark-adapted and light-adapted leaves, respectively. These findings show that the absorbed photon energy was dissipated more as fluorescence from the antena chlorophyll in 'Flying Dragon' than trifoliate orange or 'swingle' citrimelo. The satsuma mandarins grafted on these rootstocks did not, however, show the differences observed in the rootstocks by having all the same potential and actual quantum yields. It is suggested that the rootsocks do not potentially or actually electron transport in the Photosystem II (PS II) of satsuma mandarin grafted on the 3 rootstocks.

• Journal of dental hygiene science
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• v.19 no.1
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• pp.1-8
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• 2019

Background: Erosion is a gradual process that occurs fairly quickly, and the full extent of the erosive effects of acidic beverages is not yet clear. The present study aimed to determine the differences in the erosive potentials among four naturally acidic fruit nectars within the same range of titratable acidity and to determine the influence of the components of organic acids on tooth erosion. Methods: Diluted fruit nectars (mandarin 1:1.1, orange 1:1.7, lemon 1:15, grapefruit 1:20) with the same range of titratable acidity (7.9 ml) and their corresponding organic acids (0.05%, 0.1%, 0.3%, and 0.5% citric acid, malic acid, and a citric and malic acid mixture [pH 2.8], respectively) were used. Specimens were placed in conical tubes with 50 ml of each of the test solutions for 1 hour. A microhardness test and scanning electron microscopy were used to measure enamel erosion. Acid separation was carried out using high-performance liquid chromatography to analyze the composition of each test solution. Results: Similar decreases in the Vickers hardness number (VHN) were observed among the groups treated with the following diluted fruit nectars: diluted mandarin nectar ($75.9{\Delta}VHN$), diluted lemon nectar ($89.1{\Delta}VHN$), diluted grapefruit nectar ($91.7{\Delta}VHN$), and diluted orange nectar ($92.5{\Delta}VHN$). No statistically significant differences were found in the enamel surface hardness after erosion (p>0.05). Citric and malic acids were the major organic acids in the test fruits. The lemon and orange groups had the highest malic acid concentrations, and the mandarin group had the lowest malic acid concentration. Conclusion: The titratable acidity and the citric and malic acid contents of the fruits could be crucial factors responsible for enamel erosion. Therefore, fruit-based drinks should be regarded as potentially erosive.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.703-713
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• 2015

A Linear Approximated Inverse Almost Ideal Demand System, suggested by Eales and Unnevehr, is estimated with monthly data set of Korean fruits consumption. LA/IAIDS consists of 6 demand equations which correspond to domestically produced Hanrabong, overwintering mandarin, strawberry, melon and tomato with imported orange. The results indicate that price and scale flexibilities are negative, as expected. And the significance is that a 10% increase in imported orange quantity is associated with 5.5% declines in the price of Korean Hanrabong while the price of other fruits is minimally affected. In addition, the estimate of scale flexibility of Hanrabong (-2.96) is much smaller than any other fruit. Hanrabong farmer might be in the face of deficit operation as a consequence of the substitution effect if orange would be imported in accordance with the Korea-U.S. free trade agreement.

• Journal of the Korean Society of Food Culture
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• v.24 no.2
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• pp.212-218
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• 2009

This study was carried out to determine the quality characteristics of Jeju mandarin orange jellies containing sugar (control) and sugar derivative sweeteners (erythritol, isomaltooligosaccharide, sorbitol, and xylitol) to be consumed by the elderly. The gelling agents were carrageenan and gellan gum at the concentration of 0.27%, respectively. The average age of the subjects for the acceptance test was 78. The lightness (L), redness (a), and yellowness (b) values of the carrageenan gel were higher than those of the gellan gum gel using the same sugars. The L, a, and b values of the carrageenan gel made with sugar derivative sweeteners were higher than those of the respective gel made with sugar. Whereas there were almost no differences between the color values of the gellan gum gels made with sugar and sugar derivative sweeteners, respectively. The gelling and melting temperatures of the carrageenan gel with erythritol were highest and those of the respective gel with xylitol were lowest among the sugar derivative sweeteners. The gelling and melting temperatures of the gellan gum gels with erythritol and isomaltooligosaccharide, respectively, were lower, and those of the respective gel made with xylitol were higher compared to that with sugar. There was no break down in the gellan gum gel. The break down rate of the carrageenan gel made with isomaltooligosaccharide was highest and that of the respective gel with xylitol was lowest among the sugar derivative sweeteners. The hardness, adhesiveness, springiness, and chewiness of the gellan gum gel were greater compared to the carrageenan gel. The adhesiveness levels of the carrageenan gels made with sugar derivative sweeteners were lower, and their springiness was higher than the respective gel with sugar. All the TPA characteristics of the gellan gum gels made with erythritol and xylitol, respectively, were higher than the respective gel with sugar. The rupture properties of the gels were the same as their TPA characteristics. The sensory acceptance of the carrageenan and gellan gum gels made with sugar were highest among all the sweeteners. There were no significant differences in the sensory acceptance scores of the carrageenan gels made with xylitol, erythritol, and sugar, respectively, and there were also no significant differences in the sensory acceptance scores of the gellan gum gels made with xylitol, sorbitol, and sugar, respectively. Xylitol was preferred in both the carrageenan and gellan gum gels. Thus, xylitol appears to be an appropriate alternative sweetener to sugar in Jeju mandarin orange jelly for consumption by the elderly, with regard to the acceptability and stability of the gel.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.184-187
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• 2008

A new early maturing satsuma mandarin (Citrus unshiu Marc.) 'Haryejosaeng' was developed as a nucellar seedling selection of 'Tachima Wase' (C. unshiu Marc.) that was crossed with C. natsudaidai Hayata at the National Institute of Subtropical Agriculture in Jeju island in 1992. The 'Jegam ga No. 2', a first selection from the seedlings fruited in 2001 was finally named "Haryejosaeng" through field evaluation trials at three locations in Jeju island from 2003 to 2004. 'Haryejosaeng' produces seedless fruit maturing in early November, and has higher soluble solids and lower acidity than 'Miyagawa Wase', the leading early-maturing satsuma mandarin cultivar in Jeju island. Fruit weight is moderate at about 80~90 g and its shape is compressed-oblate globose with a light orange color. The rind thickness of about 2 mm provides easy peeling. The flesh shows light orange colored and contains 10 to 11 Brix and 1 to 1.1% acidity when mature. Tree shows vigorous growth and spreading thornless twigs. Alternate bearing is similar to 'Miyagawa Wase'. 'Haryejosaeng' is susceptible to citrus scab disease and melanose, but resistant to citrus canker.

• The Plant Pathology Journal
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• v.19 no.5
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• pp.248-252
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• 2003

This study was carried out to evaluate potential of Shiranuhi cultivar against inoculation of causal pathogen of citrus canker, Xanthomonas axonopodis pv. citri in Jeju Island by comparing degree of susceptibility of fruits and leaves/twigs, and analysis of incidence of canker disease. Progression of symptom, disease incidence, and percent area of lesion were surveyed for evaluation of resistance. In greenhouse condition, symptoms of bacterial citrus canker progressed more rapidly in sweet orange, a moderately susceptible cultivar, than in other four cultivars (satsuma mandarin, 'Kiyomi', 'Shiranuhi' and 'Yuzu'). At 20 days after inoculation, disease severity was the highest in sweet orange (5.0$\pm$0.0), and all tested leaves were distorted or had dropped. On the other hand, 'Yuzu' showed the lowest disease severity (2.6$\pm$0.47), followed by 'Kiyomi' (4.0$\pm$0.0), 'Shiranuhi' (4.0$\pm$0.82), and satsuma mandarin (4.3$\pm$0.47). Percent area of lesion per leaf 30 days after inoculation was the highest in sweet orange (8.31$\pm$1.78), followed by satsuma mandarin (1.51$\pm$1.25), 'Shiranuhi' (1.39$\pm$0.94), and 'Kiyomi' (1.1$\pm$0.9), while the lowest was in 'Yuzu' (0.26$\pm$0.17). Infield condition, percentage of diseased leaf in 'Shiranuhi' was very low, 5.2$\pm$2.9, compared with sweet orange, 71.0$\pm$ 11.5, while that of satsuma mandarin and 'Kiyomi' were 6.9$\pm$7.0 and 4.3$\pm$2.0, respectively. Percentages of diseased leaf was higher (17.4$\pm$7.1) than that of diseased fruit (3.2$\pm$2.5) in severely diseased trees of Shiranuhi cultivar, and the disease was not observed on twig in open field condition. Lesion sizes on leaves and fruits in open field condition were 4.1$\pm$2.2 mm2 and 5.1$\pm$5.6 mm2, respectively, while those in greenhouse condition were 8.7$\pm$5.7 mm2, 10.4$\pm$9.2 mm2 and 5.6$\pm$2.6 mm2 on leaves, fruits and twigs, respectively. The disease was observed in 5.6% out of total 107 farmers Shiranuhi fields under polyethylene film house, and average percentages of diseased tree in 31 fields of Shiranuhi cultivar and adjacent satsuma mandarin fields were 0.02% and 14.8%, respectively. Average percentage of diseased fruit was 1.6% in satsuma mandarin which was not observed in anyone of all the 31 Shiranuhi farmers fields. Therefore, it was concluded that 'Shiranuhi' cultivar is not potential against causal pathogen of citrus canker disease in Jeju Island because the cultivar has similar resistance as satsuma mandarin which occupies over 95% of total 25,000 ha in Jeju Island in polyethylene film houses protected from outside.

• Journal of the Korea Society of Computer and Information
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• v.26 no.11
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• pp.157-163
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• 2021

In this study, we investigated the antioxidants activity by measuring electron donating ability and ABTS radical scavenging ability of the extracts from Rutaceae fruits (citron, grapefruit, lemon, mandarin orange, orange, trifoliate) to evaluate its use as a antioxidants in foods and cosmetics. Rutaceae fruits extract were separated in two parts of whole fruit (pulp, pulp fegment membrane, peel) and peel, dried, and then extracted with 70% ethanol. As a result of comparing the antioxidant effect at the concentration of 10,000 ㎍/mL, the electron donating ability was higher in the dried lemon peel extract (DLPE, 88.15%) and the dried citron whole fruit extract (DCWE, 80.44%), and the ABTS radical scavenging ability was highest in lemon peel and dried peel extract at 94.85% (FLPE) and 92.83% (DLPE). In conclusion, it was confirmed that lemon showed the highest antioxidant effect among the Rutaceae fruits(citron, grapefruit, lemon, mandarin orange, orange, trifoliate), and it was confirmed that the dried peel extract had a significant effect. Therefore it is considered that the dried lemon peel extract has the potential to be used as a natural antioxidant material in food and cosmetics.