• Korean Journal of Food Science and Technology
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• v.14 no.1
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• pp.63-66
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• 1982

The pectin content in tangerine peel and the characteristics of extracted pectin and its gel were determined. The pectin contents of citrus peel and citrus albedo were 11.52% and 9.3% on a dry weight basis, respectively The equivalent weight, methoxyl content and acetyl content of the extracted citrus peel pectin were 596, 13.41% and 0.125% respectively. The intrinsic viscosity and molecular weight of extracted citrus peel pectin were higher than those of commercial citrus pectin samples. The anhydrouronic acid content and jelly grade of the extracted pectins were 98.4% and 138.1, respectively. These were higher than those of commercial citrus pectin. In the textural characteristics of gels, the gel made from the extracted pectin was shown to have lower values in hardness, cohesiveness, adhesiveness and gumminess than the gels made from commercial citrus pectins.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.884-888
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• 2009

Effect of citrus pectin oligosaccharides produced by irradiation was studied on the ability to improve lipid metabolism and hypercholesterolemia in mice fed high cholesterol diets. A total of 35 mice were divided into 5 groups and fed the following diets for 6 weeks: normal diet (C), 0.5% cholesterol (CH), 0.5% cholesterol+5% non-irradiated pectin (P), 0.5% cholesterol+5% irradiated pectin at 20 kGy (PIR), and 0.5% cholesterol+5% irradiated at 20 kGy and dialyzed (PIR-F). CH group had significantly higher serum triglycerides, total cholesterol, and low density lipoprotein (LDL)-cholesterol contents than pectin oligosaccharide-treated groups (p<0.05). Triglycerides and total cholesterol contents was the lowest in C and PIR-F and followed by PIR and P group, and CH group had significantly higher LDL-cholesterol. Serum high density lipoprotein (HDL)-cholesterol content in C group was not different from that in CH and P groups, but lower than that of PIR and PIR-F groups. These results suggest that pectin oligosaccharides produced by irradiation can reduce the levels of serum triglyceride, total cholesterol, and LDL-cholesterol in the blood of mice fed high-cholesterol diets and therefore, irradiation can be used as a tool to produce functional oligosaccharides from citrus pectin.

• Biomolecules & Therapeutics
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• v.11 no.2
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• pp.109-111
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• 2003

The single oral toxicity of Jeju citrus rind pectin (Jeju pectin) was studied in Spraque-Dawley rats of both sexes. In this study, rats were administrated orally with dosages of 100, 250 and 500 mg/kg of Jeju pectin. We daily examined number of deaths, clinical signs, body weights and gross findings for 14 days after Jeju pectin administration. When we administered different doses of 100, 250 and 500 mg/kg. We found no rats died in both sex after administration. Some clinical signs (decrease locomotor activity, salivation, soft stool, prone position, lacrimation, crouching position, convulsion, ataxic gait, incontinence of mine) were also observed during the experimental period.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.732-738
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• 2009

An acidic polygalacturonase (PG) from Aspergillus kawachii was produced by solid state fermentation employing a polyurethane foam support. The conditions used for the production of acidic PG were particle size of support (0.6 or 500 $mm^3$) and fermentation time. From the factors studied, the particle size had important influence on enzyme production. The best conditions for acidic PG production were $0.6\;mm^3$ particle size, 18 hr at $30^{\circ}C$ and initial pH of 5.0. In addition, pectin was extracted from citrus pomaces (grapefruit, lime, and tangerine) by acidic PG at $50^{\circ}C$ for 24 hr with citric acid solution. Infrared spectroscopy showed that lime pomace had more high-methoxylated (65%) endogenous pectin than was obtained than from grapefruit or tangerine pomaces. The enzymatically extracted pectin yield in dry basis (d.b.) for grapefruit and lime pectins were 6.95 and 4.25%, respectively. The citric acid solution alone also contributed to pectin extraction from citrus pomaces (7-9%, d.b.). Limited pectin extraction by acidic PG from tangerine pomace was most likely due to the presence of low-methoxylated endogenous pectin. The enzymatic method for pectin extraction using acidic PG from A. kawachii is a promising technique for releasing highly polymerized pectic substances from high-methoxylated lime or grapefruit pomaces.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.271-291
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• 2022

Pectin methylesterase (PME) plays an important role in vegetative and reproductive development and biotic/abiotic stress responses by regulating the degree of methyl-esterification of pectic polysaccharides in the plant cell wall. PMEs are encoded by a large multigene family in higher land plant genomes. In general, the expression of plant PME genes shows tissue- or cell-specific patterns and is induced by endogenous and exogenous stimuli. In this study, we identified PME multigene family members (CsPMEs) from the sweet orange genome and report detailed molecular characterization and expression profiling in different citrus tissues and two fruit developmental stages. We also discussed the possible functional roles of some CsPME genes by comparing them with the known functions of PMEs from other plant species. We identified 48 CsPME genes from the citrus genome. A phylogenetic tree analysis revealed that the identified CsPMEs were divided into two groups/types. Some CsPMEs showed very close phylogenetic relationships with the PMEs whose functions were formerly addressed in Arabidopsis, tomato, and maize. Expression profiling showed that some CsPME genes are highly or specifically expressed in the leaf, root, flower, or fruit. Based on the phylogenetic relationships and gene expression profiling results, we suggest that some CsPMEs could play functional roles in pollen development, pollen tube growth, cross incompatibility, root development, embryo/seed development, stomata movement, and biotic/abiotic stress responses. Our results shed light on the biological roles of individual CsPME isoforms and contribute to the search for genetic variations in citrus genetic resources.

• Journal of Nutrition and Health
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• v.28 no.9
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• pp.834-845
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• 1995

This study was conducted in order to establish an in vitro method simulating the physiological function of fibers along the large intestine of humans. Commercial fibers including guar gum, apple pectin, citrus pectin, CM-cellulose, alginic acid and $\alpha$-cellulose, and dietary fiber residues obtained from rice bran, barley, soybean, Korea cabbage, apple, tangerine and sea mustard were employed to determine the water-holding capacity, weight of hydrated residue and fiber content after anaerobic fermentation using human fecal inoculum for 24 hours, followed by dialysis under osmotic suction pressure. The weight of hydrated residue in commercial fibers was in the decreasing order of CM-cellulose > alginic acid, $\alpha$-cellulose > apple pectin, citrus pectin > guar gum and that in food fiber residues was in the decreasing order of rice bran, sea mustard > soybean > tangerine, Korean cabbage > barley > apple. It was demonstrated that the larger the weight of hydrated residue was, the more the weight of human stool increased. Consequently this in vitro method can be used as a preceeding test before undertaking animal or human experiment to predict the physiological effects of fiber residues from diverse food samples as well as commercially refined fibers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.396-402
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• 1999

To increase the utilization of citron(Citrus junos), manufacturing conditions of citron jelly were studied. Citron extract was diluted 7 fold for jelly processing and it's pH was 2.64. Due to the low pH of citron extract, 2.5∼3.0% of pectin was added which was slightly higher than the amount for ordinary jelly process. To reduce the loss of citron flavor and vitamin C, it was heated for 10 min. and found to be enough for proper hardness of jelly. Agar and gelatin was used as jellying agents to improve the physical properties of pectin jelly. From the result of compression curve analysis, addition of 5% and 7% of gelatin were more effective in jelly texture than agar in 1.5% and 2.5% pectin jelly, respectively. Sucrose was replaced by glucose and oligosaccharide; galactooligosaccharide, fructooligosaccharide and isomaltooligosaccharide. From the sensory evaluation analysis, 30% of sucrose and 30% of isomaltooligosaccharide in jelly was evaluated as superior to other sugars.

• Food Science and Preservation
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• v.8 no.2
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• pp.131-139
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• 2001

Kiyomi tangor(Citus unshiu x sinensis) was stored at 3$\^{C}$ and 85% relative humidity, and the changes in firmness, pectin degrading enzymes activity and other physicochemical properties of citrus fruits during storage were investigated. Decay ratio and weight loss during 180 days’ storage were increased gradually to 13.0% and 12.9%, respectively. Firmness of fruits with 2 mm probe was decreased gradually from 808.7 g-force to 406.4 g-force, and moisture of peel and flesh were decreased from 76.5% to from 89.6% to 87.6% during storage, respectively. Exo-polygalacturonase activity of peel after 150 days’ storage were increased gradually to 558.09 units/100g. Pectin methylesterase activity of peel and flesh were increased from 14.7 units/g to 2.3 units/g, and from 9.4 units/ml to 2.7 units/ml at 150days’ storage, respectively. Endo-polygalacturonase activities were not changed notably during storage. Alcohol-insoluble solid(AIS) of peel was not changed notably. During storage of the fruits water soluble pectin(WSP) of peel and flesh were increased from 474.49 mg/100g to 614.29mg/100g, and from 66.91mg/100g to 92.74mg/100g as wet basis, respectively. Hexameta-phosphate soluble pectin(HMP) of peel were decreased from 405.5mg/100g to 270.43mg/100g, hydochloric acid soluble pectin(HSP) of peel was also decreased from 544.02mg/100g to 412.64mg/100g during storage. Total pectin substance(TPS) of peel and flesh were decreased from 1,424.01mg/100g to 1,297.36mg/100g, and from 165.51mg/100g to 171.54mg/100g, respectively. Composition ratio of pectin was in order of WSP > HSP > HMP.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.659-664
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• 1996

The amount and characteristics of pectin in the albedo and flavedo layers of the citrus peels, and those of the pulp were investigated. Alcohol insoluble solid(AIS) content was the highest in albedo layer(18.1%), and the lowest in pulp(5.7%). The pulp and the albedo layer showed a potential pectin sources as containing pectins of 40.5% and 35.2% of the total polysaccharides of the pulp and the albedo layer, respectively. Total pectin contents were about 30% of the AIS and showed comparatively constant values among the byproducts. Hydrochloric acid soluble pectin contents were the hightest in the flavedo layer, 14.0%, and the lowest in the pulp, 4.4%. Over 90% of the total pectin could be extracted after 60min with 0.05N HCI at $85^{\circ}C.$ Microwave treatment reduced the extraction time significantly ; a comparable extraction yield was acquired after 10min with microwave treatment. The degree of esterification of the extracted pectin also increased with microwave treatment. Neutral sugars in the hydrolysate of the pectin were rhamnose, arabinose, galactose, glucose and xylose. No differences in molecular weight distribution of the pectin were found between the albedo and flavedo layers. Pectin of the pulp showed different molecular weight distribution from that of the peels.

• Food Science and Preservation
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• v.7 no.1
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• pp.38-43
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• 2000

Changes in firmness and pectin contents during maturation and sotrage of Stsuma mandarin (Citrus Unshiu Marc. var. miyagawa) were investigated. Firmness of fruits was decreased quickly from 1,176.8g-force to 503.6g-dorce. Satsuma mandarin was stored at 3$^{\circ}C$ and 85%${\pm}$5% relative humidity. Firmness were decreased from 538.9g-force to 336.9g-force during storage. Alcohol-insoluble solid(AIS) of peel and flesh were decreased quickly from 27.04g/100g to 12.30g/100g, and from 2.67g/100g to 1.91g/100g during maturation of fruits. During storage of fruits, AIS of peel was decreased from 14.32g/100g to 12.06g/100g . During maturation of fruits, water soluble pectin (WSP) of peel were increased from 420.82mg/100g to 601.62mg/100g as wet basis. Hexametaphosphate soluble pectin (HMP) was also increased from 450.17mg/100g to 577/53mg/100g. hydrochloricacid soluble pectin (HSP) was decreased from 1938.30 mg/100g to 695.14mg/100g. During storage of fruits, HMP and HSP of peel was decreased from 507.82mg/100g to 695.14mg/100g. During storage of fruits, HMP and HSP of peel was decreased from 527.82mg/100g to 275.47mg/100g , and from 672.28mg/100g to 351.36mg/100g, respectively. WSP of peel was increased from 543.70mg/100g to 584.31mg/100g. Total pectin substance (TPS) of peel was decreased from 2809.79 mg/100g to 1874.29mg/100g during maturation, and from 1723.80mg/100g to 1211.14mg/100g during storage, respectively. Composition ratio of pectin was in order of WSP>HSP>HMP.