• Preventive Nutrition and Food Science
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• v.8 no.4
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• pp.349-355
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• 2003

Effects of extraction conditions, gamma-irradiation and storage conditions on bioactivities of Citrus (Citrus unshiu) peel extract were investigated. The Hunter color $L^{*}$- and $a^{*}$-values of the extract increased but $b^{*}$-value decreased with an increase in absorbed irradiation dose. DPPH radical scavenging, tyrosinase inhibition and nitrite scavenging activities were not affected by irradiation but reduced by increased storage time. Nitrite scavenging activity of the extract was the highest at pH 1.2 followed by pH 4.2 and 6.0 and not changed by storage. Results indicated that there is potential for using citrus peel byproducts as a bioactive ingredient, and that gamma irradiation brightens the color of the extract without adversely altering its biological activity.ity.

• Journal of Life Science
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• v.17 no.4 s.84
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• pp.540-545
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• 2007

The purpose of this research is to study the effects of feeding dietary citrus byproducts TMR (total mixed ration) on physicochemical properties and sensory characteristics of Korean native beef loin (KNBL). The samples for experiment consist of the KNBL not fed with citrus byproducts (TMR-0) and the KNBL fed with citrus byproducts during fattening period (TMR-1). The control (TMR-0) KNBL was fed by general practical feeding (roughages and concentrates were fed separately), while the TMR-1 KNBL was fed by the same as TMR-0 until 17 months yearling but was fed by citrus byproducts feeding for 10 months after that. The $L^*(lightness),\;a^*(redness)\;and\;b^*(yellowness)$ value were not significantly different between TMR-0 and TMR-1. The pH of TMR-1 was lower than that of TMR-0 (p<0.05), the VBN content, TBARS value and EDA were not significantly different between TMR-0 and TMR-1. The water holding capacity, frozen loss and cooking loss were not significantly different between TMR-0 and TMR-1, but thawing loss of TMR-0 was higher than that of TMR-1 (p<0.05). The hardness of TMR-0 was higher than that of TMR-1, and the springiness of TMR-1 was higher than that of TMR-0 (p<0.05), but the cohesiveness, gumminess, chewiness and shear force were not significantly different between TMR-0 and TMR-1. The pH and VBN content during storage were not significantly different between TMR-0 and TMR-1, but the TBARS value of TMR-1 stored during 4 weeks was lower than that of TMR-0 (p<0.05). In case of sensory score, the color and aroma of raw meat, and the taste, juiciness and palatability of cooked meat were not significantly different between TMR-0 and TMR-1. But the flavor and tenderness of TMR-1 were superior than those of TMR-0 (p<0.05)

• Journal of the East Asian Society of Dietary Life
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• v.16 no.5
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• pp.592-599
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• 2006

This study was carried out to investigate the possibility for utilization and the effectiveness of citrus byproducts on the nutritional composition and sensory score of Jejudo native pig meat. The groups are consisting of the Jejudo native pig loin without citrus byproduct ($JNP-T_0$) and the Jejudo native pig loin fed with 8% and 15% citrus byproduct during growing and fattening period($JNP-T_1$). The contents of moisture, crude protein, crude fat, crude ash, calorie, cholesterol content Mg, P, K, Na, vitamin $B_1\;and\;B_2$, total amino acid, and total free amino acid content were not significantly different between $JNP-T_0$ and $JNP-T_1$(p>0.05). It was found that palmitic acid($25.301{\sim}27.403%$) was the highest one among saturated fatty acid while oleic acid($42.234{\sim}43.061%$) was the highest among unsaturated fatty acid in both groups. In case of sensory score, the color and aroma of raw meat, and the flavor preference of boiled meat of $JNP-T_0$ were higher than those of $JNP-T_1$(p<0.05). But the taste, texture, juiciness and palatability of boiled meat were not influenced by feeding of citrus byproduct.

• Nutrition Research and Practice
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• v.10 no.2
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• pp.131-138
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• 2016

BACKGROUND/OBJECTIVES: Citrus and its peels have been used in Asian folk medicine due to abundant flavonoids and usage of citrus peels, which are byproducts from juice and/or jam processing, may be a good strategy. Therefore, the aim of this study was to examine antioxidant and anti-inflammatory effects of bioconversion of Jeju Hallabong tangor (Citrus kiyomi ${\times}$ ponkan; CKP) peels with cytolase (CKP-C) in RAW 264.7 cells. MATERIALS/METHODS: Glycosides of CKP were converted into aglycosides with cytolase treatment. RAW 264.7 cells were pre-treated with 0, 100, or $200{\mu}g/ml$ of citrus peel extracts for 4 h, followed by stimulation with $1{\mu}g/ml$ lipopolysaccharide (LPS) for 8 h. Cell viability, DPPH radical scavenging activity, nitric oxide (NO), and prostagladin $E_2$ ($PGE_2$) production were examined. Real time-PCR and western immunoblotting assay were performed for detection of mRNA and/or protein expression of pro-inflammatory mediators and cytokines, respectively. RESULTS: HPLC analysis showed that treatment of CKP with cytolase resulted in decreased flavanone rutinoside forms (narirutin and hesperidin) and increased flavanone aglycoside forms (naringenin and hesperetin). DPPH scavenging activities were observed in a dose-dependent manner for all of the citrus peel extracts and CKP-C was more potent than intact CKP. All of the citrus peel extracts decreased NO production by inducible nitric oxide synthase (iNOS) activity and $PGE_2$ production by COX-2. Higher dose of CKP and all CKP-C groups significantly decreased mRNA and protein expression of LPS-stimulated iNOS. Only $200{\mu}g/ml$ of CKP-C markedly decreased mRNA and protein expression of cyclooxygenase-2 in LPS-stimulated RAW 264.7 cells. Both 100 and $200{\mu}g/ml$ of CKP-C notably inhibited mRNA levels of $interleukin-1{\beta}$ ($IL-1{\beta}$) and IL-6, whereas $200{\mu}g/ml$ CKP-C significantly inhibited mRNA levels of $TNF-{\alpha}$. CONCLUSIONS: This result suggests that bioconversion of citrus peels with cytolase may enrich aglycoside flavanones of citrus peels and provide more potent functional food materials for prevention of chronic diseases attributable to oxidation and inflammation by increasing radical scavenging activity and suppressing pro-inflammatory mediators and cytokines.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.766-772
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• 2009

In this study, the effects of feeding citrus byproduct on physicochemical and sensory characteristics of chicken meats were investigated. The samples consisted of chicken meats provided with only feed for laying hen without citrus byproduct (T-0), and the chicken meats fed with 1.0%, 1.5% and 2.0% citrus byproduct during the starter (initial period feed; $1{\sim}9th$ day), the grower (middle period feed; $10{\sim}24th$ day), and the finisher (latter period feed; $25{\sim}36th$ day), respectively. The $L^*$ value of thigh was significantly lower in the T-1 than in the T-0, the $a^*$ value was significantly higher in the T-1 than in the T-0 (p<0.05). The water holding capacity of thigh was significantly higher in the T-1 than in the T-0 and the cooking loss was significantly higher in the T-0 than in the T-1 (p<0.05). The acid value was significantly higher in the T-0 than in the T-1 (p<0.05). Antioxidant activity was higher in the T1 than in the T-0 (p<0.05). There was no significance between T-0 and T-1 regardless of feeding citrus byproduct, in terms of chicken's $b^*$ value, frozen loss, thawing loss, hardness, springiness, cohesiveness, gumminess, chewiness, shear force, free amino acid content of hot water extracts, taste, flavor, tenderness, juiciness and palatability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.897-902
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• 2006

This study was carried out to investigate the possibility for utilization of waste materials and the characteristics of pork by feeding citrus byproducts. The groups consisted of the pork without citrus byproduct (TB-0) and the pork fed with 6% and 10% citrus byproduct during growing and fattening period (TB-1). The contents of moisture, crude protein, crude fat, crude ash, vitamin $B_1$ and $B_2$, total amino acids, and caloric were not significantly different between TB-0 and TB-1 (p>0.05). The contents of cholesterol and the magnesium of TB-1 were lower than those of TB-0. Palmitic acid was the most abundant among saturated fatty acids while oleic acid was the most abundant among unsaturated fatty acids in both groups. In case of sensory score, the color and aroma of raw meat and taste, texture, juiciness and palatability of boiled meat were not influenced by feeding of citrus byproduct. But the flavor preference of boiled meat of TB-1 was higher than that of TB-0.

• The Korean Journal of Food And Nutrition
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• v.29 no.6
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• pp.829-834
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• 2016

Free radicals originate due to the radiolysis of cytoplasmic water with low "Linear Energy Transfer" (LET) radiations. Naringenin (Ng) is a natural antioxidative compound found in citrus fruits. This study revealed that Naringenin (Ng) reduced the radiation damage of critical organs by scavenging oxidative free radicals. In the study, Ng was orally administrated to rats daily for 7 consecutive days, prior to whole body exposure to gamma-rays. The scavenging efficacy was evaluated biochemically by measuring the concentration of cytotoxic byproducts and the activity of enzymes relevant to oxidative free radicals, after extracting the organs from the exposed rat. We observed increased levels of malondialdehyde (MDA) concentration, and decrease in the activities of superoxide dismutase (SOD) and catalase (CAT) in the exposed control group. However, pretreatment with Ng significantly reduced the MDA concentration, and increased the activities of SOD and CAT, as compared to the control group, due to the free radical scavenging by Ng. The results indicate that Ng administration prior to irradiation could protect critical organs from radiation damage.

• 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.