• Korean Journal of Poultry Science
• /
• v.11 no.2
• /
• pp.93-98
• /
• 1984

Four different silages were prepared out of citrus peel with or without supplementation with wheat bran and/or urea. Proximate nutrients and volatile fatty acids were analysed on the silages, both fresh and dried. All silages were dried and ground, and were compared with dried citrus peel (not ensiled) and wheat bran in a folding trial. A total of 360 male chicks of Maniker broiler strain was divided into and assigned to 6 treatments with 5 replications. Each experimental diet included each of 6 test material at the level of 6% and the feeding trial lasted 8 weeks, after which a metabolism trial was conducted. Results obtained were summarized as follows. 1. Ensiling increased protein content of the citrus peel on the dry matter basis and supplementing the silage material with wheat bran and/or urea further increased protein contents of the silages. 2. Adding wheat bran and/or urea to silage material also increased volatile fatty acid contents of the silages. After drying organic acid contents of the silages were reduced and there were no differences in organic acid contents of the dried citrus peel silages, differently treated, 3, Broilers fed dried citrus peel and those fed dried citrus peel silages gained numerically less weight than those fed wheat bran. But there were no significant differences in body weight gain, feed intake and feed efficiency among different treatments 4. There were no significant differences in nutrient utilizability, nitrogen retention and metabnlizable energy contents among treatments. It could be concluded that ensiling is an effective way of storing citrus peel and dried citrus peel silage could be used in broiler diets up to 6% without adverse effects.

• Korean Journal of Agricultural Science
• /
• v.39 no.2
• /
• pp.243-253
• /
• 2012

The objective of the study was to evaluate the quality characteristics of sun-dried Hanwoo beef jerky added with the extract of Citrus junos seib. or Prunus mume. Hanwoo beef shank muscles were sliced, marinated, and sun-dried at $25^{\circ}C$, relative humidity of 35%. The physicochemical quality and microbiological safety of the Hanwoo beef jerky aerobically packaged were analyzed during the storage of $25^{\circ}C$. The moisture content of beef jerky with Citrus junos seib. was the lowest among the treatments after 20 d. Citrus junos seib. and Prunus mume jerky after 10 d had significantly lower aw than those after 0 and 20 d (p<0.05). The pH values of jerky generally ranged from 5.76 to 5.84. The pH value of Prunus mume jerky was significantly higher than those of other jerky samples (p<0.05). Prunus mume jerky showed significantly lower TBARS value than the others after 20 d (p<0.05). Citrus junos seib. jerky showed a significantly lower lightness ($L^*$), redness ($a^*$) and yellowness ($b^*$) than the others during the storage (p<0.05). Prunus mume samples after 10 d had significantly higher $L^*$, $a^*$, and $b^*$ values than the others (p<0.05). With regard to sensory properties, Citrus junos seib. and Prunus mume jerky showed significantly higher flavor and overall acceptability scores than the control (p<0.05). The extracts of Prunus mume will be used in sun-dried Hanwoo beef jerky as a natural agent to retard lipid oxidation and to improve meat color.

• Applied Chemistry for Engineering
• /
• v.35 no.1
• /
• pp.42-47
• /
• 2024

Limonene was separated from waste citrus peels by a vacuum drying process with a venturi, and bioethanol was produced from dried citrus peels. Vacuum drying using venturi was very effective in removing moisture and limonene compared to hot air drying and natural drying. Citrus peels prepared by venturi vacuum drying were the most suitable for ethanol fermentation. The moisture and limonene content of the citrus peels dried for 15 hours were 17.0% and 3.2%, respectively. By venturi vacuum drying, essential oil containing limonene and floral water were obtained, respectively. The amount of essential oil separated by venturi vacuum drying was 4.21 mL essential oil/kg citrus peel, 79.9% of the separated essential oil was limonene.

• Nutrition Research and Practice
• /
• v.5 no.5
• /
• pp.389-395
• /
• 2011

In the present study, a suitable drying method was developed for citrus press cakes (CPCs), which are produced as a by-product in citrus juice plants, and the protective effect of methanol extract of CPCs prepared by far-infrared radiation (FIR) drying against $H_2O_2$-induced DNA damage was evaluated versus that of freeze-dried CPCs. Methanol extract of FIR-dried CPCs exhibited comparatively good ROS scavenging activity versus the freeze-dried CPCs at the concentration of 100 ${\mu}g$/mL. The extract strongly enhanced the cell viability against $H_2O_2$-induced oxidative damage in Vero cells. Lipid peroxidation inhibitory activity of the extract from FIR-dried CPCs was comparable to that of the extract from freeze-dried CPCs. This sample also exhibited good protective effects against $H_2O_2$-mediated cell apoptosis as demonstrated by decreased apoptotic body formation in the nuclear staining with Hoechst 33342. In the comet assay, the CPC extracts exhibited strong inhibitory effects against $H_2O_2$-mediated DNA damage in a dose-dependent manner. Thus, this study demonstrated that FIR drying effectively preserves CPC as a functionally important natural antioxidant source and the FIR drying can be adapted for drying CPCs and is more economical for massive production than freeze drying.

• Korean journal of food and cookery science
• /
• v.26 no.1
• /
• pp.88-94
• /
• 2010

This study was carried out to investigate the total polyphenol and flavonoid contents and antioxidative activities of the methanol extracts of Citrus sunki, C. unshiu and C. natsudaidai peels before and after drying. Total polyphenolic content was high in the citrus peels before drying compared to the dried peels, and highest in the order of C. sunki, C. natsudaidai and C. unchiu. On the other hand, flavonoid content was high in the dried citrus peels than in the citrus peels before drying, and was highest in the order of C. unshiu, C. natsudaidai, C. sunki, but in dried peels it was highest in the order of C. natsudaidai, C. unshiu, C. sunki. DPPH radical scavenging activity was highest in the order of C. natsudaidai, C. unchiu, C. sunki, and that in the citrus peels before drying was higher than in the dried peels. Inparticular, C. natsudaidai peels before drying showed higher activity than vitamin C in 0.5 or 1.0 mg/100 g. Hydrogen peroxide scavenging activity was highest in the order of C. unshiu, C. natsudaidai, and C. sunki in the citrus peels before drying. The dried peels were highest in the order of C. unshiu, C. natsudaidai, C. sunki at 0.5 mg/100 g, but high in order of C. natsudaidai, C. unshiu and C. sunki at more than 1.0 mg/100 g. Inparticular, all C. natsudaidai peels displayed high activity more than 87% at 2.0 mg/100 g. Clear patterns in alkyl radical scavenging activity could not be confirmed in Citrus species whether before or after drying of peels. Hydroxyl radical scavenging activity was highest in the order of C. natsudaidai, C. unshiu and C. sunki but was relatively low compared to the scavenging activity of other activated oxygen species.

• Nutrition Research and Practice
• /
• v.6 no.3
• /
• pp.187-194
• /
• 2012

In this study, the antibacterial effect was evaluated to determine the benefits of high speed drying (HSD) and far-infrared radiation drying (FIR) compared to the freeze drying (FD) method. Citrus press-cakes (CPCs) are released as a by-product in the citrus processing industry. Previous studies have shown that the HSD and FIR drying methods are much more economical for drying time and mass drying than those of FD, even though FD is the most qualified drying method. The disk diffusion assay was conducted, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined with methanol extracts of the dried CPCs against 11 fish and five food-related pathogenic bacteria. The disk diffusion results indicated that the CPCs dried by HSD, FIR, and FD prevented growth of all tested bacteria almost identically. The MIC and MBC results showed a range from 0.5-8.0 mg/mL and 1.0-16.0 mg/mL respectively. Scanning electron microscopy indicated that the extracts changed the morphology of the bacteria cell wall, leading to destruction. These results suggest that CPCs dried by HSD and FIR showed strong antibacterial activity against pathogenic bacteria and are more useful drying methods than that of the classic FD method in CPCs utilization.

• Korean Journal of Poultry Science
• /
• v.10 no.2
• /
• pp.97-101
• /
• 1983

A study was conducted to investigate possibility of utilizing dried citrus peel (DCP) as an ingridient of broiler diets. Fresh citrus peels were collected from a citrus processing plant, and were sun-dried and ground. Both chemical analyses and a feeding trial were carried out. DCP was analyzed for proximate nutrients, amino acids and some minerals. In the feeding trial, a total of 192 day-old female broiler chicks of Manor strain was divided into 16 groups of 12 birds each. Each group was fed one of the 4 different levels(0, 2, 4 and 6%) of DCP replacing an equivalent amount of wheat bran in the diet with 4 replications for 6 weeks. Body weight gain, feed intake and feed efficiency of broilers fed different levels of DCP showed no significant differences among treatments. Immediately after termination of the feeding trial, cach bird was examined for shank color using Roche's Egg Yolk Color Fan. Shank color index of birds increased consistently (P＜0.05) as the level of DCP fed increased, indicating that DCP can be used as a source of pigments. It was concluded from the results that DCP could be used up to 6% in place of wheat bran in broiler diets without adverse effects.

• Food Science and Preservation
• /
• v.10 no.4
• /
• pp.470-475
• /
• 2003

The response surface methodology was performed by central composite design for moisture content, titratable acidity, hunter's color value and organoleptic properties based on drying temperature and time of Citrus, to apply basic data to preparation of dried Citrus. Moisture content, b value and organoleptic color were affected by drying temperature ; That decreased with increase of drying temperature. Titratable acidity was affected by drying time. Organoleptic flavor and taste were affected by drying temperature and time. The optimum drying conditons for organoleptic taste were 67.56$^{\circ}C$ in drying temperature and 8.06 hr in drying time.

• Journal of the Korean Society of Food Culture
• /
• v.28 no.5
• /
• pp.488-494
• /
• 2013

This study assessed the quality characteristics of Yanggaeng prepared with different ratios of Citrus mandarin powder: 0, 2, 4, and 6%. The moisture content was lowest in the controls, while there were no significant differences among the groups supplemented with Citrus mandarin powder. The pH significantly decreased as the amount of Citrus mandarin powder increased. The lightness (L), redness (a), and yellowness (b) were lower in control groups compared to Citrus mandarin powder groups. Texture profile analysis showed that the hardness of the Citrus mandarin powder groups were lower than the control (which was the highest). The total polyphenol and flavonoid content and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity increased as the amount of Citrus mandarin powder increased. The result of a sensory evaluation test revealed no significant differences between the controls and groups with 2% Citrus mandarin powder added in color, smell, taste, texture, and overall acceptability.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.1
• /
• pp.1-7
• /
• 2010

This study was carried out to investigate total polyphenol contents, total flavonoid contents and antioxidative activities of the methanol extracts from dried Citrus sunki and C. unshiu peels. The dried C. sunki peels displayed higher total polyphenol and flavonoid contents for older dried peels. In contrast, the dried C. unshiu peels displayed higher total polyphenol contents for more recently dried and displayed high total flavonoid contents by order of 2007, 2008 and 2006. DPPH radical scavenging activities of dried C. sunki peels were high by order of 2007 (0.25 mg/mL exception), 2006 and 2008, but C. unshiu peels could not confirm clear regularity. In particular, the dried C. sunki (2008, exception) and C. unshiu peels displayed very high activities of more than 86% in 1.0 mg/mL. Alkyl radical scavenging activities of dried C. sunki peels were higher for older dried peels (2007, 1.0 mg/mL exception), and that of dried C. unshiu peels were higher for more recently dried in below 0.5 mg/mL but were higher for older peels in 1.0 mg/mL. Hydrogen peroxide scavenging activities of dried C. sunki peels were higher for older peels (2007, 2.5 mg/mL exception), on the other hand, dried C. unshiu were higher for more recently dried. In particular, dried C. unshiu peels displayed high activities of more than 85% in 2.5 mg/mL. Hydroxyl radical scavenging activities of dried C. sunki and C. unshiu peels displayed low activities compared to other reactive oxygen species as the range of $49.9\pm2.2\sim63.5\pm0.9$% in 1.0 mg/mL.