• Food Science and Preservation
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• v.23 no.7
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• pp.1012-1017
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• 2016

This study was conducted to investigate total flavonoid content, flavonoid composition, and free radical scavenging effects of by-products from five orange cultivars during the period September 2015 to February 2016. Total flavonoid content was highest in peel extracts from immature fruit harvested in September. Total flavonoid contents of all cultivars mostly decreased while ripening. Among the five cultivars, total flavonoid content was highest in Hamlin sweet orange (21.66 mg/g), followed by Sanguinello blood orange (20.39 mg/g), Shamouti orange (18.49 mg/g), Tarocco blood orange (18.46 mg/g), and Olinda Valencia orange (17.07 mg/g). With regard to flavonoid composition, all cultivar materials had high levels of narirutin and hesperidin, but naringin and neohesperidin were not detected in any of the materials. Nobiletin, as polymethoxyflavone, was detected within a$23{\sim}40{\mu}g/mL$ range in the immature fruit of all cultivars. Among all cultivars, antioxidant activities were higher in peel extracts than in pulp extracts. DPPH radical scavenging activities of peel extracts ranged from 40% to 58% while the ABTS radical scavenging activity range was 90~94%. The results indicate that orange, by-products, especially peel of immature orange fruit, could have application as natural materials with antioxidative effects.

• Food Science and Preservation
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• v.24 no.1
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• pp.74-83
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• 2017

This study was conducted to obtain the optimal conditions of hot air drying for Cudrania tricuspidata by response surface methodology (RSM). The independent variables were blanching time (60, 120, 240 sec), drying temperature (40, 60, $80^{\circ}C$) and drying time (12, 24, 36 h). The dependant variables were total polyphenol content (TPC), total flavonoid content (TFC), DPPH radical scavenging activity (DPPH), and color difference (${\Delta}E$). Viable cell colony was counted according to changes of blanching time. It was confirmed that microorganisms gradually decreased with increasing blanching time. From RSM results, the predicted values of TPC, TFC, DPPH, and ${\Delta}E$ were 8.62 mg GAE/g, 56.65 mg RE/g, 40.26% and 11.69, respectively. Experimental values within the optimal range (240 sec, blanching time; $60^{\circ}C$, drying temperature; 24 h, drying time) were 10.06 mg GAE/g, 49 mg RE/g, 44.99% and 10.53, respectively. The predicted values were similar to the experimental values. Comparing drying tendency according to changes of blanching time, moisture reduction was bigger in the blanched sample than that in control at $40^{\circ}C$. However, the differences between blanched and control decreased with increase of drying temperature. Viable cell gradually decreased as increasing blanching time.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.741-745
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• 2005

Pectin was dissolved in HCl, citric acid, and deionized distilled water (DW, 2%, v/v) and irradiated at different irradiation doses (2.5-50 kGy) by gamma ray to investigate its physicochemical characteristics and biological activity. Viscosity of pectin solution was significantly decreased by irradiation up to 10 kGy, then remained constant thereafter. Gamma-irradiation increased monosaccharide and polysaccharide levels up to 30-40 kDa. Electron donating ability of pectin solution was highest when DW was added and was increased by increasing irradiation dose (p<0.05). ${\beta}-Carotene$ bleaching assay revealed irradiation resulted in development of antioxidantive activity in pectin solution. Growth inhibition of cancer cell lines was observed in irradiated pectin solution in dose-dependent manner, with G36l showing the highest. Results suggested irradiation of pectin solution could be effective for preparation of functional pectin oligomer.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.702-708
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• 2005

Cholesterol-lowering effect of pine nut on mice was investigated by examining changes in body weight, feed intake, and triglyceride, total cholesterol, high density liporotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), and very low density lipoprotein cholesterol (VLDL-C) contents in mice plasma. Changes in body weight and feed intake between pre-designed experimental animal groups fed various contents of cholesterol and pine nut and control group fed basal diet were not significantly different. Food efficiency ratio of experimental groups fed higher than 10% pine nut was significantly higher than that of control group. Apparent differences in atherogenic index representing cholesterol-lowering effect in plasma were not found among all groups fed 0-20% pine nut. Inhibition activities of water and hexane extracts of pine nut on HMG-CoA reductase and cholesterol esterase were examined in vitro. Hexane extract showed 66% inhibition effect on HMG-CoA reductase, whereas none was observed with water extract.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.176-182
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• 2006

Sensitive and specific monoclonal antibody (MAb) was produced from hybridoma (1H11-5) obtained by fusion of myeloma cell (V653) and spleen cell isolated from mouse immunized sulfamthazine (SMZ)-HG-KLH. Direct competitive ELISA was developed for rapid detection of SMZ in milk samples using MAb against SMZ with optimized conditions between MAb and SMZ-HG-HRP conjugate, and applicable conditions for analysis of milk samples were established. Detection range of immunoassay was 0.1 to 100 ppb. Recoveries from spiked raw milk and processed milk samples averaged 82.1-120.7 and 82.1-97.1%, respectively.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1503-1510
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• 1999

This study was performed to investigate the physicochemical properties of Korean Citrus sudachi fruit which were harvested at different harvesting time(every 20 days from Sep. 3 to Nov. 8) and region(Seogwipo and Cheju city area). The average weight of Citrus sudachi fruit harvested from Seogwipo area was as twice as that of Cheju area at the same period. The moisture content in fruit peel increased by ripening of fruit, but that of fruit juice showed no difference. The content of reducing sugar in fruit peel and fruit juice increased 2 times from Sep. 3 to Nov. 8. The content of crude fiber decreased both in fruit peel and fruit juice as progression of ripening. Crude protein and ash contents decreased in fruit peel but revealed no differences in the fruit juice during the same period. pH decreased in fruit peel and juice with its ripening. The content of vitamin C decreased by ripening of fruit. The transmittance which is important quality factor in fruit juice increased from Sep. 20 to Oct. 13. The content of free sugar increased about 2 times in fruit peel from Sep. 3 to Nov. 8 and showed 4 times increase in fruit juice at the same period. In the composition ratio of mineral, Ca and K were abundant in the fruit peel, but only K was the most abundant mineral in fruit juice than any others.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1536-1541
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• 1999

Fruit leathers were manufactured from flesh and pomace of Japanese apricots and evaluated for their physical, chemical, microbiological and sensory properties. The contents of total dietary fiber(TDF) in Japanese apricot leathers(JAL) and Japanese apricot pomace leathers(JAPL) were 4.06% and 7.82%, respectively. One hundred grams of leather contained 368kcal in JAL and 352kcal in JAPL. Water activities of fruit leathers were 0.36 in JAL and 0.48 in JAPL. None of the factors had an effect on the microbiological counts of any of the organisms. The L, a and b values of the fruit leathers were higher in those made of JAF than those made of JAP. The fruit leathers made of JAF were harder than those made of JAP. Sensory panelists preferred fruit leathers made of JAP to those made of JAF in all attributes, except for their color.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1434-1439
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• 1999

The chemical characteristics of flesh and pomace of Japanese apricot were investigated. The moisture contents of flesh and pomace of Japanese apricot were 89.94% and 91.39%. Free sugars and sugar-derivatives of Japanese apricot flesh (JAF), were 0.77% glucose, 0.47% fructose, 0.35% mannitol and 0.47% sorbitol, and of Japanese apricot pomace (JAP) were 0.01% glucose, 0.09% fructose, 0.38% mannitol and 0.06% sorbitol, respectively. The organic acids of flesh and pomace of Japanese apricot were citric acid, malic acid and oxalic acid. The predominant minerals in flesh and pomace of Japanese apricot were K, P, Ca and Al. The contents of dietary fiber (DF) in JAF were 2.94% of insoluble dietary fiber (IDF), 1.07% of soluble dietary fiber (SDF) and 4.01% of total dietary fiber (TDF). IDF of JAP were 6.25%, SDF 0.51% and TDF, 6.76%.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.206-210
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• 2003

Effects of NaCl concentration (0, 1, 2, and 3%) on the physico-chemical characteristics of dark, firm, dry (DFD) and normal meat batter were examined. Before heating, pH values of DFD and normal meat batter decreased up to 0.23 (DFD) and 0.2 (normal) units, which after heating increased up to $0.16{\sim}0.28$ and $0.17{\sim}0.23$ units, as NaCl concentration increased from 0 to 3%. Cooking loss and diameter reduction of DFD meat batter were lower than those of nomal meat batter and decreased. whereas protein solubilities and emulsion stabilities of DFD and normal meat increased, with increasing NaCl concentration. Protein solubility and emulsion stability of DFD meat were higher than those of nomal meat (p<0.05). Viscosity and hardness of DFD meat batter were higher than those of normal meat batter and increased as NaCl concentration increased from 0 to 3%.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.642-647
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• 2003

In order to investigate utilization possibility of persimmon peel as a source of vinegar, we had been examined the alcohol and acetic acid fermentations of persimmon peel. In the first stage, alcohol fermentation, alcohol content was maximum value (8.22%) in 12.43 mL/g of added water, $12.41^{\circ}Brix$ of initial sugar content and 48.05 hr of fermentation time. Acidity was minimum value (0.30%) in 12.18 mL/g of added water, $13.72^{\circ}Brix$ of initial sugar content and 46.22 hr of fermentation time. In the second stage, acetic acid fermentation, acidity was maximum value (6.40%) in 2.02% of initial acidity, 67.98 rpm of agitation rate and 6.94 day of fermentation time. Browning color was minimum value in 1.50% of initial acidity, 150.0 rpm of agitation rate and 6.0 day of fermentation time. To manufacture persimmon vinegar using persimmon peel, in the first stage, optimal alcohol fermentation conditions was 12mL/g in added water, $12^{\circ}Brix$ in initial sugar concentration and 48 hr in fermentation time. In the second stage, optimal acetic acid fermentation conditions was 1.8% in initial acidity, 70 rpm in agitation rate and 6 day in fermentation time using Acetobacter sp. PA97.