• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1343-1349
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• 2017

This study was carried out to determine the simultaneous extraction conditions of functional components (lutein, ${\beta}$-carotene, total polyphenol, flavonoids, and phenolic compounds) from sweet potato leaves and to evaluate the antioxidant activities. Extraction conditions included different ethanol concentrations (1st extraction: 99.9% ethanol; 2nd extraction: 50~90% ethanol) and times (30, 60, and 90 min). The highest values of lutein and ${\beta}$-carotene content were obtained by the 2nd extraction at an ethanol concentration of 90%. The extraction yields of lutein and ${\beta}$-carotene decreased with increasing extraction time. The maximum polyphenol, flavonoid, and total phenolic acid contents and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities were 32.3 mg gallic acid equivalent/g, 17.0 mg catechin equivalent/g, 2,842.6 mg/100 g, 17.0 mg ascorbic acid equivalent/g, and 1.94 mg/mL ($IC_{50}$) at the 2nd extraction with an ethanol concentration of 60%. The optimum extraction conditions were as follows; ethanol concentrations of the extraction solvent were 99.9% (1st extraction) and 60% (2nd extraction), and extraction time was 30 min.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1327-1335
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• 2017

This study was carried out to determine the effect of cacao bean addition on the physicochemical properties of extruded rice flour. Rice-based cacao beans (0, 20, 40, 60%) were extruded at a die temperature of $130^{\circ}C$, screw speed of 200 rpm, and moisture content of 25%. As the content of cacao beans increased from 20% to 60%, expansion index decreased, while piece density and specific length increased. The water soluble index and water absorption index of the extrudate increased through extrusion cooking. Lightness decreased as cacao bean content increased while redness increased. As the content of cacao beans increased, paste viscosity decreased. Cold peak viscosity was observed in all extrudates of raw roasted cacao beans. ${\alpha},{\alpha}$-Diphenyl-${\beta}$-picrylhydrazyl (DPPH) radical-scavenging activity increased upon extrusion and cacao bean addition. As content of cacao beans increased, non-roasted cacao beans had higher total phenolic contents than roasted cacao beans. This study showed that addition of cacao beans to extruded rice snack improved antioxidant activity.

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.64-68
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• 2009

The effects of drying methods (hot air, cold air, vacuum, and infrared drying) on physicochemical and organoleptic qualities of sliced-dried persimmons (Diospyros kaki Thumb. cv. Cheungdobansi) were investigated. The weight of the sliceddried persimmons ranged from 9.30 to 12.01 g, the length from 3.55 to 4.06 cm, the width and thickness were from 3.17 to 3.73 cm and 1.82 to 2.04 cm, respectively. Hot air drying resulted in the highest hardness value as well as Hunter's L, a, and b values. Infrared drying showed the lowest L value and vacuum drying revealed the lowest a and b values. Moisture contents of the sliced-dried persimmons ranged from 38.04 to 46.41%, and soluble solid contents were 42.96-$48.44^{\circ}Bx$. The phenolic compounds and DPPH radical scavenging activity were high for infrared and vacuum drying methods, and all the sliced-dried persimmons showed relatively high antioxidant activities. The sensory evaluation results indicated that the organoleptic scores for the overall preference were high in the order of vacuum > infrared > hot air > cold air drying. These results suggest that the drying methods affected the qualities of the sliced-dried persimmons, showing that vacuum drying is the mast effective among the methods tested for manufacturing the high-quality sliced-dried persimmons.

• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.87-92
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• 2009

The antioxidant properties and protective effects of Inula britannica on ${H_2}{O_2}$-induced SH-SY5Y neuroblastoma cell damage were investigated. A series of solvent fractions, including hexane(Fr.H), petroleum ether, chloroform, ethyl acetate(Fr.EA), and water fraction(Fr.W), were prepared from the 70% methanol extracts of Inula britannica. Fr.W had the highest total contents of phenolics and flavonoids, followed by Fr.EA. The antioxidant properties of the fractions were also evaluated by analyzing their scavenging activities on 1,1-diphenyl-2-picrylhydrazyl(DPPH) radicals, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, and nitric oxide. Fr.W showed the strongest activities in all assays. The concentrations of Fr.W that resulted in 50% reductions of the DPPH and ABTS radicals were 20.7 ${\mu}g$/mL and 39.4 ${\mu}g$/mL, respectively. Fr.W showed the weakest cytotoxic activities on the SH-SY5Y cells, whereas it effectively protected ${H_2}{O_2}$-induced cell death, increasing cell survival by 35.0-77.0% at a concentration range of 62.5-250 ${\mu}g$/mL. In this range, Fr.W also significantly decreased intracellular ROS levels by 34-39%. Overall, the antioxidant properties of Inula britannica can contribute to rescuring neuronal cells from oxidative stress-induced cell injury.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.498-504
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• 2014

Allium senescens L. is perennial plant of the Liliaceae family that grows throughout Korea. In this study, we investigated the effect of Allium senescens L. methanol extracts on reactive oxygen species (ROS) production and lipid accumulation during adipogenesis. Our results indicated that 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of Allium senescens L. methanol extracts increased in a dose-dependent manner. Allium senescens L. methanol extracts suppressed ROS production and lipid accumulation during adipogenesis. In addition, Allium senescens L. methanol extracts inhibited the mRNA expression of the pro-oxidant enzyme, such as G6PDH and lead to a reduction in the mRNA levels of the transcription factors, such as sterol regulatory element binding proteins 1c, peroxisome proliferator-activated receptor ${\gamma}$, and CCAAT/enhancer-binding proteins ${\alpha}$. These results indicate that Allium senescens L. methanol extracts inhibit adipogenesis by modulating ROS production associated with ROS-regulating genes and directly down-regulating adipogenic transcription factors.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.483-488
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• 2014

To examine the physiological effects of broccoli (Brassica oleracea var. italica) leaf, the bioavailable compounds in broccoli leaf extract, and its in vitro neuroprotective effects against $H_2O_2$-induced oxidative stress were examined in this study. The chloroform fraction of broccoli leaf extract had the highest total phenolic content of all the fraction than others, and the highest 2,2"-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical-scavenging activity and malondialdehyde (MDA) inhibitory effect. Intracellular reactive oxygen species (ROS) accumulation resulting in $H_2O_2$-treated in PC12 cells was significantly lower when the chloroform fraction was present in the medium compared to that in PC12 cells treated with $H_2O_2$ alone. In a cell viability assay performed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), the chloroform fraction showed protective effects against $H_2O_2$-induced neurotoxicity and inhibited lactate dehydrogenase (LDH) release into the medium. High-performance liquid chromatography (HPLC) analysis showed that ferulic acid was the predominant phenolic compound in chloroform fraction of broccoli leaf.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.410-417
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• 2014

Berries and green tea are underutilized in the food industry despite their great potential as a functional food ingredients. The purpose of this study was to determine the extraction conditions under which total phenolic contents and antioxidant activities of berry and green tea extracts are maximized. Extracts produced using 0-80% ethanol and temperatures ranging from $5-65^{\circ}C$ were evaluated for total phenolic content (TP), as well as for DPPH and ABTS radical-scavenging activities by using response surface methodology. Both ethanol and temperature had significant effects (p<0.05). Ogaja extract produced at $67^{\circ}C$ by using 33% ethanol yielded maximum TP, ABTS, and DPPH values of 23.74 mg GAE/g, 19.77, and 25.04 mg VCE/g, respectively. Optimum conditions for mulberry and raspberry extraction were found to be $65^{\circ}C$ by using 69% and 40% ethanol, respectively. Mulberry and raspberry extracts had TP, DPPH, and ABTS values of 20.74 mg GAE/g, 23.55, and 35.44 mg VCE/g, and 26.08 mg GAE/g, 39.93, and 55.60 mg VCE/g, respectively. Green tea extraction at $57^{\circ}C$ by using 43% ethanol was found to be optimal, yielding TP, ABTS, and DPPH values of 101.15 mg GAE/g, 171.38, and 177.56 mg VCE/g, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1656-1662
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• 2012

This study was conducted to evaluate the vegetative value of sweet potato leaves and stalks by investigating their chemical composition and antioxidant activity. The major minerals were found to be Ca and K. The crude protein content of the leaves ranged from 15.57% in Geonpungmi to 20.34% in Yeonhwangmi, while that of stalks was between 3.71% in Yulmi and 5.97% in Sinchunmi. The total phenolics and flavonoids content of the leaves were about 3.0~4.0 times higher than those of stalks. The levels of polyphenols and flavonoids were high in Geonpungmi leaf and in Sinchunmi stalk. ABTS radical activities were high in Geonpungmi leaf (58.75 mg AA eq/g) and in Daeyumi stalk (14.95 mg AA eq/g). DPPH radical scavenging was high in Geonpungmi and Jeungmi leaves ($IC_{50}$, 0.11 mg/mL) and in Sinchunmi stalk ($IC_{50}$, 1.09 mg/mL).

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.999-1005
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• 2011

This study was conducted to investigate the quality characteristics of tofu (soybean curd) prepared with added Cheongyang hot pepper juice (CPJ). The moisture, crude protein, crude lipid, and crude ash contents of the control tofu were 82.98%, 10.26%, 4.86%, and 0.41%, respectively. The moisture content of tofu decreased according to the level of added CPJ, whereas the crude protein, crude lipid, and crude ash contents increased. The yield of tofu prepared with 5% CPJ significantly increased relative to that of control tofu. The turbidity and acidity increased with increasing concentration of CPJ, whereas pH decreased. The Hunter's color values of the tofu were significantly lower in L and a values and significantly higher in b values with increasing concentration of CPJ. The hardness, adhesiveness, and springiness of the tofu samples did not differ significantly according to the level of added CPJ. Capsaicin, dihydrocapsaicin, total polyphenol contents, and antioxidant (DPPH radical and ABTS radical scavenging activity) activities were significantly increased with increasing concentration of CPJ. Sensory evaluation indicated that the tofu prepared with 5% CPJ was not significantly different from the control tofu. Overall, CPJ could be used as an effective ingredient to improve the sensory and antioxidant properties of tofu without affecting the quality properties.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.367-372
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• 2015

This study was aimed at determining the antioxidant and antimicrobial effects of solvent extracts from Asparagus cochinchinensis. The Asparagus cochinchinensis was extracted with water, methanol, ethanol, n-hexane, dichloromethane, ethyl acetate, and ether. The antimicrobial activity of these extracts was determined by modified well diffusion methods against 4 species of respiratory disease bacteria (Staphylococcus aureus, Escherichia coli, Staphylococcus epidermidis, and Pseudomonas aeruginosa). In addition, the amount of total polyphenol and flavonoid content, and antioxidant activity was evaluated. Ethyl acetate extract of A. cochinchinensis exhibited higher antimicrobial activity against tested microorganisms than water, methanol, ethanol, n-hexane, dichloromethane, and ether extracts. For antioxidant activity, the ethyl acetate extract of A. cochinchinensis exhibited a notable effect on the scavenging of superoxide against DPPH ($IC_{50}=3.81mg/ml$). Finally, the total polyphenol and flavonoid contents were $14{\pm}0.7mg/g$, and $0.50{\pm}0.13mg/g$, respectively. These results can be regarded as basic research into A. cochinchinensis for the prevention of respiratory diseases. The results indicate that A. cochinchinensis may be utilized as a nutraceutical for respiratory diseases when the physiologically active substances of A. cochinchinensis are increased by further study.