• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.6
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• pp.790-797
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• 2011

We evaluated the antioxidant compounds and activity of the methanolic extracts of foxtail millet (FM), proso millet (PM), and sorghum (SG) using different pulverizing methods (pin mill and ultra fine). The particle size of the FM, PM, and SG were 102.12, 89.52, and $102.25\;{\mu}m$, respectively, using the pin mill pulverizer. The sizes were 9.43, 9.52, and $10.18\;{\mu}m$, respectively, using the ultra fine pulverizer. There was no difference in moisture, crude fat, ash, or protein content between the two different pulverizing methods. The total ${\gamma}$-oryzanol content of the FM using the pin mill and ultra fine pulverizers was 116.07 and $145.30\;{\mu}g$/g, respectively. The total polyphenol content of the SG using the pin mill and ultra fine pulverizers was 14.58 and 15.03 mg/g extract residue, respectively. There was no difference in total flavonoid or tannin content of the methanol extracts between the two different pulverizing methods. The major phenolic compounds in FM were pyrogallol, gallic acid, (+)-catechin, salicylic acid, ferulic acid, and rutin; in PM, they were pyrogallol, rutin, gallic acid, kaempfrol, and salicylic acid; in SG, they were (+)-catechin, salicylic acid, pyrogallol, myricetin, hesperidin and chlorogenic acid. SG had a higher radical scavenging activity than FM or PM extracts. The DPPH and ABTS radical scavenging activities of the SG extracts using the ultra fine pulverizer were 178.10 and 251.56 mg TE/g extract residue, respectively. We noted a significant correlation between free radical scavenging activity and polyphenolic compound.

• Journal of Food Hygiene and Safety
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• v.31 no.2
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• pp.132-139
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• 2016

The purpose of this study was to investigate the contents of antioxidant compounds and antioxidant activities in teas. A total of 99 teas were tested for their antioxidant activities based on their ability to scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical. Antioxidant activity was expressed as mg of ascorbic acid equivalents per 100 g tea sample (L-ascorbic acid equivalent antioxidant capacity, AEAC) and was expressed as mg per 1 serving size (free radical scavenging activity, $FSC_{50}$). The total polyphenol contents of the extracts was quantified using the Folin-Ciocalteu method and the total flavonoid contents of the extracts was determined using a modied method of Davis. Vitamin C was analyzed by HPLC method. According to the AEAC value, mate tea, green tea, black tea, oriental raisin tea, chamomile tea and burdock tea showed relatively high antioxidant activities. Polyphenolic compounds were the major naturally occurring antioxidant compounds found in teas and the high concentrations of total polyphenol compounds were observed in black tea, green tea and mate tea. The high concentrations of total flavonoid compounds were observed in mate tea, black tea and yam tea and the amount of vitamin C contents were found to be high in citron tea and green tea. As a result, steeping tea was much higher in antioxidant activity than either powdered tea or liquefied tea. According to the study, a high correlation was demonstrated between the total polyphenol contents and antioxidant activities in teas (r = 0.846) and correlations between the total flavonoid contents and antioxidant activities was statistically significant in teas (r = 0.625). It was found that also the proportional relationship established among the total polyphenol content and antioxidant activities. That is, antioxidant activity of teas has been confirmed to have been caused by the total polyphenol.

• Korean Journal of Food Science and Technology
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• v.46 no.1
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• pp.79-86
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• 2014

In previous work, we fermented coffee beans using solid-state culture with various fungal mycelia to enhance the physiological activity of the coffee. The coffee fermented with Monascus sp. showed a higher physiological activity than non-fermented coffee or other coffees fermented with mushroom mycelium. The aim of this study was to characterize the various fermented coffees with respect to their area of cultivation and their variety using Monascus purpureus (MP) mycelium solid-state culture. Thirty types of green coffee beans, which varied in terms of their cultivation area or variety, were purchased from different suppliers and fermented with MP under optimal conditions. Each MP-fermented coffee was medium roasted and extracted further using hot water (HW) under the same conditions. Of the HW extracts, those derived from MP-Mandheling coffees had the highest yield (13.6-15.5%), and MP-Robusta coffee showed a significantly higher polyphenolic content (3.03 mg gallic acid equivalent/100 mg) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) free radical scavenging activity (27.11 mg ascorbic acid equivalent antioxidant capacity/100 mg). Furthermore, in comparison to other MP-fermented coffees at $1,000{\mu}g/mL$, MP-Robusta coffee showed not only the most effective inhibition of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) production in LPS-stimulated RAW 264.7 cells (67.1% of that in LPS-stimulated control cells), but also an effective inhibition of lipogenesis in 3T3-L1 adipose cells (22.2% of that in differentiated control cells). In conclusion, these results suggest that Vietnam Robusta coffee beans solid-state fermented with MP mycelium are amenable to industrial applications as a functional coffee beverage or material.

• Journal of Applied Biological Chemistry
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• v.54 no.4
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• pp.258-264
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• 2011

The Korean edible mountainous vegetable, byeongpungssam, Cacalia firma Komar. (CFK) is a wild plant found in the intermountain areas in Korea. The aim of this study was to investigate its free radical scavenging activity using 1,1-diphenyl-2-picryl-hydrazyl, 2,2-azinobis(3-ethylbenozothiazoline- 6-sulfonic acid) diammonium salt, ferric reducing/antioxidant power assays, an electron spin resonance spectroscopy. We also examined its protective effect against oxidative DNA damage using agarose electrophoresis of ethanol extract of CFK. The protective activity of the extract against the DNA damage induced by HO${\cdot}$ radicals was compared to epicatechin, ascorbic acid and trolox as reference antioxidant compounds. Total phenolic content in the extract was determined spectrometrically according to the Folin-Ciocalteu procedure and calculated as gallic acid equivalents. Total polyphenolic content of the extract was measured in the leaves ($161.53{\pm}1.07{\mu}g/g$) and shoot ($142.45{\pm}0.56{\mu}g/g$). The antioxidant potential of the extracts against some radicals and DNA damage by HO${\cdot}$ radicals showed over 60%, respectively.

• Korean Journal of Plant Resources
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• v.23 no.5
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• pp.406-414
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• 2010

Antioxidative activity, including inhibitory activities of angiotensin I converting enzyme(ACE), aminopeptidase N(APN) and $\alpha$-amylase, was investigated in the methanol extracts from Theaceae plants native to Jeju island, in order to select the plant species containing bioactive materials for functional food or medicines. ACE inhibitory activity was above 50% in Ternstroemia japonica(stem bark) and Cleyera japonica(leaf), and APN inhibitory activity was low to be positive only in C. japonica(leaf, stem bark) and T. japonica(stem bark). $\alpha$-Amylase inhibitory activity was above 30% in Camellia japonica(fruit), Eurya emarginata(stem), T. japonica(stem bark) and Thea sinensis(stem). The antioxidative activity, estimated by the DPPH radical scavenging capacity, was above 30% in C. japonica(stem bark), T. japonica(stem bark) and T. sinensis(leaf). Particularly, the antioxidative activity analyzed by dot-blot test was very high in C. japonica(stem bark) relatively to those of other plants, and remained high in the low concentration($1.25\;{\mu}g/m{\ell}$). From the TLC analysis of antioxidative compounds, EGC(Rf 0.26) was found to have high activity in stem bark of C. japonica and EGCG(Rf 0.09) was found to have high activity in stem bark of C. japonica, E. emarginata, and T. japonica. Five bands (Rf 0.54, 0.46,0.44, 0.16, 0.03) which were not identified as compared with catechins were detected as polyphenolic compounds on the TLC plates sprayed with the Folin-Ciocalteu solution or the Ferric chloride-alcohol solution. These results suggests that Theaceae plants except E. japonica could be potentially used as a resource of bioactive materials for functional foods or medicines and further research is reguired to identify the bioactive substances and determine the functions of them.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.6
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• pp.884-892
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• 2014

The purpose of this study was to investigate the drying characteristics and drying models of Ainsliaea acerifolia Sch. Bip. using far-infrared thin layer drying. Far-infrared thin layer drying test on Ainsliaea acerifolia Sch. Bip. was conducted at two air velocities of 0.6 and 0.8 m/sec, as well as three drying temperatures of 40, 45, and $50^{\circ}C$ respectively. The drying models were estimated using coefficient of determination and root mean square error. Drying characteristics were analyzed based on factors such as drying rate, leaf color changes, antioxidant activity, and contents of polyphenolics and flavonoids. The results revealed that increases in drying temperature and air velocity caused a reduction in drying time. The Thompson model was considered suitable for thin layer drying using far-infrared radiation for Ainsliaea accerifolia Sch. Bip. Greenness and yellowness values decreased and lightness values increased after far-infrared thin layer drying, and the color difference (${\Delta}E$) values at $40^{\circ}C$ were higher than those at $45^{\circ}C$ and $50^{\circ}C$. The antioxidant properties of Ainsliaea acerifolia Sch. Bip. decreased under all far-infrared thin layer drying conditions, and the highest polyphenolic content (37.9 mg/g), flavonoid content (22.7 mg/g), DPPH radical scavenging activity (32.5), and ABTS radical scavenging activity (31.1) were observed at a drying temperature of $40^{\circ}C$ with an air velocity of 0.8 m/sec.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.4
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• pp.534-541
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• 2013

In the present study, the effects of heat treatments on the phenolic components and antioxidative activities of various rice cultivars (from Hwaseongbyeo, Keunnunbyeo, Hongjinjubyeo, and Heugkwangbyeo) were investigated. Each brown rice cultivar was heated at six temperatures (40, 60, 90, 120, 150, and $180^{\circ}C$) for 15 min. The total polyphenolic content (TPC) and total flavonoid content (TFC) of 70% ethanol extracts from heated brown rice were quantified using spectrophotometrical methods, and antioxidant activities determined using DPPH, ABTS radical scavenging activities and reducing power. Hongjinjubyeo had the highest TPC (6.50 mg GAE/g, DB) and ABTS radical scavenging activity (5.85 AAE/g, DB) at $60^{\circ}C$. Also, Heugkwangbyeo showed considerable values for TPC (6.57 and 6.89 mg GAE/g, DB) and ABTS radical scavenging activity (6.29 and 6.11 AAE/g, DB) at $40^{\circ}C$ and $180^{\circ}C$, respectively. Overall, the antioxidant activities of both Hongjinjubyeo and Heugkwangbyeo extracts had a strong positive correlation ($R^2{\geq}0.916$, ${\alpha}$=0.01) with TPC and TFC. These results indicate that heat treatment effectively enhances the antioxidant activity of Hongjinjubyeo and Heugkwangbyeo.

• Applied Biological Chemistry
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• v.18 no.4
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• pp.194-202
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• 1975

This study was conducted to study the properties of the water-soluble natural chelating agents from garbage compost and activated sewage sludge responsible for Fe chelation, which is closely associated with the effectiveness in correcting iron chlorosis in plant. The water-soluble fraction of these materials was fractionated by menas of Sephadex gel filtration and the fractions of Fe chehates were traced by radioactive $^{59}Fe$. The fractions were examined by ultraviolet and infrared. spectroscopy and stability constants for Fe. The water-soluble fraction from garbage compost was separated by Sephadex G-25 into approximately four fractions. Most of the added $^{59}Fe$ was associated with fraction I, which appeared at the void volume. Further fractionation by Sephadex G-50 indicated that the molecular weight of water-soluble chelating agents is in the approximate range of 5000 to 10,000. The water-soluble fraction from activated sewage sludge gave six fractions by Sephadex G-25. Most of the added $^{59}Fe$ was found in the fraction I,II, and III, The molecular weights of most chelating agents associated with $^{59}Fe$ appeared to be less than 5,000 and those of fraction I that appeared at the void volume was in the range of 5,000 to 1,000. Discrepancy between radio activity count and UV absorption indicated the heterogeneity of the fractions obtained by Sephadex gel filtration. Ultraviolet absorption spectra of all fractions separated by Sephadex G-25 and containing chelating agents showed no differences. Fraction IV and V of sewage extract showed absorption maxima and shifting similar to nucleic acid components suggesting the presence of decomposition products of nucleic acid. Similarity fraction VI contained phenolic type amino acid groups. Fraction I of compost extract contained most of the added $^{59}Fe$ and showed weak but extra definite absorption in the 1230, and $1270cm^{-1}$ region, suggesting that extra oxygen groups in polyphenolic structure were probably involved in Fe chelation. In sewage extract, fraction I,II, and III in which most of the $^{59}Fe$ was found, showed strong definite polypeptide absorption in the region of $1540cm^{-1}$ due to NH deformation and C-N stretching of amide groups in the peptidebond. These extra functional groups in fraction I, II, and III appeared to be associated with Fe chelation. The other fractions, not associated with $^{59}Fe$, still have carboxyl and hydroxyl groups, suggesting that these functional groups in these water extracts may not independently form the Fe chelates. Precipitation of ferric hydroxide precluded measuring the stability constants for Fe-chelates. However, the formation constants for Zn chelates as log K values for compost extract and sewage extract at pH 4.0 from which the strength of chelation with Fe could be presumed, were 8.23, and 9.75, respectively, indicating strong complexation with metals. The chelating capacity of compost extract containing 6.5 g organic matter per liter was 0.82 mM, and that of sewage extract containing 5.3 g per liter was 0. 64 mM.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.383-390
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• 2017

Regarding the facts that fat, which is easily oxidized, is one of the major responsible factors affecting the quality of aroma, and polyphenol compounds including chlorogenic acid (CGA) contribute the anti-oxidative activities to coffee, we investigated fat oxidation, conversion of CGA, and changes of anti-oxidative activities according to the degree of roasting and storage of 60 days. We found that the amount of extractable fat by diethyl ether is increased as the coffee beans are roasted longer. Furthermore, the acidity values of the fat are increased from $8.91{\pm}0.16$ to $17.81{\pm}0.11$, and $10.37{\pm}0.27$ to $17.93{\pm}0.09$ in the medium and dark roasted coffee beans, respectively, while it is increased from $4.47{\pm}0.11$ to $11.89{\pm}0.18$ in the green coffee bean after 60 days. The CGA contents in the coffee beans were decreased from $310{\pm}8.2$ to $282{\pm}11.2$, then to $58{\pm}0.0mg$ in 10 gr of the green, medium and dark beans, respectively, and were not changed significantly during the storage period. However, the anti-oxidative activities measured by 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid radical scavenging assays were not significantly different among the green, medium, and dark coffee beans during the storage period. Furthermore, antioxidant reactive element-luciferase assay showed that biological anti-oxidative activities were increased as coffee beans were more roasted and stored longer. As the total polyphenolic contents in the beans were significantly decreased by roasting, the results suggests that other molecules, such as, Maillard reaction products might play substantial role in anti-oxidative activity and influence cup quality of coffee.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.5
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• pp.682-688
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• 2011

The purpose of this study was to measure the blood glucose level and glycemic index (GI) in response to persimmon (Diospyros kaki Thunb) syrup extracted from persimmon and extract of persimmon by-products. Major component analyses of persimmon syrup I (PSI, 95:5 mixture of purified persimmon syrup and non-purified persimmon syrup) and persimmon syrup II (PSII, 50:50 mixture ratio of purified persimmon syrup and non-purified persimmon syrup) were $0.3{\pm}0.1$ and $0.6{\pm}0.2$ mg/g for total polyphenolic compounds and $70.6{\pm}0.6$ and $66.6{\pm}1.6%$ for total carbohydrates, respectively. Blood glucose responses of PSI and PSII were determined using both normal ICR mice and streptozotocin (STZ)-induced diabetic male Sprague-Dawley (SD) rats. Further, oral glucose tolerance test (OGTT) was performed on diabetic rats to assess the effects of the experimental diets. Blood glucose response and OGTT showed that blood glucose levels were significantly lower in mice and diabetic rats fed PSI and PSII compared to those fed diets of sugar, maple syrup, or honey. The GIs of healthy volunteers in response to PSI and PSII were calculated to be 51.9 and 35.7, respectively. On the contrary, the GIs of healthy volunteers fed diets including sugar, maple syrup, or honey were 52.6, 20.0, and 93.0, respectively. These results suggest that persimmon syrup can be used for both the treatment of diabetics and healthy people due to its beneficial effects on blood glucose level.