Antioxidant flavonoids have been isolated from the flower of Rhododendron yedoense var. poukhanense. One new flavonoid and three known flavonoids, quercetin-5-O-beta-D-glucopyranoside (1), quercetin (3), and quercitrin (4), were isolated from the butanol and ethyl acetate extracts of the plant. The new flavonoid was identified as myricitrin-5-methyl ether (2). The isolation of these flavonoids from this plant, for the first time, is a valuable finding. The flavonoids were evaluated for their antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl free radical (DPPH), TBARS (thiobarbituric acid reactive substance) and superoxide anion radical (O2-) in the xanthine/xanthine oxidase assay system. In the DPPH scavenging assay, the IC50 values were 4.5 +/- 0.48 microM for compound 2 and 9.7 +/- 0.29 microM for compound 3, which showed an antioxidant activity approximately 1.5-2 times higher than the antioxidant activity of alpha-tocopherol (9.8 +/- 0.94 microM). Additionally, the antioxidant activities of myricitrin-5-methyl ether (2) (IC50 = 1.7 +/- 0.22 microM) and quercetrin (4) (IC50 = 1.9 +/- 0.63 microM) were higher than that of L-ascorbic acid (IC50 = 7.4 +/- 0.63 microM) when evaluated using a TBARS assay. Compound 2 showed high activity in both the inhibition of xanthine oxidase (1.1 +/- 0.21 mM) and in the activation of superoxide scavenging.

The attractive purple color of blueberries (Vaccinium spp.) is unstable and susceptible to degradation during food processing and storage. The effects of various factors on the color stability of fresh blueberry juice were investigated. Total soluble solid content, pH, and total anthocyanin content were measured. Heating at 30°C and 60°C for 300 min did not influence the color stability, but heating at 100°C drastically decreased it by 33.0%. Sugars decreased color in a concentration-dependent manner. However, glucose and galactose had significantly protective effects on the color disruption than fructose, maltose, and sucrose. Organic acids lowered the color intensity in the order of citric acid> tartaric acid> malic acid> formic acid> acetic acid during 10 days of storage. Color decreased faster during long-term light exposure than in the dark. The color in the dark was kept by 58.7% after 7 weeks, while 48.9% in the light. Color retention was significantly decreased to 93.5% and 93.8% at 4°C and −20°C, respectively, after 7 weeks, while 95.40% at −75°C. We suggest that blueberry juice color can be protected by keeping the extraction temperature below 60°C with the selective addition of glucose, galactose, or citric acid. For long-term storage, it is recommended to use a light-protected container and a deep freezer at −75°C.

Cordyceps coffee, containing Cordycepin and -glucan, was developed to improve quality and functionality of coffee. We evaluated its biological activities and quality characteristics. We treated green coffee beans with mixed extracts from three medicinal mushrooms, Cordyceps mushroom (Cordyceps militaris), Phellinus mushroom (Phellinus linteus), and Chaga mushroom (Inonotus obliquus). Both control [27.00 mg gallic acid equivalent (GAE)/g] and Cordyceps coffee (37.34 mg GAE/g) had higher contents of polyphenol than the Cordyceps mushroom raw materials (23.17 mg GAE/g). 1,1-Diphenyl-2-picrylhydrazyl scavenging activity was higher for both the control and Cordyceps coffee (80.56% and 82.21 %, respectively) compared with Cordyceps mushrooms (62.89%). -Glucan content was determined by the enzyme method; the raw Cordyceps, Phellinus, and Chaga mushrooms contained 3.79%, 7.06%, and 8.57% -glucan, respectively. However, -glucan and total glucan contents were much lower in Cordyceps coffee (2.03% and 3.11%, respectively) than in the raw mushrooms. The amount of Cordycepin, as determined by high performance liquid chromatograph, was 2,274.70 mg/kg for the Cordyceps coffee and 11,533.22 mg/kg for the Cordyceps mushrooms. Through flavor pattern analysis using the electronic nose system, we showed Cordyceps coffee kept the original coffee aroma (similar as the control), and this was not obstructed by the off-flavor of the Cordyceps mushrooms. In conclusion, this study suggests that Cordyceps coffee may be a novel functional coffee containing the functional components Cordycepin and -glucan.

Nutritional components and quality characteristics of drained soybean boiling water(DBW), which is discarded in the mass production of fermented soy foods, were compared with raw soybean(Control) and Cheonggukjang(CGJ) to provide the basic data for its recycle. The contents of moisture, crude protein, crude lipid and crude ash of DBW were shown as 87%, 2.2%, 0.15% and 1.42%, respectively. Decreased total amino acid of 1,677.8 mg/100g in DBW was comparable with 29,051.1 mg/100g in control, however, there was no great difference in the proportion of essential amino acid to the total. While the total sugar contents were decreased in both DBW and CGJ with 8.39% and 7.17% each from the control of 11.50%, the reducing sugars were increased with higher amount of 6.44% in CGJ and 8.30% in DBW than 5.60% in control. pH of DBW was lower than both of the control and CGJ. Hunter's color values revealed the increase of redness(a value) and yellowness(b value) of DBW and CGJ suggesting that Maillard reaction products were produced by the heating and fermentation process.Polyphenol compounds were highly abundant in CGJ of 0.74 tannic acid equivalent(mg/g) followed by similar low amounts of 0.33 and 0.29 tannic acid equivalent(mg/g) in DBW and control, respectively. Antioxidative activity determined by Electron Donating Ability(%) using DPPH radical showed that CGJ, of which polyphenols were the highest, has the strongest electron donating ability with the lowest EC50 value of 5.91 mg/mL. DBW was much lower but similar with the control. From the above results the drained soybean boiling water was shown to have many nutritional and functional components as much as soybean, therefore, it could be a potent reusable food material.

The nutritional compositions and antioxidative activities of the Kimcheon lowbush and Pyungtaek highbush blueberries cultivated in South Korea were investigated. The approximate compositions, pH, and soluble-solid and mineral contents of P, Ca, Mg, Na, and Zn were determined. Both blueberry cultivars had mainly fructose and glucose as free sugars while disaccharides such as sucrose, maltose, and lactose were not detected in both. Oleic, linoleic, and linolenic fatty acids were the major fatty acids in both types of blueberries. The total of 16 free amino acids, including seven essential and nine non-essential amino acids, were higher in the Pyungtaek highbush blueberry. Among the amino acids, arginine was especially much higher in the Pyungtaek highbush blueberry. The anthocyanin, resveratrol, and polyphenol compounds, which are the important biologically active compounds in blueberries, were found. The anthocyanin contents of the Kimcheon lowbush and Pyungtaek highbush blueberries were 22.0 and 18.1 mg/100 g, respectively; the resveratrol contents by HPLC, 0.12 and 0.11 mg/100 g; and the total polyphenol contents, 141.3 and 138.4 mg/100 g. The electron-donating ability determined based on the DPPH radical scavenging activity was increased in a concentration-dependent manner, and it was higher than that of the Pyungtaek highbush blueberries, which implies that it is highly correlated with the higher amounts of total polyphenol, anthocyanin, and resveratrol in it. In conclusion, the two varieties of Korean blueberries can be suggested as potential sources of high-value-added functional foods.