RESUMEN
Cordyceps coffee, containing Cordycepin and ß-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%). ß-Glucan content was determined by the enzyme method; the raw Cordyceps, Phellinus, and Chaga mushrooms contained 3.79%, 7.06%, and 8.57% ß-glucan, respectively. However, ß-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 ß-glucan.
RESUMEN
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.
RESUMEN
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.