A cultivar (Malus domestica cv. Fuji) of apple was selected to make apple peel (AP) powder by three different powdering methods. Frozen AP was thawed and subsequently was dried or ground without drying. After AP was dried by hot-air drying at 60°C or freeze-drying, the dried AP was ground using a conventional blender. Separately, the thawed AP was powered by using a cryogenic micro grinding technology (CMGT). The ground AP and three types of AP powder were extracted using deionized water, 20, 40, 60, 80, or 100% methanol, followed by vacuum evaporation. The total phenolics contents (TPC), total flavonoids contents (TFC), DPPH, and ABTS radical scavenging capacities of each extract were compared to determine an efficient powdering method. Lyophilized AP powder extract using 60% methanol showed the highest TPC and DPPH radical scavenging capacity. In contrast, 60% methanol extract of the powder by CMGT, resulting in the smallest particle, exhibited the highest TFC and ABTS radical scavenging capacity. This study suggests that the extraction yield of bioactive compounds from AP may be varied according to different powdering methods and that a new powdering process such as CMGT may be applicable to develop functional foods efficiently.
This study was conducted to compare the antioxidant activities of fermented soy products such as chungkukjang, meju and doenjang with soybeans. Total phenolic, flavonoids contents and antioxidative activities of the methanol extract of soy and fermented products were compared with specific reference to alpha-diphenyl-2-picryl-hydrozyl (DPPH) radicals scavenging effects, ferric /reducing power (FRAP), inhibition of conjugated diene formation and tyrosinase activities. Total phenolic and flavonoids contents increased in soybeans after fermentation. Fermented soy products also displayed enhanced antioxidative activities in comparison with the non-fermented soybeans. There were linear relationships between total phenolic and flavonoids contents and ferric reducing/antioxidant power of the samples. Overall, the fermented soy products showed a better antioxidant activity than soybeans. Among the 3 kinds of fermented soy products, chungkukjang, meju and deonjang, doenjang exhibited the highest levels of DPPH-free radicals scavenging activity, ferric /reducing power, inhibition of conjugated diene formation and tyrosinase activities. The fermented soy products with longer fermentation time demonstrated the higher antioxidant activities as well as higher total phenols and flavonoids in the order of doenjang > meju > chunghlkjang> soybeans.
This study was carried out in order to determine the biological activities such as antioxidant activities in nine cultivars of Momordica charantia L. (Korea, China, Japan and Philippine native cultivars). Their antioxidant activities were measured using DPPH free radical scavenging, ABTS cation radical scavenging, and Nitrite scavenging ability. The highest total polyphenol content (16.82 μg/ml) measured in the native Korea cultivar, and this value was 4.0 μg/ml higher than that of the 'Verde Beuhas' cultivar (12.82 μg/ml). The 'Peacock' cultivar had the highest total flavonoid amount which was 4.38 μg/ml. The free radical scavenging activity using DPPH method was the highest in the native China cultivar (RC50 = 102.6 μg/ml). ABTS cation radical scavenging activity according to cultivars was significantly higher in 'Peacock'. Nitrite scavenging ability showed the most remarkable effect at the pH 1.2, exhibited to 81.5~86.9% by addition of ethanol extract 1μg/ml from Momordica charantia L. These results suggest that Momordica charantia L. had the potent biological activities, and that their activities exhibited differently depending on cultivars.
Artichoke extracts are widely used alone or in association with other herbs for embittering alcoholic and soft drinks and to prepare herbal teas or herbal medicinal products in Viet Nam. The objective of this paper was a screening of flavonoids and total phenolic compounds content in the parts of artichoke (Cynara scolymus L.) as flowers, leaves, roots, trunks, stumps. The total phenolic compounds and flavonoids in the parts of artichoke were extracted among 3 extraction methods as methanol extraction (EM1), mixing methanol and water method (EM2) and water extraction method (EM3). Total phenolic compounds and flavonoids were determined by UV/VIS, HPLC techniques. The apigenin 7-O-glucosides, cynarin, narirutin, gallic acid, caffeic acid were found as the main flavonoids constituents in all parts of artichoke. It showed that value of total phenolic compounds and flavonoids by EM3 were higher than that of total phenolic compounds and flavonoids by EM1 and EM2. Furthermore, the results of this study revealed that total phenolic compounds and flavonoids, obtained by these convenient extraction methods, may show the quick efficacy of artichoke in all respects of their quality and quantity.