Mi-Yae Shon

Antioxidants and free radical scavenging activity of Phellinus baumii (Phellinus of Hymenochaetaceae) extracts

This study was carried out to expand the utilization (for the pharmaceutical and food industries) of extracts of Phellinus baumii. Fractions rich in phenolics were extracted from P. baumii using various solvents. Antioxidant and free radical scavenging activity were studied using a β-carotene-linoleate model system and reactive oxygen species generation system. Total phenolic compounds in methanol and hot water extracts were 33.3 and 20.7 mg/100 ml, respectively; these values are higher than other solvent extracts. Therefore, methanol and hot water extracts exhibited good inhibition rates, of about 80–90%, by hydroxyl radical scavenging activity, hydrogen peroxide scavenging activity, effect of reducing power on metallic compound formation and antioxidant activity.

Screening for Components to Inhibit N-Nitrosodimethylamine Formation from Tomato

A tomato (Lycopersicon esculentum cv. Naomi F1) juice was separated into ascorbate and phenolic portions using a Sep-pak cartridge, and its each portion was tested for inhibition of N-nitrosodimethylamine (NDMA) formation. Ascorbate and phenolic portions of tomato juice inhibited NDMA formation by and , respectively. The phenolic portion was further fractionated by prep-HPLC and inhibitory effects of NDMA formation by 4 fractions from tomato juice was tested under the different pH conditions (pH 1.2 and 4.2). Fraction 2 inhibited NDMA formation by (pH 1.2) and (pH 4.2), respectively. Fraction 2 was further separated into 4 subfractions . Subfraction 2b especially inhibited NDMA formation by (pH 1.2) and (pH 4.2). This subfraction was confirmed o-coumaric acid through the analysis of GC-Mass spectrum, and .