Isolation and Identification of the Antioxidant DDMP from Heated Pear (Pyrus pyrifolia Nakai).
We evaluated antioxidant activities of heated pear juice (HPJ) exposed to 120, 130, and 140°C for 2 hr. HPJ was partitioned using n-hexane, chloroform, ethyl acetate, n-butanol, and water. The ethyl acetate fraction treated at 130°C for 2 hr showed strong antioxidant activity; thus, this extract was isolated and purified using silica gel column chromatography and preparative high performance liquid chromatography. The structure of the purified compound was determined using ultraviolet and mass spectrometry, (1)H-nucelar magnetic resonance (NMR), and (13)C-NMR. Antioxidant activities of the isolated compound were evaluated and compared with α-tocopherol, ascorbic acid, and butylated hydroxytoluene (BHT) using DPPH and ABTS assays. The isolated compound was identified as 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP). The DPPH radical-scavenging activity (IC50) of DDMP occurred in the following order: ascorbic acid (45.3 μg/mL)> α-tocopherol (69.2 μg/mL)> DDMP (241.6 μg/mL)> BHT (268.0 μg/mL). Furthermore, DDMP showed strong ABTS radical-scavenging activity (569.0 mg AA eq/g).
Department of Agrofood Resources, National Academy of Agricultural Science, Gyeonggi 441-853, Korea.
In Guk
IG
Hwang
Department of Functional Crop, National Institute of Crop Science, Gyeongnam 627-803, Korea.
Hyun Young
HY
Kim
Department of Functional Crop, National Institute of Crop Science, Gyeongnam 627-803, Korea.
Koan Sik
KS
Woo
Department of Food Science and Technology, Chungbuk National University, Chungbuk 361-763, Korea.
Sang Hoon
SH
Lee
Department of Food Science and Technology, Chungbuk National University, Chungbuk 361-763, Korea.
Junsoo
J
Lee
Department of Food Science and Technology, Chungbuk National University, Chungbuk 361-763, Korea.
Heon Sang
HS
Jeong
2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one; antioxidant activity; heat treatment; pear