Trans-Resveratrol Contents of Peanut Seeds Depend on Varieties and Processing Methods

The high-performance liquid chromatography(HPLC) method for the determination of trans-resveratrol in 34 germplasms and processing methods of peanut seeds has been modified. Peanut germplasms contained trans-resveratrol contents of $0.14{\sim}4.96{\mu}g/g$, but findings for the testa color were not significant. However, two germplasms, 'KIGAN' and 'CS1', contained more trans-resveratrol contents than the other germplasms. The contents of their were $2.26{\mu}g/g\;and\;4.96{\mu}g/g$. The tested processing methods caused no significant changes in trans-resveratrol contents. The contents of fresh, boiled, and roasted peanuts were 0.36, 0.32, and $0.40{\mu}g/g$, respectively in cv. Palkwang, and 0.22, 0.22, and $0.26{\mu}g/g$, respectively, in cv. Jakwang. Differences were not significant among fresh, boiled, and roasted peanuts. The grains of 'Palkwang' and 'Jakwang' contained trans-resveratrol contents of $0.34{\mu}g/g\;and\;0.24{\mu}g/g$, and testa contained $1.12{\mu}g/g\;and\;1.00{\mu}g/g$, respectively. However, when comparing absolute quantity, the trans-resveratrol contents appears to be approximately $3{\sim}4$ times higher in the testa than in the grain of the peanut, although the total contents were not different because the ratio of testa was low in peanut seeds.