Stimulating Effect of Gamma Radiation on Some Active Compounds in Eggplant Fruits

Abstract

A FIELD experiment was performed to study the effect of gamma irradiation (0.0, 50 and 100Gy) on growth parameters and bioactive compounds of different parts of eggplant. All growth parameters studied showed an increase when using a dose of 50Gy gamma rays. Also, 50Gy increased total phenolic contents (2.140, 4.039 and 2.965mg/g DW) for pulp, peel and whole fruits, respectively. A dose level at 50Gy increased flavonoid contents (0.835, 4.301 and 3.166mg/g DW) for pulp, peel and whole fruits, respectively. Moreover, tannin contents increased at a dose of 50Gy to (5.853, 7.94 and 7.79mg/g DW) for pulp, peel and whole fruits respectively; the highest contents were detected in peels followed by the whole fruits and the pulps. The DPPH radical scavenging activity of eggplant extracts varies according to the plant part. The antioxidant activity in the whole fruit was less than the peel and pulp while the highest antioxidant activity was in the peel. Otherwise, the amino acid and total soluble protein contents were higher in pulp in all treatments. Phenyl alanine ammonia-lyase (PAL) enzyme and polyphenol oxidase enzyme showed increases in their activities as gamma radiation increased to 50Gy, while increasing irradiation dose level to 100Gy reduces both enzyme activities. FT-IR showed the appearance and disappearance of function group in control and irradiated plants. Meanwhile, the results confirmed the presence of C-H stretching phenol (1020cm-1), alkane C-H blending (1450cm-1) and O-H stretching, lipid at (1450cm-1), and carbohydrate amino acids (3940.39cm-1) in eggplant plants different parts control and irradiated.