Gamma irradiation for inhibiting germination and maintaining the quality of fresh Lemongrass

This research aimed to evaluate the efficacy of gamma irradiation on shoot germination inhibition and quality maintenance in fresh lemongrasses. Lemongrass without any defects were sorted, and then removed the outer leaves before the stalk was cut into 12 inches in length. The lemongrass stalks were irradiated with gamma rays at the doses of 0 (control), 100, 200, and 300 Gy. All samples were kept in an LDPE bag at 4ºC for 21 days (simulation as the storage condition), then transferred to 25ºC for 4 days (simulation as the shelf-life condition). The results found that gamma irradiation at 100, 200, and 300 Gy could inhibit the shoot germination with non-significant differences among treatments. The quality of lemongrass found that gamma irradiation at 200 Gy showed the best effect to delay color changes and the irradiation at 200 and 300 Gy could reduce browning at the cut surface of the shoot and leave sheets, which resulted in a higher acceptant score by the consumers in terms of color and overall acceptance than non-irradiated lemongrass (control). However, gamma irradiation could reduce ethylene production as compared with the control, but had no effect on respiration rate, and the changes in vitamin C, and antioxidant capacity (DPPH method). The findings in this study indicated that gamma irradiation could inhibit germination and maintain the quality of lemongrass. In particular, gamma irradiation at 200 Gy tended to be the best treatment for maintaining the quality of lemongrass, which could be extended the storage life of lemongrass at 4°C for 21 days and 2 days at 25°C (21 + 2 days).

Keywords: Lemongrass; Radiation; Shoot inhibition; Browning