Quality and decay of irradiated mangos.
Spalding D. H., Windeguth D. L. von
Author Affiliation: Subtropical Hort. Res. Sta., ARS, USDA, 13601 Old Cutler Road, Miami, FL 33158, USA.
HortScience 23 : 187-189
Abstract : Mango cv. Tommy Atkins and Keitt irradiated with ?-rays from 60Co at dosages of 150 to 1500 Gy, then held for 3 d at 13°C followed by ripening at 24°, developed less ripe peel colour than unirradiated mangoes. Ripening of Tommy Atkins mangoes was delayed for 2 to 3 d by 150 and 250 Gy, unaffected by 500 and 750 Gy, and accelerated by 1500 Gy. The pH of juice from Tommy Atkins mangoes decreased and titratable acidity increased as irradiation dosage increased; soluble solids content was not affected by irradiation. Scald-like peel injury increased with dosage, especially at 500 Gy or higher. Internal breakdown was localized and slight, but its incidence in Tommy Atkins mangoes was increased at 250 Gy or higher. Hollow pockets in the flesh and flesh darkening were significantly increased by irradiation at 1500 Gy, but not 750 Gy. Severity of anthracnose (Colletotrichum gloeosporioides [Glomerella cingulata]) was reduced in Keitt mangoes at 500 Gy and higher. The severity of stem-end rot (Diplodia natalensis [Botryodiplodia theobromae] or Phomopsis [Diaporthe] citri) was reduced in Tommy Atkins mangoes at 1500 Gy, but not 750 Gy. The overall percentage of decayed fruit was reduced by irradiation at 750 Gy or higher. The results suggest that if irradiation is used for insect control on mangoes, dosages ? 250 Gy and above should be avoided to minimize injury.