PHYTOSANITARY IRRADIATION TREATMENTS IN RELATION TO DESAPPING AND PROCESSING TYPES AFFECT MANGO FRUIT QUALITY

Irradiation has now become an acceptable market access protocol for fruit fly disinfestation for many countries including the USA. It also improves the microbiological safety and shelf-life of fresh produce.
This study evaluated the response of three commercial mango cultivars (‘Sindhri’, ‘Samar Bahisht Chaunsa’ and ‘Sufaid Chaunsa’) of Pakistan to varying doses of gamma irradiation in combination with two types of desapping (physical vs. lime) and cleaning methods (brushed vs. non-brushed). Irradiation had significant effects on both physically and lime-desapped ‘Sindhri’ mangoes stored under ambient (30±2°C; 50-60% RH) and low temperature (13±1°C; 80-85% RH) conditions.
Fruit subjected to high irradiation doses (700 and 1000 Gy) had significantly lesser peel colour development as compared to lower doses (250 and 400 Gy). No significant effect was found on firmness, lenticels, weight loss, biochemical and organoleptic properties.
Moreover, irradiation did not significantly reduce disease development resulting in lower marketability index at ripe stage in mangoes stored for 4 weeks at low temperature.
Lime-desapped ‘S.B. Chaunsa’ fruit irradiated at 400 Gy exhibited higher firmness and better organoleptic characteristics than physically-desapped mangoes.
Regardless of processing type, irradiation at 700 Gy resulted in significantly better firmness at the ripe stage in ‘Sufaid Chaunsa’ mangoes kept under ambient conditions and slow colour development during storage at 11±1°C; 80-85% RH. However, under ambient conditions, brushed fruit had significantly better peel colour and TSS:acidity as compared to non-brushed fruit.
Overall, brushed ‘Sufaid Chaunsa’ mangoes irradiated at 700 Gy had significantly higher lenticels development and poor colour under both storage conditions.
In conclusion, irradiation at higher dose caused less colour development and more lenticels spotting.
However, the response varied with cultivars.
Between desapping types, lime desapping (0.5% lime solution; 2-3 min dip) caused more lenticels spotting compared with physical desapping.
In the case of processing type, brushed mangoes had more lenticels spots compared with non-brushed mangoes when irradiated at 400 Gy, the dose required as per USA protocol.

VII International Postharvest Symposium

A.U. Malik, M. Umar, R. Hameed, M. Amin, H.U. Asad , O. Hafeez, P.J. Hofman

mango, desapping, quarantine, quality, storage, irradiation

https://doi.org/10.17660/ActaHortic.2013.1012.91