Mango juice colour in dices showed significant statistical differences among the control and irradiated juice samples of all cultivars studied.The results(Table6) showed that the control
mango juice had a darker colour than that of their radiated juice
samples with significant (Pr0.05) differences in the luminosity
dimension scale(lightness; L*¼0 denotes black and L*¼100 indicates diffuse white).The redness(a*) and yellowness(b*) indices
increased directly with the irradiation dose and represented significant (Pr0.05) differences among the juice samples of all cultivars at different dose levels.The chroma(C*) (grey(chroma¼0)
to brilliant red(chroma¼104))value was significantly (Pr0.05)
increased in all cultivars of mango juice samples by in creasing their radiation dose.However,conflicting results were observed in hue
angle (h°) of irradiated mango juice samples from different cultivars.Similar to our study, Shahbaz et al.(2014) reported that the L*
value was significantly decreased,however a* and b* values were
significantly increased by increasing the irradiation dose in pomegranate juice samples.Opposite to these findings, Lee et al.
(2009) reported the Hunter colour L* value(brightness)in creased
significantly,however Hunter colour a* value(redness)and b*
value(yellowness)were decreased significantly by irradiation in
both fresh and stored ready-to-use tamarind juice samples.
A study done by Mitchell et al.(1992) on mangoes showed a reduction in the a* values after gamma-rays treatment at 75 and 300 Gy.