1H-Nuclear magnetic resonance imaging of ripening 'Kensington Pride' mango fruit

Abstract

Physicochemical gradients occur in mango mesocarp tissue during ripening. These gradients are reflected in water activity, which is non-uniform throughout the mesocarp. Signal intensity in proton magnetic resonance images (first echo, proton density and T₂) for green-mature `Kensington Pride' mesocarp tissue was highest near the endocarp and lowest near the exocarp. Relative signal intensity increased in the middle mesocarp as ripening proceeded, but remained relatively low in the outer mesocarp. T₂ relaxation times for inner and middle mesocarp regions fell during ripening. The data suggest that water activity in the mesocarp tissue increased in an outward-moving flux as ripening progressed. This change in water activity was associated with starch hydrolysis and other ripening-related processes that commence near the endocarp.