Definition and establishment of assessment procedures for mealiness of apple fruits using sensory and instrumental measurements were performed on ‘Boskoop', ‘Cox's Orange Pippin’ and ‘Jonagold’ samples with varying degrees of mealiness. The sensory procedure profiled mealiness as a loss of crispness, hardness, and juiciness, with an increase in the floury sensation in the mouth. High correlations between the sensory descriptors and instrumental parameters was shown through principal component analysis. The instrumental procedures (confined compression of fruit cylinders and acoustic impulse response) gave coefficients of determination for juiciness and crispness of 0.85 and 0.71, respectively. This level of accuracy indicates the possibility of establishing

Time-resolved reflectance has been used for the nondestructive measurement of optical properties in apples. The technique is based on the detection of the temporal dispersión of a short láser pulse injected into the probed médium. The time distribution of re-emitted photons interpreted with a solution of the diffusion equation yields the mean valúes of the absorption and reduced scattering coefficients of the médium. The proposed technique proved useful for the measurement of the absorption and scattering spectra of different varieties of apples, revealing the spectral shape of chlorophyll. No major variations were observed in the experimental data when the fruit was peeled, showing that the optical properties measured were those of the pulp. With this technique the change in chlorophyll absorption during storage and ripening could be followed. Finally, a compact prototype working at few selected wavelengths was designed and constructed, demonstrating potentialities of the technique for industrial applications.

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