Quantitative determination of flesh mealiness in peach [Prunus persica L. (Batch.)] through paper absorption of free juice

Abstract

A simple and rapid method was developed for quantitative determination of juiciness in peach flesh based on the absorption of free juice with ordinary absorbent paper after a flesh sample is squeezed by two metallic rolling cylinders. Juiciness data were compared with trained panel determinations on three peach cultivars kept at 4 ◦C and 90% RH for 7, 14 and 21 d plus a ripening period at 20 ◦C and 65% RH until the flesh reached 19.6±9.2 N. There was a high correlation between panel judgment and paper absorption (r2 = 0.75 in ‘Elegant Lady’, 0.77 in ‘O’Henry’ and 0.93 in ‘Ross’). A sub-sample of the juiciest and the mealiest fruit also were sorted after 14 and 21 d in cold storage. ‘Ross’, a non-melting peach cultivar, did not develop flesh mealiness during any evaluation period. During storage, there was a reduction in juiciness reaching 15% less after 21 d. Mealy fruitwere exclusively observed with melting cultivars exposed to cold storage. The proposed method for determining juice content is easily executed and shows a high association with human perception of juiciness and mealiness in peach.