Potential maturity indices and developmental aspects of melting-flesh and nonmelting-flesh peach genotypes for the fresh market.

摘要

Potential maturity indices were determined for 2 melting-flesh (FL 90-20 and TropicBeauty), and 2 nonmelting-flesh (Oro A and F186-28C) peach genotypes grown in Florida, USA. A range of developmental stages was obtained by conducting 2 harvests andseparating the fruits based on diameter. Fruits in each category were divided into 2 groups. One group was used to determine potential maturity indices: soluble solids, titratable acidity, soluble solids:titratable acidity ratio, peel and flesh colour onthe cheeks and blossom end, cheek and blossom-end firmness, ethylene production and respiration rate. The other group was stored at 0deg C for 1 week, and was ripened at 20degree C for 2 days to simulate handling conditions. Fruits were then presented to a trained sensory panel, which rated the fruits for 3 textural aspects (hardness, rubberiness and juiciness) and 6 flavour aspects (sweetness, sourness, bitterness, and green, peachy and overripe character). Principal component (PC) analysis results were combined with the sensory evaluations into a single variable that could be correlated with the objective measurements at harvest. The attributes that best correlated with the first sensory PC of each genotype, and thus are promising maturity indices, were: forFL 90-20, peel hue, peel L value and cheek firmness; for TropicBeauty, peel L value, cheek firmness and blossom-end firmness; for Oro A, cheek firmness, blossom-end firmness and cheek chroma; and for 86-28C, blossom-end firmness, cheek hue and cheek firmness.