Volatile compound fingerprinting of ‘Kaki Tipo’ and ‘Rojo Brillante’ persimmon fruits at ripe-stage eating quality

Fruits produce a wide range of volatile organic compounds (VOCs), both qualitatively and quantitatively, that are modified by numerous factors. Persimmon cv. ‘Rojo Brillante’ (PVA), the leading variety in Spain, is mostly marketed as a hard edible fruit after artificial removal of astringency, while cv. ‘Kaki Tipo’ (PVNA), widely grown in Italy, is marketed as either a seedless, soft, post-ripened fruit or a seeded hard fruit. Few studies address persimmon fruit aroma and little is known about the VOCs responsible for persimmon fruit aroma. Proton Transfer Reaction Time-of-Flight Mass Spectrometry (PTR-TOF-MS) can be used to grade and evaluate fresh or processed fruits through qualitative and quantitative measurements of VOCs. Samples of intact pulp cubes and squeezed pulp of fresh, ripened ‘Rojo Brillante’ and ‘Kaki Tipo’ persimmon fruits were analyzed by PTR-TOF-MS. Concentrations of volatile compounds varied by fruit typology, cultivar, and sampling method (intact or squeezed pulp). Comparing the entire VOC spectra of the two persimmon cultivars showed that persimmons at eating quality ripeness: (i) were characterized by few signals; (ii) had VOC signals with atomic weights under 100; (iii) had no or low concentrations of terpenes, sulfur compounds, lactones, and green leaf volatiles; and (iv) had high concentrations of short-chain alcohols and aldehydes (methanol, acetaldehyde and ethanol).