Loreto Contador

Postharvest Sensory and Phenolic Characterization of ’Elegant Lady’ and ’Carson’ Peaches

La demanda de fruta de alta calidad se ha incrementado junto con la necesidad de asegurar este atributo a los consumidores. En este sentido, el objetivo de este estudio fue caracterizar durazno (Prunus persica (L.) Batsch) de variedades de pulpa fundente (‘Elegant Lady’) y no fundente (‘Carson’), considerando su contribucion de compuestos bioactivos y su calidad sensorial en fruta madura a cosecha y luego de un periodo prolongado de almacenamiento refrigerado. Las variedades fueron evaluadas a la cosecha (F0) y luego de 30 d de almacenamiento refrigerado (F30), ademas de un periodo de maduracion a 20 oC en F0 y F30 (R0 y R30, respectivamente). Se registro el peso del fruto, firmeza de pulpa, contenido de solidos solubles (CSS), acidez titulable (TA), y color de fondo (Hue) en cada tratamiento. Ademas se cuantificaron los fenoles totales y se realizo una caracterizacion fenolica de ambas variedades a traves de un HPLC (High-Performance Liquid Chromatography) para detectar los principales compuestos fenolicos de bajo peso molecular presentes en el fruto. Finalmente un panel entrenado evaluo los principales parametros sensoriales en R0 y R30. El contenido de fenoles totales no vario significativamente como resultado del almacenamiento en frio, las diferencias observadas solo fueron atribuibles a los genotipos. Se detectaron 15 y 12 compuestos fenolicos de bajo peso molecular en ‘Elegant Lady’ y ‘Carson’, respectivamente, siendo catequina el principal compuesto encontrado en ambos cultivares, aunque en mayores concentraciones en ‘Elegant Lady’. En la caracterizacion fenolica, ‘Elegant Lady’ aparecio mas estrechamente relacionada con los flavonoides que ‘Carson’. Despues de 30 d de almacenamiento en frio, ‘Elegant Lady’ no fue aceptable para consumo debido a la aparicion de desordenes fisiologicos como harinosidad, mientras que ‘Carson’ mostro una puntuacion promedio dentro del rango de aceptabilidad.

Determination of harvest maturity of D'Agen plums using the chlorophyll absorbance index

R. Infante, P. Rubio, L. Contador, M. Noferini, and G. Costa. 2011. Determination of harvest maturity of D’Agen plums using the chlorophyll absorbance index. Cien. Inv. Agr. 38(2): 199-203. The objective determination of the optimal harvest date for plums intended either for industrial processing or for consumption as fresh fruit is a fundamental concern of the fruit industry. A portable visible/near infrared (Vis/NIR) spectroscopic device was used to sort D’Agen plums harvested around the traditional commercial harvest date. The chlorophyll absorbance index was found to be capable of segregating plums into classes of maturity according to various concentrations of soluble solids and fruit compression strenght values. Fruits with a chlorophyll absorbance index value of less than 1.59 showed no differences in flesh firmness. Plums harvested with chlorophyll absorbance index values of 1.20-1.29 had a fruit compression strenght of 1.25 N and a soluble solids concentration of 23.3%. Both of these values correspond to adequate thresholds for harvesting plums for industrial purposes. The chlorophyll absorbance index may be valuable in allowing the identification of high-quality plums either for fresh consumption or industrial processing.

Does the maturity at harvest affect quality and sensory attributes of peaches and nectarines

Abstract Fruit quality has been described as a property that depends on many factors. Harvest time is one such factor, described as negatively affecting the fruit quality of peaches and nectarines when carried out at early stages of maturity. In order to assess this, fruit from peach cultivars ‘2B40’, ‘Elegant Lady’ and ‘Sweet September’, and nectarine cultivars ‘Antares’ and ‘5A29’ were harvested at three maturity levels, based on ground skin colour (M1 = green-yellow, M2 = pale yellow and M3 = yellow), and evaluated at harvest and after a ripening period. Evaluations included instrumental characterization, sensorial analysis and e-nose. Flesh firmness was the parameter that best segregated the three maturity levels. Sensorial attributes and acceptability did not show differences between stages of maturity, while e-nose data clustered M1, M2 and M3 into different groups. These results suggest that the maturity level at harvest, within the range evaluated in this research, does not affect the sensory quality of the product, in spite of the aroma assessed with an e-nose revealing differences among them.

Phenolics contents and sensory characterisation of melting and non-melting peach

Summary There is increasing consumer dissatisfaction regarding the quality of peaches due to the rapid decay that these fruit undergo after harvest. This study aimed to determine the phenolics contents and provide sensory characterisations of four commercial melting flesh (MF) and four commercial non-melting flesh (NMF) peach cultivars. Low molecular weight phenolic compounds (LMWPC) were determined by high performance liquid chromatography coupled to a diode array detector (HPLC-DAD). A trained sensory panel with 12 members evaluated the principal quality attributes of each cultivar. Skin ground colour was different among the MF and NMF cultivars. Fifteen LMWPC were identified in peach flesh tissue. Procyanidin gallate 1, procyanidin gallate 3, procyanidin B3, and flavonoids 1, 2, and 3 were detected in all eight cultivars, while gallic acid was present only in ‘Elegant Lady’. Two main clusters were formed based on the 15 LMWPC observed, but no correlation with flesh type was observed. On the other hand, a principal components analysis (PCA) based on sensory attributes showed a clear segregation between the MF and NMF cultivars. The NMF cultivars were associated with “texture” and a low score for “visual appearance”, while the MF cultivars were associated with attributes such as “sweetness”, “juiciness”, and “flavour”. The types and amounts of LMWPC were not correlated with flesh type in both these peach cultivars (MF and NMF). LMWPC profiles were therefore more dependent on genetic background than on the specific MF or NMF trait.