Cultivar segregation according to their organoleptic perception was attempted by using trained panel data evaluated by principal component analysis in four sources of 24 peach and 27 nectarine cultivars as a part of our program to develop minimum quality indexes. Source significantly affected cultivar ripe soluble solids concentration (RSSC) and ripe titratable acidity (RTA), but it did not significantly affect sensory perception of flavor, sourness and aroma by the trained panel. On two out of 51 cultivars tested, source played a role on sweetness perception. In all of these cases, when source fell out of the proposed cultivar organoleptic group it could be explained by fruit being harvested outside the commercial physiological maturity (immature or overmature). The perception of the four sensory attributes was reduced to three principal components that explain 92% for peach and 94% for nectarine of the variation in the sensory characteristics of the cultivars tested. Season did not affect significantly the classification of three cultivars that were evaluated during these two seasons. By plotting organoleptic characteristics in PC1 and PC2 (∼76%), cultivars were segregated into groups (balanced, robust, sweet, peach or nectarine aroma, and/or peach or nectarine flavor) with similar sensory attributes; nectarines were classified into five groups and peaches into four groups. Based on this information, we recommend that cultivars should be clustered in organoleptic groups and a development of a minimum quality index should be attempted within each organoleptic group rather than proposing a generic minimum quality index based on RSSC. This organoleptic cultivar classification will help to match ethnic preferences and enhance the current promotion and marketing programs.
Carlos H. Crisosto, Gayle M. Crisosto, Gemma Echeverria and Jaume Puy
Xavier Vallverdu, Joan Girona, Gemma Echeverria, Jordi Marsal, M. Hossein Behboudian and Gerardo Lopez
Deficit irrigation (DI) applied during Stage II of fruit development has the potential of improving fruit quality in peach (Prunus persica). Existing information only covers instrumental assessment of quality. No report is available on how sensory attributes and consumer acceptance are affected. We applied DI at Stage II to ‘Tardibelle’ peach and evaluated fruit composition, sensory attributes, and consumer acceptance during the growing seasons of 2009 and 2010. Results were compared with those from trees that received conventional irrigation (CI). Stem water potential in DI trees was indicative of a moderate water stress during Stage II. In 2010, water stress persisted at the beginning of Stage III and average fruit weight was reduced in DI trees. A panel of trained judges decided that DI increased sweetness, juiciness, and the intensity of peach flavor but it reduced fruit firmness and crispness. A panel of consumers indicated increased preference for DI fruit. The higher appeal for DI fruit could have been partially the result of their more advanced maturity. Improvement of fruit quality could be an important incentive for the application of DI during Stage II because growers may expect to receive a premium price for their higher quality fruit.
Gerardo Lopez, M. Hossein Behboudian, Gemma Echeverria, Joan Girona and Jordi Marsal
The dwindling water supply, on a global scale, is making deficit irrigation (DI) more a necessity than a choice. It is therefore necessary to evaluate the effects of DI on fruit quality. Only instrumental evaluation of quality has been reported in the literature and, to the best of our knowledge, no sensory evaluation has been reported for any DI fruit including peach (Prunus persica). We applied four irrigation treatments for 50 days before harvest to ‘Ryan's Sun’ peach and evaluated fruit quality and sensory attributes. Treatments were: full irrigation (FI), no irrigation (NI), FI followed by NI (FI/NI), and NI followed by FI (NI/FI). NI reduced fruit size, delayed fruit maturity, and increased fruit dry matter concentration (DMC) compared with FI. NI also increased fruit soluble solids concentration (SSC) and titratable acidity (TA). A trained taste panel indicated that NI increased fruit firmness, crispness, and sourness, but it reduced sweetness, juiciness, and the intensity of peach flavor. A panel of consumers indicated reduced preference for NI fruit. Consumer preference was similar between NI/FI and FI fruit but was reduced in FI/NI fruit. There were no significant correlations between the instrumental quality parameters and sensory attributes. We conclude that NI before harvest impaired organoleptic peach quality. If only a small amount of water is available during the 50 days before harvest, peach organoleptic quality could be improved if this water is applied just before harvest.