Sweet cherry production has increased worldwide over the past 10 years due to high consumer demand and good returns to growers. This is particularly true in the Pacific northwestern United States where production has doubled in 8 years. Increased production elevates competition among growers for the limited supply of skilled harvest laborers. As a result, growers may begin harvest before the fruit achieves ideal harvest maturity to secure a labor force. Furthermore, it is not unusual for fruit to be harvested past optimum maturity due to an insufficient labor force.
Optimum commercial maturity of sweet cherry fruit is generally determined by red coloration of fruit exocarp, with a dark red/mahogany thought of as ideal for the industry standard cultivar, Bing (Kappel et al., 1996). We could find no published reports that assess attributes of new sweet cherry cultivars in relation to eating quality and consumer preference. The development of important quality attributes is not consistent among sweet cherry cultivars (M. Whiting, unpublished data) and therefore, a dark red skin color may not be the ideal harvest maturity for new cultivars. In the competitive sweet cherry market, it is desirable to deliver an acceptable product to the consumer. Therefore, it is important to understand the impact of harvest time and fruit maturity on fruit quality attributes and the sensory acceptance of the fruit.
Product quality is assessed by various means, but ultimately is judged by the consumer. Consumer assessments of cherry fruit quality are based on the fruit's external and internal characteristics. Visual cues of sweet cherry quality include the presence/absence of defects such as pitting and bruising, fruit shape, size, pedicel color and thickness, and exocarp coloration. Previous research has underscored the importance of exocarp color, with consumers preferring a dark red or mahogany to lighter and darker-colored fruit (Long et al., 2007). Purchase decisions are based upon visual assessment (i.e., perceived quality) and price. Important sweet cherry quality traits include fruit size, fruit color, firmness, and sweetness (Sloulin, 1990). Consumer acceptance of sweet cherries appears to be most related to sweetness, flavor intensity, and skin color (Cliff et al., 1996; Crisosto et al., 2003). For other stone fruit, the most important factors that influence the decision to purchase peaches (Prunus persica), plums (Prunus domestica), and nectarines (P. persica) were: safety of the fruit, healthy, sweet, good appearance, good value, firmness, and ripeness (Wolf et al., 2003).
Cherries have a relatively short fresh market season due to high fruit perishability (Dever et al., 1996). Furthermore, the optimum “harvest window” (i.e., period of time in which fruit are at optimum harvest maturity and storability) is perceived to be very short for sweet cherries. This underscores the importance of harvesting fruit at the ideal time. From a cherry growers' perspective, the examination of the adjustment of harvest date may allow more flexibility with regard to harvest time and perhaps an early or late delivery of acceptable cherries to the market for purchase.
Several previous studies have examined the relationship between analytical assessment of cherry quality and sensory evaluation. A trained panel was employed to evaluate sensory properties of cherries and to compare trained panel performance to analytical assessments (Cliff et al., 1996). Results showed a moderate correlation (r = 0.78) between perceived sweetness and the soluble solids concentration (SSC) to titratable acidity (TA) ratio (SAR). A high correlation was found between sourness and TA (r = 0.82) and sourness and SAR (r = −0.93). However, flavor/texture liking was unrelated to any of the analytical variables. Another study used consumer evaluations and analytical determinations to evaluate sweet cherries, but correlations were not determined between the two evaluations (Crisosto et al., 2003).
The objective of this study was to determine fruit quality differences and consumer preference for ‘Sweetheart’ sweet cherries harvested at different times: early harvest, midharvest and late harvest. This study used trained sensory panelists to provide a description of the sensory properties of the cherries, and consumer panelists to determine sensory acceptance of the cherries.
Cliff, M.A., Dever, M.C., Hall, J.W. & Girard, B. 1996 Development and evaluation of multiple regression models for prediction of sweet cherry liking Food Res. Int. 28 583 589
Corradini, M.G., Engel, R. & Peleg, M. 2001 Sensory thresholds of consistency of semiliquid foods: Evaluation by squeezing flow viscometry J. Texture Stud. 32 143 154
Crisosto, C.H., Crisosto, G.M. & Metheney, P. 2003 Consumer acceptance of ‘Brooks’ and ‘Bing’ cherries is mainly dependent on fruit SSC and visual skin color Postharvest Biol. Technol. 28 159 167
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Wolf, M.M., Martin, A.J. & Cagianut, T. 2003 An analysis of the importance of ripeness to consumers in the United States when making a purchase decision for peaches, plums, and nectarines Acta Hort. 604 61 67