Selection efficiency for raspberry postharvest shelf life affected by storage temperature and harvest season

Authors: HARSHMAN, JULIA - University Of Maryland; Lewers, Kimberly; Jurick, Wayne; WALSH, CHRISTOPHER - University Of Maryland

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/9/2013
Publication Date: 3/1/2014
Publication URL: http://handle.nal.usda.gov/10113/61473
Citation: Harshman, J.M., Lewers, K.S., Jurick II, W.M., Walsh, C.S. 2014. Selection efficiency for raspberry postharvest shelf life affected by storage temperature and harvest season. HortScience. 49:311-319.

Interpretive Summary: Raspberry is a highly valued fruit that deteriorates very quickly in storage, reducing quality of fruit presented in the market and eaten by consumers. In addition to red raspberry, consumers are interested in raspberry fruit available in other colors, such as black, purple or yellow, either for the novelty or for perceived increased health benefits. Raspberry breeders need to better define how to evaluate the novel raspberry types in order to develop new varieties with good shelf-life. This research compared fruit shelf life in room temperature storage and refrigerated storage for red, black, purple, and yellow raspberry fruit to determine which storage temperature best enabled a breeder to select raspberries with superior shelf life for use as potential new varieties. We found that the choice of storage temperature for evaluation depends on the type of raspberry (red, yellow, black, or purple). For raspberry types with two seasons per year, we also found that fruit from both seasons must be evaluated in order to obtain reliable estimates of shelf life. The information will be of interest to raspberry breeders and other scientists working towards developing raspberry varieties with better shelf-life for growers, food distributors and consumers.

Technical Abstract: Improved postharvest quality is an important goal for fresh-market raspberry breeding programs. To determine if warm or cold storage following harvest would better facilitate the breeding selection process for the assessment of postharvest decay and bleed, pesticide-free fruit from cultivars and breeding selections of red, yellow, purple, and black raspberries were stored at two temperatures. Following storage fruits were examined for decay and bleed rate at room temperature (25C) and at a cooler temperature (5C). The rate of decay was much faster in room-temperature storage than in cooler storage; however, classification of genotypes as parents or discards was not always in agreement between these two temperatures. This suggests that a breeder should determine whether room-temperature storage or cooler storage more closely resembles the postharvest environment for the targeted growers. For many bleed rate comparisons, there was no advantage from either storage temperature. However, when an advantage was evident, cold-storage evaluation identified a greater number of classes comparing black raspberry and purple raspberry genotypes, but warm-storage evaluation identified a greater number of classes comparing red and yellow raspberry genotypes. There was complete agreement on genotype breeding disposition, indicating that a breeder could evaluate genotypes for bleed in the same storage temperature chosen to evaluate decay. Selection decisions made from evaluating floricane fruit were not always in agreement with decisions made from evaluating primocane fruit, indicating that genotypes should be evaluated in both fruiting seasons.