Red raspberries, in comparison with the other three colors analyzed during the study, had the highest titratable acids (TA) and the lowest ratio of soluble solids to TA, which, the authors say, accounts for the tart raspberry flavor consumers expect.
Yellow raspberries had the lowest levels of anthocyanins and phenolics. Their TA was lower than red raspberries, but their ratio of soluble solids to TA was the second highest. "This bodes well for consumer acceptance because this measure is an important indicator of flavor," Harshman said. Although yellow raspberries were among the firmest varieties at harvest, they were found to be very susceptible to gray mold, particularly after being harvested on overcast, cool, humid days.
Black raspberries resisted leakage the least of all of the colors, particularly after rainy, humid, overcast days. The authors observed that this quality will make it challenging to move black raspberries into the wholesale fresh market.
Purple raspberries--a hybrid between red and black raspberries--had the third highest anthocyanin and phenolic content, and their flavor was intermediate between black and yellow raspberries. "Similar to black raspberries, their ability to resist juice leakage was poor, and cool weather tended to exacerbate this," the authors said.
"We have shown for the first time that when significant differences between ethylene rates and decay incidence coincide; the berries that produced the highest ethylene rates rotted the most quickly," Harshman said. "Our findings have great impact because they open the door for potential disease mitigation strategies that center around lowering ethylen
|Contact: Michael W. Neff|
American Society for Horticultural Science