ARS | Publication request: Effect of HLB on flavor of orange juice and perception of limonin and nomilin

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: November 30, 2010
Publication Date: N/A

Technical Abstract: The effect of Huanglongbing (HLB) on orange juice flavor is complex. On the one hand, fruit that are harvested from diseased trees, that are asymptomatic for the disease, produce juice that is not much different from normal juice. In some cases the asymptomatic HLB fruit juice was detected to be slightly more bitter and with other off-flavors than normal juice. However, juice from HLB fruit that are symptomatic for the disease was definitely perceived as more bitter and off-flavored. Chemical analyses showed HLB fruit to be generally lower in sugars and some fruity volatiles, sometimes higher in acids or oil content, and higher in the bitter compounds limonin and nomilin, especially for symptomatic juice. The bitter compounds, however, were at levels below the reported threshold concentrations, yet they were perceived by some panelists. This lead to further analysis of perception of these compounds in a model juice or actual juice since all other reported thresholds were in water. Results showed that thresholds were lower in HLB juice perhaps because the perception of bitterness was enhanced by the lower sugars and sometimes higher acids and oil. It is also of interest to know how much off-flavored symptomatic HLB juice could be added to normal juice before consumers could perceive a difference. It was found that 25-50% of the juice would need to be from symptomatic HLB fruit before consumers would notice a difference.