Active taste compounds in juice from oranges symptomatic for Huanglongbing (HLB) citrus greening disease

Citrus greening disease, also known as Huanglongbing (HLB), compromises the quality of citrus fruit and juice, causing increased bitterness, metallic taste, astringency and a burning mouthfeel. The chemical basis responsible for these changes remains largely unknown other than the roles of the bitter limonoids, limonin and nomilin, and of flavonoids that may cause astringency. A combination of chemical and sensory analyses was used to identify bitter components in HBL-affected orange juice (HLBOJ), and compared with juice from healthy fruit. DNA analysis of the juice revealed that HLBOJ was well infected with the bacteria, with Ct value of 27 compared with 33 for the healthy juice. There were differences (at least P