Mitigation of off-flavor in Huanglongbing-affected orange juice using natural citrus non-volatile compounds

Authors: RAITHORE, SMITA - Symrise Ag; KIEFL, JOHANNES - Symrise Ag; Manthey, John; Plotto, Anne; Bai, Jinhe; Zhao, Wei; Baldwin, Elizabeth - Liz

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/8/2019
Publication Date: 1/23/2020
Citation: Raithore, S., Kiefl, J., Manthey, J.A., Plotto, A., Bai, J., Zhao, W., Baldwin, E.A. 2020. Mitigation of off-flavor in Huanglongbing-affected orange juice using natural citrus non-volatile compounds. Journal of Agricultural and Food Chemistry. 68:1038-1050. https://doi.org/10.1021/acs.jafc.9b07756.
DOI: https://doi.org/10.1021/acs.jafc.9b07756

Interpretive Summary: In addition to causing the deterioration and death of citrus trees, huanglongbing (HLB) is associated with increased off-flavors in orange fruit and juice. The objectives of this research were to find chemical compounds which suppress bitter/astraigent off-flavor and are naturally from orange juice of peel molasses, and as such are considered "from the named fruit (FTNF)". Of the candidate compounds, feruloyl putrescine, taxifolin and neodiosmin most effectively suppressed “bitterness”, feruloyl putrescine suppressed “astringency” and “aftertaste”, while feruloyl putrescine and neodiosmin enhanced “sweetness”. These FTNF compounds may be useful for management of HLB-affected orange juice flavor.

Technical Abstract: Citrus greening disease or Huanglongbing (HLB) has reduced yields of oranges in Florida by 80%, while also reducing juice quality due to decreased sugars, sometimes increased acids, increased bitter limonoids and astringent/bitter flavonoids as well as an altered aroma profile. Compounds obtained from orange juice (OJ) and orange peel molasses (PM), and as such were considered “from the named fruit” (FTNF), were tested for their effects on HLB-affected OJ taste. These and other “target” compounds, reportedly found in citrus and with ability to affect flavor, were spiked into off-flavored HLB-affected reference juices. The spiked juice was evaluated by a trained sensory panel and compared with unspiked juice for “sweetness”, “sourness”, “bitterness”, “astringency” and “aftertaste” (undesirable aftertaste/mouthfeel). Of the “target” compounds, feruloyl putrescine, taxifolin and neodiosmin were most effective in suppressing the perception of “bitterness”, feruloyl putrescine for suppressing “astringency” and “aftertaste”, while feruloyl putrescine and neodiosmin also enhanced the perception of “sweetness”. OJ and PM fractions containing reported bitter limonoids, hydroxycinnamates, hesperidin, and/or polymethoxylated flavones, among other compounds, enhanced HLB off-tastes such as “sourness’, “bitterness”, “astringency” and “aftertaste”, and/or suppressed “sweetness”. Other fractions, containing feruloyl putrescine and/or vicenin-2 (6,8-di-C-glucosylapigenin), enhanced “sweetness” and suppressed “bitterness”, “sourness”, ‘astringency’ and/or “aftertaste”. Compounds, that improved the flavor of HLB-affected juice, and are also FTNF, may be useful for flavor management for HLB-affected orange juice.