ARS | Publication request: Influence of harvest time on flavor in ‘Valencia’ orange

Submitted to: Florida State Horticultural Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 25, 2009
Publication Date: April 14, 2009
Citation: Baldwin, E.A., Plotto, A., Manthey, J.A., Bai, J., Mccollum, T.G., Irey, M. 2009. Influence of harvest time on flavor in ‘Valencia’ orange. Florida State Horticultural Society Meeting. Paper No. HP3.

Technical Abstract: 'Valencia' oranges were commercially harvested from March to June in South Florida. This study evaluated the effect of harvest time on orange juice flavor. Fruit was harvested on March 19, April 13, May 15, or June 29, 2009, and juice was analyzed for soluble solids content (SSC), titratable acidity (TA), headspace volatile compounds, and limonoids. SSC remained stable at 10.3-11.0% regardless of harvest time. However, juice from late harvest fruit had much lower TA content. Thus, SSC/TA ratio steadily increased from 13.2 to 25.5 in March and June harvested fruit, respectively. Volatile productions for most compounds were increased by delaying harvest time, which include acetaldehyde, decanal, ethanol, hexanol, Z-3-hexenol, E-2-hexenol, linalool, octanol, a-pinene, mycene, limonene, ethyl acetate and ethyl hexanoate. Some compounds, such as methanol and valencene decreased when harvest was delayed. Ethyl butanoate and ethyl-3-hydroxy hexanoate remained at similar levels regardless of harvest date. Limonin and nomilin contents slightly decreased from March to April, however increased thereafter. Hexanal and Z-3-hexenal showed similar patterns, decreasing in April and increasing thereafter. The results indicate that after the fruit reach full maturity, 'Valencia' oranges on the tree continually metabolize acids and limonoids, and accumulate volatiles, leading to sweeter, more flavorful, and less bitter products.