ARS | Publication request: Variability in waxing-induced ethanol and aroma volatile production among mandarin genotypes

Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 8, 2011
Publication Date: April 1, 2012
Citation: Obenland, D.M., Arpaia, M. 2012. Variability in waxing-induced ethanol and aroma volatile production among mandarin genotypes. Acta Horticulturae. 945:405-412.

Interpretive Summary: Mandarins often develop off-flavors during storage that impact consumer acceptance and it would be useful to develop mandarin varieties that are less susceptible to postharvest flavor loss. Some of the poor flavor is a result of the accumulation of compounds within the fruit during storage that negatively alter the flavor profile. Ethanol, a compound often linked to poor flavor in citrus, was quantified in a diverse group of mandarin varieties following both waxing and storage or a 2-h exposure to nitrogen gas and those varieties with the most extreme differences in ethanol accumulation were assayed for other flavor-influencing compounds as well. Ethanol accumulation was found to differ greatly among the varieties and to be related to the formation of other compounds that alter flavor. Screening for ethanol production could potentially identify mandarin varieties that differ in the production off-flavor compounds and aid in better understanding the relationship between ethanol production and flavor compound accumulation.

Technical Abstract: Mandarins often develop off-flavors during storage that impact consumer acceptance and it would be useful to develop mandarin varieties that are less susceptible to postharvest flavor loss. Ethanol has long been identified as being a compound identified with flavor loss in citrus. A range of diverse mandarin genotypes were screened for their ability to produce ethanol in response to both waxing and storage or a 2-h exposure to nitrogen gas and were found to differ greatly in ethanol content both at harvest and after treatment. Headspace measurements of intact fruit were not predictive of internal juice ethanol concentrations and exposure to nitrogen did not accurately mimic the effect the effect of waxing and storage on ethanol accumulation. High ethanol production was associated with enhanced accumulation of other alcohols and esters that likely influence flavor. Screening for ethanol production could potentially identify mandarin genotypes that differ in the propensity to produce off-flavor volatiles and aid in better understanding the relationship between ethanol production and aroma volatile accumulation.