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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Commodity Protection and Quality Research » Research » Publications at this Location » Publication #238987

Title: Relationship of soluble solids, acidity and aroma volatiles to flavor in late-season navel oranges

item Obenland, David - Dave
item COLLIN, SUE - Kearney Agricultural Center
item SIEVERT, JIM - Kearney Agricultural Center
item FJELD, KENT - Kearney Agricultural Center
item ARPAIA, MARY LU - Kearney Agricultural Center

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/8/2009
Publication Date: 4/8/2009
Citation: Obenland, D.M., Collin, S., Sievert, J., Fjeld, K., Arpaia, M. 2009. Relationship of soluble solids, acidity and aroma volatiles to flavor in late-season navel oranges. Sixth International Postharvest Symposium, April 8-12, 2009, Antalya, Turkey. 877:749-755.

Interpretive Summary: Late-season navel oranges sometimes have poor flavor even though the fruit are very sweet. A better understanding of this problem is needed to be able to improve the quality of oranges harvested during this part of the season in California. Ninety-five navel oranges harvested in May were individually evaluated for flavor, soluble solids concentration, acidity, and aroma components to better understand the reasons behind the occurrence of this poor flavor quality. The flavor among the ninety-five oranges differed greatly, ranging from bad to excellent, with good flavor being associated with the perception of a sweet, rich, and fresh flavor. Soluble solids, acidity and aroma content also showed a large amount of fruit-to-fruit variability but were only weakly related to flavor. This work helped to begin to define the components negatively impacting flavor in late-season navel oranges and lays the groundwork for future research.

Technical Abstract: Late-season navel oranges in California occasionally have poor flavor even though they have high soluble solids content (SSC) and are very sweet. The reasons for this low flavor quality were investigated by evaluating individual late-season navel oranges for sensory attributes and then measuring SSC, titratable acidity (TA) and flavor volatiles from juice taken from the same oranges. A wide range in hedonic scores from below a rating of 4 (dislike slightly) to above 8 (like very much) was obtained for the ninety-five fruit evaluated, although 78% of the fruit were above a rating of 6 (like slightly). Correlation coefficients calculated between the sensory and chemical (SSC, TA and flavor volatiles) attributes were mostly non-significant and, in every case, very low, indicating that there were no clearly identifiable reasons for the flavor differences observed among the individual fruit. Partial least squares analysis using the combined chemical data as a dependent variable came to a similar conclusion and was able to account for only 25% of the variation in the sensory data by using the chemical data. It is possible that components other than those that were evaluated were responsible for the flavor differences or that the fruit were too similar in taste for our sensory panel to accurately categorize on an individual fruit basis.