Scientists Unravel Mystery of Orange Juice Off-Flavor

A group from the Leibniz Institute for Food Systems Biology at the Technical University of Munich has actually discovered the source of a formerly unknown clove-like off-taste in orange juice. The research study shows for the very first time that the unwanted taste note is because of the odorant 5-vinylguaiacol.

As the outcomes of the research study program, the compound is generally produced throughout the pasteurization procedure when residues of a cleaner respond with a natural orange juice part under the impact of heat.

This is not the very first time that the orange juice market has actually needed to compete with clove smell. So far, 4-vinylguaiacol has actually been thought about the primary reason for this unwanted taste note, which is especially plentiful in orange juices that have actually been kept for a very long time. The quantitative decision of this odorant has actually for that reason long been a recognized part of regular quality assurance.

Eva Bauersachs, thePh D. trainee at the Leibniz Institute in Freising and very first author of the research study, discusses: “Recently, however, we have received reports of orange juice samples that had a pronounced clove odor despite a low concentration of 4-vinylguaiacol. We therefore asked ourselves which other odorants contribute to this undesirable off-flavor.”

On the path of off-flavors

To examine this concern, the research study group led by Martin Steinhaus, head of the Food Metabolome Chemistry research study group at the Leibniz Institute, performed comprehensive examinations in cooperation with the Professorship of Functional Phytometabolomics and the Chair of Food Chemistry and Molecular Sensory Science at the Technical University ofMunich The goal was to recognize the odorants that trigger the formerly inexplicable off-flavor and to illuminate their origins.

Ph D trainee Eva Bauersachs is operating in the sensory laboratory at the Leibniz Institute for Food Systems Biology at the Technical University ofMunich Credit: J. Krpelan/ Leibniz- LSB@TUM

Using strategies such as gas chromatography-olfactometry and scent extract dilution analysis, the group determined the odorant 5-vinylguaiacol as the source of the off-flavor in an orange juice with a noticable clove smell. The existence of this compound in orange juice was formerly unidentified. Compared to 4-vinylguaiacol, it even showed to be more odor-active in 5 out of 6 commercially readily available orange juices with a clove-like off-flavor.

Natural part + cleaner residue + heat = off-flavor

Further research studies recommended that 5-vinylguaiacol is formed throughout pasteurization when the particular orange juice part hesperidin responds with peracetic < period class ="glossaryLink" aria-describedby ="tt" data-cmtooltip ="<div class=glossaryItemTitle>acid</div><div class=glossaryItemBody>Any substance that when dissolved in water, gives a pH less than 7.0, or donates a hydrogen ion.</div>" data-gt-translate-attributes=" [{"attribute":"data-cmtooltip", "format":"html"}]" tabindex ="0" function ="link" > acidPeracetic acid is utilized as a cleaner for cleaning-in-place( CIP) in the fruit juice market, to name a few.

“Inadequate rinsing of the machines after the CIP process could therefore have led to contamination of the orange juice with peracetic acid and caused the formation of 5-vinylguaiacol during further processing,” states primary detective Martin(*********************************************************************************************** ).Based on the brand-new clinical findings, the group advises that orange juice processing business must no longer utilize peracetic acid as a cleaner.

Reference: “Peracetic acid residues in orange juice can lead to a 5-vinylguaiacol-induced clove-like off-flavor via Baeyer-Villiger oxidation of hesperidin” by Eva Bauersachs, Veronika Walser, Klaas Reglitz, Corinna Dawid and Martin Steinhaus, 23 December 2023, Food Chemistry
DOI: 10.1016/ j.foodchem.2023138252