Consumer rejection threshold of ethyl phenylacetate and phenylacetic acid, compounds responsible for the sweet-like off odour in wines made from sour rotten grapes
Article first published online: 23 AUG 2012
© 2012 Australian Society of Viticulture and Oenology Inc.
Australian Journal of Grape and Wine Research
Volume 18, Issue 3, pages 280–286, October 2012
How to Cite
CAMPO, E., SAENZ-NAVAJAS, M.P., CACHO, J. and FERREIRA, V. (2012), Consumer rejection threshold of ethyl phenylacetate and phenylacetic acid, compounds responsible for the sweet-like off odour in wines made from sour rotten grapes. Australian Journal of Grape and Wine Research, 18: 280–286. doi: 10.1111/j.1755-0238.2012.00198.x
- Issue published online: 23 SEP 2012
- Article first published online: 23 AUG 2012
- Manuscript received: 2 February 2012; Revised manuscript received: 19 May 2012; Accepted: 16 June 2012
- consumer rejection threshold (CRT);
- ethyl phenylacetate (EPhA);
- phenylacetic acid (PhAA);
- sour rot;
- sweet-like off odour;
Backgrounds and Aims: This study aimed to determine a consumer rejection threshold (CRT) for ethyl phenylacetate (EPhA) and phenylacetic acid (PhAA) in wine. These compounds have recently been reported to be responsible for sweet-like, honey off odours in wine made from sour rotten grapes.
Methods and Results: Non-expert wine consumers (n = 35) received pairs of samples comprising a control wine against a spiked wine with an ascending concentration of the target compounds and were asked to indicate which sample they preferred. Results estimated a conjoint CRT for EPhA and PhAA of 140 and 700 µg/L, respectively. Wines spiked with a EPhA and PhAA concentration around the CRT evoked intense ‘dried fruit’ aromas that led to a decrease of the general aroma quality; these wines are significantly rejected by consumers.
Conclusions: The measured CRT provides an initial estimation of the risk concentration for EPhA and PhAA in red wine, as they represent a ‘taint’ for regular wine consumers.
Significance of the Study: These data allow wine producers to predict if a given wine will be disliked by consumers or to help guide ‘blending away’ of such wines.