Resumen de Consumer rejection threshold of ethyl phenylacetate and phenylacetic acid, compounds responsible for the sweet‐like off odour in wines made from sour rotten grapes

Eva Campo, María Pilar Sáenz Navajas, Juan Cacho Palomar, M. Ferreira

• 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.