Proceedings of the 17 th TheIIER International Conference, Hong Kong, 21 st March 2015, pp 53‐55 New Tricks for an Old Dog: Application of Silicone as a Treatment for Contaminated Wines Andreea Botezatu 1,2,a and Gary James Pickering 1,2,3,b* 1 Cool Climate Oenology and Viticulture Institute, 2 Environmental Sustainability Research Centre, 3 Department of Biological Sciences, Brock University, St. Catharines, Ontario L2S 3A1, Canada a ibotezatu@brocku.ca, b gpickering@brocku.ca Abstract‐ Wine is a $300 billion global industry for which perceived quality is a key driver of purchase behaviour. Several odorant constituents of wine detract from this quality at elevated levels, and thus de‐value the product. Important amongst these compounds are two alkyl‐ methoxypyrazines (isopropyl‐ (IPMP) and isobutyl‐ (IBMP) methoxypyrazine), and two ethylphenols (4‐ethylgaiacol (4‐ EG) and 4‐ethylphenol (4‐EP)). In this project we investigated the capacity of a polydimethylsiloxane (silicone) polymer to reduce concentrations of these four taint odorants. Red wine was spiked with either IPMP [20 ng/L] and IBMP [20 ng/L] (Study 1) or 4‐EP [200 ug/L] and 4‐EG [200 ug/L] (Study 2) and then treated with silicone pieces [surface area 350 cm 2 /L]. Solid Phase Micro‐ Extraction Multi‐Dimensional Gas Chromatography–Mass Spectrometry and Gas Chromatography‐Mass Spectrometry was used to measure the methoxypyrazines and ethylphenols, respectively, both before and after treatment with silicone. Results showed significant reductions in the target odorants after 8hrs treatment, especially for methoxypyrazines: IPMP (82%), IBMP (94%), 4‐EP (12%) and 4‐EG (18%). ‘Ladybug taint’ is caused by elevated levels of IPMP in wine, and general ‘greenness’ is largely due to excessive grape‐derived IBMP concentrations; application of silicone would appear to offer considerable remediation benefits in addressing these common wine defects. Index Terms‐ 4‐ethylphenol, 4‐ethylguaiacol, Brettanomyces, fining, ladybug taint, methoxypyrazines I. Introduction Silicone is a molecule, usually polymeric, with chain segments of the general form (R n SiO (4‐n)/2 ) m where n is between 0 and 3, and m is 2 or higher [16]. It has been widely used in industrial applications and consumer goods for decades. Major uses include a sealant for airplanes and household goods, medical/dental implants and moulds, coatings for electronics, textiles and papers, electrical insulation, and drug delivery. Applications in the food industry are equally varied, reflective of its variable thermal and physical properties, including an emulsifying and anti‐foaming agent, a rubber for baking tray coatings and spatulas, a resin for non‐stick heat resistant coatings on bake ware, and an adhesive for pressure‐sensitive labels [16]. As silicone is available in food‐grade form, is relatively non‐toxic, and has been shown to be capable of scavenging odorants in food/beverage matrices, it has potential application with grape juice and wine. Indeed, it has recently been trialled in juice and must, and found effective in reducing methoxypyrazine levels [15]. Wine is a widely consumed [2], high‐value alcoholic beverage derived from fermented fruit. However, taints and off‐flavors detract appreciably from its quality and acceptance, and can significantly reduce its value. Isopropyl‐ (IPMP), and isobutyl – (IBMP) methoxypyrazines are responsible for the off‐flavour known as ‘ladybug taint’ [3], which is due to the inadvertent incorporation of Coccinellidae beetles into the winemaking process, and methoxypyrazines also contribute to the undesirable greenness in wine made from grapes that have not achieved desired ripeness levels [4]. One of the most common off‐flavours in wine is known as ‘Brett taint’, and is caused by ethylphenols formed by Brettanomyces/Dekkera yeasts, specifically 4‐ethylphenol (4‐EP) and 4‐ ethylguaiacol (4‐EG) [5]. These compounds form unpleasant ‘barnyard’ and ‘Band‐Aid’ notes, typically in red wines. IPMP, IBMP, 4‐EP and 4‐EG are difficult to remove from wine, and winemakers have a limited portfolio of agents and materials that can be used to improve affected product. Silicone, as a GRAS‐certified and multi‐functional polymer may offer some potential to improve the quality of faulted wine, particularly those tainted with methoxypyrazines, given its efficacy in lowering levels