Novel Applications for Biomaterials: The Case of Remediation of Wine Taints Using Poly-Lactic Acid Polymer

Abstract

Wine is the world’s oldest alcoholic beverage and the most consumed in at least 20 countries. However, taints detract from its quality and acceptance, significantly reducing the value of wine. In this study we investigated the capacity of a poly-lactic acid (PLA) biopolymer to reduce concentrations of four odorants responsible for tainting many red wines:isopropyl-methoxypyrazine (IPMP),isobutyl–methoxypyrazine (IBMP), 4-ethylphenol (4-EP) and 4-ethylguaiacol (4-EG). 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 a PLA film [surface area 350 cm2/L]. Solid Phase Micro-Extraction Multi-Dimensional Gas Chromatography–Mass Spectrometry and Gas Chromatography-Mass Spectrometry were used to measure the methoxypyrazines and ethylphenols, respectively, both before and after treatment with PLA. Results showed significant reductions in all of the target odorants after 8hrs treatment: IPMP (51%), IBMP (26%), 4-EP (21%) and 4-EG (20%). Taken overall, the data suggest potential for the use of PLA in treating common wine faults, particularly ‘ladybug taint’, which is caused by elevated levels of IPMP.