Eglantine Chauffour,* Jose Santos, Barbara Scotti, and Maria Navarro
*Enartis USA, 7795 Bell Road, Windsor, CA 95492 (eglantine.chauffour@enartis.com)

Microbial contamination and its consequences are major threats to wine quality. Capable of growing under difficult conditions at any time during winemaking, spoilage microbes are opportunist organisms that are very difficult to control and eliminate. They are responsible for chemical and physical changes in wine which lead to loss of quality. The development of spoilage microorganisms is usually noticed by the presence of off-characters when their population is at the exponential phase and the wine is already damaged. Early detection of spoilage microorganisms allows winemakers to be proactive and keep them under control. Maintaining good cellar hygiene, minimizing spoilage microorganisms in juice, controlling alcoholic and malolactic fermentation, and protecting wine during aging are essential to manage microbe populations. Recent developments offer winemakers new tools to remove undesirable microorganisms through fining, thereby avoiding filtration and reducing the use of antimicrobial chemicals. Chitosan is a natural and non-allergenic polysaccharide that is produced by de-acetylation of chitin, a polysaccharide produced from Aspergillus niger. It interacts with microorganisms via charge attractions and degrades their cell walls, leading to cell death. Fining with chitosan removes the most notorious and feared spoilage microbes from juice and wine: Brettanomyces, Zygosaccharomyces, Lactobacillus, Pediococcus, Oenococcus and even Acetobacter. Chitosan can be used as a preventive or curative tool to eliminate spoilage microorganisms. Trial results showed that depending on the winemaking stage, different types of chitosan formulations should be used.

Funding Support: Enartis