Haze-preventing enzymes approved for use in winemaking

The Food Standards Code has been amended to include the haze-preventing enzymes Aspergillopepsin 1 and 2.

The move has been welcomed by the Australian and New Zealand wine industries as it provides an alternative to bentonite, a clay commonly used to remove haze-forming proteins from white, rosé and sparkling wines.

According to the Australian Wine Research Institute (AWRI), while bentonite is effective at removing proteins, its use can result in significant wine losses. It is estimated to cost the global wine industry $1 billion annually.

Aspergillopepsin 1 and 2 can be used to degrade haze-forming proteins in grape juice prior to fermentation, eliminating or reducing the need for bentonite. After the enzymes are added, the juice is heated for 60 seconds, unfolding the heat-unstable proteins and making them susceptible to enzyme attack.

The combined cost of the enzymes and juice heating step is considerably lower than the cost of batch bentonite treatment in all but the largest wineries the AWRI says.

The only supplier of a preparation of the Aspergillopepsin enzymes is Japanese company Meiji Seika Pharma, which sells a product called Proctase. However, the AWRI points out that the change to the Food Standards Code relates to the enzymes themselves and not any specific commercial product. Winemakers are advised to seek assurance from their suppliers that products are compliant with the relevant food standards.

Trials comparing the enzymes to standard bentonite use in 2012 showed no negative impacts when using the enzymes.

For more information about the trials, contact the AWRI: www.awri.com.au.