WINETECH Technical Yearbook 2021

• Both T. delbrueckii and M. pulcherrima tolerate cold conditions well and are thus suitable for use during cold mac- eration and cold storage in the pre-fer- mentative stages (Coulon et al ., 2019). • The bioprotective actions of both T. delbrueckii and M. pulcherrima do not affect S. cerevisiae activity and studies have shown that S. cerevisiae remains unaffected by the bioprotectors under normal conditions (Csutak et al ., 2013). However, at low temperatures, the bioprotectors can inhibit unwanted activity by S. cerevisiae and therefore delay the onset of fermentation (for instance during cold maceration) (Coulon et al ., 2019). The selected strains have minor effects on the composition of the grapes or must and the effects reported are considered to be more advantageous than disadvantageous: • T. delbrueckii has been associated with the production of thiol compounds when inoculated sequentially (Renault et al ., 2016). • M. pulcherrima is known to have high beta-glucosidase activity and ester production and may therefore have a positive impact on wine aroma (Parapouli et al ., 2009).

Laffort ® offers two bioprotection solutions suitable for oenological applications: • ZYMAFLORE ® ÉGIDE TDMP is a formu- lation consisting of the two strains, T. delbrueckii and M. pulcherrima. • ZYMAFLORE ® KHIO MP is a specific strain of the M. pulcherrima species. ZYMAFLORE ® ÉGIDE TDMP is particularly suitable as part of a sulphur dioxide reduction strategy. Limiting sulphur dioxide addition during winemaking poses several risks of which the growth of unwanted microorganisms is a major potential implication. The growth of unwanted microorganisms during the pre-fermentative stages will increase the microbiological pressure of the must and prevent the establishment of the inoculated S. cerevisiae yeast. This will significantly delay the onset of fermentation and consequently, the juice will be at risk of oxidation and spoilage. Remedial actions such as reducing the unwanted microbial population and reinoculation with the desired yeasts will further delay fermentation and result in additional costs. The addition of a bioprotector shortly after harvest (either by direct addition or through contact with treated winery equipment) will significantly reduce the risk of unwanted microbial growth and increase the chances

of a successful inoculation and onset of fermentation with the specific chosen S. cerevisiae yeast strain. ZYMAFLORE ® KHIO MP is especially well suited for the oenological bioprotection in low-temperature situations. Pre-fermen- tative processes such as cold soaking and cold stabulation will require low microbial activity for an extended amount of time. The growth of unwanted microorganisms

during these processes will interfere with must clarification and, again, pose the risk of an unsuccessful alcoholic fermentation.

By adding ZYMAFLORE ® KHIO MP , the medium is colonised by a microorganism with low fermentation capacity and the population sustained for several weeks, thereby preventing unwanted microbiological activity.

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