Toxicologic evaluation of potassium polyaspartate (A-5D K/SD): Genotoxicity and subchronic toxicity

Use of potassium polyaspartate on white wines: interaction with proteins and aroma compounds

The precipitation of tartaric salts represents one of the main visual sensory faults of white wines. It can be prevented by cold stabilization or adding some adjuvants, such as potassium polyaspartate (KPA). KPA is a biopolymer that can limit the precipitation of tartaric salts linking the potassium cation, however, it could interact also with other compounds affecting wine quality. The present work aims to study the effect of potassium polyaspartate on proteins and aroma compounds of two white wines, at different storage temperatures (4 °C and 16 °C). The KPA addition showed positive effects on the quality of wines, with a significant decrease of unstable proteins (up to 92%), also related to better wine protein stability indices. A Logistic function well described the effect of KPA and storage temperature on protein concentration (R² > 0.93; NRMSD: 1.54-3.82%). Moreover, the KPA addition allowed the preservation of the aroma concentration and no adversely effects were pointed out. Alternatively to common enological adjuvants, KPA could be considered a multifunctional product against tartaric and protein instability of white wines, avoiding adverse effects on their aroma profile.

Further experimental data supporting the safety of potassium polyaspartate used as a food additive in wine stabilization

Potassium polyaspartate (KPPA) is a food additive used for wine stabilization. KPAA was included in the list of additives allowed in EU, with the Commission Regulation (EU) 2017/1399, having received a positive opinion by EFSA (European Food Safety Authority) in 2016. KPAA is rich in negative charges, which are essential for its enological function consisting in binding positive ions in order to reduce wine instability. Concerns were raised on the fact that the same binding properties could be responsible for a reduction of microelement bioavailability in humans. For this reason and for the protection of consumers' health, the binding properties of potassium polyaspartate versus three minerals (calcium, iron, magnesium) was assayed using the Size-Exclusion Chromatography (SEC). Aliquots obtained by SEC were analysed for their content in polyaspartate (by microbiuret method) and bound minerals (by ICP-OES method). The results obtained by this research shows that, when potassium polyaspartate is added to wine, the negative charges of the additive are saturated, as expected by the specific role of KPAA in tartaric stabilization. In conclusions, the effect on mineral bioavailability must be considered negligible.