Einsatz von Kaliumpolyaspartat und Carboxymethylcellulose zur Vermeidung kristalliner Ausscheidungen bei Traubensaft

Impact of potassiumpolyaspartate and carboxymethylcellulose to avoid crystalline precipitations in grape juice. The use of potassium polyaspartate (KPA) and carboxymethylcellulose (CMC) has been permitted in wine and sparkling wine since 2017 (KPA) and 2009 (CMC) and is now in practice. Currently, there is only one study on CMC and no study on KPA for their ability to prevent crystalline precipitation in grape juice. In this trial, the use of KPA and CMC in white and red grape juice was tested at different concentrations (KPA: 50 – 400 ml/hl, CMC: 100 – 300 ml/hl), and their influence on the sensory quality (overall judgement, single and expanded triangle test) of the fruit juices was investigated. The mini-contact method was also tested to predict the stability of the juices with regard to crystalline precipitation, and a stability factor was calculated to estimate stability. The results show that both KPA and CMC can be successfully used to prevent crystalline precipitation in grape juice. According to the results of these experiments the required amount of the products for stabilization at storage temperature of 4 °C is 50 to 150 ml/hl KPA (Zenith Uno) and 100 ml/hl CMC (VinoStab 2.0) for white grape juice. For red grape juice, higher quantities are required for successful stabilization (200 ml/hl KPA or 300 ml/hl CMC). The required quantities are therefore mostly higher than those permitted for wine and sparkling wine. A significant sensory change in the grape juice is not to be expected when using the required quantities. The mini-contact method (calculated stability factor) is suitable for predicting the stability of grape juice to a limited extent. At a storage temperature of 4 °C the value should be depending on the ripeness (year) under the area of 2.8 to 3.7 for white grape juice, and below 2.0 for red grape juice.