Investigations into the Protein Stabilization of Musts\nand Wines by Aspergillopepsin under Different Enzymatic and Thermal\nTreatments

Protein removal with\naspergillopepsin in combination with short-time\nheating has recently emerged as an opportunity for winemakers to prevent\nprotein haze in wine. In this study, we first treated a protein-rich\nmust and wine with two different aspergillopepsin preparations along\nan identical control treatment without enzyme addition on a pilot\nplant scale. While treating wines was rather ineffective, treating\nmusts was effective in reducing protein concentrations by up to 86%,\nleading to haze-stable wines according to the common heat test. Varying\nthermal loads in further experiments, a rather mild heat treatment\nof 65 °C for 30 s compared to those in earlier studies was found\nsufficient for enzymatic protein degradation. Treating must from a\nfungus-resistant variety (cv. Fidelio) was as successful as treating\nmust from a blend of conventional varieties (cv. Gewürztraminer/Müller-Thurgau).\nTriangle sensory tests found no clear evidence of an effect on the\nquality by heat treatments with and without enzyme dosage.