Effect of Pre-Treatment on the Pressing Yield and Quality of Grape Juice Obtained from Grapes Grown in Poland

Gradual climate warming is favoring viticulture in Poland. At the same time, there is a lack of information about the suitability of grape varieties grown in Poland for processing. The primary aim of the study was to determine the effect of pre-treatment on the pressing yield of grape juice and its qualitative assessment. The study applied pre-treatment of raw material, involving either enzymatic liquefaction of the pulp in the first case or freezing and thawing of the pulp prior to pressing in the second case. There was considerable variation among the grape varieties studied in terms of the characteristics under analysis. The varietal characteristics had a significant effect on the pressing yield and the quality of the juice obtained. Pre-treatment had different effects on the pressing yield of the individual grape varieties and the quality of the obtained juices. The research carried out may improve the efficiency and quality of agricultural production with the rational use of locally grown grape hybrids.