The purpose of this study was to examine the effectiveness of selected essential oils for the control of the growth and survival of pathogenic bacteria Listeria monocytogenes ATCC 19112 and Listeria monocytogenes ATCC 19115, which are of significant importance in food hygiene. Essential oils extracted from Salvia officinalis L., Rosmarinus officinalis L., Majorana hortensis Moench., Thymus vulgaris L., Carum carvi L., Pimpinella anisum L. and Coriandrum sativum L. were evaluated.

A change of anthocyanins under different conditions of enzymatic treatments, clarification and concentration was determined. A pectin preparation Klerzyme^®120, manufactured by DSM, France, specific for "sour fruits" with pH below 3.2, was used for maceration and depectinization. Experiments were carried out by a laboratory hydraulic press. Raw raspberry juice was clarified either by membranes separation processes or by traditional treatments using gelatin and bentonite.