Tomasz Guz

Characterisation of Selected Apple Cultivars in the Aspect of Juice Production in the Condition of a Farm

Pressing is the most common method of fruit juice acquisition. Not all apple cultivars are suitable for juice pressing. The use of suitable fruit cultivars for juice pressing may reduce the cost of pressing and at the same time guarantee high quality of the juice produced. The scope of the study comprised the determination of pressing efficiency and of the quality parameters of apple juice obtained, such as acidity and the content of extract. The results of the study indicate that the efficiency of pressing and the quality of the juice obtained are significantly affected by the varietal traits of the apples. The choice of suitable cultivars allows to achieve a high pressing efficiency and to obtain juice characterised by a high content of extract and high acidity. INTRODUCTION Pressing is the most common method of apple juice acquisition (Markowski, Baron, Le Quéré, Płocharski, 2015). At present, juice pressing under industrial conditions is performed most frequently with the use of presses for periodic operation (mainly baskettype) and for continuous operation (screw-type presses, roller presses or belt presses) (Bump, 1989). Fruit processing methods employed on the industrial scale may significantly alter the nutritional properties of the fruits (De Paepe, Valkenborg, Coudijzer, Noten, Servaes, De Loose, Voorspoels, Diels, Van Droogenbroeck, 2014). Therefore, it is necessary to develop such methods of fruit processing that will minimise the negative effects of the processing on the health-promoting properties of the fruits (Rothwell, Medina-Remón, Pérez-Jiménez, Neveu, Knaze, Slimani, Scalbert, 2015). In certain countries orchard farms are equipped with complete lines for the pressing and delicate preservation of fruit juices. Recently one can observe a development of juice pressing services with the use of mobile presses, which means that juices are produced on site at the fruit producer’s farm (http://mobilejuicefactory.com/mobile-juicing/). As can be seen from the literature data, not all apple cultivars are suitable for juice pressing. The efficiency of the pressing process and the quality of the juice obtained depend on numerous factors, among which the technological properties of raw material play an important role (Renard, Le-Quéré, Baudin, Symoneaux, Le Bourvellec, Baron 2011). In Poland, more than 60 apple cultivars are entered in the National List of Varieties. However, there is a lack of complete knowledge on their applicability for juice pressing. The use of suitable fruit cultivars for juice pressing may reduce the cost of pressing and at the same time guarantee high quality of the juice produced (Eiselea, Drakeb, 2005; Sedov, Levgerova, Salina, Serova, 2010). This justifies research on various apple cultivars in the aspect of estimation of their applicability for juice pressing, especially in farm conditions (orchards), i.e. without the use of specialised preliminary processing of the fruits prior to pressing.