# Effects of the Extraction Technology on Pomegranate Juice Quality
## 1 Introduction  
Pomegranate tree (_Punica granatum_ L.), native of Southern Asia, belongs to the family of Punicaceae. This species is widely grown in Iran, India, Egypt, Lebanon, China, Spain, France, USA, Oman, Syria, Tunisia, Italy, Greece, Cyprus, Israel, Turkey, Chile, Portugal and South Africa [1, 2]. The fruit is a spherical berry, having a very consistent peel and divided into loggias, hosting grains called arils and wrapped in a garnet-red juicy pulp [3]. It is commonly consumed fresh or as juice. In addition, the fruit is used in food industry for manufacturing jellies and concentrates, as well as flavouring and colouring agents. Pomegranate juice has many health properties, as it contains anticarcinogenic, antimicrobial and antiviral compounds. In fact, pomegranate fruit is a rich source of bioactive compounds, i.e., flavonoids, phenolic acids and vitamin C, mainly found in the peel, jth and arils and, therefore, in its juice [4]. The pomegranate juice is a rich source of antioxidants, that were found to be higher than in other natural beverages, i.e., green tea and red wine. The stability and concentration of these functional properties are affected by pre-harvest factors, i.e., cultivar, agro-climatic conditions, maturity status, harvest season, irrigation and fertilisation, and post-harvest factors, i.e., storage, packaging and treatments [5]. Several studies have documented the benefits of pomergnate juice consumption in individuals affected by various disorders [6; 7]. In fact, a number of scientific studies have demonstrated that the consumption of pomergnate fruit or juice confers medicinal benefits in the prevention of cardiovascular diseases, diabetes and cancer [8; 9]. Therefore, its consumption has highly increased throughout the world in recent years, due to the potential of its components and, above all, polyphenols and anthocyanins [10]. Some studies have proved the antioxidant [11] and anti-inflammatory [12] activity of the phenolics included in the pomergnate juice. Many studies have demonstrated the influence of the extraction technology and machines on the organoleptic and physical-chemical properties of the juice. [PERSON] et al. [13] obtained juice by means of a pilot plant from steamed and peeled pomergnate fruits, respectively, by applying increasing pressure and various juice treatments (enzymatic treatment, filtration, clarification and pasteurisation). The total amounts of anthocyanins and colourless phenolics in the juice significantly differed depending on the applied technology. In [PERSON] et al. [14] a more comprehensive knowledge of fruit composition and its impact on pomergnate juice features were performed on both fresh pomergnates and juices. [PERSON] et al. [15] produced pomergnate juice samples with three different pressing programs: 1.2-4.8 bar for 25 min; 1.2-2.4 bar for 15 min; 1.2-1.8 bar for 5.5 min. Respective juice yields were 39.2%, 33.2% and 27.2%. [PERSON] et al. [16], in order to determine the effect of the extraction technology on pomergnate juice flavour characteristics, aromatic compounds and physical-chemical properties, made fresh, fresh frozen and pasteurised, as well as dried and reconstituted juice samples from Wonderful cv. fruits. The extraction technology had an effect on pomergnate juice properties but this effect was different depending on the selected technology. Above all, [PERSON] et al. [17] investigated the chemical, volatile composition and bioactive compounds extracted by means of different methods of extraction of pomergnate, cv. Wonderful (i.e., the same cultivar surveyed in this work). The results indicated that the extraction technology significantly influenced pH, titratable acidity, yield and colour of pomergnate juice and, therefore, its quality. In a previous study [18] the authors evaluated the effects of two different plants, one was constituted by a hydraulic press and the other comprised a pneumatic one, on pomergnate juice yield and health properties: they obtained a 15% higher yield by using the pneumatic press.