A Research on the possibility of different pomegranate cultivars grown in the Harran plain for using in food industry

phD THESIS A RESEARCH ON THE POSSIBILITY OF DIFFERENT POMEGRANATE CULTIVARS GROWN IN THE HARRAN PLAIN FOR USING IN FOOD INDUSTRY Hasan VARDIN DEPARTMENT OF FOOD ENGINEERING INSTITUTE OF NATURAL AND APPLD2D SCD2NCES UNIVERSITY OF ÇUKUROVA Supervisor : Prof.Dr.Hasan FENERCİO?LU Year: 2000, Pages: 117 Jury : Prof.Dr. Hasan FENERCİO?LU Prof.Dr. Nevzat ARTIK ProfDr. Ali ALTAN In this study, the methods of production and storage possibility of pasteurized pomegranate juice and its concentrate are evaluated. As the material, 3 different cultivars (noname) were used for preprocessing and 6 different cultivars (Sweet; Gök millesi, Suruç Tatlı, Sour; Ekşi Göknar, Evci, Suruç, Mild; Boncuk) were used for producing pasteurized pomegranate juice and its concentrate. Firstly, pomegranate juice was produced from sacs, halved-quartered and whole pomegranate using by a hydraulic press with different pressures and times. The juice was clarified by adding gelatine and PVPP (polyvinylpolypyrrolidone) as clarification agents. Results of gelatine and PVPP were compared with the natural clarification. As a second step, pomegranate juice was produced from 6 different cultivars in accordance with the determined pressing and clarification results. One portion of handled juice was pasteurized after heating and racking up processes. Remaining portion of juice was concentrated. Fruit juices were stored at 5°C and concentrate samples were stored at 5°C and room temperature for 9 months. The results obtained can be summarized as follows; -Substantial amounts of phenolic substances were found in fruit juice produced by pressing. It was found that other parts of the pomegranate have more phenolic substances than juice. These substances pass through juice by size reduction of the fruits before pressing. Thus, best results in pressing were obtained by using whole fruit compared with juice sacs and size reduced pomegranates. -Amouts of phenolic substances in fruit juice are increased by increasing pressure. It was evaluated mat it wouldn't be feasible for both fenolic substance and pressing cost, if pressure is taken over 10 kg/cm2. -It was founded that required amount of gelatine for clarification was 1 g/L. -Chemical composition of samples were significantly effected by processing steps, storage time and temperature during production of pomegranate juice and its concentrate (p<0,01). -According to the taste panel, two main characteristics of pomegranate juice effective in acceptance were color and taste. Sensory evaluation created a grading üst and preferred cultivars were ranked as Ekşi Göknar, Evci, Suruç, Gök Millesi, Suruç Tath and Boncuk, respectively. Key Words; Pomegranate, Pressing and Clarification, Phenolic substances, Anthocyanin, Pomegranate juice concentrate. VI