Comparison of physicochemical properties and gel performance of pectins dried by different drying methods

Pectin is used as a thickener, gelling agent and stabilizer in many foods such as jam, marmalade, jelly, various sauces and dairy products. Pectin is mostly produced from citrus peels and apple pulp which is the waste of fruit juice industry. In addition, pectin is obtained from the sunflower tray and sugar beet. Produced pectin has some commercial quality criteria and the quality criteria vary according to raw material and production conditions. In this study, it is aimed to determine the appropriate drying method which supports the quality characteristics of the product for drying process which is one of the pectin production steps. Some quality properties of orange pectins obtained by different drying methods were compared. For this purpose, firstly, pectin was extracted from orange peels. The extract was produced by separation, precipitation and washing with alcohol, respectively. The produced pectin mush was spray drying, vacuum drying, refractance window drying, hot air drying and freeze drying applications were dried. When the results obtained within the scope of the thesis study are evaluated; the degree of esterification of orange peel pectins was observed between 79.30% and 84.84%, the highest degree of esterification was determined in pectin samples which were dried by refractance window drying system. The viscosity, gel strength and gel grades of the obtained pectins were found to be higher in the pectins with refractance windows and freeze-dried than the pectins subjected to other drying methods. Drying methods was determined no effect on the amount of galacturonic acid and ash. The pectins obtained by freeze drying and spray drying methods showed the best solubility. When the results were evaluated in general, the pectins produced by refractance window drying and freeze drying methods showed similar properties. According to these determinations, it was concluded that refractance window drying method is more suitable for pectin production.