DRYING PARAMETERS OF ORANGE PULPS AT HOT AIR, INFRARED RADIATION AND HOT AIR ASSISTED INFRARED RADIATION DRYING

The citrus juice industry produces a huge amount of remains that are used as feedstuff ingredients. There is a constant concern to valorize the citrus by-products in terms of milk quality and quantity, environment, and economic aspects. The citrus products that are processed and evaluated are bitter orange, orange, grapefruit, and lemon; totally production amount is about 4 million tons in Turkey. After the citrus is processed to fruit juice, approximately 50-60% of pulp occurs. This amount shows that citrus pulp has significant economic potential for reuse and avoid environmental pollution. This study aims to evaluate the drying of orange pulps by different drying methods such as hot air drying (HAD), Infrared Radiation Drying (IRD) and combination of hot air and infrared radiation drying (HAD+IRD). The drying parameters, some macro, and minor elements, and organic acids of orange peels were explored in detail. The drying time of orange pulps were 10; 13; 21, 26; 20, 17 hours for infrared radiation drying, hot air drying, a combination of them at 70 and 80 degrees C respectively. The macro elements found in orange pulps were obtained higher at 70 degrees C IRD comparing by other drying methods. Organic acids compositions were affected individually from drying type and temperatures. The whole study is donated by the Research Council of Turkey (TUBITAK) by 101R114 numbered project.