557INFLUENCE OF BOILING TEMPERATURE LEVELS AND DURATIONS ON THE ESSENTIAL OIL, OLEORESIN, COLOUR VALUE OF DIFFERENT RHIZOME SET TYPES OF TURMERIC (Curcuma longa L.)Turmeric (Curcuma longa L.), family Zingiberaceae, is a tropical herb that is indigenous to Southern Asia. Boiling and drying are mandatory and quality determining steps in turmeric processing. But most farmers in Ethiopia boil mother and finger rhizome together, and show less concern to boiling temperature levels and durations that probably leads to loss of biochemical and physical qualities of turmeric. This study is therefore initiated with an objective of optimizing the boiling temperature level (s) and duration (s) of rhizome set types of turmeric for its quality improvement. The study was conducted at Tepi, Ethiopia. The experiment consisted of 3 temperature levels (80oC, 90oC, and 100oC), 3 rhizome types (mother, finger and mother-finger mix) and 4 boiling durations (30, 45, 60 and 75 minutes) laid out in 3X3X4 factorial arrangement in Complete Randomized Design (CRD) with 3replications. The data were subjected to the Analysis of Variance (ANOVA) by using SAS version 9.2 and significant means separated using Least Significance Difference (LSD). The combined as well individual treatment factors effect manifested a significant variation on the biochemical quality of turmeric. Mother rhizomes boiled at 100oC for 30min yielded the highest oleoresin (19.27%) and essential oil (5.40%) which was at par with value from mother rhizomes boiled at 90oC for 30min (5.40%v/w). On the other hand, the lowest oleoresin (11.38%) and essential oil (2.60%) contents were obtained from finger rhizomes boiled at 100oC for 75min. Color value was high from boiling mother rhizomes at 100oC for 45min (3.08E4), 90oC for 60min (3.04E4) and finger rhizomes at 100oC for 30min (3.05E4) while boiling of mother rhizomes at 80oC for 30min gave the least value (2.54E4). By considering the advantages of reducing the losses of time, labor, quality and difficulties in turmeric processing, these boiling methods are beneficial. But mixed mother- finger boiling is not recommended as it affects most of the quality parameters.johnbarnabas@gmail.comResearch732017 Curcuma longa,Essential oil,Oleoresin,Rhizome,temperatureShibru Zerihun Fenta,Ali Mohammed,Girma Hilemichael, John BarnabasJimma University, School of Graduate Studies, College of Agriculture and Veterinary Medicine, Jimma, Ethiopia.,Teppi National Spices Research Centre, Teppi, Ethiopia, Gambella University, Department of Horticulture, Gambella P.O.Box:126, Ethiopia,Gambella University, Department of Plant Science, Gambella P.O.Box:126, Ethiopia