Determination of curcumin content, moisture and color of powdered turmeric obtained from turmeric accessions grown under coconut in low country intermediate zone in Sri Lanka

Abstract

Turmeric (Curcuma longa) is a prominent spice, colorant, and preservative, belongs to the family Zingiberaceae, widely cultivated in Asian countries including India, China, and Sri Lanka. Curcumin is the most imperative fraction of turmeric, responsible for its biological activities. Study the variation of curcumin content in turmeric accessions grown in Sri Lanka is important to produce more and more turmeric with higher curcumin contents. This study was mainly focused to determine the curcumin content of different turmeric accessions collected from different locations of Sri Lanka and cultivated under coconut at the Intercropping and Betel Research Station, Department of Export Agriculture at Dampallassa, Narammala with similar agronomic practices. Curcumin content was evaluated dry weight basis using the spectrophotometer. The results clearly revealed that there were significant differences (p<0.05) among turmeric accessions in curcumin contents. Curcumin contents were ranged from 0.3458±0.037% to 4.9881±0.0141%. From the results, it was evident that the curcumin content of T12, T26, T3, T2, T8, and T5 complies with the range identified in the Sri Lankan standard level (3-6%). Further, turmeric powder found in world market have marked the average curcumin content from 2% to 6% by weight. Locally grown accessions also resulted in between curcumin contents and it proves that Sri Lankan turmeric is suitable for exports. Moisture contents of all turmeric accessions were in the agreement of standards of Sri Lanka Standards Institute (SLSI) which is 12% in maximum. Moreover, cluster analysis revealed that all accessions were classified into three groups which will be extremely useful to initiate breeding programs.