Color improvement of red swordtail fish by betalain extracted from dragon fruit peel

Abstract

The colors improvement; lightness (L*), redness (a*) and yellowness (b*) in red swordtail fish by betalain (BTL) extracted from dragon fruit peel were evaluated. The fish were feed by commercial dietary pellet which spray with BTL; 0, 40 and 60 milligrams/kilogram. After 8 weeks the average of L*, a* and b* values of every treatment were not statistical significant (p>0.05) those might be cause from spirulina sp. added in commercial feed. The treatments were feed by 40 and 60 milligram/kilogram showed higher tendency of average L*, a* and b* than 0 milligram/kilogram. The growth rate of every treatment were not statistical significant (p>0.05) and the survival rate of BTL intake groups were higher than without BTL. So BTL were not growth inhibit substance. In the other hands BTL might be the natural immune stimulation substance.