Samples (µg/mL) Dilution factor PAA (AU) Measured L-AA concentrations (µg/mL)1 Recovery (%) COV2 r2
  Dragonfruit vitamin water   1/50   684.25 ± 1.41   489.50   102.13   2.46   0.997
(479.28) 1/25 1290.47 ± 0.44 474.50 99.00    
  1/9 3514.37 ± 3.27 461.34 96.26    
  1/4 7932.46 ± 0.02 479.32 100    
             
Camu powder extract 1/45 285.54 ± 3.15 168.30 95.22 2.12 0.999
(176.74) 1/8 1381.97 ± 71.00 163.04 92.25    
  1/4 2861.67 ± 9.69 171.40 96.97    
  1/2 5620.27 ± 21.69 169.44 95.86    
             
Orange vitamin water 1/4 7996.65 ± 7.03 480.00 100 1.87 0.999
(480.00) 1/10 3294.70 ± 0.11 494.20 102.96    
  1/25 1361.94 ± 0.13 502.00 104.58    
  1/50 684.25 ± 1.41 489.50 101.98    
             
Pressed berry juice 1/2 3784.89 ± 55.15 113.74 103.23 6.28 0.995
(110.14) 1/5 1774.24 ± 12.42 131.70 119.58    
  1/10 870.84 ± 3.67 126.30 114.67    
  1/20 435.99 ± 2.98 120.40 109.31    
             
Tropical juice 1/5 7548.66 ± 5.79 570.03 100.00 3.81 0.999
(570.03) 1/12 3230.86 ± 3.54 581.46 102.00    
  1/20 1993.46 ± 2.55 593.39 104.10    
  1/100 396.43 ± 3.71 542.43 95.16    
PAA values are means ± SD of two determinations (n=2); 1L-AA concentrations calculated using y=mx+c; 2Precision between four concentration levels. Abbreviations: AU: Absorbance Unit; COV: Coefficient of Variation; PAA: Peak Absorbance Area; r2, Correlation Coefficient
Table 1: Linearity of samples (Peak absorbance area vs. Dilution factor).