According to Pearson’s correlation analysis (Table 1) values
from the iCheck CAROTENE method have a close relationship with
the values obtained by AOAC methods with an average of r2 of
0.99 ranging from 0.82 (free range duck) to 1.00 (free range
chicken). The relationship between the values obtained by the
iCheck and HPLC method was in average r2 of 0.94 ranging from
0.85 (free range duck) to 1.00 (free range chicken) (Figs. 1 and
2). With such high average r2 value the agreement can be interpreted
as almost perfect. Raila, Enjalbert, Mothes, Hurtienne,
and Schweigert (2012) also demonstrated that both the iCheck
and HPLC method showed a very good agreement based on correlation
coefficient of r2 > 0.98; (p < 0.001). In this case ß-carotene
was determined in cattle blood plasma and results were compared
to HPLC analysis. Results of this study support the good
agreement between the new method and standard methods such
as spectroscopy or HPLC.