Instrumental factors influencing absorption measurements for fluid food color determination.
The differences in color coordinates obtained from the use of different spectral features in the calculation are studied. Seven groups of food (olive oil, vanilla milkshake, brandy, honey, grape juice, vinegar, and orange juice) and an anthocyanin petunidin solution (natural pigment present in several vegetables) with different pH values were selected. Tristimulus values were calculated by considering the different sources of errors (truncation, abridgement, or different bandwidths). Results obtained were corrected by using the methods recommended (see References). These methods of abridgment work well in general, although in some circumstances (20 nm bandwidth or larger), specific spectral weighting functions have to be used to obtain a negligible error. Therefore, it is interesting to know how much difference can be expected from those factors in order to avoid confusion between color differences attributable to instruments and those attributable to actual color changes.
Universidad de Sevilla, Area de Nutrición y Bromatología, Facultad de Farmacia, 41012, Sevilla, Spain.
Cristina
C
Montes
Joaquin
J
Campos
Alicia
A
Pons
Francisco J
FJ
Heredia
D000465:Algorithms; D000872:Anthocyanins; D005504:Food Analysis / Q000379:methods*; D005505:Food Coloring Agents / Q000032:analysis*; D012015:Reference Standards; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet
D000872:Anthocyanins; D005505:Food Coloring Agents