3.7. Analysis of food samples
The proposed FDH fructose biosensor was applied to the analysis
of foodstuffs like commercial fruit juice samples, honey, soft
drinks and energy drinks. The fructose content was determined
applying the calibration graph method and the samples were analysed
in five replicates. The results were compared to those obtained
with the enzymatic commercial spectrophotometric assay
kit. As can be seen from Table 3, there is a good agreement between
the results obtained with the biosensor and the reference
spectrophotometric kit. It is interesting to observe that the results
obtained with the reference spectrophotometric kit all show
slightly higher values, probably because of the multienzyme cascade
reactions, which take place in the kit and that can cause interferences
from other compounds, especially other sugars, whereas
the FDH biosensor is strictly specific for fructose, as demonstrated
above.