Fluorescence fingerprints and chemical attributes of spice extracts

The data uploaded here are the fluorescence fingerprints (FFs) of spice extracts along with four chemical attributes: total polyphenol contents (TPC), total flavonoid contents (TFC), scavenging antioxidant contents (SCA) and reducing antioxidant contents (REA). The spice extracts were prepared by extracting three different types of spice seeds (anise seeds, dill seeds and fennel seeds) by 13 extraction protocols. The calibration dataset contains 3 replicates for all combinations of spice seeds and extraction protocols. Each replicate was prepared separately. The test set was created by measuring the FFs and all 4 chemical attributes of samples from one randomly chosen replicate after one year of storage at 4 °C. FFs were obtained from original extracts (no dilution) and extracts diluted 2 times, 5 times and 10 times using a Hitachi F-7000 spectrophotometer (Hitachi, Japan) at a right-angle scanning setup. Samples were measured in quartz cuvettes in the excitation and emission wavelength range of 200–700 nm at 5 nm intervals and 5 nm slit width. In the preprocessing stage, data were unfolded, and scattering zones were removed (first order light, ± 30 nm; second order light, ± 40 nm; third order light, ± 40 nm). The FFs obtained from the four levels of dilutions were concatenated into a meta-data matrix. We hypothesized that the concatenation of multiple FFs measured at different dilutions would give comprehensive information on the extract, leading to higher estimation accuracy of the chemical attributes.