This work aims the development of an analytical alternative to determine phenolic compounds in fruits exploiting a greener microwave-assisted extraction and photometric detection by smartphone-based colorimetry. Acerola cherry (Malpighia emarginata) was selected as a model and the extraction was optimized by the Doehlert design, taking into account temperature, solvent composition, and extraction time. The Folin–Ciocalteau method was used to determine total phenolic content in the extracts, with a 5-fold reduction in reagent amount and waste generation. The optimal extraction was achieved with 17% v/v ethanol, at 38 °C, for 50 min. The total phenolic content determined by the proposed procedure (146 ± 4 mg GAE g⁻¹ dry weight) agreed with the reference procedure (145.0 ± 0.7 mg GAE g⁻¹ dry weight) at the 95% of confidence level. Due to these characteristics, the proposed approach is an alternative for screening fruits in research with bioactive compounds.

Cinnamon (Cinnamomum zeylanicum) is a spice largely consumed worldwide, but there is still restricted information about its fingerprint. This work aimed to investigate the mineral composition as a possible marker for the classification of cinnamon samples. To this aim, the mineral composition (P, S, Mg, Ca, K, Cu, Zn, B, Fe, Al, Mn, and Si contents) of 56 ground cinnamon samples from different regions of the State of São Paulo, Brazil was determined by inductively coupled plasma optical emission spectroscopy (ICP OES). Principal component analysis was exploited for sample classification, and the microelements presented the best correlation: PC1, PC2, and PC3 explained 93% of the observed variance at 95% confidence level. Si, Al, Fe, and Cu presented the most significant contributions to cluster analysis. Samples were classified into six groups, in which those presenting C. zeylanicum were well clustered, and the samples acquired in bulk as well as those whose labels declared traces of grains and/or spices presented the highest variability. Thus, it was pioneeringly demonstrated the possibility of identifying C. zeylanicum in commercial cinnamon powders, using microelements as authenticity markers.