Food Control. 127, 108113 (2021). Review of various techniques used for adulterant authentication in spices and herbs, including identification of unusual profile of a component, differentiation from the normal standard compound and identification of marker or foreign material in the product. The document provided an overview of chromatographic methods, including TLC and HPTLC for adulterant detection, and its combination with mass spectrometry. 

Food Control. 122, 107816 (2021). HPTLC of histamine in fish samples on a silica gel read-out strip coated with a ninhydrin@TiO2 complex (0.1 M titanium butoxide and 5 % ninhydrin as precursors) as self-visualization nanomaterial in the histamine target zone (hRF value of 24). Samples were developed using n-butanol - acetone - ammonia 20:5:2. Detection after heating at 80 °C for 30 s. Linearity was between 15 and 320 mg/kg. The LOD for histamine was 5 mg/kg. 

Food Chem. 346, 128929 (2021). HPTLC of rutin, kaempferol, linarin, isoquercetin, astragalin, avicularin and trans-tiliroside in herbal tea flowers obtained from five Tilia species, namely T. cordata, T. platyphyllos, T. europaea, T. americana, and T. tomentosa on silica gel with tetrahydrofuran - dichloromethane - formic acid - acetic acid - water 9:9:4:2:3. Detection by spraying with 1 % methanolic diphenylboric acid-β-ethylamine ester, followed by heating at 100-105 °C for 2 min. Qualitative identification under UV light at 254 and 366 nm.

Food Chem. 362, 130167 (2021). HPTLC of monosaccharides rhamnose, xylose, arabinose, mannose, glucose, galactose and sucrose in cladodes from Opuntia ficus-indica and Opuntia joconostle on silica gel with acetonitrile - 0.3 % ammonium hydroxide 17:3. Detection by dipping into thymol (0.2 %) and sulfuric acid (5 %) in methanol reagent, followed by heating at 95 °C for 2 min.

Food Chem. 341, 128271 (2021). HPTLC of finger millet (Eleusine coracana L.) on silica gel with n-butanol - water - acetic acid 4:1:1. Detection by spraying with ninhydrin, followed by heating at 100 °C. Amino acid profiling under UV light at 546 nm. The hRF values for 21 standard amino acids ranged from 2 to 51.

Food Chem. 357, 129135 (2021). HPTLC of cinnamon on silica gel with toluene - ethyl acetate - methanol 6:5:3. Nine detection modes were used: 1) white light illumination, 2) UV 366 nm, 3) UV 254 nm, and six different derivatization reagents applied by immersion: 4) primuline reagent (100 mg primuline, 20 mL water and 80 mL acetone), 5) p-anisaldehyde sulfuric acid reagent (1 mL methoxy benzaldehyde, 140 mL methanol, 16 mL acetic acid and 8 mL sulfuric acid), 6) vanillin sulfuric acid reagent (1 g vanillin, 80 mL ethanol and 0.8 mL sulfuric acid), 7) diphenylamine aniline o-phosphoric reagent (2 % each of diphenylamine and aniline in 100 mL isopropanol plus 20 mL o-phosphoric acid), 8) Fast Blue B salt reagent (100 mg Fast Blue B salt in 100 mL ethanol, 70 %) and 9) natural product reagent (1 g 2-aminoethyl diphenyl borate in 100 mL ethanol), followed by heating at 110 °C (5), 120 °C (4, 6) or 140 °C (7, 8) for 3-5 min. Effect-directed profiling was performed through eight different assays: HPTLC–Aliivibrio fischeri bioassay, HPTLC–Bacillus subtilis bioassay, HPTLC–tyrosinase inhibition assay and densitometric evaluation, HPTLC–α–glucosidase and β–glucosidase inhibition assays, HPTLC–AChE and BChE inhibition assays, HPTLC–DPPH assay. Compounds were further characterized by heated electrospray ionization high–resolution mass spectrometry (HESI–HRMS).

Food Chem. 343, 128400 (2020). HPTLC fingerprint of Citrus bergamia fruits from the islands of Kefalonia, Corfu and R. Calabria on silica gel with chloroform - methanol - water 13:9:3. Qualitative identification under UV light at 280 nm.

Food Chem. 362, 130132 (2021). HPTLC of betanin (1) and vulgaxanthin I (2) in beetroot (Beta vulgaris L. subsp. vulgaris) on RP-18 silica gel with water - acetonitrile -  trifluoroacetic acid 40:10:1. Quantitative determination by absorbance measurement at 535 nm for (1) and 484 nm for (2). The hRF values for (1) and (2) were 38 and 58, respectively.