EVALUATION OF CYANIDIN-3-O-GLUCOSIDE FROM DIFFERENT BLACK RICE VARIETIES OF MANIPUR UTILIZING FTIR SPECTROSCOPY AND HPTLC METHOD

Black rice is a rice species, Oryza sativa Linne (Gramineae), which is sticky, high in nutrients, and primarily grown in Asia. In recent years, the health benefits of black rice varieties have been reported due to the presence of a bioactive compound, anthocyanin, which has highly potent activity with high macronutrients. The present study aimed to evaluate and quantify the metabolites, focusing on describing the structure of Cyanidin-3-O-glucoside (CY3G) as a biomarker of anthocyanin present in the extract of black rice. Four different black rice varieties black rice extracts of Poireiton (BREP), Kokngangbi (BREK), Amubi (BREA), and Sempak (BRES) were collected, and phytochemical analyses performed using different standard methods. Compared to other black rice varieties, Amubi, BREA has the highest phenolic (63.23±0.76 mg/g GAE), flavonoid (28.09±0.68 mg/g QE), and anthocyanin (17.69±0.45 mg C/g DEW) content. It also exhibited the highest potent antioxidant activity, with IC₅₀ values of 29.1 ± 1.11 mg/ml in the ABTS assay and 98.83 ± 0.61 mg/ml in the DPPH assay. The FTIR spectroscopy analysis result shows a similar intensity of the peak absorbance in the 400–4000 cm^-1 region of functional groups related to the biomarker compound CY3G in the black rice sample. The HPTLC analysis generated polynomial calibration curves for the 100–600 ng spot -1 concentration range for both the standard biomarker and sample, yielding a satisfactory correlation coefficient, R0.999. The retention factor (RF) and spectral correlation confirmed the method’s specificity.