DOI: https://doi.org/10.55373/mjchem.v27i4.59

Keywords: FTIR Analysis; polyherbal optimisation; principal component analysis; synergistic antioxidant effects

Abstract

Phyllanthus emblica, Camellia sinensis, and Allium sativum L. (black solo garlic), contain phytochemicals associated with antioxidant properties. However, most studies have focused on these plants individually, thus overlooking the investigation of synergistic effects. Hence, sixteen aqueous extract formulations with varying proportions were developed in this study using a simplex lattice mixture design generated by Design Expert software. Antioxidant properties were quantitatively assessed through colorimetric analyses, measuring total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) spectrophotometrically. Principal component analysis (PCA) was applied to differentiate between the extracts, and Fourier Transform Infrared Spectroscopy (FTIR) was utilised to analyse their functional groups and specific characteristic regions. The results indicated a synergistic effect in most combinations, with P. emblica and C. sinensis contributing the highest TPC and DPPH values across the formulations. The optimised formulation (36.4 % P. emblica, 17.5 % C. sinensis, and 46.1 % A. sativum L.) yielded 1205.1 ± 20.1 mg GAE/g for TPC and 96.2 ± 0.1 % for DPPH. FTIR spectra revealed the wavenumber ranges associated with functional groups of TPC, which strongly correlated with the chemometric results (R² = 1). PCA demonstrated a clear correlation between FTIR data and antioxidant properties. These findings suggest that polyherbal formulations may be useful in the development of natural antioxidant-rich products in the food industry.