Metabolite Profiling of Rice Bran from Four Rice Varieties as a Potential Feedstock for Biovanillin Production: A UV-Vis, FTIR-ATR, and Chemometric Approach

Rice bran, a byproduct of the rice milling process, is known to contain various bioactive compounds, including phenolic acids such as ferulic acid—an essential precursor for the biotechnological production of vanillin, a high-value natural flavouring agent. This study aimed to investigate the metabolite profiles of rice bran derived from four locally cultivated rice varieties in Padang City: Sokan, Anak Daro, IR 42, and IR 10. Analytical profiling was conducted using Ultraviolet-Visible (UV-Vis) spectroscopy and Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance (FTIR-ATR), followed by chemometric analysis via Principal Component Analysis (PCA). The results revealed distinct absorbance patterns and spectral features among the varieties, particularly in relation to phenolic, hydroxyl, and carbonyl functional groups. These differences reflect varietal influences on the chemical composition of rice bran, potentially driven by genetic and environmental factors. PCA enabled clear differentiation among the rice bran samples based on their spectral fingerprints, reinforcing the relevance of selective raw material sourcing in bioconversion processes. Overall, this study highlights the untapped potential of rice bran as a renewable and locally available feedstock for biovanillin production, supporting the sustainable valorization of agricultural residues.