A Comparative Study of the Molecular Constituent Profile Among Brussels Sprout Leaf Layers by Mid-Infrared Spectroscopy and Chemometrics

Brussels sprouts (Brassica oleracea) are of great nutritional interest due to their functional ingredients and health benefits. This study aimed to investigate the molecular composition of different leaf layers of Brussels sprouts using ultraviolet-visible spectrophotometry and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy combined with chemometric techniques. Results revealed significant differences in chlorophyll and carotenoid content, with the outer leaves exhibiting the highest levels. ATR-FTIR analysis identified distinct molecular constituents, including glucosinolates, phenolics, lipids, and polysaccharides, that varied across leaf layers. Discriminant analysis effectively classified the leaf layers based on their spectral data with high accuracy, highlighting distinct molecular ingredients.