The Biochromatics of Plants: Extraction, Characterization, and Application of Pigments from Various Plants

Abstract

Pigments are chemical compounds that absorb light in the wavelength range of the visible region. Synthetic pigments in effluents pose a serious environmental threat due to their non-biodegradable nature, prompting a shift towards exploring eco-friendly alternatives. The focus has shifted towards the diverse array of natural pigments for applications in food, pharmaceuticals, and textiles, prioritizing human health preservation. The stability of pigments is influenced by various factors such as pH, light exposure, temperature, and complexation with other substances. This study aimed to develop a stable, eco-friendly biocolour using extracts from Rubus fruticosus L., Bixa orellana L., Adhatoda vasica L., and Beta vulgaris L. Phytochemical analysis revealed the presence of key constituents like phenols, flavonoids, alkaloids, and tannins. Purification through flash column chromatography and thin-layer chromatography determined pigment separation, with UV spectrophotometry used for quantification based on Lambert beer law. HPTLC fingerprinting identified carotenoids, anthocyanins, betalains, and chlorophylls. FTIR analysis determined functional groups, while LCMS provided information on molecular aspects. Encapsulation, co-pigmentation, and entrapment methods were employed to enhance stability. Antioxidant and antibacterial activities were assessed, and heavy metal content determined using atomic absorption spectroscopy. Extracted pigments found applications in food, textiles, tablet coating, cosmetics, and candles. The methanol extract of Bixa orellana L. demonstrated superior stability across various applications. This study advocates for the promising use of natural pigments, promoting consumer health and facilitating the production of eco-friendly biocolours devoid of synthetic additives.