Extraction, purification, and applications of vanillin: A review of recent advances and challenges

Vanillin is a natural aromatic flavoring compound extensively used in various industries such as food, cosmetics, and pharmaceuticals. However, due to the limited natural resources and environmental concerns, there has been a significant focus on exploring sustainable vanillin extraction in recent years. This review aims to present a comprehensive overview of recent advances in sustainable extraction, purification, and applications of vanillin from various sources such as vanilla pods, lignin, and fermentation broth, while also discussing the challenges and opportunities for improving the sustainability of vanillin extraction. The review covers various extraction techniques, including enzymatic, green solvent, microwave-assisted, pulsed electric field, and supercritical fluids, which have been investigated for sustainable vanillin recovery. Additionally, purification methods, including crystallization, membrane separation, and chromatography, that have recently been developed to efficiently recover and purify vanillin, are discussed. The effectiveness of these methods is evaluated based extraction efficiency, purity, and cost-effectiveness. Furthermore, the article explores the latest and unconventional applications of vanillin in biomedical, pharmaceuticals, drug delivery systems, and battery energy. This comprehensive review provides valuable insights into the sustainable production of natural vanillin and its diverse applications, underscoring the need for an environmentally friendly approach to vanillin production.