Coumarins, Psoralens and Polymethoxyflavones in Cold-pressed Citrus Essential Oils: a Review

Cold-pressed Citrus essential oils namely lemon, bergamot, lime, grapefruit, mandarin, sweet and bitter orange are obtained from the peel of Citrus fruits. They were normally used in food, cosmetic, and pharmaceutical industries as ingredients. Essential oils extraction processes produce oils with different sensory qualities, and often these processes are expensive and have a low yield. For such a reason adulteration process are frequent, so careful attention must be paid to ensure the oils’ genuineness and authenticity. Moreover, psoralen levels are continuously monitored by opinions and regulations released from International Fragrance Association and the European Parliament due to their photoactivity. This review aims to browse the scientific literature of the past 30 years on the characterization of the non-volatile fraction of cold-pressed Citrus essential oils to discuss results achieved so far and highlight future prospect.