Valorizations of Marigold Waste for High-Value Products and Their Industrial Importance: A Comprehensive Review

The municipal authorities in developing nations face serious challenges marigold flower garbage management. primary issue is that they never are reused after prayers. Flower waste of Tagetes erecta, T. patula, and Calendula officinalis L. commonly used for carotenoid flavonoid extractions and, subsequently, incense stick biogas production. Marigold plants also phytoremediation during their growth stage. lutein industry booming due to its increasing market demand, expected reach ~2121.2 billion tons by 2022, where marigolds a major contributor globally. process isolating from saponified oleoresin yields product with 70–85% purity. Lutein xanthophyll (70–88%) petals, maximum 21.23 mg/g was extracted. This review discusses the properties selective species, compositions, extraction different flavonoids carotenoids, especially lutein. Moreover, methods lutein, collection waste, subsequent utilization derive several value-added products discussed. Among physical treatments, ultrasonic-assisted enzymatic treatment 5% solids loading were maximum-yielding methods.