Coconut husk valorization: innovations in bioproducts and environmental sustainability

The coconut husk (CH) is a significant byproduct of the green coconut agroindustry (which produces coconut water, coconut oil, and coconut milk), constituting approximately 15% of the total fruit weight. CH is often discarded improperly, leading to significant environmental issues. This CH decomposes over several years, contributing to greenhouse gas emissions and contaminating soils and water bodies. Traditionally, the CH has been used for charcoal production, agricultural substrate, and manufacturing products. However, there is increasing interest in valorizing CH through biotechnological processes to produce higher-value bioproducts, such as biofuels and enzymes. This review article assesses the latest trends in CH utilization, exploring both traditional methods and innovative biotechnology-based technologies. Bibliometric analysis on CH utilization indicated a significant increase in publications over the past decade, highlighting the potential of fermentation-based approaches to convert CH lignocellulosic content into bioproducts, such as biofuel, enzymes and biomaterials that have a higher commercial value than those traditionally obtained. Reports in the literature also suggest that the pretreatment methods applied enhance bioconversion yields, leading to higher bioproduct yields. These results indicate new advancements in CH management and the development of cleaner technologies for enhanced bioproduct synthesis. This approach to biotechnological production can mitigate the environmental impact of coconut waste while strengthening economic development and ecological conservation.