Abstract
Natural surfactants are surface-active molecules synthesized from renewable resources (i.e., plants, animals, or microorganisms) and possess properties comparable to conventional surfactants, making them an environmentally friendly potential alternative to petrochemical surfactants. Additionally, they exhibit biological properties such as anti-microbial properties, biodegradability, and less toxicity, allowing their use in everyday products with minimal risk to human health and the environment. Based on their mode of production, natural surfactants can be classified into first-generation or bio-based surfactants and second-generation or biosurfactants, although their definition may vary depending on the author in the literature. This review offers an extensive classification of bio-based surfactants and biosurfactants, focusing on their composition, natural sources, production methods, and potential applications across various industries. Furthermore, the main challenges and future perspectives are discussed.