Extraction and Characterization of Lignin from Instant Coffee and its Anti-UV Application in Stabilized Pickering Emulsion

• Published in: Waste and biomass valorization 2024, Vol.15 (6), p.3651-3658
• Main Authors: Xin, Hanwen, Xu, Jingyu, Zhou, Jinghui, Wang, Xing
• Format: Article
• Language: English
• Subjects: Acids; Coffee; Emulsions; Engineering; Environment; Environmental Engineering/Biotechnology; Green products; Industrial Pollution Prevention; Instant coffee; Lignin; Original Paper; Pigskins; Renewable and Green Energy; Sun screens; Ultraviolet radiation; Waste Management/Waste Technology
• ISSN: 1877-2641; 1877-265X
• DOI: 10.1007/s12649-023-02404-0

In recent years, there has been an increasing demand for environmentally friendly products. In this context, lignin has garnered significant attention as a natural and renewable biomass material. It is suspected that certain instant coffee species contain a certain amount of green and non-toxic edible lignin due to the similarity between the extraction process of instant coffee and the hydrothermal extraction process of lignin. However, there is currently no research available on these lignin samples. This study aims to fill this gap by extracting and analyzing lignin from five common instant coffee brands. The acid precipitation method was used to extract lignin, and the contents of acid-insoluble and acid-soluble lignin were calculated. Subsequently, the acid-insoluble lignin was structurally characterized, and the samples were tested for their antioxidant, UV protection, and antibacterial properties. The results showed that these coffee lignin exhibited excellent properties. To further apply these excellent properties, they were prepared them into stable Pickering emulsions and tested their UV resistance. The emulsions were successful in maintaining the colour of pigskin even after 4 h of exposure to 254 and 365 nm UV light. This suggests that coffee lignin has potential for use in the development and production of non-toxic, environmentally friendly sunscreen products.