Browsing by Author "Costa, Patrícia S."
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- High value-added lignin extracts from sugarcane by-productsPublication . Mota, Inês F.; Burgal, João da Silva; Antunes, Filipa; Pintado, Manuela E.; Costa, Patrícia S.This study evaluates the production of lignin bioactive extracts from sugarcane bagasse (SCB) and straw (SCS) alkaline black liquors using greener precipitating agents (methane sulfonic acid (MSA), formic acid (FA) and lactic acid (LA)) as replacers of sulfuric acid (SA), the most common one used in industry. Results showed that the highest precipitation yield was achieved by LA when applied to SCB (14.5 g extract/g SCB). Lignin SCB extracts were similar in composition in terms of total carbohydrates (61–70 %), lignin (22–30 %) and inorganics (1.6–2.6 %). Regarding the SCS extracts, similar yields were obtained among all extracts, however; differences in composition were observed between SA and greener precipitating agents, particularly in terms of sugar content. All extracts exhibited radical scavenging activity; overall the extracts were more effective in the scavenging of ABTS radical. FA was the most promising alternative to SA to recover lignin bioactive extracts. This work suggests organic acids as good candidates for obtaining valuable extracts from alkaline pulping of SCB and SCS instead of the conventional sulfuric acid, thus suggesting a green solution for this biomass valorization.
- Sugarcane light-colored lignin: a renewable resource for sustainable beautyPublication . Mota, Inês F.; Antunes, Filipa; Fangueiro, Joana F.; Costa, Carina A. E.; Rodrigues, Alírio E.; Pintado, Manuela E.; Costa, Patrícia S.Lignin has emerged as a promising eco-friendly multifunctional ingredient for cosmetic applications, due to its ability to protect against ultraviolet radiation and its antioxidant and antimicrobial properties. However, its typical dark color and low water solubility limit its application in cosmetics. This study presents a simple process for obtaining light-colored lignin (LCLig) from sugarcane bagasse (SCB) alkaline black liquor, involving an oxidation treatment with hydrogen peroxide, followed by precipitation with sulfuric acid. The physico-chemical characterization, antioxidant and emulsifying potential of LCLig, and determination of its safety and stability in an oil-in-water emulsion were performed. A high-purity lignin (81.6%) with improved water solubility was obtained, as a result of the balance between the total aromatic phenolic units and the carboxylic acids. In addition, the antioxidant and emulsifying capacities of the obtained LCLig were demonstrated. The color reduction treatment did not compromise the safety of lignin for topical cosmetic applications. The emulsion was stable in terms of organoleptic properties (color, pH, and viscosity) and antioxidant activity over 3 months at 4, 25, and 40 °C.