Esterification of lutein from Japanese knotweed waste gives a range of lutein diester products with unique chemical stability

Metličar, Valentina (author), Albreht, Alen (author)

A valorization strategy for an aggravating type of plant waste is put to the test herein. It envisions the use of Japanese knotweed green leaves as a sustainable source of free lutein, from which bioactive diesters could be prepared as potential valueadded products with improved properties. To this end, 13 structurally distinct model lutein diesters were synthesized and the relationships between their structure and stability were systematically determined. The forced degradation data show that the stability of a particular lutein diester may depend to a large extent on the type of exposure (elevated temperature, light, oxidant, or acidic environment) and, more importantly, not every esterification attempt necessarily leads to an enhancement of lutein’s chemical stability. However, three branched and bulky products─lutein di(2,2-dimethylpropanoate), lutein di(2-methylpropanoate), and lutein di(3-methylbutanoate)─proved to be particularly relevant, as they consistently exhibited 1.5−21-fold higher stability compared to free lutein, regardless of the stress conditions used. Finally, we show that the Japanese knotweed plant matrix had a significant negative or positive effect on pigment degradation kinetics that could not be easily predicted. Thus, the proposed valorization strategy is quite feasible, but the esterification approach should be tailored to the intended use of a lutein diester.

• Language: English
• Keywords: xanthophylls, lutein, capsanthin, β-cryptoxanthin, zeaxanthin, violaxanthin, supercritical CO$_2$ extraction, invasive alien plant species, degradation, organic reactions, plants, stability
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2022
• Number of pages: Str. 6072–6081
• Numbering: Vol. 10, iss. 18
• PID: 20.500.12556/RUL-140638
• UDC: 577
• ISSN on article: 2168-0485
• DOI: 10.1021/acssuschemeng.2c01241
• COBISS.SI-ID: 108949507
• Publication date in RUL: 16.09.2022

Record is a part of a journal

• Title: ACS sustainable chemistry & engineering
• Shortened title: ACS sustain. chem. & eng.
• Publisher: American Chemical Society
• ISSN: 2168-0485
• COBISS.SI-ID: 519846169

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: biokemija, rastlinski odpadki, japonski dresnik, trajnostni viri, pigment