Enzymatic synthesis of short-chain flavor esters from natural sources using tailored magnetic biocatalysts

• Published in: Food chemistry 2019-10, Vol.296, p.1-8
• Main Authors: Vasilescu, Corina, Todea, Anamaria, Nan, Alexandrina, Circu, Monica, Turcu, Rodica, Benea, Ioana-Cristina, Peter, Francisc
• Format: Article
• Language: English
• Subjects: Biocatalysis; Carboxylic Acids - chemistry; Carboxylic Acids - metabolism; Core shelled magnetic biocatalyst; Enzymes, Immobilized - chemistry; Enzymes, Immobilized - metabolism; Esters - analysis; Esters - metabolism; Flavor esters; Fungal Proteins - chemistry; Fungal Proteins - metabolism; Gas Chromatography-Mass Spectrometry; Immobilization; Lipase; Lipase - chemistry; Lipase - metabolism; Magnetite Nanoparticles - chemistry; Silicon Dioxide - chemistry; Sol-gel
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2019.05.179

•A new multilayer magnetic biocatalyst was designed combining immobilization methods.•The catalytic efficiency was determined in solventless esterification reactions.•Natural isoamyl esters of four carboxylic acids were synthesized in good yields.•The novel magnetic lipase was efficient in several reuse cycles. Immobilized lipases are excellent biocatalysts for the enzymatic synthesis of short- and medium-chain fatty esters used as food flavor compounds. Herein a new approach for a magnetic core-shell biocatalyst by immobilization of Candida antarctica B lipase is reported, coating single-core magnetic nanoparticles with an organic shell, preferably poly(benzofurane-co-arylacetic acid), followed by the covalent attachment of the enzyme and embedment of the primary biocatalyst in a silica layer. Although covalent and sol-gel immobilization were efficient on their own, their combination can ensure additional operational stability through multi-point linkages. Moreover, silanes holding glycidoxy groups, which can also form covalent linkages, have been successfully used as precursors for the silica coating layer. The structural, magnetic and morphological characteristics were assessed by TEM, SEM-EDX, X-ray photoelectron spectroscopy and vibrating sample magnetometry. The new biocatalysts demonstrated high catalytic efficiency in the solventless synthesis of isoamyl esters of natural carboxylic acids, also in multiple reaction cycles.