Covalent Immobilization of Naringinase over Two‐Dimensional 2D Zeolites and its Applications in a Continuous Process to Produce Citrus Flavonoids and for Debittering of Juices

Abstract

The crude naringinase from Penicillium decumbens and a purified naringinase with high α‐L‐rhamnosidase activity could be covalently immobilized on two‐dimensional zeolite ITQ‐2 after surface modification with glutaraldehyde. The influence of pH and temperature on the enzyme activity (in free and immobilized forms) as well as the thermal stability were determined using the specific substrate: p‐nitrophenyl‐alpha‐L‐rhamnopyranoside (Rha‐pNP). The crude and purified naringinase supported on ITQ‐2 were applied in the hydrolysis of naringin, giving the flavonoids naringenin and prunin respectively with a conversion >90 % and excellent selectivity. The supported enzymes showed long term stability, being possible to perform up to 25 consecutive cycles without loss of activity, showing its high potential to produce the valuable citrus flavonoids prunin and naringenin. We have also succeeded in the application of the immobilized crude naringinase on ITQ‐2 for debittering grapefruit juices in a continuous process that was maintained operating for 300 h, with excellent results.

A Career in Catalysis: Avelino Corma

“…The catalytic benefits of these highly accessible delaminated materials have been demonstrated in very diverse fields, including petrochemistry (i.e., cracking, hydrocracking, and aromatic alkylation), − fine-chemistry (i.e., olefin epoxidation, synthesis of acetals, Beckman rearrangement, and synthesis of diamino diphenylmethane (DADPM)) − or biomass transformations (i.e., syntheses of alkyl 5-benzyl-2-furoates, and xylenes), as will be discussed in other sections of this Account. , Interestingly, the large exposed external surface area in these delaminated 2D zeolites has permitted their functionalization with enzymes, allowing the design of very interesting materials combining the benefits of both heterogeneous and enzymatic catalysts. − …”

Enzymatic and chemo-enzymatic strategies to produce highly valuable chiral amines from biomass with ω-transaminases on 2D zeolites

“…Recently, we have reported that the pure silica 2D ITQ-2 zeolite is an excellent carrier to support enzymes such as naringinase [ 33 ] and alcohol dehydrogenases [ 34 ] that have been used efficiently, in both batch and flow mode, in the production of citrus flavonoids as well in the production of chiral alcohols from racemic mixtures through a chemo-enzymatic cascade process respectively. The ITQ-2 zeolite that can be prepared by a dual-templating one-step synthesis or by the delamination of a layered Mobil twenty two (MWW) zeolite precursor [ 35–38 ] is a 2D system of 2.5-nm-thick thin sheets.…”

The effects of α‐L‐rhamnosidase, β‐D‐glucosidase, and their combination on the quality of orange juice

“…However, the bitterness cannot be completely removed by ultrafiltration (Loizzo et al, 2019). In recent years, adding the enzyme naringinase in orange juice processing has become a common practice for the removal of naringin from fruit juice (Carceller et al, 2020), due to its specific hydrolysis of the substrates (Borzova et al, 2018;Zhu et al, 2017).…”