title: Immobilised native plant cysteine proteases: packed-bed reactor for white wine protein stabilisation.
abstract: This research presents a feasibility study of using a continuous packed-bed reactor (PBR), containing immobilised native plant cysteine proteases, as a specific and mild alternative technique relative to the usual bentonite fining for white wine protein stabilisation. The operational parameters for a PBR containing immobilised bromelain (PBR-br) or immobilised papain (PBR-pa) were optimised using model wine fortified with synthetic substrate (Bz-Phe-Val-Arg-pNA). The effectiveness of PBR-br, both in terms of hazing potential and total protein decrease, was significantly higher than PBR-pa, in all the seven unfined, white wines used. Among the wines tested, Sauvignon Blanc, given its total protein content as well as its very high intrinsic instability, was selected as a control wine to evaluate the effect of the treatment on wine as to its soluble protein profile, phenolic composition, mineral component, and sensory properties. The treatment in a PBR containing immobilised bromelain appeared effective in decreasing both wine hazing potential and total protein amount, while it did not significantly affect the phenol compounds, the mineral component nor the sensory quality of wine. The enzymatic treatment in PBR was shown to be a specific and mild technique for use as an alternative to bentonite fining for white wine protein stabilisation.
authors.affiliation: Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, via S. Camillo de Lellis, 01100 Viterbo, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Benucci
authors.affiliation: Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, via S. Camillo de Lellis, 01100 Viterbo, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Lombardelli
authors.affiliation: Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, via S. Camillo de Lellis, 01100 Viterbo, Italy.
authors.forename: Katia
authors.initials: K
authors.lastname: Liburdi
authors.affiliation: Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, via S. Camillo de Lellis, 01100 Viterbo, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Acciaro
authors.affiliation: Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, via S. Camillo de Lellis, 01100 Viterbo, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Zappino
authors.affiliation: Department for Innovation in Biological, Agro-food and Forest Systems, University of Tuscia, via S. Camillo de Lellis, 01100 Viterbo, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Esti
keywords: Chitosan beads; Covalent immobilisation; Native plant cysteine proteases; Packed-bed reactor; Total wine proteins; Wine hazing potential