Lira, E

Lobos, M

López, F.

MARANGON, MATTEO

Quiroz, W

Salazar, F. N

Silva, C

English

López, F.

Archivio istituzionale della ricerca - Università di Padova

Original Citation:Characterisation and Oenological Interest of Nine Commercial BentonitesPublisher:Published version:DOI:Terms of use:Open Access(Article begins on next page)This article is made available under terms and conditions applicable to Open Access Guidelines, asdescribed at http://www.unipd.it/download/file/fid/55401 (Italian only)Availability:This version is available at: 11577/3200171 since: 2016-10-12T14:29:56ZUniversità degli Studi di PadovaPadua Research Archive - Institutional RepositoryMATERIALS & METHODSINTRODUCTIONREFERENCESBentonites and wine samples: Fining trials were performed using nine types ofbentonite (Fig. 2) added each at three different rates (50, 100 and 200 g/hL) to aChardonnay standard wine vintage 2012 from Casablanca valley, Chile. All thebentonites were water hydrated at 5% (p/V) for 24 hours before use.Elements analysis: The determination of elements in bentonite, wine sample andtreated wine was done by using inductively coupled plasma optical emissionspectrometry (ICP-OES) and specifically by atomic fluorescence spectrometry to Ascase.Physical properties of bentonites: The surface properties of the bentonites werestudied with Brunauer-Emmett-Teller (BET) model adsorption with liquid N using asurface analyzer (Micromeritics ASAP 2000, USA) and assuming a cross-sectionalarea of 0.162 nm2 for nitrogen. Before the adsorption measurements were taken,the samples were outgassed under a vacuum of 0.001 mbar at 120 °C. Themorphology of the material was studied by X-ray diffraction (XRD) using a nickel-filtered Cu Kα1 radiation (λ=1.5418 Å) in the 2θ range 10-70° through a SIEMENSD5000 diffractometer.Protein content and heat protein instability: The protein content was determined byBradford’s method and the protein stability according to heat test at 80 ° C for 2 hand at 4 ° C for 2 h, with ∆NTU < 2 taken to mean stability.CHARACTERISATION AND OENOLOGICAL INTEREST OF NINE COMMERCIAL BENTONITES[1] OIV, 2003. Bentonites. Resolution OENO 11/2003. Office International de laVigne et du Vin.[2] Catarino S., Madeira M., Monteiro F., Rocha F., Curvelo-Garcia A.S and deSousa R.B.,. Effect of bentonite characteristics on the elemental composition ofwine. Journal of Food Chemistry and Agricultural, 2008, 56, 158-165.RESULTS & DISCUSSIONBentonites are hydrous aluminium silicates belonging to the montmorillonite group (Fig.1). The brute formula is: Si4 (Al (2-x) R x) (O10, H2O)(Cex, nH2O) or Si4(Al(2-x)Rx)(H2O)n [1].Information on elemental composition and technical properties of commercialbentonites can be not accessible in the literature or provided by the manufacturers.Bentonite addition may influence the elemental composition of the wine and affect itssensory properties, legal quality and health safety [2].The aim of this work was to study the release and removal of elements from commercialbentonites to wine by using inductively coupled plasma optical emission spectrometry(ICP-OES). Fining trials were performed using a Chardonnay standard wine and ninetypes of bentonite added each at three different rates. The structure and morphology ofthe bentonites were determined by BET method and X-ray diffraction, respectively. Thetechnological efficiency of bentonites was evaluated by measuring the amount ofprotein removed, the residual protein instability of the wine, and their settling capacity.Salazar F.N.*a, Silva C.a, Marangon M.b, Quiroz W.c, Lobos M.d, Lira E.e, López F.eaFacultad de Rescursos Naturales, School of Food Engineering, Pontificia Universidad Católica de Valparaíso, Waddington 716, Valparaíso. Chile. E-mail: fernando.salazar@ucv.cl bThe Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, AustraliacLaboratorio de Química Analítica y Ambiental, Instituto de Química, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330, Valparaíso, ChiledFacultad de Ciencias, Universidad de Valparaíso, Departamento de Química y Bioquímica, Universidad de Valparaíso, Av. Gran Bretaña 1111, Valparaíso, ChileeDepartament d’Enginyeria Química, Facultat d’Enologia, Universitat Rovira i Virgili, Avinguda dels Països Catalans 26, Tarragona, 43007, SpainElements analysis: A total of fifteen elements were detected. The addition ofbentonite resulted in an increased concentration of As, Cd, Fe, Mn, Mo, Na, Ni, andZn in wine, while for Cu and K reductions proportional to the dosage used wereobserved. Cristobalite and quartzFeldsparProtein content and heat proteininstability: Among the ninebentonites studied, a great variabilityin terms of protein removal (Fig. 2)and settling capacity (Fig. 5) wasobserved, with only four bentonitesbeing able to stabilize the wine at 50g/hL (Fig. 2).Physical properties of bentonites: Anaverage pore size of 20 Å wasobserved in all bentonites, while theirsurface areas presented highdistribution, with the sodium-activated calcium bentonite showingthe highest (Table 1). X-ray diffractionprofiles highlighted the presence ofdifferent levels of diffraction patterns,with cristobalite and quartz being themost represented (Fig. 3).02468101214160510152025Ca Ca Na/Ca Na Na Na Na Na NaTotal proteincontent(mg/L)Proteininstability(∆NTU)Bentonites100 g/hL(KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8)(SiO2)(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2·nH2OMontmorillonite00-003-0019 (D) - Bentonite - Na-Al-Si-O-OH-H2O - Y: 10.94 %Y + 40.0 mm - HVP-M1 - File: D8_BRI75348.raw - Type: 2Th/TY + 35.6 mm - M2-BN - File: D8_BRI75349.raw - Type: 2Th/Th lY + 31.1 mm - M3-BSV - File: D8_BRI75350.raw - Type: 2Th/TY + 26.7 mm - M4-BSVC - File: D8_BRI75351.raw - Type: 2Th/Y + 22.2 mm - M5-MALI - File: D8_BRI75352.raw - Type: 2Th/TY + 17.8 mm - M6-BV - File: D8_BRI75353.raw - Type: 2Th/Th lY + 13.3 mm - M7-BGA1 - File: D8_BRI75354.raw - Type: 2Th/Y + 8.9 mm - M8-BGA2 - File: D8_BRI75355.raw - Type: 2Th/TY + 4.4 mm - M9-BLE - File: D8_BRI75356-1.raw - Type: 2Th/TM9-BLE - File: D8_BRI75356.raw - Type: 2Th/Th locked - Start:Lin (Counts)01002003004005006007008002-Theta - Scale5 10 20 30 40 50 60 70 80 90This work was supported by the Chilean National Commissionfor Research, Science and Technology (CONICYT-Chile) throughGrant FONDECYT INICIACION Nº 11121594.ACKNOWLEDGEMENTSNa Na Na Na Na Na Na/Ca Ca Ca Na Na Na Na Na Na Na/Ca Ca CaOur classificationFig. 2 Capacity of protein removal and protein stability ofdifferent commercial bentonites classified according toelements analysis and using different doses.22.4% 14.9% 10.7% 25.6% 21.4% 20.3% 19.2% 8.6% 4.3% Settling capacity (percentage of wine lees)Supplier information Na Na Na Na Na Na Na Na/Ca NaCaSwelling capacity 37% 36% 37% 14% 13% 13% 12% 11% 10%Fig. 1 The crystal lattice structureof Montmorillonite.The elemental composition of the bentonites studied showedconcentrations of Fe and Al above the OIV specifications,while As was below the OIV limit in only one bentonitesample [1].The element analysis classified the commercial bentonites assodium, calcium and sodium-activated calcium which is notagreement with the reported by the manufacturers to all case.It was also demonstrated that the use of commercialbentonites in white wine affect the elemental composition ofthe wine.200 g/hL50 g/hLFig. 3 Power x-ray diffraction of different commercial bentonitesFig. 4 Swelling property of differentcommercial bentonitesFig. 5 Wine lees obtained by using 200 g/hL ofdifferent commercial bentonitesSAMPLE* Area BET Pore volume Half pore width(m2/g) (cc/g) ÅNa 23.483 0.043 18.972Na/Ca 60.965 0.112 20.758Na/Ca 63.801 0.078 20.758Na 27.367 0.077 19.845Na 32.771 0.070 20.758Na 26.565 0.070 18.972Na 57.625 0.129 19.845Na 28.107 0.069 20.758Na 44.820 0.073 18.972Table 1 Physical properties of different commercial bentonites* Classification of the bentonites according to themanufacturer information

Characterisation and Oenological Interest of Nine Commercial Bentonites

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Characterisation and Oenological Interest of Nine Commercial Bentonites

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