Lucidi 8

Separation Techniques

SOLID - SOLID

SOLID - LIQUID

LIQUID - LIQUID

SOLUTES - LIQUID

Tartaric Stabilization Subtractive techniques

COLD STABILIZATION

ION-EXCHANGE RESINS

ELECTRODIALYSIS

• Saturation

– PC[K+] [HT-] = PS(Ks)

H2O + H2T H3O+ + HT-

[H3O+] [HT-]

[H2T]

Ka1 =

H2O + HT- H3O+ + T2-

[H3O+] [T2-]

[HT-]

Ka2 =

K+ + HT- KHT[K+] [HT-]

[KHT]

Ks =

[K+] [HT-] =

Characteristics of the solids

Crystals

• Precipitation

– PC[K+] [HT-] > PS(Ks)

4

Char

acte

rist

ics

of

the

soli

ds

Cry

stal

s

Rib

érea

u-G

ayo

n e

t al

., 2

00

6

Electrodialysis (ED)

• Selective membranes (permeable to ions)

• Electric field (DV = 1 V/cm)

Cottereau, 2009

Electrodialysis modules Up to 700 pairs of membranes in the machine

http://www.vason.com

m.p.a.: membrane permeable to anions compartment 1: the ions are diluted

m.p.c.: membrane permeable to cations compartment 2: the ions are concentrated

Ribereau-Gayon et al.,2006

0,2-3,0 mm

Electrodialysis machine Arrangement of the modules

http://www.vason.com

Electrodialysis

• Membranes

– 100-200 mm thickness

– Permeable to cations: -SO3-

– Permeable to anions: quaternary NH4+

– Grafted on polymer matrix

• Selecting suitable membranes

– Allows the best results (few modifications of wine)

– Allows other modifications (e.g. pH reduction)

– EC regulation 606/2009 establish membrane characteristics

Electrodialysis

• Operating conditions

– Conductivity preliminary test

– Results used to establish the conductivity limit for stopping the treatment

– Continuous monitoring of conductivity of both treated wine and brine

– Recirculation of wine and brine (concentrated ionic solution)

Electrodialysis

• Effects on wine composition

– K+ eliminated more than other cations

– Ca2+ remains almost unchanged

– Anions less affected

– Result: decrease of pH

– H2T is the most affected anion (even 10-15 %

diminution)

– Slight drop of volatile acidity and alcoholic strength

– Polyphenols, polysaccharides, amino acids and volatile

compounds: poorly affected

– Better conservation respect to cold treatments

Electrodialysis

• Effects on wine composition

Ribéreau-Gayon et al, 2006

Separation Techniques

SOLID - SOLID

SOLID - LIQUID

LIQUID - LIQUID

SOLUTES - LIQUID

Dealcoholization techniques

• Several uses in food and chemical industry

• Dealcoholization of wine

Ethanol

• Primary alcohol: tetrahedral C1, hybridized sp3,

is bound to two hydrogen and to one hydroxyl

group (-OH)

• Molecular formula C2H6O

• MW 46,07

• Density 0,79 g/cm3

• Soluble in water (hydrogen bonds)

• Boiling point 78,4 °C

Ethanol

• EtOH is toxic for humans; it acts on liver and

nervous cells; LD50 oral ingestion: 1.400 mg/kg

b.w.

• Average content in wine: 100 g/L (12,6 % v/v)

• It comes from sugars fermentation (yeasts)

• 16-18 g/L lead to 1 % v/v ETOH

• European Commission allows wine

dealcoholization [Reg. (EC) 606/2009]

– No more than 2 % v/v

– EtOH conc. should not lower than 8,5 % v/v

Alcohol Effect on Aromas

• Masking of aroma (Robinson et al., 2009)

• Reduction of aroma of volatility

Ethanol effect on taste

Fischer & Noble, Am. J Enol. Vitic., 1994

Health benefits

• Benefits for consumers unable to take

alcohol for medical reasons

• Reduced calories intake

• Decreased risk from alcohol-related illness

and desease

• Benefits for pregnant women and breast-

feeding mothers

Social Benefits

• Improved productivity and function after

activities involving alcohol (e.g. business

lunches)

• More acceptable social behavior

• Lower risk of accident while driving

• Lower risk of prosecution and legal

problems (criminal offence)

Dealcoholised Wine’s Categories

(DLRAW)

Dealcoholisation

No-alcohol

(< 0,5 % v/v)

Low-alcohol

(0,5-1,2 % v/v)

Reduced-alcohol

(1,2 % to 5,5-6,5 % v/v)

Techniques for producing

DLRAW (Pickering, 2000)

Reduction of fermentable sugar

concentration in grape or juice

Use of unripe juice

Juice dilution

Freeze concentration and

fractionation

Enzymes (e.g. glucose oxidase)

Removal of alcohol from wine Thermal: distillation under vacuum

or atmospheric pressure;

evaporation; freeze concentration

Membrane: dialisys; reverse

osmosis; pervaporation

Adsorption: resins; silica gel

Removal of alcohol from

wine

Extraction: organic solvents;

supercritical carbon dioxide

Other Dilution of wine

Arresting fermentation early

Low-alcohol-producing yeast

Combination of above

methods

Techniques for producing

DLRAW (Pickering, 2000)

Dealcoholization Techniques

• Reduction of must sugar content

• Spinning Cone Column (liquid – liquid)

• Membrane techniques

– Also other applications (solutes – liquid)

REDUCTION OF MUST

SUGAR CONTENT

Selection of yeasts with low

alcohol yield

• Classical approach:

– Batch fermentations (fermentazioni scalari)

– Candida / Torulaspora (Kutyna et al., Trends in Food

Science & Technology, 2010)

• Interspecific hybrids (S. cerevisiae)

• Limited reduction of alcohol content (0,5 – 1,0 % v/v)

• By using Saccharomyces yeasts the reduction can be

more consistent (e.g. 3 % v/v)

Glucose oxidase Pickering, 2000

• Oxidation of Glu to gluconic acid by using

glucose oxidase

• Oxidation required

• High levels of total acidity

– 66 g/L of gluconic acid for a 4 % v/v EtOH

reduction)

JUICE WINE

TEST GOX TEST GOX

Ethanol % v/v < 0.10 < 0.10 10.45 6.23

pH 3.25 2.93 3.13 3.05

Titratable acidity g/L 7.08 26.67 8.05 27.82

Glycerol g/L 0.44 0.40 5.04 5.04

Glucose g/L 84.72 10.71 < 1.00 < 1.00

Fructose g/L 89.81 87.21 < 1.00 < 1.00

Total gluconic acid g/L < 0.30 72.66 < 0.30 66.74

Tartaric acid g/L 4.27 1.65 2.93 1.78

Malic acid g/L 3.88 3.47 4.29 4.04

Glucose oxidase Pickering, 2000

Dilution (H2O) of musts

• In the U.S., where the approach is more pragmatic, you work for a

reduction of up to a maximum of 2 % alcohol v/v by dilution with

water of the grape too rich in sugar (over 22 Brix).

• The intervention is justified by several considerations on the

physiology of ripeness. In fact, according to various authors (Boulton,

2009), during ripening we can have a synthesis of sugars in grape up to

a standard of 22 Brix (13 – 13,5 % v/v); higher values come from

dehydration

• So: why do not re-add to the juice (not to the wine) the water lost by

dehydration? The intervention is limited to a maximum of 2 % v/v

• The practice has meaning and it also finds good technical explanation,

but, even if the transformation of water into wine has already been

reported (Holy Bible), it is unlikely that the European culture of wine,

and also in the OIV, may accept such kind of intervention

R. Ferrarini

SPINNING CONE COLUMN

(SCC)

SCC is a vertical

cylinder in stainless

steel, in which an inert

gas with a stripping

action, removes, under

vacuum, a vapor stream

of volatile compounds

from the liquid or from

the lees

Liquid/

slurry

inlet

Vapor

plus

volatiles

outlet

Gas

vapor

inlet

Pullet

for

drive

belt

Liquid

outlet

Spinning Cone Column

(Cono Rotante Sottovuoto)

SCC - Operating principle

Inside, the SCC contains

two sets of inverted

cones. A series of fixed

cones is attached to the

inner wall of the cylinder.

Another set of cones is

attached to the rotating

shaft, parallel to the fixed

set, thus constituting a

device in which the fixed

cones alternate with

mobile ones

Spinning cone

shaft

Spinning

cone

Stationary

cone

The product is loaded at the top of

the column (red flow). Driven by

gravity, it flows down from the upper

surface of the first fixed cone and

drops in the first rotating cone, where

the centrifugal force distributes the

liquid in a thin film, and subjects it to

turbulent motions, forcing it to come

out of the edge of the SC, falling in

the fixed cone below

In this way the product flows cone by

cone up to the exit of the column

Liquid vapor

flow

Downward

liquid

flow

Liquid &

vapor mixing

Spinning

cone

shaft

SCC - Operating principle

Spinning cone column

Operating principles • An ascending vapor flow (blue

flow), passing through a thin film

of liquid, collects the volatile

compounds, that are concentrated.

The flap on the underside of the

rotating cone induces a high degree

of turbulence by increasing the

vapor stream

• The turbulence, the thin film of

liquid, the vapor stream and the

length of the path made by the

liquid, lead to a high transfer of

volatile compounds from the liquid

to the vapor stream, in a contact

time of few seconds, without heat

damage to the product

Liquid/

slurry

inlet

Vapor

plus

volatiles

outlet

Gas

vapor

inlet

Pullet

for

drive

belt

Liquid

outlet

Liquid/gas flow in a SCC

Three-phase system:

1. Gas phase (or vapor)

2. Continuous liquid: thin

layer of liquid, in the

inner part of the column

3. Dispersed liquid in the

passage of the gas

(liquid spray)

Spinning cone column

internal circulation of the liquid

• MLC: continuous liquid

• MLD: dispersed liquid

• MLDCIRC: dispersed

liquid circulates (this

part is carried back by

the spinning cone

above)

• MLD0 = MLC

Spinning Cone Column

• The vapor flow escapes from the top of the column

and passes through a condensation system, which

captures the volatile compounds condensing them in

liquid phase

• The remaining liquid or dregs are evacuated with a

pump located at the bottom of the column

• Re-injection: a very small amount of the stripped wine

exiting from the base of the column is converted into a

form of low temperature vapor created in the high

vacuum environment in the column

Step 6

THE PROCESS

Fully ripe

fruit in

vineyard

=

wine with

big flavour

but

high alcohol

Small

portion

of total blend

shipped to

Spinning

Cone

Wine

aromas

removed by

SCC &

held

separately

Alcohol

removal by

SCC from

de-

aromatized

wine

Wine

aromas

added back

to de-

alcoholized

wine

Blending

this

fractions

back to main

body of

original

wine to

achive

desidered

alcohol level

Step 1 Step 2 Step 3 Step 4 Step 5

SC

C p

lant

SCC plant

Final considerations

• ADVANTAGES:

– High efficiency

– Limited duration of the liquid at the operating

temperatures

– Possible to work on viscous fluids

– Good energy efficiency

• DISADVANTAGES

– Heating; for dealcoholization 38 °C are needed

MEMBRANE TECHNIQUES

Membrane Techniques

• Simple

• Good performances

• Economical convenience

• Pervaporation

• Osmotic processes & Nanofiltration

• “Contactor” membrane

• Combination of techniques

– e.g. reverse osmosis and distillation

Pervaporation (Gas Membrane Separation)

Pervaporation www. http://chemelab.ucsd.edu

• Discovered in 1917 by Kober

• The first full-scale plant was installed in Brazil in 1982

for the production of ethanol

• Gas Membrane Separation

• Modern membrane and module fabrication techniques

have made Pervaporation industrially feasible

• This method has become a more cost-effective unit

process for many food manufacturers

• It is applied for the dehydration of solvents in

azeotropes, the separation of organic mixtures and the

removal of organics from water


• Pervaporation is the separation of

liquid mixtures by partial

vaporization through a non-porous

selectively permeable membrane

• The permeate changes from liquid

to vapor during its transport through

the membrane

• A gradient in the chemical potential

of the substance (partial pressure or

activity) on the feed side and the

permeate side is the driving force

for the process

• This force is kept maximum by

applying low pressure to the

permeate side of the membrane


PV applications in azeotrope

separation

The technique can be

conveniently used because the

process is not influenced by the

equilibrium between the phases

A large number of alcohols,

esters and other volatile

compounds can be separated

from azeotropes with water

and/or methanol in economic

conditions

Products purified by PV

Pervaporation membranes

Depending on the material which constitutes the

membrane:

• Hydrophilic Pervaporation

• Hydrophobic Pervaporation

Pervaporation membranes

• Membranes are available in different

configurations: plate and frame, tubular, hollow

fiber and spiral wound.

• Various materials (e.g. polymer and ceramic)

• Membranes used in pervaporation are normally

manufactured as composites (mechanical reasons)

• Polydimethylsiloxane (PDMS) has been proven to

have the best performance

PV

– M

od

ule

Con

figu

rati

on

Areas of pervaporation:

membranes and applications

PV: application fields


Mass transfer of a single component across the

membrane occurs in 4 steps:

1. Mass transfer from the bulk of feed to the membrane

interface

2. Selective absorption into the membrane at the feed

side

3. Selective diffusion through the membrane

4. Desorption into the vapor phase at the permeate side

Solution – Diffusion Model

The transport through the membrane can be summarized in

three steps:

1. Absorption

2. Diffusion

3. Desorption (phase change – evaporation)

Desorption

Diffusion

Absorption

Sorption (Assorbimento)

Physical – chemical process by which one substance

becomes attached to another

• Absorption (absorbimento): incorporation of a

substance in one state into another of a different state

(e.g. liquids absorbed by solids; gases absorbed by

liquids)

• Adsorption (adsorbimento): physical adherence or

bonding of ions and molecules onto the surface of

another phase (e.g. reagents adsorbed to a solid

catalyst surface)

Sorption (Assorbimento)

Absorption

(absorbimento)

Adsorption

(adsorbimento)

1. Absorption

• Absorption of component in the polymeric matrix of

the membrane

• The percentage of absorption of a given component is

connected to the total energy required to dissolution of

the component itself in the polymer; generally the

component of the mixture which requires the lowest

energy, is preferably absorbed in the polymer

• The selectivity of the membrane to the components of

the mixture is determined in this phase

2. Diffusion

• Diffusion of the component through the membrane

• It depends on:

– Mixture composition

– Membrane polymer

– Operating parameters

• The diffusion through the membrane follows the

chemical potential gradient (driving force of PV)

60

2. Diffusion

61

2. Diffusion

3. Desorption

• Desorption of the compound which passed

through the membrane

• Phase change: from liquid to gaseous

• Mass transport is a function of the total vapor

pressure of the permeate

• For more than one component, total pressure of

the permeate is equal to the sum of the partial

pressures of all components

1. Vacuum Pervaporation (Vacuum PV)

– Dominant mode of operation; transmembrane pressure

difference is increased by a vacuum system

– Liquid feeding (Pervaporation - PV)

– Vapor feeding (Vapor Permeation - VP)

2. Thermopervaporation (Thermo PV)

3. Sweep Gas Pervaporation (Sweep Gas PV)

– Partial pressure is lowered by the sweeping of inert

gas


Vacuum PV

• The driving force is given by the application of

vacuum at the permeate side. The partial pressure of

the permeate in the vapor state and the pressure

gradient across the membrane is kept by resorting to a

vacuum pump or by a condenser

Vacuum pump/

condenser

Scheme of a PV plant

Scheme of a Vapor Permeation

(VP) plant

Thermopervaporation

• The partial pressure difference between the feeding

and the permeate side is generated by a thermal

gradient through the membrane. The temperature of

the mixture (feeding side) must be heated above the

temperature of the permeate

• The vapor pressure generated between retentate and

permeate is the driving force

Heater

Condenser

Sweep Gas PV

• The driving force is given by a partial pressure

difference generated by an inert gas sweeping the

permeate side.

• Heating sweeping gas improves the process

• A condenser at the permeate side removes the

permeate from the sweep gas

Condenser

Heater

Resistance to mass transfer

• PV is also influenced by:

– concentration of the boundary layer (strato

limite) at the feeding side

– structure of the support (composite membranes)

– concentration of the boundary layer (permeate

side)

• Polarization

– Increase of concentration of certain components

on the surface of the membrane

Polarization

• Increases with high

flows through the

membrane and low

turbulence of the

solution

• Reduced by using

hydrophobic

membranes

Temperature

• Arrhenius Law:

J = J0 e-E/RT

• Flow increases with

temperature

• Effects:

– Modification of

absorption and diffusion

rate

– Modification of the

driving force troughout

the membrane (ΔHVAP)

0

0,2

0,4

0,6

0,8

1

1,2

1,4

40 50 60 70

Temperature (°C)

Flu

x, J

(k

g/m

2h

)

Permeate Ethanol Others

J = Mass transfer coeff. or

permeate total flow (kg/m2h)

J0= Permeability constant

E = Activation energy (J/mol)

R = Gas constant (J/mol K)

T = Temperature (K)

Temperature

• PV requires the evaporation of part of the liquid

• The enthalpy of evaporation (HVAP) must be

compensated by heating the feeding side

• For consistent flows and compound with a high heat

of vaporization temperature decreases significantly

• Generally the temperature gradient along the

membrane is stable

Temperature

A typical process involves the use of heat

exchangers between the modules of the

membranes to heat the mixture and thus

compensate for the HVAP

Effect of PV on wine components

• Main compounds (acids, sugars): no modification

• Microstructure: compounds are forced by ethanol

and by heating to cross the membrane

• Lost of aroma compounds (the 70 % of the whole

wine aroma is found in the permeate)

• It is possible to separate them from permeate

(EtOH 35-38 % v/v) by distillation and re-adding

them to dealcoholized wine

PV plants

http://www.zeolitesolutions.co.uk/technology.htm

PV technology

Characteristics of a PV process

• Low energy

• No contamination

• Permeate must be volatile at the operating

conditions

• Independent on the liquid/vapor equilibrium

Osmotic Processes

Ethanol and Osmotic Pressure The first evidence of the osmotic phenomena dating back to

1700 by Abbot Antoine Nollet; a pot filled with “spirits”

(alcohol), closed with a pig's bladder was immersed in water;

after a few hours the membrane swelled for the osmotic pressure

created by ethanol: water flows inside the pot

Osmosis

• A partially permeable membrane (e.g. cell membrane)

submerged in water; water molecules pass through the

membrane from an area of low solute concentration (e.g. outside

the cell) to one of high solute concentration (e.g. inside the cell);

this is called osmosis

• The membrane is semipermeable, allowing to pass only solvent

molecules (creation of an isotonic environment)

• Driving force: osmotic pressure

• Pure solvent contains more free energy (DG – higher escaping

tendency), so solvent molecules tend to diffuse to a place of

lower free energy (lower escaping tendency) in order to equalize

DG (net flow of water toward the side with the solution)

• Entropy explanation: system contains less entropy (DS) if there

are two solutions of different concentrations

http://en.wikipedia.org/wiki/File:Osmose_en.svg

Osmosis

Reverse Osmosis

• Elimination of large molecules and ions

from solutions

• Application of a pressure to the solution on

one side of the selective membrane

• The solute is retained on the pressurized

side and the pure solvent is allowed to pass

to the other side

• The external pressure reverses the natural

flow of pure solvent, thus, is reverse

osmosis

Osmotic Processes

FORWARD OSMOSIS

Osmosi Diretta

REVERSE OSMOSIS

Osmosi Inversa

• In enology only reverse

osmosis can be applied as

provided by OIV and by the

European Community law

[Regulation (EC) 491/2009]

• Forward osmosis could also

be applied, even though

materials and applications

for this process have had

little success

Osmotic Processes

Nanofiltration

Nanofiltration (NF)

• NF is a cross-flow filtration technology

• Pore size between ultrafiltration (UF) and reverse osmosis

(RO)

• Nominal pore size of the membrane: 1 nm

• Nanofilter membranes are rated by molecular weight cut-

off (MWCO) rather than nominal pore size

• Typical MWCO: < 1000 Da

• Transmembrane pressure required: up to 3 MPa (0,03 bar)

- lower than the one used for RO

• Reduction of operating cost respect to RO

• Lower Fouling

Dealcoholization by osmotic

processes only

WINE

H2O + EtOH

H2O

RO (NF)

Addition of water required: loss of isotopic traceability

• RO: lower performance, higher integration of water, lower loss of other wine constituents

• NF: more powerful process; less integration of water, but loss of some constituents (acids); lower fouling

0

20

40

60

80

100

120

Alcol

Ac. ta

rtaric

o

Ac. m

alico

Ac. la

ttico

Ac. a

cetic

o

Polife

noli Tot

. K Ca

Mg

4-et

ilfen

olo

4-et

ilgua

iaco

lo

NF 1

NF 2

NF G

NF F

RO S

Rejection of different osmotic membranes (NF

& RO) for wine treatments

NF membranes are more permeable (lower rejection) to ethanol

than osmotic membranes

Contactors Gaseous Membranes

Contactor Membranes

• A gas-liquid interface (or liquid-liquid) is immobilized

inside the pores of a hydrophobic membrane (Goretex or

Teflon)

• Exchange of matter without dispersing one phase into the

other

• A film of microporous hydrophobic material (about 0,2

μm) supports a “gas membrane” that separates the two

phases; the exchange of matter occurs in gaseous form

• Applications

– Separation of gas from liquids

– Osmotic Distillation (evaporation)

90

Contactor Membranes

Contactor: Hollow Fiber Module

Osmosis & Nanofiltration

Applications

Must

Permeate

Concentrate NF

Must

Permeate

Acids, extract

Concentrate

Concentrate

40 Brix

UF

NF

Management of sugar content

• Sugar Reduction

• Must Concentration

Layout 2

Layout 1

Redux® Vaslin Patent

Reduction of sugar content (Cottereau, 2010)

Reduction of sugar content (Cottereau, 2010)

FO - Self-enrichment of grape must

«Draw» Solution (brine)

(glycerol 70-80 %)

MUST

Feed Solution

PW1

PW2

Hydrophobic

membrane

Membrane area = 12.4 m2,

Temperature = 9-15°C,

Glycerol conc. = 61-78 wt%

Concentration

of grape juice

Volatile acidity reduction

Total acidity reduction

Reducing total acidity and/or volatile acidity

Layout 1

Layout 2 Wine

Permeate

Retentate

Anionic resins

NF

Wine

Permeate

(acids)

Retentate

Neutralization

NF

NF Org. acids salts conc.

Reducing Brett off

flavor

pH reduction

K+ elimination

Reducing pH / Reducing Brett off flavor

Layout 1

Layout 2 Wine

Permeate

Retentate

Adsorbent

NF

Wine

Permeate

Retentate

Cationic resins

NF

Increasing wine extract

Wine

Permeate

Concentrate NF

In this case the NF is

used to increase wine

extract, limiting the

increase of EtOH,

total acidity and

potassium

Contrary to what

occurs by RO

1. Wine treated with osmotic (RO) or nanofiltration membranes; production of a permeate containing part of wine alcohol

2. Elimination of EtOH from permeate by distillation

3. Reintroduction in wine of the dealcoholized permeate

4. Critical points: high cost, high temperatures, loss of aromas

Reduction of alcoholic strength: distillation of the permeate

obtained by treating wine by reverse osmosis

Contactor - Dealcoholization of wine

Pure Water

Throw-away or recirculated

WINE

Feed Solution

PW1

PW2

Hydrophobic

membrane

Dealcoholization – Sauvignon Blanc,

California (Fisher U., 2010)

0

1

2

3

4

5

6alcoholic odor (LSD = 0.558)

apple (LSD = 0.664)

lemon (LSD = 0.487)

berry fruit

(LSD = 0.748)

floral (LSD = 0.600)

vanilla (LSD = 0.559)

fresh green (LSD = 0.604)

green bean (LSD = 0.482)oaky-moldy (LSD = 0.515)

sweat (LSD = 0.689)

bitter (LSD = 0.751)

sour (LSD = 0.523)

fruity by

taste (LSD = 0.700)

aftertaste (LSD = 0.534)

alcoholic-burning

(LSD = 0.624)

Base Wine 11 % Vaccum Distillat. 0.5 % Reverse Osmosis 0.5 %

Dealcoholization • Continuous process

• Wine is recirculated trough the

membrane

• Water is thrown away

• Complete dealcoholization can be

obtained

0

1

0 1 Time

Co

nce

ntr

ati

on

0

1

2

0 1

Time

Conce

ntr

ati

on

• Wine and water are

recirculated

• EtOH conc. Tends to the same

value for both wine and

extractant

Dealcoholization • Discontinuous process

Other volatile compounds removed

during dealcoholization process

Volatile compound evolution during

dealcoholization

0,00

20,00

40,00

60,00

80,00

100,00

0 20 40 60 80 100

Dealcoholation (%)

Co

mp

osit

ion

(%

) Acetaldeide

Ethylacetate

Methanol

Propanol

Isobutilic

Isoamilic

Elimination of volatile compounds

Dealcoholization (% v/v)

Elim

ination

(%

)

0,0

10,0

20,0

30,0

40,0

50,0

60,0

70,0

80,0

TQ -2% -3% -4% -5% -6%

pp

m

Dealcolazione

Etil-acetato

Soave Valpolicella

Elimination of Ethyl acetate

Dealcoholization (max 2 % v/v) of Italian wines

16.60 14.95 15.93 14.60 13.90 12.89 14.00 12.30 16.60 14.95 15.93 14.60 13.90 12.89 14.00 12.30

Dealcolazione % (% v/v) Diminuzione (%)

Esteri etilici Acetati C6 Aldeidi

Sfurzat A - 9.94 (1,65) -39.8 -36.0 -11.9 -22.1

Sfurzat B - 8.35 (1,33) -13.3 -10.0 -21.6 -25.0

Chianti - 7.27 (1,01) +25.8 -19.5 -10.4 -36.8

Valpolicella -12.14 (1,70) -26.7 -37.7 -14.4 -54.7

16.60 14.95 15.93 14.60 13.90 12.89 14.00 12.30 16.60 14.95 15.93 14.60 13.90 12.89 14.00 12.30


Alcoli terpenici Norisoprenoidi

Sfurzat A - 9.94 (1,65) -12.3 -14.6

Sfurzat B - 8.35 (1,33) -16.3 -22.3

Chianti - 7.27 (1,01) -5.0 -1.5

Valpolicella -12.14 (1,70) +10.1 -8.4


16.60 14.95 15.93 14.60 16.60 14.95 15.93 14.60 13.90 12.89


Oak Lattone Terpineolo

Sfurzat A - 9.94 (1,65) -24.5 -13.1

Sfurzat B - 8.35 (1,33) -18.3 -19.5

Chianti - 7.27 (1,01) +3.1


Contactors Avoid aroma loss (Memstar) & reduce water consumption (Juclas)

OI

VINO

MC

H2O + EtOH

H2O

OI (NF)

VINO

MC

H2O

+

EtOH H2O

MEMSTAR

JUCLAS

Percent diminution of some volatile

compounds

Dealcoholization trials Wine analysis

Analytical

determination

Unit WHITE WINE RED WINE

START END START END

Alcoholic strenght % vol. 10,08 < 0,5 10,59 2,54

Dry extract g/L 18,5 19,8 26,8 28,1

Ash g/L 2,15 2,32 3,67 3,65

Alkalinity of ash g/L 19,2 20,4 29,2 29,6

Total SO2 mg/L 51 47 105 100

Free SO2 mg/L 6 4 22 15

pH 3,21 3,10 3,54 3,42

Total acidity g/L 6,0 6,3 5,6 5,9

Acetic acid g/L 0,12 0,07 0,51 0,29

Reducing sugars g/L 0,22 0,22 0,16 0,14

Glycerol g/L 4,68 5,19 7,12 7,48

Analytical

determination

Unit WHITE WINE RED WINE

START END START END

Tartaric acid g/L 3,83 3,74 3,69 3,77

Malic acid g/L 2,37 2,54 0,03 0,41

Lactic acid g/L 0,60 0,56 1,78 1,62

Acetaldehyde mg/L 40 22 52 43

Total phenolics mg/L 96 108 1184 1269

Leucoanthocyanins mg/L 7 7 2207 2798

Catechins mg/L 1,1 1,5 217 219

Anthocyanins mg/L / / 96 106

OD 420 nm 0,087 0,084 1,76 1,76

OD 520 nm / / 2,09 2,13

OD 620 nm / / 0,46 0,44

Intensity / / 4,31 4,33

Hue / / 0,84 0,83

Potassium mg/L 555 553 841 873

Magnesium mg/L 47 47 / /

Dealcoholization trials Wine analysis

Essential literature

• Peri C. La filtrazione nell’industria alimentare. Edizioni AEB, Brescia,

Italy (1983).

• Ribéreau-Gayon P., Dubourdieu D., Doneche B., Lonraud A. Handbook of

Enology. Volume 1. The Microbiology of Wine and Vinifications (2nd

Ed.). John Wiley & Sons Ltd., Chichester, U.K. (2006).

• Ribéreau-Gayon P., Glories Y., Maujean A., Dubourdieu D. Handbook of

Enology. Volume 2. The Chemistry of Wine, Stabilization and Treatments

(2nd Ed.). John Wiley & Sons Ltd., Chichester, U.K. (2006).

• Margalit, Y. Elementi di chimica del vino. Eno-One, Reggio Emilia (2005)

• De Vita P., De Vita G. Corso di meccanica enologica (3a Ed.). Hoepli,

Milano (2004)

• Records A., Sutherland K. Decanter centrifuge handbook (1st Ed.).

Elsevier Advanced Technology, Oxford (2001)

• Pickering G.J. Low- and Reduced-alcohol Wine: A Review. Journal of

Wine Research, 11(2): 129-144

Documents

Lucidi 8