winemaking
Comparison of effect of four commercial
pectolytic enzyme preparations in Muscat Gordo
Wine industry research looks at the vital role played by pectinases and how they increase free-run
juice yields and aid clarification and settling of juice in the winemaking process.
Simon Kinley
Introduction
Enzymes are now commonly used in
wineries around the world to perform a
range of tasks but the most common type
used in winemaking is pectinase. There
are many different brands of pectinases
available, but which performs the best in
the winery?
A major Riverland winery ran
production-scale trials to compare their
current pectinase enzymes with three
competitors. The results of these trials
are presented later in this article to help
other winemakers make the best choice
for their operation. But firstly, let’s look
at where pectin comes from and how
pectinase enzymes work.
Where does pectin come from?
Figure 1 illustrates the composition of
grape skin, showing the middle lamella
that mainly consists of pectin.
How do pectinases work?
Pectinase enzymes degrade pectin in
grapes to:
increase free-run juice yields, and
aid clarification and settling of juice.
They can improve filtration by decreasing
the juice’s viscosity and by promoting the
agglomeration of small particles in both
settling and flotation systems. Figure 2
illustrates the various cleaving points of
pectin lyase, pectin methylesterase and
polygalacturonase on a pectin chain.
Pectin levels in grapes vary
significantly and depend on the cultivar,
ranging from 0.6 to 2.6 grams per litre
(Amerine and Joslyn, 1951). The Muscat
Gordo cultivar typically has high pectin
levels, so presents a significant challenge
for pectolytic enzymes. It was for this
very reason that a major Riverland
winery chose that cultivar for their 2012
production-scale trials. (The winery
crushes more than 130,000 tonnes each
vintage, with some 10,000 tonnes of this
being Muscat Gordo.)
Results from this trial are outlined
below to illustrate the performance
between different pectin enzyme
preparations currently available. The
winery conducted all trials and results
independently in their laboratory.
88 Grapegrower & Winemaker
Outer, primary cell wall
with random cellulose
microfibrils in pectin
Middle lamella
between cells –
mostly pectin
The outer cell wall is made of cellulose microfibrils
embedded in a matrix of pectins, hemicelluloses
and proteins. In woody tissue, this wall also
contains lignin. The inner secondary cell wall is
composed of pectin and some lignin. The middle
lamella, which binds the cells together, is made
mainly of pectin.
Inner, secondary
cell wall with regular
cellulose microfibrils
embedded in pectin
and hemicellulose
Figure 1. Enzymes in Juice Production, D.Madden, ‘In a jam and out of juice’, 2001.
Mode of action of the main pectolytic enzymes
PECTIN LYASE (PL)
PECTIN METHYLESTERASE (PME)
endo POLYGALACTURONASE (PG)
Galacturonic acid
Carboxylic acid
Methyl group
Figure 2. ‘Enzymes in winemaking’, K. Lourens, Wineland, South Africa, 2004.
www.winebiz.com.au
October 2012 – Issue 585
2012 Muscat Gordo Trial results
The winery compared four different enzyme preparations as
follows:
Optivin 5XL Plus (supplied by E.E. Muir & Sons)
Pectin Enzyme B
Pectin Enzyme C
Current pectinase enzyme
The aim was to determine the difference in performance in two
core areas by each of these enzyme preparations: namely yiel
per tonne of fruit and time taken to reach a pectin negative lab
result. Free run and pressing volumes were added together to
give the total yield per tonne of each enzyme. Typical lab resul
for both free run and pressings of all 2012 fruit are presented
in Figure 3.
d
ts
Figure 3 - Average 2012 Muscat Gordo analysis from this winery.
Temp
Be
pH
FSO2
TSO2
Average free run analysis
16
14
3.90
15
60
Average pressings analysis
18
14
4.05
5
40
Extraction rates between enzyme preparations
All enzymes were applied to juice at the manufactur
er’s
recommended rate, and were added at the crusher via a dosing
pump. Figure 4 illustrates the yield differences between th
e
four different enzyme preparations.
Pectinase enzyme B had the lowest yield and was the
refore used
Current Supplier
Enzyme C
Enzyme B
Optivin 5XL Plus
0.0%
2.0%
4.0%
6.0%
8.0%
10.0%
Figure 4. Percentage change in juice yield of Muscat Gordo fruit.
Optivin 5XL Plus
Enzyme B
Enzyme C
Current Supplier
0
0.5
1
1.5
2
2.5
Figure 5. Free run pectin negative result times (hours).
October 2012 – Issue 585
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Grapegrower & Winemaker
89
winemaking
as the base point for this comparison. The
current supplier’s enzyme and pectinase
enzyme C produced 3-4% more juice
than Enzyme B but the Optivin ®5XL
Plus produced yield increases of 9%
compared to the lowest yielding enzyme.
Pectin stability comparison
between enzyme preparations
Pectin-stability tests were used to measure
the time taken to stabilise batches of
juice with the four different enzyme
preparations. Tests were performed on
both the free run and the more difficultto-stabilise pressing fraction. The pectinstability test involves mixing five millilitres
of juice with 10ml of 80% ethanol; the lab
assigned a pass result when a juice sample
flocculated, leaving a clear solution at that
hour. The times illustrated in the tables
are the average times taken to achieve this
stability. Figure 5 illustrates the difference
in free run pectin negative results, while
Figure 6 illustrates the difference in
pressing results.
Significant variation in the free run
results were observed between the current
enzyme and the three other enzyme
preparations tested. The current enzyme
took twice as long to generate a pass result
with the free-run juice. More differences
Optivin 5XL Plus
Enzyme B
Enzyme C
Current Supplier
0
0.5
1
1.5
2
2.5
Figure 6. Pressings pectin negative result times (hours).
were observed in the pressing results. The
current enzyme took around 2.5 hours,
Enzymes B and C took between 1.5 and
two hours, while Optivin 5XL Plus only
took an hour to achieve a pass result.
Simon Kinley, E.E. Muir & Sons technical
sales manager for winemaking and brewing.
[email protected]
References
Amerine, M. A. and M. A. Joslyn. 1951 Table Wines.
The technology of their production in California.
Berkeley, CA. University of California Press.
Lourens, K. Nov 2004 Enzymes in winemaking,
Wineland, South Africa.
Madden, D. 2001 In a jam and out of juice, Enzymes
in juice production.
UNITED KINGDOM
British wine snobs learning to love screw tops
and boxes
BRITISH WINE BUFFS have ditched their snooty attitude
towards screw tops, boxes and pouches, according to research
which shows that alternatives to the traditional cork and glass
bottle are increasingly popular options for consumers.
As many as four in 10 (39 per cent) wine drinkers now agree
that wine in a box or a pouch is as good quality as bottled wine,
while just 26 per cent think that boxed is inferior, according to
the study by the research company Mintel.
Meanwhile, screw tops are seen as even less of an issue for
wine lovers, with just 17 per cent claiming not to trust screwcap
quality wine.
Chris Wisson, senior drinks analyst at Mintel, said :
“Recent years have seen many wine drinkers reappraising
their perceptions and use of wine in differing formats and
packaging styles. Boxed wine has the added advantage of
the wine keeping for a longer period of time than in a bottle,
facilitating more flexible usage and encouraging moderate
drinking. Reducing wastage, boxed wine provides an ideal
solution in a market which is both environmentally and cost
conscious.”
Globally, an estimated 10 per cent of still wines are sold in
cartons but wine producers have recognised growing consumer
enthusiasm for wines packaged in more convenient, lightweight
formats.
The Guardian
90 Grapegrower & Winemaker
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October 2012 – Issue 585
The Hunter Valley’s newest winery is an inspiring
and confident architectural statement.
Building a new winery
is a labour of love
A Hunter Valley family demonstrates its commitment to the wine
industry by designing and building a winery and cellar door at Pokolbin.
Background
LEOGATE ESTATE WINES, established
by Bill and Vicki Widdin, is situated in
Pokolbin, New South Wales and has a single
vineyard with 60ha under 40-year-old
vines, producing Semillon, Chardonnay,
Verdelho, and Shiraz. Originally planted
by the late Len Evans of Rothbury Estate
in the 1970s, the vineyard was purchased
by the Widins in two parts in 2008
and re-amalgamated. Mick Burgoyne was
appointed vineyard manager in early
2009. Under his leadership, the vineyard
team has rejuvenated the old vines so
that they are now producing quality fruit
equal to the best in the country. Major
awards from the NSW Small Winemakers
Show: Trophies to the 2011 Leogate Estate
Western Slopes Reserve Shiraz for Best
Shiraz and for Best Red Wine of the Show;
gold medal to 2011 Leogate Estate The
Basin Reserve Shiraz, also in the final
taste-off. The 2011 Western Slopes was
also awarded the 2012 Winewise Trophy
for Best Shiraz; the first time for some
years that a Hunter Valley red has won a
nationwide trophy.
What inspired you to
Brokenback Vineyard?
purchase
Vicki and I have always been both wine
lovers and associated with the country
(Black Angus cattle), firstly in Orange
and, for the last 20 years, in the Tamworth
district. Our farm business is called
October 2012 – Issue 585
the
Zeals Pastoral Co. We have a stud with
400 registered breeders and a commercial
herd with 3,000 breeders. Growing wine
grapes is a short farming step from cattle
and fodder production.
Why did you decide to establish your own
winery?
We quickly found that there is little profit
in grape production. This led to having
our first vintage, in 2009, made under
contract. Being farmers – and for better
or worse – we prefer to do our own thing.
For the 2010 and 2011 vintages, we rented
the winery area in the Tempus Two
Building and purchased all the winery
plant and equipment from the Roche
Family. We thus entered the winemaking
business.
What was the inspiration behind the design
of your stunning cellar door?
Vicki and I have previously built a house
or two, and have seen a few cellar doors
elsewhere. We took the view that the main
objective was to make the atmosphere as
welcoming as possible.
What considerations did you take into
account for the winery building?
We found that the Tempus Two Winery
was much admired in the Hunter
Valley, so although we designed a larger
building, we followed the Tempus Two
set out closely.
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What role did your winemaker play?
Our winemaker, Mark Woods, was very
much involved personally with the
relocation of the plant and equipment,
and was particularly instrumental in
bringing the new winery into operation.
How did you approach the task of selecting
an architect?
Vicki was the designer of the cellar door
in toto.
Who drew up the building plans?
The building plans were first drawn up
by John Banson, a Tamworth building
and home designer and myself, refined by
Bill Bryan, and finally adapted by Peter
Sweeney of Eco Enterac.
What was involved in the process of
transferring ideas from the preferred design
(i.e. Tempus Two) to your own actual design?
Once we decided that the Tempus
Two Winery set out was as good as we
could aim for (i.e. that we could not
identify any better design to suit our
plant and equipment), winemaker, Mark
Woods and I worked on our 2000 square
metre winery shed with the builder,
Eco Enterac of Tamworth, who has built
a great many larger sheds, including
woolsheds and wheat storage sheds, to
plan the placement of each item of plant
(including the crush, the press, tanks
and vats) and continually reassess the
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