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Report 4 (of 6): Grape Expectations
- Germany
Introduction
Disposal of grape marc, the waste
from wine production, has long been a problem for
wineries. Once the juice has been extracted, the skin,
stalks and seeds are all redundant. In total, more
than 20 per cent of wine production is waste, comprising
thousands of tonnes. The marc, if not treated effectively,
can cause a number of environmental hazards ranging
from surface and groundwater pollution to foul odours.
However, one wine producer is capitalising on the
waste, spotting that there is more to be squeezed
from grapes than a great vintage and turning grape
marc into high quality compost, fertiliser and grape
seed oil.
Piles of grape marc attract flies
and pests, and can spread disease. Leachates (solutions
of tannins and other compounds from the marc, flowing
out of material) can cause oxygen depletion in the
soil and infiltrate surface, soil and groundwaters.
Historically, winemakers produced grape spirit from
grape marc, but an oversupply of grape spirit led
to a global drop in prices. This meant the producers
were no longer able to recover costs from their grape
marc and had to pay freight to dispose of the mountains
of waste. With increased wine production, it became
imperative to relieve an oversupply of grape marc.
Timrott Bioprodukte winery is in the
Palatinate region of south-west Germany, one of Europe's
prime grape growing areas. Kurt Timrott first heard
of the scientific properties of grape waste from Vienna
University, learning that grape marc is high in nutrients
and ideal for turning into high quality organic products.
Building on his knowledge of the industry and organic
farming techniques, Kurt started a new production
process, making compost, natural fertiliser and grapeseed
oil. The company plant is now over 20,000m2
and produces a variety of grapeseed products. The
European Union provided tax benefits to improve the
economic viability of grapeseed oil production.
How to Make Compost
Composting is a controlled biological
process in which organic materials are decomposed
(broken down) by micro-organisms. It is made by roughly
breaking up the waste material and leaving it to decompose.
It must decompose before any nutrients are released.
Unlike many manures and fertilisers, grape marc is
low in sodium and chloride and has a higher nutrient
value than other organic waste. It fosters healthy
and strong plant growth.
Processed and composted, or humified,
grape marc mostly consists of organic matter. The
marc is subjected to a one-year humification process,
through which the energy contained in grape marc is
released and new active agents and substances can
emerge. Once crushed, the compost is left for three
months before the crushing and grinding are repeated.
The temperature is kept high at 60° Centigrade (either
by artificial means or by compacting the material
tightly together) to ensure that all pathogens are
killed and the product is clean and free from disease.
It takes 18 months to turn grape waste into nutrient-rich
organic compost. Compost is then used to feed the
vines and bagged for other consumers.
Producing Grapeseed Oil
Another valuable by-product of grape
marc is grapeseed oil. Grape seeds have a high energy
content concentrated in their oil. Grapeseed oil is
high in nutrients, being rich in vitamin E, a bioflavonoid
called procyanidine which is 20 times stronger than
vitamin C, single and polyunsaturated fatty acids,
of which linolenic acid, an essential fatty acid,
is about 70 per cent. The oil is primarily used for
cooking and in salads. It can also be used as a beauty
product and is absorbed quickly into the skin.
Seeds are crushed to extract the oil
and then filtered before bottling. The quality of
the grapeseed oil is dependent on the grapes it is
extracted from. The oil content varies from grape
to grape, somewhere between 6 and 21 per cent, which
will need to be determined to establish whether it
is high enough to make a good quality cold-pressed
oil. The higher the quality of oil, the higher the
premium paid for it. The seed oil is cold pressed
and treated carefully to preserve all the essential
properties.
Grape marc is vulnerable to infection
from a number of damaging moulds, which can cause
degradation of oil and occupational health and safety
risks if not handled promptly and effectively. Unfermented
marc was much more susceptible to infection than fermented
and consequently more vulnerable to oil quality degradation
and safety risks. It is therefore suggested that prompt
handling of unfermented material is of paramount importance.
The seeds are best separated and dried
quickly after the fruit has been processed in order
to produce oil with a low acid value and promptly
dried to avoid becoming contaminated by mould. An
effective and reliable pre-drying step is required
to remove free moisture from the seed before drying
in a rotary drum drier. The grape marc is run through
a revolving cylinder, which removes pulp, then dried
in rotary driers. The grape residues are either subjected
to wet de-seeding or dried and then de-seeded. The
whole drying process needs to be gentle to reduce
the risk of oil degradation with the seeds needing
to be dried sufficiently so that they can be stored
safely until required for processing. Seeds are then
pressed to extract the oil and this is filtered to
remove particulate matter from the oil.
Source: EcoRecycle Victoria and Minor
Oil Crops
Commercialising Products
If the commercialisation of grapeseed
oil is to be successful it is important that the oils
that are produced are acceptable to the general public
and therefore have market potential.
The key challenges to producing grapeseed
oil were identified in a study completed for Ecorecycle
Victoria. These were: gaining knowledge of the characteristic
of the raw materials, handling requirements, extraction
techniques and recovery. The report outlined the following
stages involved in establishing grape marc processing.
- Establish and trial the methodology
of collection and separation of grape seed from
marc
- Analyse recovery and quality of
oil from seed (i.e. free fatty acid etc content
of oil)
- Establish techniques for the cold-pressing
and purification of grapeseed oil
- Demonstrate techniques for adoption
and promote feasibility to industry
- Determine seed characteristics
e.g. percentage of wine grape harvest that becomes
grape marc, percentage seed and skin in marc, moisture
content and oil content of seed.
- Handling and safety trials. Grape
marc is a by-product of the winemaking industry
and is therefore not handled in the optimum manner
to avoid degradation and contamination.
- Pilot processing (collection, separation,
drying, storage and extraction)
- Product analysis (consumer acceptance)
Consider the following financial aspects:
- Price and availability of oil seed
- Yield and quality of oil seed
- Capital cost of venture
- Working capital equipment (rotary
washers, presses, and solvent extraction equipment,
refining equipment)
- Operating costs (raw materials,
labour, maintenance, energy, transport, packaging
and overheads)
- Throughputs and yield of product
combined with costs and prices to project payback
period (time taken to recoup costs)
Source: EcoRecyle Victoria Grape Marc
Utilisation - Cold Pressed Grapeseed Oil and Meal
Processing grape marc is likely to
prove a profitable and efficient way of disposing
of large amounts of waste while utilising the high
nutrient value of grape waste.
Further Information
Timrott Bioprodukte
Ahlmuehle 4
D-76831 Ilbesheim/Landau
Germany
Tel: +63 41/3 00 34
Fax: +63 41/3 37 10
E-mail: mailto:info@timrott-bioprodukte.de
www.timrott-bioprodukte.de/
Ecorecycle Australia Report on Grape Marc Utilisation
- Cold Pressed Grapeseed Oil and Meal by the Cooperative
Research Centre for International. Food Manufacture
and Packaging Science, Robert Jordan - February 2002.
Looks at many ways in which grape marc can be used
and provides an extremely thorough analysis of all
the issues involved in turning grape marc into usable
products that will be of relevance to wine producers
worldwide.
Report
www.ecorecycle.vic.gov.au
Small Scale Vegetable Oil Extraction
Natural Resources Institute
ISBN 085954-387-0
http://www.nri.org/
Guidance on how to dispose of organic waste
www.gdc.govt.nz
The Australian Wine Research Institute
http://www.awri.com.au/practical_solutions/
ITDG Technical Brief: Principles of Oil Extraction.
Raw material preparation, Methods of extraction, Clarification
of oil, Packaging and storage of oil, Use of by-products,
Quality assurance, Oil processing as a business and
contacts for equipment
www.itdg.org
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