Presentation On Biotechnology In Wine Industry
Wine is an alcoholic beverage made from fermented grapes or other
fruits. The natural chemical balance of grapes lets them ferment without
the addition of sugars, acids, enzymes or water. Yeast consumes the
sugars in the grapes and converts them into alcohol and carbon dioxide. It
is believed that winemaking technology was first developed in Caucasia
(currently part Georgia). Italy, France and Spain produced more than 35%
of the total world production of grapes. More than 80% of the grapes
grown each year are fermented, and the rest are used for fresh
consumption or dried for raisins. World wine production has varied from
250 to 330 million hectolitres since 1970, with the production level
reaching 282 million hectolitres in 2001. Italy, France, and Spain produce
about 50% of the world’s wine. Other major wine producers include the
USA, Argentina, South Africa, Germany, Australia, Portugal and Chile.
GRAPE CULTIVARS AND WINE TYPES
Grouping of cultivars based on evolutionary evidence may be obtained
using modern techniques such as DNA fingerprinting , RFLP (Restriction
Fragment Length Polymorphisms) and AFLP. (Amplified fragment length
Raisins and grape berries have been typed by microsatellites and Clonal
line diversity has been investigated with satellite markers. Many authors
have evaluated these markers for cultivar identification and parentage
studies Ampelo CAD, a Computer Aided Digitizing system for determining
ampelographic measurements is another means of simplifying the
Currently there are four majors groups of grapevine cultivars that include
the pure line of Vitis vinifera, the French–American hybrids, the American
hybrids (Vitis labrusca), and some interspecific cultivars .
Vitis vinifera Cultivars
The genus Vitis is divided into two distinct subgenera, Vitis and
Except for V. rotundifolia and V. popenoei, all the rest of the species are
members of the largest subgenus Vitis.
The difference between the two genera is in the number of their
chromosomes; 38 for Vitis and 40 for Muscadinia. Crossing between
species of Vitis and Muscadinia is possible, but often result in non-fertile
progenies. Most commercial cultivars belong to the species V. vinifera.
Vitis vinifera cultivars are used to produce both white and red wines.
There is room for improving quality attributes of V. vinifera cultivars using
Modern techniques such as genetic engineering.
Chardonnay is the most prestigious white French cultivar.It also yields one
of the finest sparkling wines. Under optimal conditions, chardonnay
produces wine with an aroma of apple, peach and melon. The cultivar is
susceptible to powdery mildew and bunch rot.
Riesling is Germany’s most appreciated variety, Wines made from these
varieties of grapes have the characteristics of a fresh, aromatic, and well
Sauvignon Blanc is originally from France. Some clones possess a floral
character, but most Sauvignon Blanc wines have the aroma of green
peppers. Clusters produce small size berries, resistant to bunch rot and
downy mildew. But Sauvignon Blanc is susceptible to powdery mildew
and black rot.
Traminer is an aromatic cultivar, It is used to produce dry and sweet
Savagnin is an France cultivar, is a clone of Traminer with a mild aroma.
Muscat Blanc is mostly used in the production of dessert wines. They also
possess high levels of soluble proteins and flavanoids.
Cabernet Sauvignon is the most well known red variety, because of its
association with Bordeaux, one of Europe’s finest red wine producing
areas. The wine has a black currant aroma under favourable conditions.
The berries are small, seedy, and acidic, with darkly pigmented tough skin.
Merlot is a red variety grape, similar to Cabernet Sauvignon, which has
the advantage of growing in cooler regions and moist soils.
Pinot Noir is a famous French variety from Burgundy, suitable for the
production of rosé and sparkling wines.
Barbera ranked third after Sangiovese and Trebbiano in Italy, Because of
its high acidity it is often blended with some low acidic cultivars, but can
also be used to make fruity wines by itself.
Nebbiolo is basically grown in Northwestern Italy, The wine produced
from Nebbiolo is high in tannin and is acidic with a good aging potential
but This cultivar is susceptible to powdery mildew and to bunch rot.
French–American hybrids are the second largest group of cultivars and are
derived from crosses between V. vinifera and one or more of the
following: V. riparia, V. rupestris, and V. aestivalis. Primarily developed in
France, their expansion was banned in the European Economic
Community (EEC) in the late 1950s, because of their high yield and their
Baco Noir resulting from a cross between Folle Blanche and V. riparia,
yields wine with a specific flavor and a very good aging potential.
Marechal Foch derived from a cross between V. riparia and V. rupestris ,
This hybrid has characteristics such as early maturation, winter hardiness,
high productivity, and resistance to downy mildew.
Vidal Blanc has excellent winemaking properties, making it suitable for
the production of high quality ice wines.
Most important American hybrids are derived from V. labrusca. The major
characteristics of American hybrids are low sugar content and high acidity,
and abundant flavor.
The group of American hybrids derived from V. rotundifolia have low
sugar content, but are resistant to indigenous diseases, especially to
American hybrids are extensively grown in Eastern North America, South
America, Eastern Europe and Asia.
GENETIC ENGINEERING OF WINE GRAPES
Standard breeding techniques are time consuming and expensive. Genetic
engineering introduces the genes of choice without destroying the
specific characteristics of cultivars.
The steps involved in genetic engineering include the isolation,
amplification, and insertion of the target gene into the intended
An example is the insertion of a protein Coat gene for the grapevine fanleaf virus (GFLV) into rootstock varieties in order to enhance their
There are several laboratories around the world working on gene transfer
technologies in grape vines.
Clones are forms of cultivars, derived vegetatively from a single parental
plant, such that all derivatives are initially genetically identical.
Basically, cuttings are multiplied and repeatedly assessed for their
viticultural and fruit-bearing characteristics and their resistance to
Clonal selection is the primary means by which cultivar characteristics can
be modified without significantly changing its specific attributes.
The main objective of clonal selection is the elimination of all systemic
infectious organisms including pathogens.
In order to control the desirable variations, some breeders suggest
planting several clones rather than just one. There is no unanimous
criterion for quality. However, some parameters such as º Brix, pH, and
acidity are used to assess maturity. Parameters such as the level of
glycosyl glucose, the polyphenol content, and the color density are
commonly used as potential indicators of wine quality
Mutations can be created by exposing meristematic tissue to mutagenic
chemicals or radiation. Somaclonal selection enhances the expression and
selection of clonal variation.
It also involves the selective growth enhancement of cell lines. For
example, isolation of transgenic vines or lines possessing tolerance for
salinity or fungal toxins is done by exposing cells to mutagenic agents,
such as chemicals and radiation, during cell culture.
GENETIC ENGINEERING OF YEAST FOR
The two main organisms involved in fermentation are Saccharomyces
cerevisiae and Leuconostoc oenos. Traditionally, indigenous yeasts
conduct the fermentation. The reason for using specific yeasts is to avoid
the production of off flavors sometimes associated with wild yeasts.
New techniques such as mitochondrial DNA Sequencing and gene marker
analysis allow identification of strains responsible for fermentation.
Kloeckera apiculata is the most frequently isolated wild yeast in grapes,
believed to contribute greatly to the complexity of the wine.
Saccharomyces cerevisiae is the most important yeast species, because it
may function as wine yeast, baker’s yeast, distiller’s yeast, and brewer’s
Saccharomyces paradoxus isolated from oak tree exudates, is assumed to
be the ancestral form of Saccharomyces cerevisiae.
Saccharomyces species such as S. uvarum and S. bayanus also can
effectively conduct fermentations and they are used in special
applications; e.g., S. uvarum ferments well at temperatures down to 6°C
and synthesizes desirable sensory components, whereas S. bayanus is well
adapted for the production of sparkling wines.
Other wild yeasts of sensory significance are:
1. Candida stellata persists in fermenting juice and produces high
concentrations of glycerol increasing the mouth feel of wine.
2. Torulopsis delbruekii positively influences sensory attributes of wine by
producing low concentrations of acetic acid and succinic acid.
3. S. cerevisiae possess a wide range of winemaking characteristics such as:
(a)low production of acetic acid and hydrogen sulphide (b) Ability to
ferment glucose (c) Fermentation at high pressure and at low
temperature and (d) Its ability to flocculate rapidly and completely after
Major characteristics to an ideal yeast for
So2 tolerance: An ideal type of yeast should be able to dominate the
fermentation even at this 70 ppm level of SO2 in free state.
Cold tolerance : fermentation below 14ᵒc.
Low foaming activity
Efficient conversion of sugar into alcohol
Production of desirable metabolites
Low production of undesirable metabolites: Such as acetaldehyde, acetic
acid, sulphur dioxide and hydrogen sulphide.
Resistance to “Killer” yeasts
Flocculation: An ideal yeast strain should flocculate at the end of the
fermentation, leaving the wine clear and requiring less rigorous filtration
Wine as functional food
Polyphenols: The most abundant antioxidants in our diets are
polyphenols. Antioxidants protect against cellular damage caused by free
radicals in the body. Cellular damage caused by free radicals can lead to
development of diseases like heart disease and cancer.
Resveratrol: In the past few years increasing attention has been focused
on resveratrol, which is found in high amounts in grape skins and red
wines. Resveratrol is a phytoalexin, a type of antibiotic compound and
acts as Potential breast cancer protection, Potential skin cancer
protection and also provides protection against CVD(Cardio vascular