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Food biotechnology
Biotechnology
• Application of scientific and engineering principles to processing
of materials by biological agents to provide goods and service
• Any technological application that uses biological systems, living
organisms, or derivatives thereof, to make or modify products or
processes for specific use
• Use of living systems and organisms to develop or make useful
products, or "any technological application that uses biological
systems, living organisms or derivatives thereof, to make or
modify products or processes for specific use" (UN Convention on
Biological Diversity, Art. 2).
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Scope
•Microorganisms
•Plant
•Animal
• Enzymes
Biotechnology
In food Processing sector, biotechnology involves
• use of micro-organisms for the preservation of food and for
the production of a range of value-added products such as
enzymes, flavour compounds, vitamins, microbial cultures
and food ingredients.
• target the selection and manipulation of micro-organisms
with the objective of improving process control, product
quality, safety, consistency and yield, while increasing
process efficiency.
• use of microbial innoculum for enhancing properties such
as the taste, aroma, shelf-life, safety, texture and nutritional
value of foods.
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Fermented foods
• Fermented foods as those foods which have been subjected
to the action of micro-organisms or enzymes so that
desirable biochemical changes cause significant modification
to the food
Fermentation processes- organism/commodity
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Types of fermentation processes
• Solid substrate fermentation (SSF) is defined as any fermentation
process performed on a non-soluble material that acts both as
physical support and source of nutrients in absence of free flowing
liquid (Pandey, 1992).
• Solid- state fermentation (SSF) involves the growth of
microorganisms on solid materials under aerobic
conditions in near absence of free water i.e. at very low
water activity (aw).
• The low moisture content means that fermentation can only be
carried out by a limited number of microorganisms, mainly yeasts
and fungi, although some bacteria have also been used (Pandeyet
al., 2000a).
• Submerged fermentation
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Fermentation
Benefits
Applications
• Production of a wide array of
traditional fermented foods
• Detoxification e.g. cyanide in gari
• Improvements in food sensory
qualities (flavour, texture)
• Improvements in food nutritional
qualities (protein digestibility,
vitamin synthesis)
• “Natural” technology
• Probiotic effect
• Production of a vast array of
Oriental foods e.g. tempe and
soy sauce
• Conversion of “waste” to
“wealth”
• Manufacture of beer and other
alcoholic beverages
• Cheese-making
• Production of yoghurt and other
cultured milks
• Production of single-cell protein
Factor
Submerged fermentation
Solid substrate
fermentation
Substrates
Soluble substrates (sugars)
Polymer insoluble substrate:
starch, cellulose, pectin, lignin
Aseptic conditions
Heat sterilization and aseptic control
Vapor treatment, non sterile
conditions
Water
High volumes of water consumed and
effluents discarded
Limited consumption of water:
low aw, no effluent
Metabolic heating
Easy control of temperature
Low heat transfer capacity
Aeration (O2)
Limitation of soluble oxygen. High level
of air required
Easy aeration and high surface
exchange air/substrate
pH control
Easy pH control
Buffered solid substrates
Mechanical agitation
Good homogenization
Static conditions preferred
Energy consideration
High energy consuming
Low energy consuming
Effluent and pollution
High volumes of polluting effluents
No effluents, less pollution
Volume of equipment
High volumes and high cost of
technology
Low volumes and low cost of
equipment
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Some traditional Nigerian fermented foods (Aworh, 2008)
Fermented
Food
Raw Material (Substrate) Microorganisms involved
Uses
Gari
Cassava pulp
Leuconostoc sp., Lactobacillus sp.
Streptococcus sp., Corynebacterium
manihot, Geotrichum candidum
Main meal
Fufu
Whole cassava roots
Lactobacillus sp., Leuconostoc sp
Main meal
Lafun
Cassava chips
Leuconostoc sp., Lactobacillus sp.
Corynebacterium sp., Candida tropicalis
Main meal
Ogi
Maize, sorghum, millet
Lactobacillus plantarum, Lactococcus
lactis, Saccharomyces cerevisiae,
Rodotorula sp., Candida mycoderma,
Debaryomyces hansenii
Breakfast
cereal,
weaning
food
Iru
African locust bean
(Dawadawa) (Parkia biglobosa)
Soybean
Bacillus subtilis
B. licheniformis
Condiment
Ogiri (Ogili)
Bacillus spp.
Escherichia spp.
Pediococcus sp.
Condiment
Melon seed (Citrullus
vulgaris),
Fluted pumpkin (Telfaria
occidentalis),
Castor oil seed (Ricinus
communis)
Some traditional Nigerian fermented foods (Aworh, 2008) contd
Fermented Raw Material
Food
(Substrate)
Microorganisms involved
Uses
Kpaye
Prosopsis africana
(algarroba or
mesquite)
Bacillus subtilis
Bacillus licheniformis
Bacillus pumilus
Condiment
Ugba
(Ukpaka)
African oil bean
(Pentaclethra
macrophylla)
Bacillus licheniformis
Micrococcus spp.
Staphylococcus spp.
Delicacy
usually
consumed
with stock
fish or
dried fish
Burukutu/P Sorghum
ito/Otika
Millet
Maize
Saccharomyces spp.
Lactic acid bacteria
Alcoholic
drink
Shekete
Maize
Saccharomyces spp.
Alcoholic
drink
Warankasi
(Soft
cheese)
Milk
Milk coagulated by plant rennet.
Lactic acid bacteria produce lactic
acid from lactose.
Meat
substitute
Agadagidi
Plantain
Saccharomyces spp.
Alcoholic
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General requirements for fermentation process
• Microorganisms for carrying out
the process
• Substrate to be converted to
useful products
• Maintenance of fermentation
conditions
• Provision of recovery and
purification of products
• Effluent treatment
• Packaging and marketing of
products (including facilities)
Methods of microbial inoculation in food
fermentations
• Spontaneous inoculation of fermentation processes
• “Appropriate” starter cultures as inoculum of
fermentation processes
• Defined starter cultures as inoculum of fermentation
processes
• Defined starter cultures developed using the
diagnostic tools of advanced biotechnologies
• GM starter cultures
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Spontaneous inoculation of fermentation processes
• In many developing countries, fermented
foods are produced primarily at the
household and village level, using
spontaneous methods of inoculation.
• Spontaneous fermentations are largely
uncontrolled.
• A natural selection process, however,
evolves in many of these processes which
eventually results in the predominance of
a particular type or group of microorganisms in the fermentation medium.
• Disadvantages: inefficiency, low yields of
product and variable product quality
“Appropriate” starter cultures as inoculum of fermentation
processes
• “Appropriate” starter cultures are
widely applied as inoculum from the
household to industrial level in lowincome and lower-middle-income
economies.
• These starter cultures are generally
produced using a backslopping
process which makes use of samples
of a previous batch of a fermented
product as inoculants (Holzapfel,
2002)
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Defined starter cultures as inoculum of fermentation
processes
• “Defined starter cultures” consist of single or
mixed strains of micro-organisms (Holzapfel
2002).
• Defined cultures are produced by pure culture
maintenance and propagation under aseptic
conditions.
• They are generally marketed in a liquid or
powdered form or else as a pressed cake.
• Used in the commercial production of dairy
products such as yoghurt, cheeses and alcoholic
beverages. Many of these cultures are tailored to
produce specific textures and flavours.
• Methodologies used in the development and
tailoring of these starters are largely proprietary
to the suppliers of these starters
Defined starter cultures developed using the
diagnostic tools of advanced biotechnologies
• Use of DNA-based diagnostic
techniques for strain differentiation
can allow for the tailoring of starter
cultures to yield products with
specific flavours and/or textures
• Random amplified polymorphic DNA
(RAPD) techniques have been applied
in the molecular typing of bacterial
strains in flavour development
• Development of three different
defined starter cultures which are
currently used for the commercial
production of products having
different flavour characteristics
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GM starter cultures
• No commercial GM microorganisms that
would be consumed as living organisms exist.
• Products of industrial GM producer organisms
are widely used in food processing and no
major safety concerns have been raised
against them
• Rennet (rennin) production
• α-amylase, gluco-amylase, lipase and
pectinase and bio-based fine chemicals (lactic
acid, amino acids, antibiotics, nucleic acid and
polysaccharides) are produced in China using
GM starter cultures
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