Genetically modified food
The greater concern in food biotechnology is the integration of both
modern biological knowledge and techniques and current bioengineering principles in food processing and preservation.
Modern biotechnological techniques will have considerable importance in influencing trends in the food market, namely cost, preservation, taste, consistency, colour and above all, health aspects.
Every year more than a million children die and another 3,50,000 go
blind from the effects of vitamin A deficiency. Employing genetic
engineering techniques, Potrykus of Switzerland and Peter Beyer of Germany transferred genes that make carotene in daffodils into Oryza sativa.
Ordinarytechniques of plant breeding do not offer a way to enrich the crop. Extracting carotene genes from daffodils, Potrykus and Beyer had introduced these genes into the soil bacterium.
Agrobacterium tumefaciens, the transgenic agrobacteria were then incubated with rice embryos in plant tissue culture medium. As the bacterium infects the rice cells, they also transfer the genes for making beta carotene.
A number of examples are available where transgenic plants suitable for food processing have been developed.
(i) Tomatoes with elevated sucrose and reduced starch could also be
produced using sucrose phosphate synthase gene.
(ii) Starch content in potatoes could be increased by 20 to 40 per cent by using a bacterial ADP glucose pyrophosphorylase gene (ADP GPPase).
(iii) Vaccines, antibodies and interferons can be consumed directly along with tomato, banana and cucumber.
Edible vaccine
Acute watery diarrhoea is caused by Escherichia coli and Vibrio
cholerae that colonize the small intestine and produce enterotoxin.
Attempts were made to produce transgenic potato tubers that they could still retain vaccines in their tubers, even after the tubers had become 5 per cent soft after boiling. 50 per cent of vaccine was still present in the tubers.
Edible antibodies
Transgenic plants are being looked upon as a source of antibodies.
They can also provide passive immunization by direct application.
Edible interferons
Interferons are the substances made of proteins and are anti-viral in
nature. Scientists have successfully produced transgenic tobacco and maize plants that secrete human interferons . Today, rice crops have been enriched with vitamin A through gene manipulation. Similarly, pulse crop have been tampered with to produce lysine-rich pulse seeds. Such genetically modified food (GMF) are now becoming components of human staple food.
It is hoped that one day genetically engineered plants will have one
or more of these attributes:
i. They will show tolerance against heat, cold, drought or salt.
ii. They are more nutritious.
iii. They can be stored and transported without fear of damage.
iv. They require less fertilizer.
v. They produce chemicals and drugs that are of interest to humans.
Other links
Plant physiology – photosynthesis and its significance
BIOLOGY IN HUMAN WELFARE Introduction & Food production
Aspects of plant breeding and Types
Hybridization in plant breeding
Polyploid breeding, Mutation breeding, Breeding for disease resistance
Genetic engineering, Improved varieties, Role of biofertilizers
Green manuring, Mycorrhiza as biofertilizer
Crop diseases and their control, Rice – Oryza sativa
Groundnut or peanut – Arachis hypogea
Citrus canker, Tungro disease of rice
Biocontrol of insect pests Bacterial pesticides
Bio war, Genetically Modified Organisms (GMO) in biological warfare
Biopiracy, Bioresources, Biomolecules, Biopatent, Biotechnology
Medicinal plants including microbes
Commonly Available Medicinal Plants
Economic importance of Food plant Rice
Oil plant Groundnut Economic importance
Fibre plant – Cotton Economic importance
Timber yielding plant Teak Economic importance