Post harvest discolouration of fruits and vegetables is a problem in food industry. Lack of acceptance of discoloured food. Using food additives with sulfites, are questioned about their health effects. HOW TO STOP? Post harvest discolouration of fruits and vegetables is a problem in food industry. Lack of acceptance of discoloured food. Using food additives with sulfites, are questioned about their health effects.

1. BY
SATHYA.T,
MSC MICROBIOLOGY,
TIRUPUR KUMARAN COLLEGE ,
TIRUPUR.
MODIFICATION OF FOOD PLANT TASTE AND
APPERANCE PREVENTING
DISCOLOURATION

2. WHY?
Post harvest discolouration of fruits and
vegetables is a problem in food industry.
Lack of acceptance of discoloured food.
Using food additives with sulfites, are
questioned about their health effects.

3. WHAT’S HAPPENING?
• Enzymes responsible for the initial step in the
discolouration.
Monophenols & Polyphenol
Oxidation
O-diphenols Oxidase(PPO)
O-quinone
• PPO nucleus encoded enzymes with 59,000
molecular weight.

4. HOW TO STOP?
Vector constructed with full-length or partial potato
polyphenol oxidase CDNA in either the sense or antisense
orientation.
Under the control of cauliflower mosaic virus 35S
promotor, the granule bound starch synthase promotor, or
the palatin type I promoter.
Transformed with these constructs are considered to have
good level of resistance to black spot.

5. P35s
PGBSS
palatin
tNos
Right Border
Ti plasmid
Inserted into A.tumefaciens
Plant cell
transformed into plant cell
Multiplication of cells
Potato having resistance against
black spots