2. Outline
1. Food Preservation
2. Need for preservation
3. Biopreservation and its relevance
4. Methods of preservation
A) Physical methods of preservation( Heat and
Energy)
i) Addition of chemical preservatives
i) Hight temperature
ii) Low temperature
B) Chemical & Biological methods of preservation
iii) Special Treatments
3. ii) Action of microbes
a) Bioprotective Cultures
b) Fermentates
v)Bacteriophages
iii) Antimicrobial agents of natural origin
a) Direct antimicrobial preservatives
b) Indirect antimicrobial preservatives
iv) Antioxidants
5. Findings and Conclusions
4. Recap
• Food Preservation is any treatment or
processing given to food in order to make
maximum benefit out of it.
• There are various methods of preservation
including chemical preservatives.
• But now a days food borne illness
outbreaks are increasing.
• New studies shows that many food
preservatives are genotoxic and causes
other health effects
5. • Hence the consumer demand is for
safe food with ‘natural preservatives’
• Wherever we can derive a
preservative effect from a natural
source we can call it as
BIOPRESERVATIVE.
• There are commercially available
biopreservatives which are till now
shown to be safe.
Recap
7. A. BIOPROTECTIVE CULTURES
• Food fermentations – oldest
preservations known to man.
• Better keeping qualities and
organoleptically pleasing
characteristics.
• Most explored fermentation area –
Dairy fermentation
• Majority of fermentations are
dependent on lactic acid
bacteria(LAB)
8. B. FERMENTATES
• Fermentates are fermented food
ingredients
• Variety of raw materials - typically
milk, sugar, or plant-derived material
• The fermentation is designed to
provide a high yield of antimicrobial
metabolites
9. C. BACTERIOPHAGES
Phages that attack bacteria.
They are harmless to humans, animals,
and plants .
Drug-resistant bacteria have become a
global
problem.
Phages are specific and efficient in
host recognition.
Phages kills host cells by releasing
11. A. Antimicrobial agents of
natural origin
Direct
antimicrobial
preservatives
Indirect
antimicrobial
preservatives
• Bacteriocin
s
• Essential
oils
• Antibiotics
• Enzymes
• Flavoring
agents and
polyphosphate
s
Today’s Outline
B. Antioxidants
12. Direct antimicrobial
preservatives
1. Bacteriocins
Antibacterial proteins produced by bacteria
that kill or inhibit the growth of other bacteria
Bacteriocins are produced by LAB found in
numerous fermented and non-fermented foods
Nisin - the only bacteriocin widely used as a
food preservative.
Many other are characterized chemically and
genetically but their structure–function,
biosynthesis, and mode of action, many
aspects of these compounds are still unknown
16. • US makes it compulsory to get
approved as GRAS.
• EU given E234 for nisin and can be
labelled as “nisin preservative” or
“Natural preservative”
• In Denmark, bacteria used to
produce food additives must not
produce toxins or antibiotics
• nisin
Regulatory considerations
17. Nisin in foods
EU AUSTRALIA/ NEW-
ZELAND
Ripened and processed
cheese
Sauces
Clotted cream Soups
Puddings such as
semolina or tapioca
Salads dressings,
Mascarpone Ready-to-eat and
processed meat
products
Pasteurized liquid egg
18. Direct antimicrobial
preservatives
2. Essential oils
Aromatic and volatile liquids
extracted from plants and spices.
Preservative effect has been
documented extensively.
Major disadvantage is it results in
negative organoleptic changes.
It can be overcome by using
synergies between several
compounds.
19. 2. Essential oils
• The active compounds can be divided into
four groups according to their chemical
structure
Essenti
al oils
Terpenes
Terpenoi
ds
Phenyl
propanoid
s
others
p-Cymene
Thymol
Carvacrol
Eugenol,
Cinnamaldehyde
Vanillin
Allicin, Allyl
isothiocyan
ate
20. Mode of antibiosis
o Mechanism of action has not been
studied in great detail
o Not attributable to one specific
mechanism but that there are
several targets in the
cell
Locations and mechanisms in the
bacterial cell thought to be sites of
action for EO components
21. Direct antimicrobial
preservatives
3. Antibiotics
The first commercial use of an antibiotic in
the processing of a perishable food became
possible on an interstate basis in 1955.
As a consequence FDA cleared chlortetra
cycline for use "in and on uncooked
poultry.“
Based on researches, cooked meat was not
containing chlortetraccline and tolerance
was set to 7ppm
22. Direct antimicrobial
preservatives
3. Antibiotics
Challenge is it leads to antibiotic
resistant strains of pathogens.
Laws consider it as an adulterant.
Data regarding safety of residues are not
available.
Tetracycline group (chlortetracycline,
oxytetracycline, and tetracycline) is most
efficient in preserving dressed
chicken( doubled shelf life).
23. Direct antimicrobial
preservatives
3. Antibiotics
For fish ice containing
chlortetracylcine at 5 ppm is used.
For beef infusion to carcass is used.
It kills starter cultures(cannot be
used in fermented products).
Mode of action by preventing protein
synthesis.
25. Applications
• Egg white lysozyme inhibits the outgrowth
of C. tyrobutyricum in ripened, yellow
cheeses such as Edam or Gouda
• Hen egg white lysozyme as a food additive
in cheese in the European Union, E-1105
• In Gouda cheese lysozyme safeguard
against growth of L. monocytogenes
• lactoperoxidase system has been
demonstrated to work efficiently to
preserve raw milk without refrigeration
26. Regulatory Consideration
• US : GRAS for any enzyme to be used
as food additive.
• EU: Already gave E number to egg
white lysozyme (E-1105).
• Not mentioning about addition of
enzymes as food additives but
mentions about use of enzymes as
process aids.
27. Indirect antimicrobial
preservatives
Flavoring agents and polyphosphates
Essential oils are majorly added for
flavoring.
Phosphates are primarily added for
improving tenderness, moisture
retention, reducing shrink during
cooking etc.
Adding relatively high levels of
phosphates for emulsification
coincidentally provides microbiological
28. Antioxidants
• Antioxidants are primarily used for prevention
of rancidity in fats, oils, fat foods etc.
• Rancidity affects the nutritional and sensory
value of foods.
• Nutritional: Oxidized fatty acids initiate CVD
and cancer.
• Lipid hydroperoxides decompose liposoluble
vitamins, such as vitamin E, vitamin C, and
vitamin A.
• Hydroperoxides reacts with primary amine
group of proteins and reduce biological value
29. Antioxidants
• Rancidity also affects the sensory
quality and results in consumer
rejection.
• Oxidative rancidity can be prevented
by addition of antioxidants.
• Antioxidants prevents the chain
reaction of free radicals.
• Antioxidants can be synthesized
chemically and extracted from natural
sources
30. Natural antioxidants are present in
oilseeds
Antioxidants
Oilseed Antioxid
ant
Oleuropein
aglycone
Olive Deodorizing
Lignan(phenolic
group)
Sesame
seed
Roasting
Gossypol Cotton
seed
Toxic to humans
Evening
primrose
Catechin -
31. Natural Sources
• Oil seed cakes.
• Hull of oil seeds.
• Cereals and legumes.
– Rice bran – commerically used – oryzanol.
• Legume hulls
– Rich in flavonoids
• Fruits , vegatables flavones,
anthocyanins and related compounds
32. Natural Sources
– Lycopene of tomato.
– Citrus fruits – flavones and glycosides
• Herbs & spices
– Tea leaf – catechin - >20%
– Commercially available
antioxidant – Extracted
from Rosemary
33. Applications
• Stabilization of lard and meat
products.
• Stabilization of fish and fish oil.
• Stabilization of vegetable oils
and plant foods.
• stabilization of essential oils and
cosmetics against oxidation.
34. Conclusions
There is a huge call for ‘natural’ food
products.
Hence food preservatives which can be
labeled as ‘Natural’ will increase consumer
confidence.
Any such preservative used for above
purpose can be brought under the purview of
BIOPRESERVATIVES.
There are lot of studies regarding the
preservative actions of different bio
preservatives.
35. Conclusions
But the toxicological studies of the same
have to be conducted.
Biopreservatives can be a better alternative
for the harmful chemical preservatives
which are now being used.
Several studies gave proven that origin of
many lifestyle diseases and other health
problems is from the consumption of
processed food.
FSSAI has to take initiatives to bring safe
Biopreservatives under its jurisdiction.
36. Conclusions
The number of studies on
Biopreservatives are comparatively
very less in India.
Government of India has to support
new researches in the field of
Biopreservatives.
