IJOI

2. PRESENTED BY:
SAQIB RASHID LONE
14PFT011

3. Introduction:-
 There are many different forms of
processing to which food may be
subjected before we eat it.
All of these processes have some
effect on the nutrient con tent.
For example, during the freezing of
peas there is about a 10 per cent loss
of vitamin C.

4. Cont…
 Nearly every food preparation process reduces
the amount of nutrients in food. In particular,
processes that expose foods to high levels of
heat, light, and/or oxygen cause the greatest
nutrient loss.
 Nutrients can also be washed out of foods by
fluids that are introduced during a cooking
process.
 Vitamin c is the most thermolabile vitamin and is
also easily leached into cooking water or canning
syrup.

5. Typical Maximum Nutrient Losses (as compared to raw food)
Vitamins Freeze Dry Cook Cook+Drain Reheat
Vitamin A 5% 50% 25% 35% 10%
Beta Carotene 5% 50% 25% 35% 10%
Lycopene 5% 50% 25% 35% 10%
Vitamin C 30% 80% 50% 75% 50%
Thiamin 5% 30% 55% 70% 40%
Riboflavin 0% 10% 25% 45% 5%
Niacin 0% 10% 40% 55% 5%
Vitamin B6 0% 10% 50% 65% 45%
Folic Acid 5% 50% 70% 75% 30%
Vitamin B12 0% 0% 45% 50% 45%
Minerals Freeze Dry Cook Cook+Drain Reheat
Calcium 5% 0% 20% 25% 0%
Iron 0% 0% 35% 40% 0%
Magnesium 0% 0% 25% 40% 0%
Phosphorus 0% 0% 25% 35% 0%
Potassium 10% 0% 30% 70% 0%
Sodium 0% 0% 25% 55% 0%
Zinc 0% 0% 25% 25% 0%
Copper 10% 0% 40% 45% 0%

6. Nutrients may be lost
during cooking in two
ways :1. By degradation ,which can occur by
destruction or by other chemical changes
such as oxidation.
2. By leaching into the cooking medium
Vitamins are susceptible to both processes
while minerals are affected only by leaching.

7. Loss of vitamin C in relation to
time and temperature during steaming
of
red cabbage:-

8. Consuming Raw Foods
 The amount of nutrient loss caused by
cooking has health-conscious consumers to
eat more raw foods.
 However cooking is also beneficial, because it
kills potentially harmful microorganisms that
are present in food supply.

9. Effects of Freezing on
nutrients:-
 freezing can be a very good way to preserve
the nutritional value, texture and flavor of
many foods, many of the vitamins and
minerals will keep fairly well in frozen foods.
Research showing that anthocyanin
flavonoids can be well preserved during
freezing. Even though they are rather
delicate, a recent study found no significant
reduction in the levels of anthocyanins in
blueberries after three months of freezing.

10. Cont…
 About 25% of the vitamin C and a greater
percentage of folate are lost during the
blanching process that occurs before foods
are frozen. About 10% of thiamin (vitamin B1)
is also lost during blanching.

11. Effects of drying on
nutrients:-
 Drying using four different methods viz.,
osmo-air drying, direct sun drying, indirect
solar drying and oven drying. The osmo-air
drying method was found to be the best
method for drying of aonla because of better
retention of nutrients like ascorbic acid and
sugars.
 The level of antinutrients like tannins was
also found to be lower in osmo-air dried aonla

12. Cont…
 compared to other methods of drying because of
leaching. Browning of the dehydrated fruits was
also minimal in the case of osmo-air dried fruits.
The nutrient content in osmo-air dried aonla was
satisfactory after 90 days of storage.

13. Effects of heat processing on
nutrients:-
 Heat processing is one of the most important
methods for extending the storage life of food
stuffs , however heat processing also has a
detrimental effect on nutrients since thermal
degradation of nutrients can and does occur
 Therefore thermal processing makes it
possible to extend and increase availiability of
foodstuff to the consumer but the foodstuff
may have a lower nutrient content compare

14. Cont….
 To the fresh food stuff.
 The challenge to the food processing industry
is to minimize the loss of nutrients during
thermal processing while providing an
adequate process to ensure an extended shelf
life.

15. Effect of microwaves on
nutrients:-
 Microwave cooking has gained considerable
importance as an energy-saving, convenient,
and time-saving cooking method. Most
reports indicated that microwave cooking
resulted in higher moisture losses compared
with conventional methods.
 Overall, the nutritional effects of microwaves
on protein, lipid, and minerals appear
minimal.

16. Cont…
 There is no report on the effects of
microwaves on carbohydrate fraction in
foods. A large amount of data is available on
the effects of microwaves on vitamins.
 In conclusion, no significant nutritional
differences exist between foods prepared by
conventional and microwave methods.

17. Nutrition additives
 Any natural or synthetic substances, such as
salt, monosodium glutamate, or citric acid, used
in the commercial processing of food as
preservatives, antioxidants, emulsifiers, etc, in
order to preserve or add flavour, colour, or
texture to processed food…

18. REMEMBER…
The more heavily processed foods are the
less nutritious they become…