This presentation describes the effect of processing and storage conditions on nutrients in food namely carbohydrates, proteins, lipids, vitamins and minerals.

1. Basics of human nutrition
CAT 1
presentation on,
Effect of processing and storage on nutrient content
Presented by,
Pooja Parab
20FBT213

2. Carbohydrates
Fats
Vitamins
Minerals
Proteins
Nutrients

3. Effect of Processing and Storage on Proteins
Changes during processing:
• Heat denatures protein and make them digestible by proteolytic enzymes.
• Improvement of nutritional value by deactivating certain anti-nutritional factors.
• Denaturation due to mild heat causes hydrolysis of peptide bond, loss of enzyme activity, loss of
crystallization of protein, increase in intrinsic viscocity.
• Mild heat causes linkage between end epilson amino group of lysin with reducing substances
• At 115 degree Celsius, cysteine is oxidized to disulphide or disulphene.
• Change in temp and time of milk pasteurization can lead to unfolding of beta lactoglobulin, sunlight attacks
methionine and converts it into methionol.
• Alkali treatment in the preparation of concentrates and isolates leads to formation of new amino acids such
as lysino- alanine, Lanthronine and ornithine .
Changes during storage:
• Ionizing radiations used for food preservation can cause changes in amino acids.
• Millard reaction

4. Effect of Processing and Storage on Carbohydrates
Changes during processing:
• There is significant improvement in quality and digestibility of carbohydrates after malting
process.
• Milling helps to hydrolyze the indigestible oligosaccharides
• During wet heat treatments as in blanching and boiling, considerable loss of low molecular
weight carbohydrates as well as micronutrients into processing water happens.
• Non enzymatic browning
• Gelatinization increases digestibility by amylolytic enzymes, recrystallization of starch k/a
retrogradation makes the carbs less digestible
Changes during storage:
• Carbohydrates are relatively stable.
• Adverse brown pigments can form in case of frozen and dried foods with proteins

5. Effect of Processing and Storage on Lipids
Changes during processing:
• Excessive heating may cause formation of carbonyl compounds due to decomposition of
unsaturated fatty acids which gives reaction similar to non enzymatic browning.
• Irradiation may cause reactions similar to oxidative rancidity with loss in fat soluble
vitamins.
• Several carbonyl compounds may formed that can be carcinogenic.
Changes during storage
• During frozen storage, release of lipases and phospholipases takes place that can cause
oxidative rancidity.
• During prolonged storage, fat may undergo quality deterioration.
• Enzymes, moisture, air can cause oxidative and hydrolytic rancidity leading to off flavour
development.
• Lipid oxidation produces hydroperoxides or peroxides which reacts with fat soluble
vitamins and makes them nutritionally useless.

6. Effect of Processing and Storage on Vitamins and Minerals
Vitamin and mineral content of food:
• Bran of cereals contains more vitamin B than
cortex
• Vitamin C, Niacin, Riboflavin higher in peels of
fruits
• Fresh citrus fruits show high conc of Vit C in outer
peel and inner white skin
• In carrots, palm fruits, potatoes vitamins are higher
in peels than that in root and flesh
Effect of processing
Effect of storage
Trimming, milling and peeling, excessive blanching.
25% thiamine is lost when potatoes are boiled, 40% thiamine is lost when
meat is roasted, when bread is baked, 25% thiamine is destroyed.
Milk loses substantial amount of vit B2 and vit C if stored in clear bottles in
sunlight within few hours.
Loss of vit from fruits at room temperature.

7. Effect of some processing and storage techniques
Technique Effect
Cooking
• Makes food more digestible.
• Decreases toxic effect, microbes. increases
palatability.
• Leaching out of vitamins
Baking
• Minimal adverse effect on vit and minerals
• Increases in phytate hydrolysis
• Decreases biological value of some nutrients
Frying
• Ascorbic acid is oxidised to DAA
• Vitamin retension
Pasteurization • HTST and UHT more preferable

8. (contd)
Technique Effect
Salting
• Results into the liquid exuding from the flesh,
taking with it some water soluble proteins,
vitamins and minerals
• Some proteins are denatured by salt
Canning
• Nutrient loss due to destruction during heating
• Water soluble vit and minerals may dissolve in the
can
Smoking
• Reduces oxidative changes
• Causes nutrient loss due to associated heat, flow
of gases and interaction of smoke components
with proteins

9. Recommended solutions
• Minimizing the loss of nutrients such as lipids, vitamins due to oxidation by wrapping
foods in moisture proof and oxygen impermeable packaging materials.
• After processing enrichments
• Strictly following the storage conditions of temperature and relative humidity for the
particular food product and also avoiding temperature fluctuations.
• Adopting high energy transfer processing method such as (HTST) to reduce the treatment
time.
• Adopting non thermal processing methods such as pulsed light, high hydrostatic pressure
technology, ohmic heating, and ultrasound technologies wherever applicable.
• Improving packaging systems in food storage and distributions.
• Creating awareness among people about the effect of over processing on the nutrients and
suggest possible ways to avoid it.

10. References
• Dandago et.al., 2009. Changes in nutrients during storage and processing of
Foods - a review, Techno science africana journal, volume 3 number 1.
• Hurst, W.C. Reynolds, A.E., Schuler, G.A. and Christian, J.A (1993).
Maintaining Food Quantity in Storage. University Of Georgia Cooperative
Extension Service Bulletin 914.
• A. E. Bender, 1966. Nutritional effects of food processing. J. Food Technol.
1:261
• Manju B. Reddy and Mark L.,1999. a review- The impact of food
processing on the nutritional quality of vitamins and minerals, Department
of Food Science and Human Nutrition Iowa State University, Ames, Iowa
50011.

11. Thank you!