FOOD PRESERVATIONFOOD PRESERVATION

Necessity

Methods

Cold Chain

References:

1) R.S.Khurmi, J.K.Gupta

2) Arora & Domkundwar

3) IIT Khragpur Notes

Applications of RefrigerationApplications of Refrigeration

Four major areas:

a) Food preservation   b) Chemical and process industries c) Special Applications d) Comfort / industrial air-conditioning

Food Preservation Food Preservation

What is food preservation?Retaining food over a period of time without

being contaminated by pathogenic organisms or chemicals and without losing its colour, texture, flavour and nutritious value.

Why food preservation? Seasonal availability of food Different type of food at different locations

Food Preservation

a) Food processing:Slow freezing or sharp freezingQuick freezingAir blast freezers

b) Food Preservation: Cold storages

c) Distribution: Refrigerated vehicles

Food Preservation Food Preservation

Advantages: Increases the shelf life of food Retain the quality of food – colour,

texture, flavour & nutrition value Increases food supply Adds variety to the food decreases wastage of food

Food Preservation Food Preservation Food Product Average Useful

(days)Storage life

0oC 22oC 38oC

Meat 6-10 1 < 1 Fish 2-7 1 < 1 Poultry 5-18 1 < 1 Dry meats and fish

> 1000 > 350 & < 1000

>100 & < 350

Fruits 2 - 180 1 – 20 1 – 7 Dry fruits > 1000 > 350 &

< 1000 >100 & < 350

Leafy vegetables 3 - 20 1 – 7 1 – 3

RECOMMENDED STORAGE TEMP

PRODUCT STORAGE TEMP

MILK 4 DEGCBUTTER 2 TO 8 DED CICE CREAM (-) 20 TO (-)22 DEG CVEGETABLES 2 TO 8 DED CFRUITS 0 TO 4 DEG CMEAT (-) 20 DEG CPHARMA PRODUCT 2 TO 8 DED CFROZEN FISH (-) 18 TO (-) 29 DEGCCHEESE (-) 18 DEG CSWEETS 2 TO 8 DED C

FFRRIIDDGGEE

..

Food spoilage

Food components: Proteins Carbohydrates Fats Vitamins Minerals

Destruction of any of these component is food spoilage.

Cause of food spoilage

Spoilage due to physical change

impact, bruising and squeezing

desiccation or dehydration

Spoilage due to chemical change

internal spoiling agents : Enzymes

external spoiling agents:

bacteria, yeast, moulds (fungus)

Methods of food preservation

Heat processing Dehydration Chemical preservation Canning Pasteurization Freezing

Freezing for food preservation

Slow or sharp freezing Quick freezing

smaller ice crystals

no separation of minerals, salts

Immersion freezing

Indirect contact freezing

Air blast freezers

Cold stores

To store food products after processing Prefabricated insulated panels Air tight door in sandwich construction Safety anti-locking arrangement Temperatures – positive or sub-zero Layout – air lock, sorting-cum-intermediate

storage area, store compartments Important points – temperature, RH, air

motion, product mix, duration

Prefabricated Cold store

Cold Storage: FCUs

Cold Storage : Interior

Cold Storage : Material Arrangement & Air Movement

Cold ChainCold Chain Cold chain is a temperature-controlled

supply chain. Pre-cooling chambers at farm Processing unit – freezing, packing Manufacturer’s cold storage Distributor’s cold storage Retailer’s cold storage Refrigerated display cabinets Residential refrigerator Refrigerated transport

Source Precooling`

TransportRetailDistribution Center

Processing Shipping

COLD CHAIN : TOTAL SOLUTIONS

Carrier OMM II 20050

CARRIER COMMERCIAL REFRIGERATIONCold chain

Convenience stores

Distribution centers

Cash and carry

Farms/food processors

Regional supermarkets

Multinationalhypermarkets

Pre-CoolingPre-Coolingofof

Fruits & VegetablesFruits & Vegetables

Methods of Pre-coolingMethods of Pre-cooling

Different methods of Pre-Cooling includes:

1) Hydrocooling2) Vacuum Cooling3) Forced Air Cooling4) Contact Icing5) Evaporative Cooling

Caution. No matter what cooling method is employed, the produce should never be allowed to re-warm once it has been cooled.

Blast Freezing ApplicationBlast Freezing Application

• Seafood

• Poultry, Meat

• Fruit & Vegetable

• Ready Meals

Cold Storage ApplicationCold Storage Application

• Distribution/Logistic Center

• Frozen produce

• Processing Room

CA Storage ApplicationCA Storage ApplicationStorage comparisons for a typical Apple: