Introduction: Food preservation

What Are Foods?Foods are materials (raw, processed, or formulated) that

are consumed orally by humans or animals for growth, health or pleasure.

Generally, there is no limitation on the amount of food that may be consumed (as there is for a drug in the form of dosage).

This does not mean that we can eat any food item as much as we want. Excessive amounts could be lethal, for example, salt, fat, and sugar.

The preservation method is mainly based on the types of food that need to be prepared or formulated.

Definition of “Food preservation” :

Food preservation involves the action taken to maintain foods with the desired properties or nature for as long as possible.

First, it is important to identify the properties or characteristics that need to be preserved.

One property may be important for one product, but detrimental for others. For example, the consumer expects apple juice to be clear whereas orange juice could be cloudy.

Why Preservation?

To overcome inappropriate planning in agriculture Produce value-added products Provide variation in diet

In food preservation, the important points that need to be considered are:

A: The desired level of quality

B: The preservation length

C: The group for whom the products are preserved

Definition of Quality???

A: The desired level of quality

Definition: Quality is …

“the degree of fitness for use”

or “the condition indicated by the satisfaction level of consumers”

Quality is an deceptive, ever-changing concept.

When food has deteriorated to such an extent that it is considered unsuitable for consumption, it is said to have reached the end of its shelf life.

In studying the shelf life of foods, What is more important?

Quality or Safety?

In studying the shelf life of foods: Safety is the first attribute, the second is other quality.

The product quality attributes can be quite varied, such as: Appearance microbial characteristics Organoleptic properties …

Organoleptic: Sensory properties that can be detected by the sense

organs. Include:

1) Taste

2) Texture

3) Astringency

4) Aroma

1- Taste The tongue can distinguish five separate tastes:

1) sweet

2) salt

3) sour (or acid)

4) bitter

5) savoury (or umami)

Sweet, salt, sour and bitter are classic tastes.

*Savoury: means tasty, having a pleasant flavor

*Umami: The Japanese name for a savoury flavour, now

considered one of the five basic senses of taste. It is name given to the special taste of monosodium

glutamate (the sodium salt of glutamic acid), some other amino acids, protein and the ribonucleotides.

These are flavour enhancer: A substance that enhances or potentiates the flavours of other substances without itself imparting any characteristic flavour of its own.

2- Texturephysical properties

3- Astringency (perceived in the mouth) The action causing a contraction of the epithelial tissues of

the tongue Due to tannins (tannic acid) found in a variety of plants

such as unripe fruits, tea, …)

4- Aroma (perceived in the nose)

Loss of quality is highly dependent on types of : Food and composition Formulation (for manufactured foods) Packaging Storage conditions

B: The preservation lengthAfter storage for a certain period, one or more quality

attributes of a food may reach an undesirable state.At that time, the food is considered unsuitable for

consumption and is said to have reached the end of its shelf life.

“Best-before date” is set shorter than the shelf life with a good margin.

How ever, if product stored at the recommended conditions it is usually safe and palatable to consume a product a long time after the best-before date.

Products may be marketed with the production date “pack date” and “best-before date.”

Alternative markings is “expiration date”, which may be closer to shelf life than “best-before date”.

C: The group for whom the products are preserved

Nutritional requirements and food restrictions apply differently to different population groups.

Food poisoning can be fatal, especially in infants, pregnant women, the elderly, and those with depressed immune systems.

TQM =?HACCP=? ISO=?GMP=?GHP=?

TQM = Total quality managementHACCP Hazard Analysis and Critical ControlPointsINTERNATIONAL STANDARDS ORGANIZATION

(ISO)Good Manufacturing Practice (GMP)Good Hygiene Practice (GHP)