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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 .
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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 preservationinvolves 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: • Taste • Texture • Astringency • 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 savouryflavour, 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 flavoursof other substances without itself imparting any characteristic flavour of its own.
2- Texture physical 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 length • After 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 palatableto 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 management • HACCP Hazard Analysis and Critical Control • Points • INTERNATIONAL STANDARDS ORGANIZATION (ISO) • Good Manufacturing Practice (GMP) • Good Hygiene Practice (GHP)