• Traditional perservation method consists of drying, fermentation and refrigeration

• Nature way of method

• Natural sources example salt, sugar & vinegar

  
  

• Modern include canning, pasteurization, freezing, irradiation and addition of chemical.

• Use chemical preservation

• High technology machines for different types of preservation such as retord machines for ready to eat food for longer shelf life

• Traditional: naturally derived preservatives - salt, smoke

• Commercial: synthetically derived - sodium benzoate

Scale

• Traditional: small scale

• Commercial: large scale

Preserving techniques

• Traditional: natural methods - drying, smoking and fermentation

• Commercial: modern methods - flash freezing, freeze drying

Traditional Food Preservation Method: Drying

- Example: Sun-Drying Fruits

- Description: In traditional settings, fruits like apricots, grapes (for raisins), and tomatoes are often dried in the sun. This method reduces the moisture content, inhibiting the growth of bacteria, yeasts, and molds.

Commercial Food Preservation Method: Canning

- Example: Canned Vegetables

- Description: In commercial contexts, vegetables are often preserved by canning. This involves placing the food in jars or cans, heating them to a temperature that destroys microorganisms, and sealing them to prevent contamination.

Comparison:

- Cost: Sun-drying is generally low-cost, utilizing natural resources like sunlight and air. Canning, however, requires more investment in equipment and materials (cans, seals, and heat processing units).

- Shelf Life: Canned foods typically have a longer shelf life compared to dried foods, as the canning process ensures a sterile environment, preventing recontamination.

- Nutrient Retention: Drying may lead to some nutrient loss, especially in vitamins sensitive to light and air. Canning can also result in some nutrient loss, but it often retains more nutrients compared to drying.

- Flavor and Texture: Dried foods tend to have a concentrated flavor and chewy texture, while canned foods retain more of their original texture and flavor, albeit sometimes slightly altered by the canning process.

Isn't it fascinating how different methods can affect the food we eat in such varied ways?

Traditional Food Preservation Methods involve Drying which is removal of moisture from food one of the traditional example is Sun drying, air drying. Secondly will be salting which is Use of salt to draw moisture out and create an inhospitable environment for bacteria. One of the traditional salting method is known as pickling.

Nextly for commercial Food Preservation Methods we have commercial canning which describe large-scale canning using industrial processes and uses of tin and high heat. The last method is Chemical Preservatives. This Uses of substances to inhibit spoilage and microbial. One of the example is sulfades.

Convection

• Takes place when heated particles in a gas or liquid flow from a heated area to a cooler area, taking heat with them.

• Form of heat transfer that combines conduction with mixing.

A gas oven or cooking in boiling water are good examples. When heated, the particles of a liquid (e.g. water) or a gas (e.g. air) become lighter and rise, while colder particles sink to the bottom and one than handed in turn.

Some example of cooking method that uses convection is baking, roasting

• There are total 2 type convection which can be natural or mechanical based on what is generating the flowing movement.

Natural Convection:

occurs when the transfer of heat is caused by the inherent movement of water particles from a warmer area to a cooler one, which creates circular flow.

Example: pot of water is heated.

Mechanical Convection:

uses fans to create the flow that moves the heated particles.

Example: convection ovens. (save time and energy by cooking food faster.)