Food Preservation
Objective هدف Identify methods to preserve food
Overview مرور Purpose Food Preservation Techniques/Methods
Purpose Foods are preserved to make them last longer and give foods the flavors/colors that are expected Preserve = last longer
Methods of Food Preservation Refrigeration: Slows down microorganism growth Required temperature ranges are 0-5oC for refrigeration
Methods of Food Preservation Freezing: At temperatures < 0°C: No microorganism growth Chemical reactions are slowed Frozen food will be kept frozen and stored at a product temperature of -17oC or below. Note: Freezing is not a method of killing bacteria
Methods of Food Preservation Heat Pasteurization Killing the most resistant problematic microbes in the food Heat pasteurization starts to kill pathogenic bacteria at 60°C
What about reducing Aw? Dehydration Removing water from a food Dried Fruit Smoking Mild surface dehydration Anti-microbial properties of smoke
Methods of Food Preservation Fermentation Organic acid and other chemical production by bacteria and/or fungi in a food (these are “good” microbes in foods) Examples are pickles
Methods of Food Preservation Additives Organic acids Manufacturers add acid directly to the food Preserves food similar to fermentation – acid is added vs. made by bacteria
Summary Purpose Food Preservation Techniques/Methods
Review Questions 1. Why are foods preserved? 2. What is the purpose of refrigeration? 3. Is freezing a method to kill bacteria? 4. At what temperature does heat pasteurization start to kill bacteria? 5. What is an example of dehydrated food?
Questions? سوالات