Food Preservation Flashcards
spoilage:
microbial, chemical, or physical processes that can affect the nutritional value, color, texture and edibility of food
Preservation:
Anti browning agents
Antioxidants
Stabilizers
Antimicrobials
Physical
antimicrobial:
Targets:
Foodborne pathogens
Spoilage microorganisms
Types
Bacteriostatic
*Stop or inhibit
Non-Microbial Causes of Food Spoilage
Chemical
Physical
Enzymes
Chemical reactions in Chemical Spoilage:
chemical processes such as oxidation, hydrolysis, and maillard reaction contribute to food spoilage by altering the color, flavor, and texture of food. These reactions are often accelerated by exposure to air, light, and heat
Oxidation:
removal of electrons from atoms. Occurs upon exposure to oxygen in air
Lipid oxidation=
rancidity
what is the chemical gas that causes the ripening of fruit?
ethylene gas
what ways are there to prevent oxidation?
antioxidants (ex: vitamins A,C, and E), prevent contact with oxygen, some foods are packaged in nitrogen
Enzymes:
Naturally occurring enzymes in food can cause spoilage by catalyzing biochemical reactions that lead to the degradation of proteins, fats, and carbohydrates, resulting in changes such as rancidity, softening, and loss of flavor
Other enzymes include…
- phenolase, peroxidase- oxidation
- cellular amylase- starch to sugar
- pectinesterase- modifies cell wall pectins, leading to softening
how to prevent enzyme spoilage?
blanching
Microbial Spoilage:
Contamination by pathogens= spoilage
Preventing Microbial Spoilage:
Traditional antimicrobials
Naturally occurring antimicrobials
Traditional Chemicals:
Have been used for many years
Are approved by many countries
Can be made synthetically
Often considered “bad” by consumers
naturally occurring traditional chemicals used for food preservation:
Acetic acid, vinegar
Benzoic acid, cranberries
Sorbic acid, rowanberries
Nitrite, leafy greens, vegetables
nitrites are used in..
Used in cured meats
Heat + nitrates + proteins=
nitrosamines (carcinogens)
to avoid turning nitrites into carcinogens…
Don’t overcook meats (burnt bacon)
Most meats now contain low nitrite
Physical Methods of Preventing Microbes
Salt, honey, inhibit microbial growth, kill microbial cells (ex: heating)
