NU FS100 Lecture Notes - Lecture 9: Food Preservation, Refrigerant, Solution

• School: University of Alberta
• Department: Nutrition and Food Sciences
• Course: NU FS100
• Professor: Blanca Enriquez

Document Summary

The use of low temperature can extend the shelf life of foods and acts as a method of food preservation. Low temperature slows of stop the growth of microbes (there is no more moisture to grow) but does. Reduces (slow down) the rate of food deterioration. Extends shelf life for a couple weeks or days. Refrigerant: the liquid that evaporates inside the fridge to create cold temperatures. Works best when foods are cooled right after slaughter or harvest. Has minimal effects on taste, texture, and nutritional value. Technology used for a lot of convenience foods. Extends shelf life for a couple months to years. Dissolved substances take a higher freezing point. Chemical changes during freezing: enzymes in vegetables. Vegetables require blanching prior to freezing for top quality. Over blanching can cause loss of colour, and under blanching can stimulate enzyme activity: enzymes in fruits. Enzymes can cause browning and vitamin c loss in fruits.