FDSC 310 Lecture Notes - Lecture 10: Pressure Regulator, Humidifier, Active Packaging

• School: McGill University
• Department: Food Science
• Course: FDSC 310
• Professor: Ramaswarmy

Document Summary

Lecture 10- special ca systems, membrane ca and hypobaric storage. Membrane storage systems (ca/ma) membrane ca is based on gas diffusion through special films/membranes to achieve and maintain ca. Idea originated through the use of plastic films as a pre-packaging material. Used for both creation and maintenance of ca. Resulting ca condition depends on permeability, area of membrane, and concentration gradient, respiration rate, quantity of produce. Both permeability and respiration rate depend on a variety of other factors like temperature, gas concentration. Porous membrane (non specific) equal permeability to o2 and co2. 1- equal permeability to o2 and co2 assumption on respiration rate, o2 absorbed= co2 released (rq=1). We need the membrane to have more permeability for co2 than for o2. Lets choose membrane with co2 permeability= o2 permeability x 19/5. This gives o2 entry rate = co2 leaving rate, by inversely matching permeability ratio with concentration ratio.