NU FS100 Lecture Notes - Lecture 9: Blanca Enriquez, Pressure Cooking, Spray Drying
15 Feb 2018
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Document Summary
Preservation principle: to reduce growth of microorganism, extend shelf life, easier to transport. Powdered milk decreased weight increased amount to be transported in container in space so it is dehydrated, more stable when less water, longer shelf life. It is harder to remove when bounded to carbohydrate. Common drying methods: heat: heat the surface, spray: used in case of liquids. Interchange of heat and water: freeze: expensive method. Rate of dehydration is increased to get better quality and desirable: surface area: more area in contact with air. It"ll take time to cook at the top of the mountain. Inside a pressure cooker, more heat transferred so cooked faster. Remove atmospheric pressure to dehydrate water at lower boiling point water removed at lower temp. inexpensive process. Useful in concentrated milk otherwise it"ll be caramelized. Y axis moisture content in percentage and time in x axis in drying curve. Some changes during drying: browning reactions: desirable in some undesirable in some.
