ANFS102 Lecture Notes - Lecture 13: Cottage Cheese, Isoelectric Point, Lysozyme
11 Apr 2017
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Document Summary
Fibrous tertiary structure with a large amount of ordered secondary structure: globular proteins. Protein properties: various properties impact foods, useful in product development, impact may restrict processing methods. Amphoteric: proteins are able to act as an acid or base depending on the ph, allows them to resist small changes in ph, gives buffering capacity. Isoelectric point: ph at which the protein is electrically neutral (pl) Proteins will precipitate out of solution at pl since they have no charge and without the repulsion forces molecules cannot interact with each other: cottage cheese. Milk + lactic acid -> the ph is equal to the pl of casein proteins so proteins precipitate. Water-binding capacity: water molecules (h20) bind to protein backbone, side chains impact binding capacity of protein. Many charged and polar groups increases water-binding capacity. Many hydrophobic groups reduce this: close to pl proteins bind less water.
