ANSC 3120 Lecture Notes - Titration, Lignin, Cellulose

• School: University of Guelph
• Department: Animal Science
• Course: ANSC 3120
• Professor: c

Document Summary

Proximate analysis (6 major classes of food chemicals: southgate method, van soest method further analysis of cho/fibre. Crude by modern analytical standards but a 1st step in understanding food is a collection of chemicals. Determination of moisture allows further analysis to be a dry matter basis. Potential errors: drying removes other volatile components. Eg volatile fatty acids (2 4c); alcohols. Not used in human food labelling: human food labelled on an as is basis". Widely used in agriculture: more accurate to formulate diets on a dry matter basis, dry matter would be confusing for people looking at products in stores. Now, you have a sample of dry matter Weighed and dried sample is extracted with ether (organic solvent) Ether fraction transferred to new tube and dried. Crude fat meant to be: triglyceride, cholesterol, phospholipids, fatty acids. Potential errors: other lipid soluble compounds. Total fat: pufa, mufa, saturates, trans essential, cholesterol. Chloroform methanol: gas liquid chromatography, fatty acid composition.