Proximate Analysis Flashcards
What is Food Analysis?
development, application and study of analytical methods for characterizing foods and their constituents
What’s the equation for % Moisture?
(wet weight - dry weight) / (wet weight) x 100%
What’s the equation for Ether Extract ( % Crude/Estimated Fat)?
(weight of ether extract) / (wet weight of sample) x 100%
Is dry weight over or underestimated? Why?
- underestimated
- loss of vitamins and minerals during drying
Is Ether Extract ( % Crude/Estimated Fat) over or underestimated? Why?
- overestimated
- other things are dissolved by solvent
What’s the equation for % Ash (Mineral Content)?
(weight of ash) / (wet weight of sample) x 100%
What’s the equation for % Protein (Nitrogen)?
[ (N in sample)(6.25) / (wet weight of sample) ] x 100%
Is % Protein (Nitrogen) over or underestimated? Why?
- overestimated
- assumes all proteins are 16% nitrogen
- there are additional sources of nitrogen
What’s the equation for % Crude Fiber?
[(weight of ash + crude fiber) - (weight of ash)] / (wet weight of sample) x 100%
What’s Crude Fiber?
- mostly ligand and cellulose (insoluble fibers)
Does % Crude Fiber over or underestimate Dietary Fiber?
underestimates
What are Soluble Fibers?
- pectins, gums, mucilages
- form a gel in water (dissolve)
What are Insoluble Fibers?
- cellulose, lignin, hemicellulose
- remain intact in water (don’t dissolve)
What’s Dietary Fiber?
describes all fiber (insoluble and soluble)
What’s the equation for % Nitrogen Free Extract (Digestible Carbohydrate Content)?
100% - (% moisture + % crude fat + % ash + % crude protein + % crude fiber)