Proximate analysis.

* the compounds in green are determined quantitatively

** Note that carbohydrates calculated by difference also contain some non-carbohydrate components, like organic acids.

Read the following statement and indicate whether it is true or false

Total carbohydrates (available and unavailable together) determined with “by difference” methods includes also fibre, lignins and non-carbohydrate compounds as organic acids. Therefore a single value for carbohydrates does not reflect the diverse nutritional properties of carbohydrates.

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One way to determine carbohydrates is by difference. This approach is based on Weende’s proximate method of analysis where major compounds ( in g/100g) in a food are identified based on the chemical properties of the compounds (see scheme). Thus minor constituents (present in mg or m g per 100 g) are ignored. Originally this approach was developed for the analysis of animal feeds but is also applied to food analysis. The scheme below shows that for carbohydrate calculation, the other major constituents in the food are determined individually, summed and subtracted from the total weight of the food.

true

false

Right. In the first part of this case you learned that carbohydrates consist of a wide variety of components which each their own characteristic nutritional properties. Therefore a single value for carbohydrates does not reflect this diverse range of nutritional properties. This is the reason that most FCDB also include values for individual carbohydrate classes (for example starch, sugars, sucrose, lactose, fructose, glucose, etc.)

Not right.

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b