How to test for the sweetness of substance?

[real]

any testing solution or other method that can test for the sweetness of some substance. I mean except using the mouth.

 

[real]

any people can help on this problem?

 

[GCT]

it's kind of a weird suggestion, sweetness is subjective, in order to determine whether a substance is "sweet" you'll need to test it subjectively and statistically.

 

[Ouabache]

If you're measuring a solution known to have sugar in it. You can measure the sweetness using Brix refractometry. It is commonly used to measure sweetness of fruit juice and wine.

 

[real]

how about measure the sweetness of the sweetener?
i doesn't contain any sugar.

 

[Ouabache]

how about measure the sweetness of the sweetener?
i doesn't contain any sugar.

GCT summed that up very well, it is subjective and requires a statistical sampling by tasters (just like grading the quality of tea after a harvest).

 

[real]

then why i can find the detail that some sweeteners are about 100times sweetness of sucrose, and some is about 1000 times. how can the scientist get this kind of value?

 

[Ouabache]

http://www.science.edu.sg/ssc/detailed.jsp?artid=67&type=6&root=3&parent=3&cat=30
There are no laboratory instruments to perform the task, no absolute or even arbitrary units of sweetness. Instead we have to rely on the human tongue and the hope that if we average the findings of large numbers of tongues we can obtain useful data. The data scientists obtain will still not be in absolute units but will be expressed relative to some arbitrary standard, usually sucrose.
The above reverence agrees with my and GCT's assesment that further measurement is purely subjective (following the underlined hyperlink).

A typical way a panel assess sweetness is to make a dilution series of the solution. (10:1, 100:1, 1000:1 etc...) At some dilution, the entire panel will no longer taste any sweetness. A relative scale is constructed based on this taste test. (similarly http://www.garlic-central.com/chiles/scoville.html Units were developed to measure heat (spicey) units).