Sucrose test sample

Procedure To the flasks containing 20.0 mL of each Test Preparation and to the Blank Preparation, add 5.00 mL of Acetate Buffer. At zero time, and at regular time intervals so that each test sample is analyzed in the same elapsed time, place the flasks containing the Test Preparations and the Blank Preparation in a circulating water bath maintained at 30.0° 0.1°. Equilibrate the samples for 10 min in the water bath. In the same order and with the same time intervals, rapidly pipet 25.00 mL of equilibrated Sucrose Substrate Solution into the test flasks. Incubate for 30.0 min, and stir continuously. Terminate the reaction by adding 10.00 mL of Sodium Carbonate Solution, and swirl to mix. Place the flasks containing the Test Preparations and the Blank Preparation in a water bath maintained at 20.0° 0.1° for 30 min. Use a... 

Molasses is used as a main carbon source in many fermentations. Most of the carbohydrates such as glucose, fructose and sucrose in molasses can not be determined by spectro-photometric methods because test samples are not optically clear. Many reports on enzyme electrodes for these carbohydrates have been published (15,19,20,21). However, enzyme electrodes are not suitable for determination of these carbohydrates because enzymes are unstable and inhibitors of enzymes sometimes exist in a fermentation broth. 

Incubate at 40°, 10 ml. of sucrose solution with 1 ml. of sugar-free invertase extract, prepared from yeast. After ten to fifteen minutes test samples of the mixture for reducing sugar, or demonstrate the presence of glucose and fructose by the osazone test, which, however, does not differentiate between these two sugars. 

Sensory Analysis. A paired comparison test was run to determine if the difference in oil droplet size in the emulsion changed the perceived intensity of the orange flavor. The coarsest emulsion (3.87 pM) and the Microfluidized sample (0.90 pM) from the third set of spray dried samples were compared. The solutions were prepared using 200 ppm flavor in a 10% (w/v) sucrose solution with 0.30% of a 50% citric acid solution added. The amount of each powder required to attain 200 ppm orange oil was calculated on the basis of percent oil in each powder (determined by Clevenger analysis). A pair of samples at approximately 10 C was given to each of 24 untrained panelists. The samples were coded with random numbers. Half the panelists were asked to taste the coarsest sample first while while the other half tasted the Microfluidized sample first. This was done to determine whether or not adaptation was a factor. The panelists were asked to indicate which sample had the most intense orange flavor. 

It is difficult to arrive at a definite conclusion from this work. The major criticism which has been made of this and similar testing is that at least 15 samples are required in order to provide statistical significance at 0.5 % sucrose based on cane yield. Variations in the yield from field blocks are commonly as high as 10%, and often more. 

Figure 13.2.2 Current sensitivity test of the cHPLC-NMR probe (sample, 200 mM sucrose in D2O H resonance frequency, 600 MHz detection volume, 750 nl)...

Taste was tested by offering the subject aqueous solutions of sucrose (2 to 16% in steps of 2.0%) and sodium chloride (1 to 4% in steps of 0.5%), in an irregular pattern of concentrations, in which the subject had to say if the taste was the same, stronger, or weaker than that of the sample offered before. 

Figure 3.68. The proton solvent presaturation test. The data were acquired on a 400 MHz spectrometer equipped with a dual H C inverse probe and the sample was 2 mM sucrose and 0.5 mM DSS in 90% H2O/10% D2O.

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