The determination of reduced sugar and total sugar 3,5-denitrification salinoic acid color ratio.

, purpose
to master the basic principles of reduced sugar and total sugar determination, learn color method to determine the operation of reduced sugar and the use of charcoal meter.
, principle,
reduction sugar determination is the basic method of sugar quantitative determination. Reduced sugar refers to sugars containing free aldehyde or ketones, monosaccharies are reduced sugars, double sugars and polysaccharies are not necessarily reduced sugars, where lactose and maltose are reduced sugars, sucrose and starch are non-reducing sugars. Using the different solubility of sugar, the single sugar, double sugar and polysaccharides in plant samples can be extracted separately, and the non-reductive double sugars and polysaccharides can be degraded by acid hydrolyzing to reduced to reduced monosaccharides, and then the content of reduced sugar and total sugar in the sample (reduced sugar in glucose content) can be determined separately.
Reduced sugars are oxidized into glycoic acid and other products under alkaline conditions
heating
and 3,5-nitrosic acid is reduced to brown-red 3-amino-5-nitrosic acid. Within a certain range, the amount of reduced sugar is directly related to the depth and light of the brown-red substance color, and the light density value is measured at 540nm wavelength using a 12guangometer, the standard curve is checked and calculated, and the content of reduced sugar and total sugar in the sample can be found. Since polysaccharide hydrolysates monosaccharides, each broken glycoside bond needs to be added to a molecule of water, so the polysaccharide content should be multiplied by 0.9.
, experimental materials, main instruments and
reagents
1. Experimental materials
wheat flour; precision pH
test paper
.
2. Main instruments
(1) plug glass scale
test tube
:20mL×11
(2) large centrifuge tube: 50mL×2
(3)
Beo
:100mL×1
(4) Triangle Bottle: 100mL×1
(5) Capacity Bottle: 100mL
×3
(6) scale straw: 1mL×1; 2mL×2; 10mL×1
(7)
thermostat
bath Pot
(8) boiling water bath
(9)
centrifuge
(10) torque
balance
(11) hydrometer
.