Determination of soluble sugar content in plants (anthrone method)

related topics .
, Purpose
:
sugars are one of the important components of
supery
and are the main raw materials and storage materials of metabolism. Different load conditions, different maturity can affect the content of sugar in fruits and vegetables. Therefore, the determination of soluble sugar in fruits and vegetables can understand and identify the quality of fruits and vegetables.II, principlesugars are dehydrated by thick sulphuric acid to produce glycodehyde or its derivatives, the reaction is as follows:acetaldehyde or hydroxymethylphenidate further and oxycodone
reagents
shrink to produce a blue-green substance, which has the greatest absorption at 620nm wavelength in the visible light region, and its light absorption value in a certain range is positively related to the content of sugar.
method can be used for the determination of the content of monosaccharose, oligosaccharine and polysaccharose, and has the advantages of high sensitivity, simple and fast, suitable for the determination of trace samples and so on., experimental materials, instruments and reagents
1. Material: cabbage leaves, citrus
2. Instrument:
hydrometer ringer
water tank with plug scale
test tube
(3)
funnel
100ml
capacity bottle
scale test tube rack scissors research
3. Reagents:
(1) 200 mg/ml standard glucose: AR grade glucose 100mg, distilled water dissolved, fixed to 500ml.
(2) ketone reagents: 1g ketones, dissolved with ethyl acetate, fixed capacity to 50ml, brown bottle shelter storage;
(3) thick sulphuric acid 4, experimental method
1. The production of the glucose standard curve
take 6 20 ml cold test tubes, number, according to the table data to make a series of different concentrations of standard glucose solution.
Add 0.5 ml of ketone reagents to each tube, then slowly add 5 ml of thick H2SO4, shake well, open the test tube plug, boil in a boiling water bath for 10 minutes, remove cooling to room temperature, at 620 nm wavelength, measure the light density value (OD) of each tube solution, with the standard glucose content as the horizontal coordinates, the light density value for the vertical coordinates, make a standard curve.2. Extraction of soluble sugar in the sample
called taking 1 g of cabbage leaves, shredding, placed in the research, adding a small amount of distilled water, grinding into a homogenous slurry, and then transferred to a 20 ml scale test tube, with 10 ml distilled water to wash the research, washing liquid into the scale test tube together. Bring to the boil in a boiling water bath for 10 minutes, after cooling
filtering
, the filter is collected in a 100 ml capacity bottle, with distilled water to the scale, shake the spare.
3. Sugar content determination
1 ml of extract was absorbed with a pipet in a 20 ml plug-scale test tube, plus 1 ml of water and 0.5 ml of ketone reagents. Slowly add 5ml thick H2SO4 (Note: thick sulphuric acid in water will produce a lot of heat!) ), after covering the test tube plug, gently shake well, and then put in the boiling water bath for 10 minutes (color blank with 2 ml of distilled water mixed with 0.5 ml of ketone reagents, and together in the boiling water bath to keep warm for 10 minutes). After cooling to room temperature, the color is compared at a wavelength of 620nm to record the light density value. Check the standard curve to find the corresponding glucose content (g).5, the results of the calculation 6, note
(1) plus thick H2SO4 should be slowly added, so as not to generate a large amount of heat and boil, burn the skin, if the above situation, should be quickly rinsed with tap water.
(2) water bath
open
tube plug when heating the water..PDF full download:
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