Preguntas frecuentes

How to test the transmittance of low acyl gellan gum?

APPARATUS

Electronic balance (accurate to 0.001g)

Spectrophotometer 

Thermo-tank ( 5 ~ 50℃) 

Water bath ( 10 ~100℃)

PROCEDURE

Weigh 0.6g sample ( accurate to 0.01g ), transfer to 250mL beaker and add 120mL distilled water, weigh the total weight of beaker and solution and note it. Put the beaker in water bath ( 80℃) and stir it by glass bar for three times, 30 seconds for each time, heat for 20 minutes to ensure that the gellan gum dissolved totally, then add 2.7% calcium chloride ( CaCl₂ ) 2mL, then take the beaker out, swab up the outer wall of the beaker, add the water to make up a loss. Agitate to make the solution evenly, pour the solution into 10mm cuvette and put the cuvette in Thermo-tank immediately, stand it for 15 minutes, using Spectrophotometer to determine the transmittance at 497nm, against the blank. Make three samples parallelly, determine their transmittance and take the average value.