Thank you for the explanation. Will the starch color be differ between starch with higher content of amylopectin and normal starch? or all starch will result in dark blue color? Thank you
Hi Bondan. Thanks for the question. I did not know the answer to this question, so I looked into it. Amylose turns blue with iodine, while amylopectin turns a purplish-red (brown) colour. If you use a spectrophotometer, you can determine the percentage of amylose in a sample. A protocol I discovered states you heat the starch solution to 95'C for 15 min. Mix 20 uL of heated starch, with 980 uL of your iodine solution. Measure the absorbance at 525 nm and 700 nm (Blank = 20 uL water + 980 uL iodine solution). Use the following formula to determine the percentage amylose = [3.039 - (7.154 x (OD700/OD525))] / [(3.048 x OD700/OD525) - 19.192]. Please note that I have not tried this yet. If you give it a try, please let me know how it goes.
Thank you for the explanation. Prof, do you know where i can get lab tests done? I'm trying to produce tinctures and I want to ensure that there are polysaccharides present and hopefully the quality/potency of it.
This was a qualitative test for polysaccharides to determine if they are present. Sounds like you are looking for a quantitative test to determine the concentration of polysaccharides in your products. Unfortunately, I do not know of any commercial labs that do this, but I am sure they exist. You would just need a set of standards (solutions with known concentrations of polysaccharides) and compare them to your products using the Standard Curve method.
Thanks for the feedback. Sorry but I cannot tell you what each of the samples are. I have provided a list of what they might be. This video is used by students to make observations and then conclusions on what they believe each sample might be. They would not need to if to gave away what each one was.
Thank you for the explanation. Will the starch color be differ between starch with higher content of amylopectin and normal starch? or all starch will result in dark blue color? Thank you
Hi Bondan. Thanks for the question. I did not know the answer to this question, so I looked into it. Amylose turns blue with iodine, while amylopectin turns a purplish-red (brown) colour. If you use a spectrophotometer, you can determine the percentage of amylose in a sample. A protocol I discovered states you heat the starch solution to 95'C for 15 min. Mix 20 uL of heated starch, with 980 uL of your iodine solution. Measure the absorbance at 525 nm and 700 nm (Blank = 20 uL water + 980 uL iodine solution). Use the following formula to determine the percentage amylose = [3.039 - (7.154 x (OD700/OD525))] / [(3.048 x OD700/OD525) - 19.192]. Please note that I have not tried this yet. If you give it a try, please let me know how it goes.
@@ProfessorDrewCollop Thank you prof, I might try the iodine first. considering I don't have access to spectrophotometer device.
Thank you for the explanation. Prof, do you know where i can get lab tests done? I'm trying to produce tinctures and I want to ensure that there are polysaccharides present and hopefully the quality/potency of it.
This was a qualitative test for polysaccharides to determine if they are present. Sounds like you are looking for a quantitative test to determine the concentration of polysaccharides in your products. Unfortunately, I do not know of any commercial labs that do this, but I am sure they exist. You would just need a set of standards (solutions with known concentrations of polysaccharides) and compare them to your products using the Standard Curve method.
@@ProfessorDrewCollop Hey Prof, Thanks for replying and correcting me. Appreciate it.
Great video prof. May I ask the names of the samples?
Thanks for the feedback. Sorry but I cannot tell you what each of the samples are. I have provided a list of what they might be. This video is used by students to make observations and then conclusions on what they believe each sample might be. They would not need to if to gave away what each one was.
@@ProfessorDrewCollop Oh okay! Thanks for replying prof :)