Isopure Smoothie and a Sore Throat

Is this reflux?  I know that I probably already know the answer but... I haven't experienced this before. I have been drinking 8 oz of an Isopure smoothie (orange-berry or orange-peach) one time a day. For the rest of the day I have a sore throat and a funny cough. It is so yummy though. I thought I finally found a shake that wasn't chocolate, vanilla or strawberry. I have 5cc in a 10cc band. Thank you for your help.

If it's just happening with this shake you might be allergic to something in it.

Thank you very much

I do not have my band yet.  But for years I have not been able to drink orange juice and most things with orange in it, including orange popsickles.  I get a sorethroat and sometimes even sores in my mouth.  I can eat oranges and I have been tested negative for any food allergies.  There is just something about the acidity I guess. 

I'm not a fan of the Isopure clear drinks because they seem to coat my throat and they leave a funny...well, it's not a taste and it's not a sore throat...I don't know what to call it Everyone I've talked to loves them, so I thought it was just me.

Thank you both for your replies. I too have been tested for food allergies and they found nothing. But this reaction isn't normal. My sister is highly allergic to orange juice so maybe that is it. I have also tried the grape isopure and that leaves a funny taste too! I will have to stop drinking the ispure.