As you know part of the digestion of starches happens in the mouth from the salivary amylase, that happens when you thouroughly chew the food.
My question is if you eat staches from a well blended soup, like a soup with potatoes does the full digestion of the starches happens given that you are not chewing barely or at all.
Yes. Digestion of starches begins in the mouth, but continues in the small intestine with the help of other enzymes. For example, pancreatic amylase is secreted from the pancreas to the small intestines and continues the breakdown of starches to produce short oligosaccharides, maltose, maltotriose, and dextrins.
As someone with Congenital Sucrase-Isomaltase Deficiency (CSID) I figured I’d share any information I have been taught about this. Salivary amylase plays a very small roll (<5%) and only breaks down starch into maltose (two glucose) and dextrins (more than two glucose). The same goes for pancreatic amylase. Sucrase-isomaltase is what does the most work for starch digestion and can handle full starch molecules, sucrose, maltose, and isomaltose. Maltase-glucoamylase does a small part of the work and digests maltose and can also digest full starch molecules, but not even close to as well as sucrase-isomaltase. So even if you drank the soup without having any saliva you would be fine. Unless you have my disease which means you avoid sucrose completely and limit starch intake.