Question

analyse the reason behind the appearance of sweet taste in the food item some time after chewing​

Answer 1

it's because of some of the food left in mouth

Answer 2

This is by and large due to the fact that all foods generally contain some carbohydrate, be it may in large or small quantities. The enzymes used to aid in digestion are contained within the buccal cavity, and as such when one masticates a bite of food more enzymes are produced. Carbihydrates are broken down by these enzymes into sugar. Sugar is sweet and these sweet end products taste sweet.