I have been looking for Trehalose today. I found it at a premium super market. It was located on the same shelf as coffee sugar and I guessed it is usually used for coffee and tea to substitute for normal sugar. In my case, I am going to use it for sushi rice. If it is used for rice, it makes it more moist and softer with slight sweetness. I prefer it to normal sugar to make sushi rice. You can try it if you want to improve your home made sushi.