Study of mechanisms underlying the infusion of starch-based food materials by oil-based liquid foods.

摘要

Infusion is the process defined as filling in the pores of starch-based food materials by partially wetting liquid foods so as to obtain a relatively higher calorie food product in a lower bulk volume. The main objective of this research was to investigate the effects of the physical properties of the liquid (surface tension, angle of contact, and viscosity) and the pore structure of the starch-based solid (porosity, and pore size distribution) on the infusion process.;Chessmen Butter Cookies (Pepperidge Farms) and Wonder White Sandwich Bread (ITT Continental Baking Co.) were selected as the starch-based porous solid food materials. Bread is a highly expanded product (porosity = 0.92), while cookies are relatively dense products (porosity = 0.58). Safflower oil (surface tension = 32dyn/cm; viscosity = 47centipoises) and silicone oil (surface tension = 20dyn/cm) of the same viscosity were selected to study the effect of surface tension. Silicone oils of 47 and 490 centipoises viscosity were chosen to study the effect of viscosity. Chocolate syrup was selected to assess the effect of nonNewtonian behavior.;Both bread and cookies contain pores larger than 200;Infusion of oils into starch-based food materials is a very efficient process which occurs between vacuum and 200,000dyn/cm