HTM 2700 Lecture Notes - Lecture 14: Potato Starch, Grape, Starch

• School: University of Guelph
• Department: Hospitality and Tourism Management
• Course: HTM 2700
• Professor: Alison Crerar

Document Summary

Week 5 lecture 14 wednesday, february 10, 2016. Sol = dispersed colloidal particles in a continuous liquid medium: thickened mixture which can be poured from a container. Gel = high degree of attraction between a continuous system of solid material that holds finely dispersed liquid: 3d. Used pectin (brand name certo) to make grape jelly. Sol: grape juice, sugar, acid and pectin heated together, hot mixture was thick, but still pourable (colloidally dispersed) Gel: mixture allowed to cool, mixture set and took on shape of jars, 3d. Dispersed particles are scattered throughout the continuous phase due to the 3 stabilizing factors: brownian movement, like charges repelling, layer of (cid:862)(cid:449)ater of rehydratio(cid:374)(cid:863) If stabilizing factor removed, the dispersed particles will bond together. Pectin molecules: negatively charges at the ph of fruit juice. Therefore, pectin molecules are stable colloidal dispersions in water: hydrophilic (water-loving) Have a layer of water of hydration around outside of molecule.