HTM 2700 Lecture Notes - Lecture 2: Lecithin, Foodborne Illness, Hydrophile

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

Document Summary

Foods are mixtures of substances in various molecular states- gas, liquid, and solid. Two parts to a dispersion system: dispersed phase= subdivided particles, continuous phase= substances in which the dispersed phase is scattered. Two phase dispersion system: beaten egg whites. Special sub groups of liquid/ liquid dispersion system. = liquids, which are not capable of staying mixed together, by themselves, for any length of time e. g. ) oil and water/ oil and vinegar (oil is dispersed in the water and vinegar) One immiscible liquid is dispersed in the other immiscible liquid. Oil is always dispersed in vinegar or water. Has an affinity for both phases of an emulsion. Most common emulsifier is lecithin in egg yolk. Has a hydrophilic end and an hydrophobic end. In mayonnaise the 2 ends of the lecithin emulsifier in egg yolk will orient themselves as follows: Food safety: foodborne illness (foodborne infection vs. foodborne intoxication, foodborne mediated toxin)