HTM 2700 Study Guide - Final Guide: Hydrogen Sulfide, Bain-Marie, Sodium Bicarbonate

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

Document Summary

Acid (added or naturally occurring organic acids speeds up rate of protopectin. Sugar slows down protopectin solubilization by forming hydrogen bonds with protopectin. Sugar hydrogen bonds with protopectin (oxidative enzymatic browning is too many marks to talk about) Cooking in alkaline conditions (adding baking soda or use of hard water) *this most likely won"t be one of the issues on the final. Anthocyanins become blue/bluish or green/greenish under alkaline conditions. Colour fades in flavonoids in acidic conditions. Carotenoids fade in conditions with heat and acid. Chlorophyll becomes pheophytin which is olive / dull green in acidic conditions. Water activity: lower than for bacteria and yeasts, 0. 78-1. 0, minimum is 0. 61. Temperature: wide range, ideal is 20-30 c, readily destroyed by heat. Oxygen: grows best in aerobic conditions, fermentative yeasts grow slowly in anaerobic ph: ideal 4-4. 5 and range is 4. 0-6. 5) Water activity: fairly high (only osmophilic yeasts can grow in very low aw)