HTM 2700 Lecture Notes - Lecture 23: Bain-Marie, Tomato Soup, Micelle

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

Document Summary

Week 8 lecture 23 wednesday, march 9, 2016. Milk consists of whey and casein proteins. They are colloidally dispersed proteins within the water (continuous phase) When these proteins denature, primarily adverse (bad) reactions happen during cooking which causes these proteins to precipitate (fall) out of colloidal dispersion. Whey will denature when overheated, therefore use a double boiler. Casein micelles are colloidally dispersed at a ph of milk (ph 6. 7) Negative charges around casein micelles repel each other and keep micelles stable. O(cid:448)erall (cid:272)harge o(cid:374) (cid:373)i(cid:272)elles (cid:271)e(cid:272)o(cid:373)e (cid:858)0(cid:859: brings casein micelles to their iep (ph 4. 6) = curdling. Or gelatin if conditions are cold (ex. Polyphenolic compounds are found in: light-coloured, low acid fruits and vegetables (potatoes, apples, etc. , asparagus, green peas, strong tea and coffee. Polyphenolic compounds remove water of hydration around casein micelles: micelles denature, denatured micelles adhere together and form larger, less stable molecules. Larger molecules precipitate out of colloidal dispersion = curdling.