FSCN 1012 Lecture Notes - Lecture 6: Joule, Dietary Fiber, Calorimetry

• School: UMN
• Department: Food Science and Nutrition
• Course: FSCN 1012
• Professor: Reneta Korczak

Document Summary

Basic definitions for this chapter: temperature: a quantitative measure of an object"s hotness or coldness, heat: the energy transfer from one body or system to another. Bomb calorimeter: measures total energy value of foods, type of direct calorimetry, heat of combustion. Increase in water temperature directly reflects the heat released: the heat liberated by oxidizing a specific food (total energy value, carbohydrates, 4. 2 kcal, lipids, 9. 4 kcal, proteins, 5. 65 kcal. Net energy value of foods: actual energy available to the body, coefficient of digestibility, affected by dietary fiber, atwater general factors, carbohydrates: 4 kcal/g, lipids: 9 kcal/g, proteins: 4 kcal/g. Direct calorimetry: directly measures energy metabolism (heat production, human calorimeter, airtight chamber, changes in water temperature relate directly to an individual"s energy metabolism. The respiratory quotient (rq: the ratio of carbon dioxide produced to oxygen consumed, the rq provides information about the nutrient mixture catabolized for energy, rq values, 1. 00 for carbohydrate, 0. 70 for fat, 0. 82 for protein.