Food Biochemistry and Food Processing

Chapter 5

Water Chemistry and Biochemistry*

C. Chieh

103

Introduction
The Compound Water
The Polar Water Molecules
Water Vapor Chemistry and Spectroscopy
Hydrogen Bonding and Polymeric Water in Vapor
Condensed Water Phases
Solid H 2 O
Other Phases of Ice
Vapor Pressure of Ice Ih
Liquid H 2 O—Water
Vapor Pressure of Liquid H 2 O
Transformation of Solid, Liquid, and Vapor
Subcritical and Supercitical Waters
Aqueous Solutions
Colligative Properties of Aqueous Solutions
Solution of Electrolytes
Self-Ionization of Water
Solutions of Acids and Bases
Titration
Solutions of Amino Acids
Solutions of Salts
Buffer Solutions
Hydrophilic and Hydrophobic Effects
Hard Waters and Their Treatments
Ionic Strength and Solubility of Foodstuff
Water as Reagent and Product
Esterification, Hydrolysis, and Lipids
Water in Digestion and Syntheses of Proteins
Water in Digestion and Synthesis of Carbohydrates
Water, Minerals and Vitamins
Food Chemistry of Water
Water as a Common Component of Food
Water Activity

Aquatic Organisms and Drinking Waters

Water and State of Food

Interaction of Water and Microwave

Water Resources and the Hydrological Cycle

Acknowledgments

References

INTRODUCTION

Water, the compound H 2 O, is the most common

food ingredient. Its rarely used chemical names are

hydrogen oxide or dihydrogen monoxide. So much

of this compound exists on the planet earth that it is

often taken for granted. Water is present in solid, liq-

uid, and gas forms in the small range of tempera-

tures and pressures near the surface of the earth.

Moreover, natural waters always have substances

dissolved in them, and only elaborate processes pro-

duce pure water.

The chemistry and physics of water are organized

studies of water: its chemical composition, forma-

tion, molecular structure, rotation, vibration, elec-

tronic energies, density, heat capacity, temperature

dependency of vapor pressure, and its collective

behavior in condensed phases (liquid and solid). In a

broader sense, the study of water also includes inter-

actions of water with atoms, ions, molecules, and

biological matter. The knowledge of water forms the

foundation for biochemistry and food chemistry.

Nearly every aspect of biochemistry and food chem-

istry has something to do with water, because water

is intimately linked to life, including the origin of

life.

*Modified from Handbook of Water Chemistry, copyright
2004 © by Chung Chieh. Used with permission.

Food Biochemistry and Food Processing

Edited by Y. H. Hui

Copyright © 2006 by Blackwell Publishing