Introduction to the Chemistry of Food

Michael Zeece

• Publisher: Academic Press
• Year: 2020
• ISBN:
  9780128117262
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

Introduction to the Chemistry of Food describes the molecular composition of food and the chemistry of its components. It provides students with an understanding of chemical and biochemical reactions that impact food quality and contribute to wellness. This innovative approach enables students in food science, nutrition and culinology to better understand the role of chemistry in food. Specifically, the text provides background in food composition, demonstrates how chemistry impacts quality, and highlights its role in creating novel foods. Each chapter contains a review section with suggested learning activities. Text and supplemental materials can be used in traditional face-to-face, distance, or blended learning formats.

• Describes the major and minor components of food
• Explains the functional properties contributed by proteins, carbohydrates and lipids in food
• Explores the chemical and enzymatic reactions affecting food attributes (color, flavor and nutritional quality)
• Describes the gut microbiome and influence of food components on its microbial population
• Reviews major food systems and novel sources of food protein

Chapter One

Chemical properties of water and pH

Abstract

This chapter describes the structure of water and the importance of hydrogen bonds to its physical and chemical properties. Water's high pointing point and surface tension result from extensive hydrogen bonding between molecules. The polar nature of water molecules determines the solubility of other substances, or lack thereof. Acid-base chemistry, pH, and their relevance to food are discussed. Chemical leavening, for example, employs acid-base chemistry to produce bread doughs that rise without yeast. The water content of food affects its texture and rate of spoilage. The concept of water activity and its importance to controlling spoilage, is described.

Keywords

Acid; Base; pH; Weak acid; Buffer; Ionization; Hydrogen bond; Titratable acidity; Dipole; Solute; Solubility; Sublimation; Surfactant; Colloid; Water activity; Humectant

Learning objectives

This chapter will help you describe or explain:

• Water’s structure

• The hydrogen bond and its importance to water

• What a food acid is, including examples

• pH and titratable acidity

• The importance of water to food color, taste, and texture

• Why oil is not soluble in water

• Water activity and its importance to food quality and safety

Introduction

Water is the major component of all living things and therefore an important part of food. Water affects the texture, taste, color, and microbial safety of everything we eat. The moisture content of food is a good indicator of its texture. In general, it equates with a softer food texture. For example, the texture of yogurt, meat, bread, and hard candy decreases in that order and parallels the respective moisture content of these foods. Water is the vehicle that carries taste molecules to receptors in the mouth. For example, the sweetness of cherries, bitterness of beer, sourness of lemons, saltiness of pretzels, and pungency of peppers results from compounds (tastants) dissolved in water. The method of cooking (wet or dry) affects food flavor and color. Food cooked using wet methods, such as boiling, are generally low in flavor and color. In contrast, foods cooked with dry methods, such as frying or grilling have greater flavor and color. The moisture content of foods, such as milk, is directly related to its potential for microbial spoilage. Control of water available to spoilage organisms can be accomplished by lowering the food's water activity level (a_w) with humectants or by dehydration. Both are common practices in food preservation. This chapter describes the properties of water and chemistry in food. It also describes the chemical concepts of acids and their relationships to food safety and spoilage.

These questions will help you explore and learn about water and its effects on food.

1. • How can surface tension be demonstrated using a cup of water and a paperclip?
2. • Why did my can of pop explode in the freezer?
3. • Why does it take longer to boil potatoes in Denver than in Chicago?
4. • What is a pKa?
5. • Gee fizz, what makes soda pop so tasty?
6. • Why did the biscuit dough package explode in the refrigerator? Hint: The answer ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Acknowledgments
• Chapter One. Chemical properties of water and pH
• Chapter Two. Proteins
• Chapter Three. Carbohydrates
• Chapter Four. Lipids
• Chapter Five. Vitamins and minerals
• Chapter six. Flavors
• Chapter Seven. Food additives
• Chapter Eight. Food colorants
• Chapter Nine. Food systems and future directions
• Index