Food Analysis Fourth Edition edited by S. Suzanne Nielsen Purdue University West Lafayette, IN, USA ABC II part Compositional Analysis of Foods 6 chapter Moisture and Total Solids Analysis Robert L. Bradley, Jr. Department of Food Science, University of Wisconsin, Madison, WI 53706, USA
[email protected] 6.1 Introduction 87 6.2.1.4 Types of Pans for Oven Drying 6.1.1 Importance of Moisture Assay 87 Methods 90 6.1.2 Moisture Content of Foods 87 6.2.1.5 Handling and Preparation of 6.1.3 Forms of Water in Foods 87 Pans 90 6.1.4 Sample Collection and Handling 87 6.2.1.6 Control of Surface Crust Formation 6.2 Oven Drying Methods 88 (Sand Pan Technique) 90 6.2.1 General Information 88 6.2.1.7 Calculations 91 6.2.1.1 Removal of Moisture 88 6.2.2 Forced Draft Oven 91 6.2.1.2 Decomposition of Other Food 6.2.3 Vacuum Oven 91 Constituents 89 6.2.4 Microwave Analyzer 92 6.2.1.3 Temperature Control 89 6.2.5 Infrared Drying 93 S.S. Nielsen, Food Analysis, Food Science Texts Series, DOI 10.1007/978-1-4419-1478-1_6, 85 c Springer Science+Business Media, LLC 2010 86 Part II • Compositional Analysis of Foods 6.2.6 Rapid Moisture Analyzer Technology 93 6.5.4 Infrared Analysis 99 6.3 Distillation Procedures 93 6.5.5 Freezing Point 100 6.3.1 Overview 93 6.6 Water Activity 101 6.3.2 Reflux Distillation with Immiscible 6.7 Comparison of Methods 101 Solvent 93 6.7.1 Principles 101 6.4 Chemical Method: Karl Fischer Titration 94 6.7.2 Nature of Sample 101 6.5 Physical Methods 96 6.7.3 Intended Purposes 102 6.5.1 Dielectric Method 96 6.8 Summary 102 6.5.2 Hydrometry 96 6.9 Study Questions 102 6.5.2.1 Hydrometer 97 6.10 Practice Problems 103 6.5.2.2 Pycnometer 97 6.11 References 104 6.5.3 Refractometry 98 Chapter 6 • Moisture and Total Solids Analysis 87 6.1 INTRODUCTION (d) Glucose syrup must have ≥70% total solids.