Preface

The United Nations predicted that the global population would reach 9.7 billion by 2050 and 10.4 billion by 2100. With this growth, there will be a heightened demand for high-quality proteins, as they are an essential nutrient and important food ingredient. Moreover, the rise in consumer awareness for health and fitness, increasing disposable income, growing demand from the millennial population for supplements, and the rise in popularity of alternative proteins as substitutes for meat and animal products are driving the growth of the protein ingredient market.

Many studies have investigated the functional properties of protein ingredients, such as their solubility, foaming, emulsification, gelation, water holding, and oil absorption properties. However, there is limited research on their flavour characteristics and protein–flavour interactions in different processing conditions and formulations. Certain proteins have distinct odours, hindering their widespread applications. For example, soy and pea proteins are often described as having a green, beany off-flavour by consumers. Profiling flavour compounds and removing or masking the off flavours are crucial for product development and quality control. This book provides consolidated information on the flavour of food protein ingredients and highlights areas for further research, serving as a resource for the food industry and researchers studying food proteins and flavours.

In this book, we use terms such as traditional proteins (from animal sources like meat, seafood, dairy, and eggs), plant/vegetable proteins (from plants like cereals, pseudocereals, and legumes), and novel proteins (from bacteria, fungi, algae, edible insects, and cultured meat) to describe food proteins from various sources. Leaf and oilseed proteins are grouped under novel proteins as they are not widely used. Chapter 1 provides an overview of the global protein market, sensory and flavour properties, problems associated with food protein ingredients, and the use of proteins and peptides as precursors to generate flavours through the Maillard reaction. Chapter 2 discusses the current knowledge on consumer acceptance of food protein ingredients, e.g., protein concentrates, isolates, and hydrolysates, and protein-based and enhanced food products. Consumer acceptance from both survey studies and consumer sensory studies is included. Chapters 3 and 4 cover protein–flavour interactions and the influencing factors. Specifically, Chapter 3 introduces the development of analytical methods for measuring both reversible and irreversible binding between proteins and flavour compounds. Chapter 4 discusses the various factors that could affect the formation of reversible or irreversible bonds between flavourings and various proteins, as well as their impact on flavour perception. Chapters 5–10 summarize the volatile and sensory characterizations of specific food proteins and protein-based products, including dairy (Chapter 5), fish (Chapter 6), soy (Chapter 7), pulse (Chapter 8), cereal and pseudocereal (Chapter 9), and novel (Chapter 10) proteins. The topics covered in these chapters include volatile profiles, volatile formation, factors influencing volatile formation during processing and storage, and off-flavour removal.

Jing Zhao and Changqi Liu