Functional Carbohydrates

Development, Characterization, and Biomanufacture

Jian Chen, Yang Zhu, Song Liu

• Publisher: CRC Press
• Year: 2017
• Print ISBN: 9781498718776
• eBook ISBN: 9781315353890
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

"Functional carbohydrates" is the term used to describe those carbohydrates that play an important role in strengthening immunity, decreasing the level of blood-lipid, and regulating the intestinal flora of humans, beyond those simply used as the energy-supplying materials. To date functional carbohydrates mainly cover dietary fiber, functional polysaccharides, functional oligosaccharides, sugar alcohols, and other functional monosaccharides. Functional Carbohydrates: Development, Characterization, and Biomanufacture facilitates tracking the important progresses in functional carbohydrates. This book addresses the history and recent developments of a selected number of important functional carbohydrates and it introduces the source, properties, and applications of a number of functional carbohydrates. It describes in detail the biomanufacture of these carbohydrates based on fermentation or enzyme catalysis, including the strain screening and improvement, optimization of fermentation process, and product downstream processing.

1History and Developments in Functional Carbohydrates

Song Liu, Guocheng Du, Jian Chen, and Yang Zhu

1.1Introduction

1.2Hyaluronic Acid

1.3Curdlan

1.4Cyclodextrins

1.5Galactooligosaccharides

1.6Functional Hydrolysates of Hemicellulose

1.7Ganoderma Polysaccharide

1.8Glucosamine and N-Acetyl Glucosamine

1.9Sugar Alcohols

References

1.1Introduction

From the point of nutrition, carbohydrate is one of the most important nutrients in the human diet when daily intake is considered. According to dietary advice, 50–60% of total energy that we consume should come from carbohydrates. Many foods contain large amounts of carbohydrates. Not until the early 1980s did the scientific community begin to focus on the physical diversity of carbohydrates. Since then, the knowledge related to the physiological role of carbohydrates and their effect on health and disease has experienced deep development. “Functional carbohydrates” is the term used to describe those carbohydrates that have more nutritious value than traditional carbohydrates and that play an important role in strengthening immunity, decreasing the level of blood-lipid, regulating the intestinal flora of humans, etc. With the growing diversity of carbohydrates, functional carbohydrates now mainly cover dietary fiber, functional polysaccharides, functional oligosaccharides, sugar alcohols, and other functional monosaccharides.

For achieving good results in application, several functional carbohydrates have recently received considerable attention, including hyaluronic acid, curdlan gum, Ganoderma polysaccharide, cyclodextrin, oligosaccharides from hemicellulose, galactooligosaccharide, glucosamine, N-acetylglucosamine, and various sugar alcohols. In this review, the structures, functions, and sources of these representative functional carbohydrates will be summarized briefly.

1.2Hyaluronic Acid

Hyaluronic acid is a kind of mucopolysaccharide that is composed of disaccharide repeating units (N-acetyl glucosamine [GlcNAc] and D-glucuronic acid [GlcUA]) by alternate beta-(1-3) and beta-(1-4) glycosidic bonds (Weissmann and Meyer 1954). In 1934, hyaluronic acid was first extracted from bovine vitreous body (Meyer and Palmer 1934). Hyaluronic acid was naturally distributed in various tissues of vertebrate’s mesenchymal cells and the capsule of some bacteria (Prehm 1984, 1990; Chong et al. 2005), and it was involved in many important metabolic and physiological processes (Necas et al. 2008). Hyaluronic acid could function as lubricant and buffer zones of joints as well as a filling agent of the colloidal structure of the lens. In addition, hyaluronic acid was also involved in cell immobilization and intracellular signal transduction through those specific or nonspecific interactions with the protein components of cells (Karjalainen et al. 2000). Depending on the sources, the main chain length of hyaluronic acid could be 2000–25,000, or even higher, disaccharides unit (approximately 400 Da for each disaccharide). The spatial structure of hyaluronic acid presented a unique rigid helix column, and directional arrangement of a large number of hydroxyl groups forms strong hydrophilic and hydrophobic regions (Lee and Spicer 2000). Due to the negative charges, the GlcUA carboxyl of hyaluronic acid repel each other, resulting in a huge space that can hold a lot of water (1000 times heavier than hyaluronic acid itself; Scott et al. 1984; Laurent et al. 1996). Due to its unique properties, hyaluronic acid has been widely used in medicine, cosmetics, and food industries (Chong et al. 2005; Kogan et al. 2007).

Hyaluronic acid has long been extracted from animal tissues (e.g., cockscomb). The production of hyaluronic acid was thus limited by the quality of raw materials, extraction costs, and especially the animal epidemic risk (Laurencin and Nair 2008). Hyaluronic acid is currently produced by microbial fermentation using the hemolytic species Streptococcus C with a weak pathogenicity (Liu et al. 2011). In contrast to those traditional extraction methods, microbial fermentation has many advantages, including simple production process, abundant raw material, high purity, low cost, and environment friendliness. The research on the production of hyaluronic acid by microbial fermentation was initiated in the 1980s in Japan, and then scientists in Britain and the United States and other countries began to study fermentation production of hyaluronic acid (Triscott and van der Rijn 1986; Johns et al. 1994). The yield and productivity of hyaluronic acid have been greatly improved by using different strategies, such as strain improvement, optimization of metabolic pathway, and culture condition (Huang et al. 2006; Liu et al. 2008). Due to the rapid development of molecular biology and DNA sequencing ...

Table of contents

• Cover
• Half Title Page
• Title Page
• Copyright Page
• Contents
• Preface
• Editors
• Contributors
• Chapter 1 History and Developments in Functional Carbohydrates
• Chapter 2 Microbial Production of Hyaluronic AcidCurrent State, Challenges, and Perspectives
• Chapter 3 Curdlan OligosaccharidesProduction and Application
• Chapter 4 α-CyclodextrinEnzymatic Production and Applications
• Chapter 5 Recent Progress on Galactooligosaccharides Synthesis by Microbial β-Galactosidase
• Chapter 6 Biodegradation and Utilization of Hemicellulose
• Chapter 7 Production of Ganoderma lucidum Polysaccharides by Fermentation
• Chapter 8 Glucosamine and N-acetylglucosamine Production by Microbial FermentationAdvances and Perspectives
• Chapter 9 Functional CarbohydratesDevelopment, Characterization, and Biomanufacturing of Sugar Alcohols
• Index