Starch-based Blends, Composites and Nanocomposites (RSC Green Chemistry, 37, Band 37) - Hardcover

Hardcover

ISBN 10: 184973979X ISBN 13: 9781849739795

Verlag: Royal Society of Chemistry, 2015

Inhaltsangabe

Starch is one of the most widely available natural biomaterials and is commonly used in biodegradable packaging. This book provides a comprehensive overview of recent developments in starch-based materials.

The book focuses on the types of starch available from different sources, in particular the various aspects of preparation, structure, processing, morphology, properties and applications of starch materials and their polymer blends, composites and nanocomposites. It is ideal for students and researchers in chemistry, polymer science, materials science, biotechnology and life sciences working in bio-based and biodegradable polymers and composites, well as those interested in its applications.

Über diesen Titel

Von der hinteren Coverseite

Starch is one of the most widely available natural biomaterials and is commonly used in biodegradable packaging. This book provides a comprehensive overview of recent developments in starch-based materials.

The book focuses on the types of starch available from different sources, in particular the various aspects of preparation, structure, processing, morphology, properties and applications of starch materials and their polymer blends, composites and nanocomposites. It is ideal for students and researchers in chemistry, polymer science, materials science, biotechnology and life sciences working in bio-based and biodegradable polymers and composites, well as those interested in its applications.

Aus dem Klappentext

Starch is one of the most widely available natural biomaterials and is commonly used in biodegradable packaging. This book provides a comprehensive overview of recent developments in starch-based materials.

The book focuses on the types of starch available from different sources, in particular the various aspects of preparation, structure, processing, morphology, properties and applications of starch materials and their polymer blends, composites and nanocomposites. It is ideal for students and researchers in chemistry, polymer science, materials science, biotechnology and life sciences working in bio-based and biodegradable polymers and composites, well as those interested in its applications.

Auszug. © Genehmigter Nachdruck. Alle Rechte vorbehalten.

Starch-based Blends, Composites and Nanocomposites

By P. M. Visakh, Long Yu

The Royal Society of Chemistry

Copyright © 2016 The Royal Society of Chemistry
All rights reserved.

ISBN: 978-1-84973-979-5

Contents

Chapter 1 Starch: State-of-the-Art, New Challenges and Opportunities Visakh P. M., 1, 
Chapter 2 Starch: Introduction and Structure-Property Relationships Khongsak Srikaeo, 17, 
Chapter 3 Preparation and Characterization of Starch Nanocrystals Mehran Ghasemlou, Seyed Mohammad Taghi Gharibzahedi and Marlene J. Cran, 60, 
Chapter 4 Natural Fibre-reinforced Thermoplastic Starch Composites J. Sahari, S. M. Sapuan, Y. A. El-Shekeil, M. R. Ishak and R. Akhtar, 109, 
Chapter 5 Applications of Starch Nanocrystal-based Blends, Composites and Nanocomposites Verônica M. A. Calado and Andresa Ramos, 143, 
Chapter 6 Chemical Modification of Thermoplastic Starch Antonio José Felix Carvalho, 217, 
Chapter 7 Outstanding Features of Starch-based Hydrogel Nanocomposites Antonio G. B. Pereira, André R. Fajardo, Artur J. M. Valente, Adley F. Rubira and Edvani C. Muniz, 236, 
Chapter 8 Starch-based Blends Jiwei Li and Xuegang Luo, 263, 
Chapter 9 Fracture and Failure of Starch-based Composites Celina R. Bernal, 326, 
Chapter 10 Application of Starch Nanocomposites in the Food Industry Khongsak Srikaeo, 352, 
Chapter 11 Effects of Additives on the Properties of Starch Wei Wang, Hong Yang and Min Cui, 403, 
Subject Index, 433, 

CHAPTER 1

Starch: State-of-the-Art, New Challenges and Opportunities

VISAKH P. M.

Tomsk Polytechnic University, Lenin Av. 30, 634050 Tomsk, Russia Email: visagam143@gmail.com

1.1 Starch: Introduction and Structure–Property Relationships

Starch is a polysaccharide consisting of D-glucose units, referred to as homoglucan or glucopyranose, and has two major biomacromolecules – amylose and amylopectin. Amylopectin is a much larger molecule than amylose, with a molecular weight of 1x107–1x109 and a heavily branched structure built from about 95% α-(1[right arrow]4) and 5% α-(1[right arrow]6) linkages. Amylopectin unit chains are relatively short compared with amylose molecules, with a broad distribution profile. Starch varieties contain primarily two different types of anhydroglucose polymers, amylase and amylopectin.

Both amylose chains and the exterior chains of amylopectin can form double helices, which in turn may associate to form crystalline domains. In most starches these are confined to the amylopectin component. Double helices form more or less ordered arrays where the ordered structures are crystalline entities. The starch granule is a very complex structure, the complexity being built around variations in the composition (α-glucan, moisture, lipid, protein and phosphorylated residues) and structure of the components. In wheat, the starch surface protein friabilin has attracted much attention because of its proposed association with grain hardness.

Integral proteins have a higher molecular weight than surface proteins (~50–150 and ~15–30 kDa, respectively) and include residues of enzymes involved in starch synthesis, especially starch synthase. Starches also contain relatively small quantities (<0.4%) of minerals (calcium, magnesium, phosphorus, potassium and sodium), which are, with the exception of phosphorus, of little functional significance. As the starch paste cools, the viscosity increases due to the formation of a gel held together by inter-molecular interactions involving amylose and amylopectin molecules. The retrogradation of amylose in processed foods is considered to be important for properties relating to stickiness, ability to absorb water and digestibility, whereas retrogradation of amylopectin is probably a more important determinant in the staling of bread and cakes.

Most starches contain a portion that digests rapidly [rapidly digesting starch (RDS)], a portion that digests slowly [slowly digesting starch (SDS)] and a portion that is resistant to digestion [resistant starch (RS)]. Starch modification not only decreases retrogradation, gelling tendencies of pastes and gel syneresis but also improves paste clarity and sheen, paste and gel texture, film formation and adhesion. These highly functional derivatives have been tailored to create competitive advantages in new products, improve product aesthetics, lower recipe/production costs, eliminate batch rejects, ensure product consistency and extend shelf-life while clearly making starch relevant in all stages of a food product's life cycle. Modification of starch is an ongoing process as there are numerous possibilities. There is a huge market for the many new functional and added-value properties resulting from these modifications.

1.2 Preparation and Characterization of Starch Nanocrystals

Acid hydrolysis is possibly the most common and optimized method to produce starch nanocrystals. Acid treatment dissolves the regions of low lateral order to reveal the concentric lamellar structure of starch granules. By this approach, water-insoluble and highly crystalline residues may be converted into stable suspensions by a subsequent vigorous mechanical shearing action. During acid hydrolysis, regions of low lateral order and also amorphous phases in the starch granules start to dissolve, while the highly crystalline water-insoluble lamellae remain undissolved. Le Corre et al. conducted an experiment to determine whether starch from many different sources could be used to prepare starch nanocrystals and if the amylose content and/or botanic origin of the starch influenced their final properties. Starch nanocrystals are reported to be derived from starch granule crystallites and result from the disruption of the semicrystalline structure of native starch granules at temperatures below the gelatinization temperature. Under these conditions, the amorphous regions in starch granules are hydrolysed, which allows the separation of nanoscale crystalline residues. Starch nanocrystals of different sizes and shapes can be obtained depending on the origin of the starch and the isolation process. Xu et al. prepared starch nanocrystals from corn, barley, potato, tapioca, chickpea and mung bean starches using an acid hydrolysis method.

Mélé et al. studied the processing of nanocomposite materials consisting of natural rubber filled with waxy maize starch nanocrystals. Angellier et al. employed starch nanocrystals in natural rubber composites and found a remarkable enhancing effect, but when the starch nanocrystal content exceeded 20%, the enhancement decreased. Bouthegourd et al. reported the extraction and characterization of potato starch nanocrystals and their nanocomposites with a natural rubber latex matrix with the preparation performed using sulfuric acid at 40 °C. Kim et al. claimed that obtaining individual nanoparticles from starch was almost impossible regardless of the origin of the starch. In another study by the same group, a hydrolysis process combined with a physical treatment such as ultra-sonication for the formation of a uniform dispersion of starch nanocrystal was investigated.

Li et al. reported three stages corresponding to the stepwise hydrolysis of the amorphous, semicrystalline and crystalline layers of the starch structure. Some authors have suggested that high-amylose starches are more susceptible to acid hydrolysis than those with lower amylose contents, which are more easily hydrolysed. This can be explained...

Details zur Ausgabe

• Verlag: Royal Society of Chemistry
• Erscheinungsdatum: 2015
• Sprache: Englisch
• ISBN 10: 184973979X
• ISBN 13: 9781849739795
• Einband: Gebundene Ausgabe
• Anzahl der Seiten: 439
• Herausgeber: Visakh P M, Yu Long
• Kontakt zum Hersteller: Nicht verfügbar
• Verantwortliche Person: preigu; mail@preigu.de; ; Lengericher Landstr. 19; Osnabrück; 49078; Deutschland