Starch granules: structure and biosynthesis.

Preface * Fatty acids and fertility in dairy cows * Environmental and genetic influences on successful heifer rearing * Reducing dietary phosphorus inputs within dairy systems * Practical aspects of feeding grass to dairy cows * Practical considerations of feed evaluation systems for dairy cows * Adapting livestock production systems to climate change * Legislation affecting animal production systems * Mycotoxin issues in farm animals and strategies to reduce mycotoxins in animal feeds * The effect of nutrition on stress and immunity * Potential applications of GM technology * Influence of feed processing technology on pig performance * Piglet starter feeding in a changing business environment * Organic acids in pig diets * Amino acid requirements in piglets with special emphasis on tryptophan and valine * Factors affecting pork quality * List of participants * Index

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Recent Advances in Animal Nutrition

Morphological, thermal and rheological properties of starches from different botanical sources

Starch-composition, fine structure and architecture

Water, the most abundant constituent of natural foods, is a ubiquitous plasticizer of most natural and fabricated food ingredients and products. Many of the new concepts and developments in modern food science and technology revolve around the role of water, and its manipulation, in food manufacturing, processing, and preservation. This article reviews the effects of water, as a near-universal solvent and plasticizer, on the behavior of polymeric (as well as oligomeric and monomeric) food materials and systems, with emphasis on the impact of water content (in terms of increasing system mobility and eventual water "availability") on food quality, safety, stability, and technological performance. This review describes a new perspective on moisture management, an old and established discipline now evolving to a theoretical basis of fundamental structure-property principles from the field of synthetic polymer science, including the innovative concepts of "water dynamics" and "glass dynamics". These integrated concepts focus on the non-equilibrium nature of all "real world" food products and processes, and stress the importance to successful moisture management of the maintenance of food systems in kinetically metastable, dynamically constrained glassy states rather than equilibrium thermodynamic phases. The understanding derived from this "food polymer science" approach to water relationships in foods has led to new insights and advances beyond the limited applicability of traditional concepts involving water activity. This article is neither a conventional nor comprehensive review of water activity, but rather a critical overview that presents and discusses current, usable information on moisture management theory, research, and practice applicable to food systems covering the broadest ranges of moisture content and processing/storage temperature conditions.

Beyond water activity: recent advances based on an alternative approach to the assessment of food quality and safety

The molecular composition and physical aspects of starch structure are examined in relation to starch properties and utility. The structures and molecular properties of amylose and amylopectin are further considered for their effects on properties of starch granules and pastes, and whether or not they act independently or in concert with one another. Discussion of amylopectin focuses on models featuring clusters of short chain molecules that are interlinked and regularly spaced. Low and wide angle X-ray diffraction studies are cited to confirm the cluster model and the role of amylopectin in starch crystallinity. The diversity of starch is evident by its depostion in one or more sites within a plant and by the variety of plants in which the starch is found. In addition, starches differ widely in size, shape and composition.

Molecules to Granules: A Comprehensive Starch Review

The structures and transformations of the starch crystal forms A, B, C and V are reviewed from the viewpoint of their industrial importance. Reviewed also is the non-crystalline or amorphous state of starch and its role in determining the physical properties of native and gelled starches.

Starch Crystal Transformations and Their Industrial Importance

The terminology and methodology associated with basic starch phenomena

Publisher Summary Cereal grains, tubers, and roots are the main sources of starches for industrial and consumer applications. Following synthesis, starch is stored in the plant as compact micron-sized granules that are partly crystalline and, hence, water-insoluble, facilitating starch isolation and handling. The first step in starch utilization disrupts the granular structure leading to granule swelling and the hydration and solubilization of starch molecules. These events, collectively referred to as starch gelatinization, are affected by heating the granules that are slurried in water. For thickening foods, sizing and coating papers, sizing textiles, use in drilling muds or adhesive formulations, and use in a host of other applications, starch gelatinization in aqueous media is the first step. When starch is cooked, the flow behavior of a granule slurry changes because the suspension becomes a dispersion of swollen granules, partially disintegrated granules, and molecularly dispersed granule contents. The cooked product is called a starch paste. Transition from a suspension of granules to a paste is accompanied by a large increase in apparent viscosity. During cooling, paste consistency increases as molecular association forms a cross-linked network that increases paste resistance to deformation. In a cooled state, pastes may remain fluid or form a semi-solid or solid gel showing considerable strength.

Henry F. Zobel

Papers

Molecules to Granules: A Comprehensive Starch Review

Starch Crystal Transformations and Their Industrial Importance

The terminology and methodology associated with basic starch phenomena

Gelatinization of starch and mechanical properties of starch pastes

Developments in Carbohydrate Chemistry