Henry Advances in Food and Nutrition Research

1. Auflage 2015
ISBN: 978-0-12-802427-0
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, Band Volume 74, 146 Seiten

Reihe: Advances in Food and Nutrition Research

Advances in Food and Nutrition Research recognizes the integral relationship between the food and nutritional sciences and brings together outstanding and comprehensive reviews that highlight this relationship. Contributions detail scientific developments in the broad areas of food science and nutrition and are intended to provide those in academia and industry with the latest information on emerging research in these constantly evolving sciences. - The latest important information for food scientists and nutritionists - Peer-reviewed articles by a panel of respected scientists - The go-to series since 1948

Autoren/Hrsg.

Henry, Jeya

Inhaltsverzeichnis

1;Front Cover;1
2;Advances in Food and Nutrition Research;4
3;Copyright;5
4;Contents;6
5;Contributors;8
6;Preface;10
7;Chapter One: Leveraging Agriculture for Nutrition Impact through the Feed the Future Initiative;12
7.1;1. Background;13
7.1.1;1.1. The nutrition narrative;13
7.1.2;1.2. Renewed focus: Agriculture and nutrition linkages;15
7.2;2. Linking Agriculture and Nutrition;17
7.2.1;2.1. Current understanding of the linkages between agriculture and nutrition;17
7.2.1.1;2.1.1. Agriculture and nutrition pathways;17
7.2.1.1.1;2.1.1.1. ProductionConsumption pathway;18
7.2.1.1.2;2.1.1.2. IncomeFood and health care purchase pathway;18
7.2.1.1.3;2.1.1.3. Women´s empowerment pathway;20
7.2.1.1.4;2.1.1.4. The enabling environment for the pathways;21
7.2.1.1.4.1;2.1.1.4.1. Food market environment;21
7.2.1.1.4.2;2.1.1.4.2. Natural resources environment;22
7.2.1.1.4.3;2.1.1.4.3. Health, water, and sanitation environment;23
7.2.1.1.4.4;2.1.1.4.4. Knowledge and norms;23
7.2.1.2;2.1.2. Guiding principles;24
7.2.2;2.2. The Feed the Future initiative;25
7.3;3. The Landscape Analysis of Feed the Future Activities;26
7.3.1;3.1. Background of landscape analysis;27
7.3.1.1;3.1.1. Objective;27
7.3.1.2;3.1.2. Scope;27
7.3.1.3;3.1.3. Frameworks for landscape analysis;27
7.3.1.4;3.1.4. Limitations of landscape analysis;28
7.3.2;3.2. Key findings and considerations;29
7.3.2.1;3.2.1. Activity approaches;29
7.3.2.2;3.2.2. Target populations;29
7.3.2.3;3.2.3. Value chains and the selection criteria;30
7.3.2.3.1;3.2.3.1. Factors behind value chain selection;30
7.3.2.3.2;3.2.3.2. Regional emphasis;32
7.3.2.4;3.2.4. Integration of nutrition in Feed the Future activities;32
7.3.2.5;3.2.5. Agriculture-to-nutrition pathways;33
7.3.2.5.1;3.2.5.1. ProductionConsumptionNutrition pathway;33
7.3.2.5.2;3.2.5.2. IncomeFood and health purchaseNutrition pathway;33
7.3.2.5.3;3.2.5.3. Women´s empowerment pathway;34
7.3.3;3.3. Observations and discussion;34
7.3.3.1;3.3.1. Inclusion of nutrition objectives and indicators;34
7.3.3.2;3.3.2. Monitoring intermediate steps along agriculture-to-nutrition pathways;35
7.3.3.3;3.3.3. Tackling women´s roles and gender norms;36
7.3.3.3.1;3.3.3.1. Women´s time and workload constraints;36
7.3.3.3.2;3.3.3.2. Gender roles and norms;37
7.3.3.4;3.3.4. Targeting;37
7.3.3.4.1;3.3.4.1. Inclusion of both men and women in agriculture and nutrition interventions;37
7.3.3.4.2;3.3.4.2. Working with more vulnerable beneficiaries in zones of influence;38
7.3.3.4.3;3.3.4.3. Communications for better coverage in co-located activities;38
7.3.3.5;3.3.5. Value chain selection;39
7.3.3.5.1;3.3.5.1. Investing in nutrient-dense value chains;39
7.3.3.5.2;3.3.5.2. Potential unintended consequences on market prices;39
7.3.3.6;3.3.6. Market access to diverse, nutrient-dense foods;40
7.3.3.7;3.3.7. Social and behavioral change along value chains and agriculture-to-nutrition pathways;40
7.3.3.7.1;3.3.7.1. Messaging;40
7.3.3.7.2;3.3.7.2. Delivery;42
7.3.3.8;3.3.8. Multisectoral coordination;42
7.3.4;3.4. Recommendations from landscape analysis;43
7.3.4.1;3.4.1. Design and modify interventions and indicators based on context assessments;44
7.3.4.2;3.4.2. Empower women by building a supportive family and social environment;44
7.3.4.3;3.4.3. Target social and behavioral change activities along all agriculture-nutrition pathways;44
7.3.4.4;3.4.4. Focus on opportunities for nutrition throughout the value chains;45
7.3.4.5;3.4.5. Document incremental results to build the evidence base;45
7.4;4. Moving Forward;45
7.4.1;4.1. Technical briefs on the connections between agriculture and nutrition;45
7.4.2;4.2. Understanding the connections between agriculture and nutrition in the food system;49
7.5;5. Conclusion;54
7.6;Acknowledgment;55
7.7;Disclaimer;55
7.8;References;55
8;Chapter Two: Health Benefits of Prebiotic Fibers;58
8.1;1. Prebiotic Fibers;58
8.1.1;1.1. Definitions and properties of dietary fiber;58
8.1.1.1;1.1.1. Physiological properties of dietary fibers;60
8.1.1.2;1.1.2. Effect on bowel movement;61
8.1.1.3;1.1.3. Favorable colonic fermentation;62
8.1.1.4;1.1.4. Effect on serum lipids and blood glucose;63
8.1.1.5;1.1.5. Overweight;63
8.1.1.6;1.1.6. Colon cancer;63
8.1.2;1.2. Definition of prebiotics;64
8.2;2. Physiological Effects of Different Prebiotic Fibers;65
8.2.1;2.1. Lactulose and lactitol;65
8.2.1.1;2.1.1. Lactulose;65
8.2.1.2;2.1.2. Lactitol;66
8.2.2;2.2. Galactooligosaccharides;66
8.2.2.1;2.2.1. Galactooligosaccharides from lactose (GOS);66
8.2.2.2;2.2.2. Soybean galactooligosaccharides;68
8.2.3;2.3. Fructans;69
8.2.3.1;2.3.1. Levans;69
8.2.3.2;2.3.2. Fructooligosaccharides from sucrose;70
8.2.3.3;2.3.3. Inulin and oligofructose from chicory roots;72
8.2.4;2.4. Glucose-based prebiotic fibers;75
8.2.4.1;2.4.1. Iso-malto-oligosaccharides;76
8.2.4.2;2.4.2. Polydextrose;76
8.2.4.3;2.4.3. Soluble Gluco Fiber;77
8.2.4.4;2.4.4. Other resistant starches;78
8.2.5;2.5. Gums and other complex polysaccharides as prebiotic fibers;79
8.2.5.1;2.5.1. Guar gum;79
8.2.5.2;2.5.2. Acacia gum;79
8.2.5.3;2.5.3. Arabinoxylo-oligosaccharides and xylo-oligosaccharides;80
8.2.5.4;2.5.4. Other candidates;80
8.3;3. Nutrition and Health Claims Based on Prebiotic Fibers;81
8.3.1;3.1. Nutrition claims;81
8.3.2;3.2. Health claims for prebiotic dietary fibers;82
8.3.2.1;3.2.1. Health claims in the United States;83
8.4;4. Future Developments;85
8.4.1;4.1. Final remarks;88
8.5;References;88
9;Chapter Three: Vegetarian Diets Across the Lifecycle: Impact on Zinc Intake and Status;104
9.1;1. Introduction;105
9.2;2. Definitions of Vegetarian Diets;106
9.3;3. Zinc Intake and Bioavailability;107
9.3.1;3.1. Phytate, zinc, and calcium;107
9.4;4. Mechanisms of Zinc Homeostasis;109
9.5;5. Determination of Zinc Status;110
9.6;6. Vegetarian Diets and Zinc Status in Healthy Adults;111
9.6.1;6.1. Prevalence of vegetarian diets in adults;111
9.6.2;6.2. Adaptations to a vegetarian diet;112
9.6.3;6.3. Comparative studies of zinc status in adults;113
9.7;7. Vegetarian Diets and Zinc Status in Pregnancy and Lactation;121
9.7.1;7.1. Comparative studies of zinc intake in pregnancy;121
9.7.2;7.2. Comparative studies of zinc biomarkers in pregnancy;123
9.7.3;7.3. Zinc status and functional outcome in pregnancy;124
9.7.4;7.4. Zinc status during lactation;124
9.8;8. Vegetarian Diets and Zinc Status in Children;125
9.8.1;8.1. Prevalence of vegetarian diets in children;126
9.8.2;8.2. Comparative studies of zinc status in children;127
9.8.3;8.3. Infants;127
9.8.4;8.4. Young children;129
9.8.5;8.5. Adolescents;130
9.9;9. Vegetarian Diets and Zinc Status in the Elderly;131
9.9.1;9.1. Comparative studies of zinc status in the elderly;131
9.10;10. Limitations and Further Research;133
9.11;11. Conclusion;134
9.12;References;134
10;Index;144

Leseproben

Chapter Two Health Benefits of Prebiotic Fibers
Diederick Meyer1    Sensus BV, Roosendaal, The Netherlands
1 Corresponding author: email address: [e-mail] Abstract
This chapter describes the various compounds that can act as prebiotic fibers: their structure, occurrence, production, and physiological effects (health effects) will be presented. The basis for the description is the latest definitions for dietary fibers and for prebiotics. Using as much as possible data from human studies, both the fiber and the prebiotic properties will be described of a variety of compounds. Based on the presented data the latest developments in the area of prebiotics, fibers and gut and immune health will be discussed in more detail as they show best what the potential impact of prebiotics on health of the human host might be. Keywords Prebiotics Dietary fibers Health effects 1 Prebiotic Fibers
1.1 Definitions and properties of dietary fiber
The definition of dietary fiber has been the subject of an almost endless debate, mainly because dietary fiber is not one single chemical entity like starch or cellulose. Some based the definition on physiological features, whereas other used its chemical composition. The original description by Hipsley (1953) described dietary fiber as nondigestible constituents of plant cells walls. Later, Trowell and others expanded the description to “consisting of plant polysaccharides and lignin which are resistant to hydrolysis by digestive enzymes of man.” More importantly, these authors also came up with the dietary fiber hypothesis related to health observations (Trowell, 1972, 1976). The definition of dietary fiber was based on (one of) its physiological features, namely, its nondigestibility. Based on this feature, fiber determinations were developed mimicking the human digestion in a glass tube, to determine the fiber content of food, e.g., to assist food industry and enforcing authorities with nutritional labeling. In 1985, these efforts led to an approved AOAC method (AOAC 985.29) and in many countries it was used as a de facto definition of dietary fiber: material determined by this method is dietary fiber (AOAC 985.29, 2012). Soon it turned out that many nondigestible carbohydrates with physiological functions as dietary fiber were not assessed by this method or by other methods based on AOAC 985.29. This has led to the development of a battery of assays aimed at determining specific dietary fibers, such as AOAC 997.08 and 999.03 for fructans (AOAC 997.08, 2012; AOAC 999.03, 2012), or AOAC 2000.11 for polydextrose (AOAC 2000.11, 2012). A more detailed description of the development of dietary fiber definitions and assessments can be found in Prosky (2001) and Tungland and Meyer (2002). Figure 1 (left-hand picture) shows the situation before the latest developments that will be described below. Figure 1 Analysis of dietary fiber before the development of AOAC 2009.01/2011.25 (left-hand side) and after (right-hand side). Reprinted with permission from Official Methods of Analysis of AOAC International. Copyright 2012 by AOAC International The whole discussion on the definition has now led to two definitions for dietary fiber for labeling; they both are based on the nondigestibility. In the EU, dietary fiber (dietary fiber) means carbohydrate polymers (either naturally occurring or obtained by physical, enzymatic or chemical means, or synthetic polymers) that are not hydrolyzed by the digestive enzymes in the small intestine of humans. The carbohydrate polymers must have a degree of polymerization (DP) of three or more monomeric units (European Commission, 2008/100/EC) and for isolated fibers and synthetic polymers a beneficial physiological effect has to be proven based on generally accepted scientific evidence. The definition adopted by Codex Alimentarius Commission (2009; Alinorm 09/32/26) is based on the same type of carbohydrate polymers, but on those having a DP of 10 and above. However, a footnote which forms an integral part of this definition, states that the decision on whether or not to include carbohydrates from three to nine monomeric units should be left to national authorities (see also Harris & Pijls, 2009). Also this definition requires evidence for a beneficial physiological effect for carbohydrates obtained by physical, enzymatic or chemical means, and synthetic polymers. It should be stressed that from a physiological point of view, there is no reason to exclude oligomers with DP < 10 (Howlett et al., 2010). With this definition in mind, a universal method determining all dietary fibers in food was developed (McCleary, 2007; McCleary et al., 2010). These methods are now available as validated methods (AOAC 2009.01 and AOAC 2011.25) and they can be used to assess the total dietary fiber content of food irrespective of the type of fiber present (see Fig. 1) (AOAC 2009.01, 2012; AOAC 2011.25, 2012). Not surprisingly, also these methods have their disadvantages; apart from the laborious procedure it now emerges that some fibers still partially escape detection (e.g., Zielinski, DeVries, Craig, & Bridges, 2013). In connection with the issue about the DP required to classify as dietary fiber as in the Codex definition, it should be stressed that these or any other approved analytical method cannot discriminate dietary fibers with DP < 10 from those with DP = 10 (Betteridge, Caers, Lupton, Slavin, & Devries, 2012). 1.1.1 Physiological properties of dietary fibers Dietary fiber is acknowledged worldwide for its positive effects on health and well-being. The benefits include positive effects on bowel habit, a favorable effect on fermentation in the colon, a reduction of blood (LDL-) cholesterol levels and an improvement of blood glucose and insulin levels. Moreover there are associations from epidemiological evidence mainly between a lowered risk for colon cancer and for obesity with appropriate fiber consumption (e.g., EFSA, 2010b; Health Council of the Netherlands, 2006). An overview of the effects of different kind of fibers is presented in Table 1. Some dietary fibers, such as pectins or some gums, also have physiological effects due to their influence on the rheology of the intestinal content; a high viscosity is generally connected with a delayed gastric emptying and increased small intestinal transit time. A viscous environment in the small intestine may also inhibit absorption of nutrients with its physiological consequences. Table 1 Physiological effects of various fiber types Gastric emptying Lower rate None ? No effect Glucose absorption curve Flattening Unknown ? ? Fermentation in colon Large extent Hardly Variable Completely Bowel habit + ++ + + Blood cholesterol Lowering No effect Variable Lowering (+)+: (strong) positive effect; ?, no or conflicting data. It should be noted that the evidence for much of the health benefits described below comes from epidemiological associations. In many cases it is not easy to carry out trials for such benefits with isolated dietary fibers, as these trials will take too long (e.g., for the lowered risk for colon cancer, or a lowered death rate from cardiovascular disease) and thus are very costly to carry out. For many of these diseases the lack of suitable and validated biomarkers also plays an important role; as an example, whereas the serum lipid level of cholesterol is an accepted biomarker for the risk for cardiovascular disease, such markers are not available for colon cancer, or obesity. 1.1.2 Effect on bowel movement The best known effect of dietary fiber is its influence on stool: it decreases the time for food passage through the entire gastrointestinal tract and increases fecal bulk. In fact, this feature is used by some authorities as a basis for their guidelines for fiber intake (Health Council of the Netherlands, 2006; Institute of Medicine, 2005). Moreover, these effects can also be investigated easily in intervention studies with isolated fibers. As shown in Table 1 insoluble fibers have the strongest effect on bowel habit as they act as fecal bulking agents; e.g., what bran provides from 2.6 to 4.9 g/g (Cummings, Beatty, Kingman, Bingham, & Englyst, 1996; Maki et al., 2009), whereas soluble fibers such as pectin or inulin only provide about 1–2 g/g (e.g. Den Hond, Geypens, & Ghoos, 2000; Salminen et al., 1998). Their main effect is on stool consistency and frequency of defecation as they increase the softness of fecal matter. 1.1.3 Favorable colonic fermentation Dietary fibers reach the colon intact and there they can be fermented by specific colonic bacteria and converted into short-chain fatty acids (SCFA), lactic acid and gas. The extent of the fermentation depends very much on the type...