Dietary fibers in the prevention of type 2 diabetes mellitus

This chapter reviews how dietary fibers can be used to prevent Type 2 diabetes mellitus. Dietary fibers are a heterogenous group of food compounds. The physicochemical properties of dietary fibers determine their effects on gastrointestinal and metabolic health, including effect on gastro-intestinal transit, glycemic response, microbial composition and fermentative capacity. Most fiber rich foods contain insoluble, prebiotic and viscous fibers in varying ratios. The chapter begins by discussing underlying mechanisms of action of insoluble fibers. It then goes on to discuss the various dietary fiber intervention studies, specifically focusing on prebiotic fibers and soluble viscous fibers. The chapter concludes by highlighting the importance of consuming high levels dietary fiber and whole grains and their positive impact on metabolic health.

Advances in understanding the nutritional value of antioxidants in wheat

Whole grain wheat has a diverse supply of hydrophilic and lipophilic antioxidants which include phenolic compounds (phenolic acids, flavonoids, anthocyanins which are present only in pigmented wheat, alkylresorcinols, and to a lesser extent proanthocyanidins), carotenoids (mainly lutein and zeaxanthin) and tocochromanols (α, β, γ and δ - tocopherols and tocotrienols). This diversity of antioxidants function to protect consumers from radical-induced oxidative damage caused by various free radicals produced endogenously from metabolic processes and exogenously from sunlight and other chemicals and environmental pollutants. They also chelate metal ions which could catalyze oxidation reactions in the physiological system, thereby providing antioxidant protection. However, phenolic compounds might exert pro-oxidant effect when bound to heavy metal ions. This effect could be prevented by the diverse antioxidant system in wheat.

Advances in understanding the nutritional value of starch in wheat

This chapter provides a nutritional overview of the wheat starch structure, function, digestibility of diverse wheat starches, and highlights interactions of starch and other biomolecules such as proteins, lipids, and non-starch polysaccharides.

Advances in understanding the genetics of the nutritional properties of cereals: maize and oat proteins

This chapter reviews advances in understanding the genetics of the nutritional properties of cereals, particularly focusing on maize and oat proteins. It covers the genetics of maize and oat nutritional properties and the progress that has been made in terms of quality and the importance of these grains as macro- and micro-nutrients in humans.

Developments in fractionation methods to improve extraction of aleurone or its beneficial compounds from wheat grain

In wheat grains, the aleurone layer is located between the peripheral tissues and the starchy endosperm and is rich in soluble proteins, minerals, lipids, vitamins and micronutrients and contains several compounds with antioxidant activities. However, along grain fractionation it is mainly recovered in bran fractions, generally used to feed animals or for energy production. These last few years, the cereal scientist community and companies developed research and new processing technologies (mainly protected with patents) in order to more deeply exploit its potential. This was mainly based on a better knowledge of its composition and properties helped by a better monitoring of its behaviour along milling, debranning and further isolation. This chapter summarizes main strategies for aleurone layer isolation and pinpoints out how its cell walls or cellular content may be of interest to obtain. It also highlights potential drawbacks, synergistic effect of different compounds, question of bioavailability and possible future trends.

Developing millet-based cereal products with enhanced nutritional properties

There is a growing awareness today about climate change and its expected ravaging effects on agricultural productivity, food production and ultimately, food and nutrition security. Against this backdrop, drought-tolerant hardy crops are gaining importance as significant sources of food and nutrition especially in the most vulnerable parts of the world mainly in sub-Saharan Africa and Asia. In this regard, the millets, which are major cereal staples in many parts of Africa and Asia are of importance for food and nutrition security in these regions. Millets are processed into various foods using traditional processing methods such as fermentation and malting and modern technologies such as extrusion cooking. This chapter focuses on how these processing methods can enhance the nutritional properties of millet-based foods. The simple practice of compositing millets with other plant foodstuffs for enhanced nutritional quality of millet-based foods is also explored.

Fiber-associated wheat lignans and colorectal cancer prevention

Wheat, as a staple food, has been largely consumed worldwide. In addition to nutritional values, whole grain including fiber-enriched wheat bran has been reported to provide many nutraceuticals such as wheat lignans. This chapter reviews recent epidemiological and animal data on wheat lignans and their role in colorectal cancer prevention. It covers aspects of the lignan structure, biosynthesis, analysis, metabolism and potential health benefits with emphasis on anti-proliferative, anti-oxidant, anti-inflammation, anti-estrogenic and cell cycle arrest mechanisms. Human epidemiological studies suggest dietary intake of lignans is associated with reducing risk of many chronic diseases such as cardiovascular disease, chronic bowel inflammation, and certain types of cancer including colorectal cancer. The bioactivity of wheat lignans has been shown to be influenced by their chemical forms and microbial flora-induced metabolites. Compelling animal study data suggest that dietary lignans or wheat lignans contribute to colorectal cancer prevention; however, further clinical intervention studies appear warranted.

Advances in understanding the nutritional value of lipids in wheat

Lipids are a small component in the wheat grain composition (2-4%) and roughly, two thirds (66%) of them are contained in the germ, 15% are in the bran and particularly in the aleuronic layer, whereas about 20% are distributed in the endosperm, partly within the starch granules. They include a variety of different structural types, i.e. carboxylic acids (or fatty acids); mono, di and triacylglycerols (triglycerides or neutral fats); phospholipids; glycolipids; waxes; terpenes; steroids and alkylresorcinols. This chapter reviews the importance of lipids in wheat kernels and their significance in wheat technology and products. It also addresses the significance of wheat lipids and associated substances in human nutrition. A discussion on the wheat germ and how this wheat germ can be used to produce wheat oil is also included.

Developing hulled wheat-based cereal products with enhanced nutritional properties: emmer, einkorn and spelt

Hulled wheats (emmer, einkorn, and spelt) have low yields but are suitable for organic and low-input agriculture under marginal or high-stress conditions. However, data on the composition of hulled wheats, often also called ‘ancient wheats’ is still scarce, especially on bioactive components such as vitamins. This chapter shows that einkorn, emmer and spelt have some nutritional benefits compared to modern durum or common wheat varieties. Hulled wheats have superior properties in constituents such as protein, some minerals (e.g. calcium) and carotenoids (e.g. lutein). Einkorn might be an alternative for people suffering from wheat sensitivities due to improved gliadin digestibility and low abundance of amylase-trypsin inhibitors. A significant disadvantage is the lower content of total dietary fibres. The genetic diversity of hulled wheats can be used for breeding e.g. for Zn biofortification or reducing immunogenic potential.

Understanding the nutritional and nutraceutical properties of sorghum

Sorghum is a globally grown cereal. Many sorghum varieties contain high levels of polyphenolic compounds with potential health benefits. With a growing interest in using diet as a preventative measure against chronic diseases, the benefits of sorghum need to be examined. This chapter discusses current research on sorghum and its bioactive compounds, particularly the diversity of polyphenolic compounds present in sorghum. The effects of the phenolic compounds against cancer, their anti-inflammatory properties, anti-obesity effects and effects on gut microbiome are discussed. The chapter also discusses anti-nutritional effects of sorghum polyphenols as well as the effects of processing on bioactive compounds and bioavailability.