**2.4 Carbohydrates**

Carbohydrates are an essential component of legume seeds and possess a bioactive property against chronic diseases. Chickpeas have been shown to be a good source of carbohydrates, such as dietary fiber, starch, and oligosaccharides [39, 40]. Pigeon peas have a high content of carbohydrates (57.6%), which is the same in cotyledons. Black gram beans have also been documented to possess soluble mucilaginous polysaccharides along with dietary fiber.

*Nutraceutical Properties of Legume Seeds: Phytochemical Compounds DOI: http://dx.doi.org/10.5772/intechopen.100171*

**Figure 5.** *Chemical structure of major phytosterols:* β*-sitosterol (a), campesterol (b), stigmasterol (c).*

#### *2.4.1 Dietary fiber*

Dietary fiber has been demonstrated to be a beneficial food component and is made up of a combination of polymeric non-starch substances (such as cellulose, hemicellulose, and pectin) that are resistant to enzymatic digestion in the human gastrointestinal tract [41]. The dietary fiber contents of legume seeds vary according to the species, variety, and processing method. Dietary fiber, also called cell wall material, is of a lower level in cotyledon than testa [42]. Fiber concentration ranges from 8 to 27.5% and is between 3 and 14% of soluble fiber from almost gain legumes consumption. The gut bacteria metabolize and convert the solute fiber into fatty acids, which aid in the health of colonic cells. Guar beans have been identified to have the richest amounts of fiber, as well as soluble fiber (12.5%), among other legumes [41].

Some research projects have shown that dietary fiber can interact with other bioactive compounds such as phenolic compounds, which play an important role in health advantages. The interaction is accomplished through the formation of hydrogen, hydrophobic and covalent linkages between phenolic compounds, and components of legume cell wall fibers [43].

#### *2.4.2 Resistant starch*

Legumes are one of the best sources of resistant starch, and this component is not digested by humans. Resistant starch (RS) concentrations in legume seeds have been found to be higher than in cereals and many tubers (**Figure 6**) [45]. Cowpeas, lentils, peas, kidney beans, and white beans displayed the RS content of 0.6, 3.4, 2.5, 2, and 4.2 g/100 g of total seed material, respectively [3]. Legume seed processing has an effect on the RS content. Alonso et al. [46] showed that the formation of RS increased after refrigeration of legumes, which corresponded to the fact that cooling after gelatinization can develop the formation of RS.

**Figure 6.** *Chemical structure of resistant starch: Glucose units (a), amylose (b), amylopectin (c) [44].*
