**2. Antioxidant potential of wheat grain**

Rising investigations have proved that certain types of cancer, coronary heart disease, and potential health benefits are reduced by the intake of whole wheat. Phytochemicals and nondigestible carbohydrates are the beneficial bioactive factors present in whole wheat grain [11–14]. In wheat grain there are small molecular weight phytochemicals known as bioactive molecules. They consist of but they are not inadequate to carotenoids, phenolic acids, tocopherols, and lignans. Oxidative damage to the most important compounds such as enzymes and DNA by different mechanisms is prevented by these bioactive molecules. To dismiss the attack of reactive oxygen species (ROS) such as singlet oxygen molecule or hydroxyl radicals on biological molecules, bioactive molecules directly react with these ROS molecules [15].

There are an adequate number of bioactive compounds present in the wheat grains instead of aleurone which is mainly consist of protein granules. The wheat bran also contained the major proteins in the wheat grain [16]. The above investigation indicates the utilization and production of "super bran" and other wheat-based food and components rich in bioactive molecule present in wheat. Other bioactive factors and bioactive molecule-rich wheat grain should be produced after studying the results of old investigations [17]. The bioactive compounds particularly the phenolics are found in the bran portion of the cereal grains and occur in different forms mainly free, soluble conjugated, as well as insolublebound forms [18].

In wheat bran, the availability of bioactive molecule potential can be influenced by postharvest treatment, milling practice, and storage conditions investigated in few investigations. The outcomes of the above investigations showed that yeast treatment and postharvest enzymatic particle size of bran and storing practices can considerably change bioactive molecule accessibility in food products containing wheat [19].

Remarkably, the bioactive molecules of selected food have been investigated in food products and the properties of processed food atmosphere on bioactive molecule accessibility in food products containing wheat. To have little health support, bioactive foods are dynamic and are well acknowledged in Ref. [15]. The accessibility and bioavailability of various ingredients from wheat are very beneficial regarding health perspective in targeting specific body organs. Collaboration of wheat bioactive molecule with different food compounds and also the end merchandise to process food environments such as thermal treatment on the universal bioactive molecular properties of wheat products are not understood. Lignans and phenolic acids present as wheat phenolics are known as bioactive molecules [20].

The bioavailability and availability of bioactives can be altered by food matrix. The bioavailability of bioactive molecules presents in wheat such as lignans and phenolic acids from different wheat-based food products and ingredients has been investigated in pilot human and animal investigations. The natural bioactive molecule rich in wheat-based functional food is very important to augment human benefits [21].

There are number of analytical techniques has been established for the determination of phytochemical composition, bioactive molecular properties of wheat grain and their fractions. Among different fluorometric and spectrophotometric methods, electron spin resonance (ESR) spectroscopy considered a better approach because it deals with the presence of free radicals and considered a better analytical method for wheat bioactive molecules. These analytical methods can be used on different botanicals and cereal grains [22].

#### **2.1. Phenolic compounds present in wheat**

**1. Introduction**

366 Wheat Improvement, Management and Utilization

**2. Antioxidant potential of wheat grain**

Wheat (*Triticum aestivum* L.) is used as a staple food by human since the late Stone Age (ca. 6700 BC) [1]. It is also a promising source of bioactive compounds such as phenolic acids, tocotrienols, tocopherols, carotenoids, phytosterols, and flavonoids and antinutritional factors, such as phytic acids and oxalates. Wheat cultivars exert antioxidant activity due to the presence of phytochemicals, such as phenolic acids, carotenoids, anthocyanins, and tocopherols [2]. They are also enriched with basic nutrients, i.e., proteins, vitamins, and minerals including calcium, iron, zinc, phosphorous, etc. The percentages of the phytochemicals are greatly influenced by multiple factors, such as soil type, cultivar type, topography, temperature, and humidity [3]. The population is more diverting toward the consumption of natural antioxidants due to their safe status and effectiveness in the physiological system when compared to synthetic antioxidants. They neutralize the effects of free radicals, act as metal chelators, and terminate the oxidative enzyme inhibitors and reactive oxygen species (ROS) reactions [4]. These free radicals enhance the uncontrolled growth of cells, produce the genetic defects in DNA, and leak the antioxidant enzyme concentration from the cells [5]. Similarly, low-density lipoprotein (LDL) is responsible for the development of coronary diseases [6]. The polyphenols from the wheat have preventive role against reactive oxygen species through neutralizing the hydroxyl and peroxy radicals, thereby suppressing the lipid peroxidation [7]. The human body contains two antioxidant systems: enzymatic including glutathione peroxidase and superoxide dismutase (SOD) and nonenzymatic, i.e., vitamin C, β-carotene, vitamin E, and selenium [8]. Extraction is a process which is used for the recovery and isolation of phytochemicals from wheat cultivars. The quantification of phytochemicals from wheat is affected by multiple factors, i.e., extraction time, solvent, solute/solvent ratio, efficiency of mass transfer, temperature, and particle size [9]. There are frequently methods which are used to determine the antioxidant potential of wheat such as DPPH, ORAC, and FRAP. High-performance liquid chromatography and gas chromatography are direct indicators of antioxidant capacity [10].

Rising investigations have proved that certain types of cancer, coronary heart disease, and potential health benefits are reduced by the intake of whole wheat. Phytochemicals and nondigestible carbohydrates are the beneficial bioactive factors present in whole wheat grain [11–14]. In wheat grain there are small molecular weight phytochemicals known as bioactive molecules. They consist of but they are not inadequate to carotenoids, phenolic acids, tocopherols, and lignans. Oxidative damage to the most important compounds such as enzymes and DNA by different mechanisms is prevented by these bioactive molecules. To dismiss the attack of reactive oxygen species (ROS) such as singlet oxygen molecule or hydroxyl radicals on

biological molecules, bioactive molecules directly react with these ROS molecules [15].

There are an adequate number of bioactive compounds present in the wheat grains instead of aleurone which is mainly consist of protein granules. The wheat bran also contained Cereals are used as staple foods due to a promising source of nutrients including carbohydrates, vitamins, proteins, and minerals. They are also consisting of a wide range of bioactive compounds and exert health-promoting effects such as anticancer, cardio-prevention, diabetes, and aging [23]. These bioactive compounds exhibited multiple physiological mechanisms including antioxidant activity, enhancement of immune system, mediation of hormones and facilitation of substance transit via digestive tract, production of butyric acid in the colon, and assimilation of substances in the gut [24, 25].

Among these cereals, wheat (*T*. *aestivum* L.) is a significant source of minerals, proteins, water-soluble vitamins, and dietary fibers. The wheat grain is divided into three parts such as endosperm (80–85%), bran (13–17%), and germ (2–3%) and comprises all essential nutrients. Generally, wheat grain kernel contains carbohydrates (70%), protein (12%), water (12%), fat (2%), crude fiber (2.2%), and minerals (1.8%), respectively. Moreover, wheat grain kernel is a potential source of minerals, including magnesium, phosphorus, zinc, manganese, iron, selenium, copper, and potassium [26]. Likewise, wheat is also enriched with a wide range of bioactive compounds, including phenolic acids (136.8–233.9 μg/g), alkylresorcinols (AR) (99.9–316.0 μg/g), phytosterols (562.6–1035.5 μg/g), and tocols (19.3–292.7 μg/g) [27, 28]. Phenolic acids are widely distributed in different parts of grains, i.e., testa, pericarp, and aleurone [29]. In wheat, several phenolic acids are present such as chlorogenic acid, ferulic acid, caffeic acid, *p*-coumaric, and sinapic acid, respectively. These compounds are present as bound forms, respectively, as phenolic acids (85%) in maize, wheat and maize (75%), and rice (62%). Cinnamic acids have been categorized as bioactive ingredients of the diet because they are bound to structural compounds of the cell wall [30, 31]. The schematic representation of wheat grain fractions is shown in **Figure 1**.

**Figure 1.** Schematic representation of wheat grain fractions.

Ferulic acid (4-hydroxy-3-methoxycinnamic acid) is present in different parts of vegetables, fruits, and grains as well as also endorses the health-promoting perspectives [29, 32]. Wheat flour is the prime ingredient, which is used to prepare different products of bread industry such as pasta. Wheat is also a promising source of dietary fibers along with preventing and curing some digestive disorders [33]. Endosperm is separated from the bran and germ through grinding, sieving, and purifying steps in conventional wheat roller milling. Furthermore, endosperm is also grounded to wheat flour on the basis of refinement and then used to prepare the bread, whereas bran, aleurone layer, starchy endosperm, and germ are used as milling by-products. Similarly, wheat bran is used by animals due to higher nutritional profile which exerts beneficial physiological effects. The bran-based products are shown with more health perspectives when compared to refined flour. Consumers are more interested to utilize the bran-based products, such as cookies, bread, pasta, breakfast cereals, cakes, snacks, and more [34].
