Preface

Chapter 7 **Antioxidants in Maca (Lepidium meyenii) as a Supplement in**

Chapter 8 **The Use of Iodine, Selenium, and Silicon in Plant Nutrition for**

**the Increase of Antioxidants in Fruits and Vegetables 155** Julia Medrano-Macías, Rosalinda Mendoza-Villarreal, Valentín Robledo-Torres, Laura Olivia Fuentes-Lara, Francisca Ramírez-Godina, Miguel Ángel Pérez-Rodríguez and Adalberto Benavides-

**Nutrition 137** Serol Korkmaz

**VI** Contents

Mendoza

Free radicals are atoms or molecules containing unpaired electrons. Damage occurs when the free radical encounters another molecule and seeks to find another electron to pair its un‐ paired electron. Free radicals can cause mutation in different biological compounds such as protein, nucleic acids, and lipids, and the damage caused by the free radicals can lead to vari‐ ous diseases (cancer, cardiovascular disease, aging, etc.). Healthy foods are considered as the main source of antioxidant compounds, and from the beginning of human life, the ancient Egyptian people had a varied and healthy diet. They also ate well. Even the poorest people ate a healthy diet, that consisted of fruits and vegetables, which are rich in different antioxidant compounds. Antioxidants are helpful in reducing and preventing damage from free radical reactions because of their ability to donate electrons, which neutralize the radical without forming another. Ascorbic acid, for example, can lose an electron to a free radical and remain stable itself by passing its unstable electron around the antioxidant molecule. Unfortunately, new data indicate that the synthetic antioxidants used in the industry could have carcinogenic effects on human cells, thus fueling an intense search for new, natural, and efficient antioxi‐ dants. Therefore, the current book discusses the role and source of antioxidant compounds in nutrition and diets. Also, the current book includes nine chapters contributed by experts around the world, and the chapters are categorized into two sections: "Antioxidant Com‐ pounds and Biological Activities" and "Natural Antioxidants and Applications."

Section 1 (Chapters 1–3) describes the meaning of free radicals and antioxidants and the re‐ lated terms and abbreviations, the methods for determination of antioxidant activity, and the biological activities of antioxidant compounds.

Section 2 (Chapters 4–8) illustrates the main food sources of antioxidant compounds and their role and the mode of action of each antioxidant type, in addition to the application of antioxidant compounds in the industry, medicine, and other fields.

The current book is very interesting for students, researchers and scientists in the field of biological science and applications.

I would like to thank all the contributing authors for their time and great efforts in the care‐ ful construction of the chapters and for making this project realizable.

I am grateful to Mrs. Marina Dusevic (Author Service Manager) for her great efforts, encour‐ agement and guidelines during my preparation of this book.

Finally, I would like to express my deepest gratitude toward my parents, my wife (Ghada M. Azzam), and my daughters (Hana, Farida, and Zaina) for their kind cooperation and en‐ couragement, which help me in the completion of this book.

> **Dr. Emad A. Shalaby** Department of Biochemistry

**Section 1**

**Antioxidant Compounds and Biological**

**Activities**

Faculty of Agriculture Cairo University, Cairo, Egypt

**Dr. Ghada M. Azzam** Egyptology Department Faculty of Archeology Cairo University, Cairo, Egypt **Antioxidant Compounds and Biological Activities**

Finally, I would like to express my deepest gratitude toward my parents, my wife (Ghada M. Azzam), and my daughters (Hana, Farida, and Zaina) for their kind cooperation and en‐

> **Dr. Emad A. Shalaby** Department of Biochemistry Faculty of Agriculture

> > **Dr. Ghada M. Azzam** Egyptology Department Faculty of Archeology

Cairo University, Cairo, Egypt

Cairo University, Cairo, Egypt

couragement, which help me in the completion of this book.

VIII Preface

**Chapter 1**

**Provisional chapter**

**Antioxidants from Natural Sources**

**Antioxidants from Natural Sources**

Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.75961

Imtiaz Mustafa

**Abstract**

**1. Introduction**

Haseeb Anwar, Ghulam Hussain and

Haseeb Anwar, Ghulam Hussain and Imtiaz Mustafa

**Keywords:** antioxidants, vegetables, fruits, plants, herbs

DOI: 10.5772/intechopen.75961

Antioxidants are the defense system of the body against the damage of reactive oxygen species, which is normally produced during the various physiological processes in the body. There are various sources of these antioxidants like endogenous antioxidant present in the body and exogenous food source. In recent decades, alternate of synthetic food antioxidants by natural ones has fostered interest on vegetable sources and the screening of inexpensive raw materials particularly from the agriculture for identifying new antioxidants. Polyphenols are the significant plant compounds with antioxidant activity, though not the only ones. Some but not only restricted to biological properties such as anticarcinogenicity, antimutagenicity, antiallergenicity, and antiaging activity have been reported for natural and synthetic antioxidants. Among the sources of natural antioxidants, the most important are those coming from routinely consuming vegetables and fruits; however, antioxidant from other plant and agriculture waste should not be ignored.

The formations of oxygen reactive forms as a result of rigorous oxidative processes taking place in human organism are the potent precursors of systemic cells and tissues damage. Antioxidants being an inhibitor of the oxidation process remove these free-radical intermediates by oxidized themselves [1], even at quite diminutive concentration, and thus have assorted physiological function in the body to stop these oxidation reactions ultimately protecting the body from harmful chain reactions [2]. Thus, they have reviewed by many researchers as nature's answer to physiological and environmental stress, atherosclerosis, aging, and cancer [3]. Body's endogenous defense system against these free radicals plays

> © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

#### **Antioxidants from Natural Sources Antioxidants from Natural Sources**

Haseeb Anwar, Ghulam Hussain and Imtiaz Mustafa Haseeb Anwar, Ghulam Hussain and Imtiaz Mustafa

Additional information is available at the end of the chapter Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.75961

#### **Abstract**

Antioxidants are the defense system of the body against the damage of reactive oxygen species, which is normally produced during the various physiological processes in the body. There are various sources of these antioxidants like endogenous antioxidant present in the body and exogenous food source. In recent decades, alternate of synthetic food antioxidants by natural ones has fostered interest on vegetable sources and the screening of inexpensive raw materials particularly from the agriculture for identifying new antioxidants. Polyphenols are the significant plant compounds with antioxidant activity, though not the only ones. Some but not only restricted to biological properties such as anticarcinogenicity, antimutagenicity, antiallergenicity, and antiaging activity have been reported for natural and synthetic antioxidants. Among the sources of natural antioxidants, the most important are those coming from routinely consuming vegetables and fruits; however, antioxidant from other plant and agriculture waste should not be ignored.

DOI: 10.5772/intechopen.75961

**Keywords:** antioxidants, vegetables, fruits, plants, herbs

#### **1. Introduction**

The formations of oxygen reactive forms as a result of rigorous oxidative processes taking place in human organism are the potent precursors of systemic cells and tissues damage. Antioxidants being an inhibitor of the oxidation process remove these free-radical intermediates by oxidized themselves [1], even at quite diminutive concentration, and thus have assorted physiological function in the body to stop these oxidation reactions ultimately protecting the body from harmful chain reactions [2]. Thus, they have reviewed by many researchers as nature's answer to physiological and environmental stress, atherosclerosis, aging, and cancer [3]. Body's endogenous defense system against these free radicals plays

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

an imperative role, which can further supported by the supplementation of antioxidants in the diet. Generally, antioxidants can be divided into two major categories such as synthetic and natural. The main targeted site of these free radicals damage and defensive approach of antioxidants in the body is at the cellular level. Based up on this, these antioxidants can also be classified as enzymatic and nonenzymatic antioxidants. Enzymatic antioxidants primarily include glutathione peroxidase, catalase, and superoxide dismutase. There are also several other enzymes in the body that contribute to the total antioxidant capacity, which reflects in the serum [4]. Nonenzymatic antioxidants contain several subdivisions mainly vitamins such as A, E, C, and to lesser extent vitamin D, enzyme cofactors (Q10), peptides and some minerals (zinc and selenium). The major ingredients from the natural sources are polyphenolic compounds, which are reported to have significant antioxidant potential [5]. A detailed classification and subclassification has been displayed in **Figure 1**.

potential but are not the routine dietary source (e.g., medicinal plants and wild herbs). Among these, the routine dietary sources are very important as these can be easily available and more suitable for the dietary interventions. The need is to identify and generate awareness about these sources, which can be rated from top to down regarding antioxidant potential. The people who are habitual of consuming these vegetables and fruits in their routine meal are reported to be less affected by various chronic diseases [8], and studies have also endorsed the long-term healthy impact of consuming these nature-origin diets. Most common dietary supplements are comprised of vitamins C and E from synthetic as well as natural sources. Vitamin C is rich in the citrus fruits, which is a renowned fact, so fruits such as orange, lemon, blueberries, strawberries, grapes, prunes, and plums; red beans; spinach; kale; broccoli flowers; and alfalfa sprouts have good amount of antioxidants [9]. Fortunately, these are the part of our routine diet; however, their availability pertaining to the geographical distribution as well as cultivation is an important factor. Though international trading made them available throughout the world and even in the off season as well, the consumption of seasonal and fresh fruits is always encouraged. Vitamin E is a fat-soluble vitamin and exerts its antioxidant effect by reducing fat oxidation in the body [10]. Synthetic form of this vitamin is comprised of α-tocopherol, which is widely used as food supplement. The natural form of this vitamin contains mixed tocopherols almost having eight isomeric forms of α-tocopherol. The availability of these mixed tocopherols enhances the

Antioxidants from Natural Sources

5

http://dx.doi.org/10.5772/intechopen.75961

percent absorption of vitamin E from the natural sources in the human body.

antioxidants will be the prime focus of the researchers [11].

this decade, was forecasted [11].

antioxidant capability of the body.

**2. Natural antioxidants**

An enormous growth has been observed in the vitamin supplement market during the past decade. It is estimated worth \$68 billion with the US renders to be major shareholder, i.e., around 30%. A \$421 million for just vitamin E and \$361 million for vitamin C business has been recorded from Europe. Moreover, according to a report from Business insight, an annual growth of 4.5% in US vitamin and mineral market, i.e., almost \$30 billion in the first half of

The targeted approach of the researchers around the world to date is to find natural sources of antioxidants, which will be inexpensive and closer to the nature. These findings will be the superior substitute of synthetic supplements in food, pharmaceutical, and cosmetic industries [12]. Though significant harmful effects of synthetic supplements have not been reported to date, a common concept of closer to nature is obviously a better approach in the supplementation. The coming decade will be the era of natural products, and exploration of natural

The main objective of the current chapter is to overview and summarize the natural sources with antioxidant potential. The summarized data will be a useful information for the professional and nonprofessional readers to gather a fair information regarding dietary and non-dietary sources in the nature, which can be the part of the routine diet to enhance the

The nature is always a significant and rich source of countless ingredients that can be served as health-promoting agents. Many of these natural sources include routinely used fruits, vegetables,

Natural antioxidants are primarily phenolics that may occur in all parts of plants [6], such as fruits, vegetables, nuts, seeds, leaves, roots, and barks. In the recent past, some toxicological studies regarding the use of synthetic antioxidants have shown their unwanted or adverse effects. These reports have urged the researchers to focus their study on exploring the natural sources with reasonable antioxidant potential [7]. Moreover, the availability and economy are significant concerns too in the context of using these natural antioxidants. The antioxidants from the nature can be categorized into the various subclassifications. However, two major categories are like antioxidants from commonly consumed or routine natural diets (e.g., vegetables, fruits, cereals, and beans) and secondly from plant or herb source that have fair antioxidant

**Figure 1.** Classification and subclassification of antioxidants found in natural sources.

potential but are not the routine dietary source (e.g., medicinal plants and wild herbs). Among these, the routine dietary sources are very important as these can be easily available and more suitable for the dietary interventions. The need is to identify and generate awareness about these sources, which can be rated from top to down regarding antioxidant potential. The people who are habitual of consuming these vegetables and fruits in their routine meal are reported to be less affected by various chronic diseases [8], and studies have also endorsed the long-term healthy impact of consuming these nature-origin diets. Most common dietary supplements are comprised of vitamins C and E from synthetic as well as natural sources. Vitamin C is rich in the citrus fruits, which is a renowned fact, so fruits such as orange, lemon, blueberries, strawberries, grapes, prunes, and plums; red beans; spinach; kale; broccoli flowers; and alfalfa sprouts have good amount of antioxidants [9]. Fortunately, these are the part of our routine diet; however, their availability pertaining to the geographical distribution as well as cultivation is an important factor. Though international trading made them available throughout the world and even in the off season as well, the consumption of seasonal and fresh fruits is always encouraged. Vitamin E is a fat-soluble vitamin and exerts its antioxidant effect by reducing fat oxidation in the body [10]. Synthetic form of this vitamin is comprised of α-tocopherol, which is widely used as food supplement. The natural form of this vitamin contains mixed tocopherols almost having eight isomeric forms of α-tocopherol. The availability of these mixed tocopherols enhances the percent absorption of vitamin E from the natural sources in the human body.

An enormous growth has been observed in the vitamin supplement market during the past decade. It is estimated worth \$68 billion with the US renders to be major shareholder, i.e., around 30%. A \$421 million for just vitamin E and \$361 million for vitamin C business has been recorded from Europe. Moreover, according to a report from Business insight, an annual growth of 4.5% in US vitamin and mineral market, i.e., almost \$30 billion in the first half of this decade, was forecasted [11].

The targeted approach of the researchers around the world to date is to find natural sources of antioxidants, which will be inexpensive and closer to the nature. These findings will be the superior substitute of synthetic supplements in food, pharmaceutical, and cosmetic industries [12]. Though significant harmful effects of synthetic supplements have not been reported to date, a common concept of closer to nature is obviously a better approach in the supplementation. The coming decade will be the era of natural products, and exploration of natural antioxidants will be the prime focus of the researchers [11].

The main objective of the current chapter is to overview and summarize the natural sources with antioxidant potential. The summarized data will be a useful information for the professional and nonprofessional readers to gather a fair information regarding dietary and non-dietary sources in the nature, which can be the part of the routine diet to enhance the antioxidant capability of the body.
