**1. Introduction**

According to the Centers for Disease Prevention and Control (CDC), presently the most preventable and chronic health conditions are cardiovascular diseases, cancer, type 2 diabetes and obesity [1]. These diet related diseases account for an estimated number of 678,000 deaths annually [2]. Consumer demand for high quality, fresh and nutritious foods has increased over the years due to the need for a healthy diet and the associated consumption of fruits and vegetables, which is required for improved health. Organizations such as the World Health Organization (WHO),

© 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.

the Food and Agriculture Organization (FAO), the United States Department of Agriculture (USDA) and the European Food Safety Authority (EFSA) have recommended the consumption of fruits and vegetables to lower the risk of cardiovascular diseases and cancer due to their high content of micronutrients and fibers [3]. Thus, the main contributor to the protective effect of fruits and vegetables against chronic diseases are largely due to their phytochemical content.

such as stroke, cancer and metabolic syndromes. Phytochemicals are grouped based on their chemical structure and function. To date thousands of phytochemicals have been identified in fruits, vegetables and grains and the most important groups are phenolic compounds, nitrogen-containing compounds, alkaloids, organosulfur compounds, phytosterols, and carotenoids [11]. The most studied groups of dietary phytochemicals related to human health are

An Evaluation of the Impact of Novel Processing Technologies on the Phytochemical…

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Carotenoids are the red, yellow and orange color plant pigments of fruits and vegetables. To date approximately 600 types of carotenoids have been identified. They are mostly present as fat soluble, colored pigments in plants [12]. They can be separated into two groups; carotenes and xanthophylls. The two primary forms of carotenoids are β-carotene and α-carotene [12]. Other essential carotenoids include zeaxanthin, lutein and lycopene. The health benefits of carotenoids are due mainly to their antioxidant effects and physiological functions as provitamins. However, post-harvest technologies and processing greatly affect the composition and bioavailability of carotenoids in fruits and vegetables. Fruits and vegetables such as papaya, mangoes, carrots, sweet potatoes, pumpkin and cantaloupes are rich in β-carotene, whilst tomatoes, pink grapefruits, and watermelons contains high levels of lycopene [10]. In a study by Leoung and Oey, it was found that the highest content of carotenoids was found in red peppers followed by carrots, apricots, plums and peaches, whilst cherries contained the lowest amount of carotenoids [13]. Since carotenoids are a precursor of vitamin A, they have been found to decrease the incidence of diseases such as cancer of the lungs, pancreas and gastrointestinal tracts, cardiovascular diseases and eye-related diseases [14]. According to Toniolo et al., a case-control study conducted in New York between the years 1985–1994, showed that the carotenoids lutein, zeaxanthin, lycopene, α carotene and β carotene were responsible for decreasing the risk of breast cancer [15]. In another study by Giovannucci, it was observed that a decrease in prostate cancer was associated with a consumption of tomatoes due to their high lycopene content [16]. With respect to cardiovascular diseases, studies showed that the blood plasma of patients suffering with coronary artery disease, contained lower levels of zeaxanthin, lycopene, β carotene and α carotene [17]. This is in agreement with a study conducted by Knekt et al. who showed that a higher intake of β carotene and several carotenoids, led to a lower risk of major coronary heart diseases [18].

Phenolic compounds most commonly occur as antioxidants in fruits, and vegetables. Amongst the major classes of phenolic compounds with health benefits are flavonoids such as anthocyanins and non-flavonoids such as phenolic acids [19]. The many benefits of phenolic compounds include; antioxidant, anti-carcinogenic, antimutagenic and anti-inflammatory effects [20]. Amongst the most common phenolics are flavonoids. These are found in plant tissues and are often responsible along with carotenoids and chlorophylls for the blue, purple, yellow, orange and red colors in fruits and vegetables [20]. Within the group of flavonoids, are anthocyanins, which is responsible for reducing cardiovascular diseases. Anthocyanins are mainly found in red fruits like berries and grapes [21]. Non-flavonoid phenolic compounds, such as phenolic acids can be grouped into two major constituents; hydroxybenzoic acids

carotenoids and phenolic acids [11].

**2.1. Carotenoids**

**2.2. Phenolic compounds**

Phytochemicals are nonnutrient, biologically active compounds and are commonly found in vegetables, fruits, grains and other crop plants. The major groups of phytochemicals based on their chemical structure are polyphenols, terpenoids, sulfur compounds, and alkaloids [4]. In the fight against diseases, phytochemicals act as antioxidant, antibacterial, antifungals, antivirals, anti-inflammatory and cholesterol reducing agents [5]. Studies have shown that polyphenols found in potatoes have the ability to inhibit the enzymes responsible for Alzheimer's disease [6]. Consumption of blueberries containing high levels of phenolic acids, flavonols, anthocyanins and proanthocyanidins were associated with the prevention of degenerative and chronic diseases [7].

In developed countries, approximately 75% of all deaths are due to non–communicable diseases (NCDs) related to an unbalanced diet [8]. Developing countries are also overburdened due to over and under nutrition [8]. Associated with an increasing demand for fresh cut fruits and vegetables in developed countries, developing countries are now following suit due to an increased level of education and awareness for healthy food amongst consumers [3, 7]. The need for nutritious, ready to eat convenience foods has thus given rise to minimally processed fruits and vegetables (MPVFs) [7, 9], which are mildly processed such that they possess "fresh-like" attributes [9]. Some key attributes that ensure the marketability of MPVFs are the maintenance of nutritional value especially phytochemical content, flavor, color, texture, appearance and shelf life.

Some methods used to minimally process fruits and vegetables, negatively affect its phytochemical content and thus, the consumer does not benefit from the desired health benefits. Thermal processing allows for a longer shelf life by reducing microbial load and inhibiting enzymes that leads to deterioration, but it also decreases the level of phytochemicals in the fruits and vegetables [7, 10, 11]. Thus, this has prompted food scientists and researchers to find new ways to process fruits and vegetables without compromising the nutritional content and quality. Novel, nonthermal processing such as pulsed electric field (PEF), pulsed light (PL), ultra sound (US), high pressure processing (HPP) and cold plasma (CP) techniques have been promising in maintaining the integrity of phytochemicals and the nutritional quality of fruits and vegetables, inclusive of minimally processed ones [10]. Such technologies have the potential to be adapted in developing countries. This chapter will explore the use of nonthermal processing technologies and their effects on key phytochemicals such as carotenoids, flavonoids and phenolic acids in several fruits and vegetables with a focus on health benefits.
