**2. Sources of phytochemicals and functions**

Scientific evidence has shown that phytochemicals are highly beneficial in lowering the risk of several noncommunicable diseases [10]. They are known to have the ability to treat diseases 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 carotenoids and phenolic acids [11].
