# Nutritional Analysis of Red-Purple and White-Fleshed Pitaya (_Hylocereus_) Species
## 1 Introduction
Due to their nutraceuticaltial and beneficial properties, phytonutrients found in medicinal plants such as polyphenols (especially phenolic acids) are worth considering. These compounds are important bioactive secondary metabolites that have long been studied for their enhancement and prevention capacities and are therefore considered potential sources for pharmaceutical and medical applications. Pitaya has a moisture content of around 80%, protein content between 0.4 and 2.2 g, carbohydrate content between 8.5 g and 13.0 g, and its total sugar content is around 6.0 g per 100 g fresh weight [25; 26]. Especially the red and white fleshed pitaya fruits are a rich source of phenolic compounds, vitamins (B1, B2, B3, C, niacin, pyridoxine and cobalamin), minerals (calcium, potassium, phosphorus, sodium, iron and zinc), proteins, fats, carbohydrates, sugars, fiber and volatiles [16; 27; 28; 29]. It is also associated with high antioxidant capacity of bioactive compounds, such as polyphenols, flavonoids and betacyanins, that have important functions for human health [12; 28; 30; 31; 32]. Some epidemiological studies have shown that pitaya has various bioactivities such as antioxidant, anticancer, antimicrobial, anti-hyperlipidemic, anti-diabetic, hepatotoxicity, and wound healing [6; 12; 17; 19; 33; 34]. Therefore, pitaya appears to have many important compounds. Thus, the fruit not only has economic value but also has a high potential for application in the food and pharmaceutical industry. Additionally, the fruit peel, pulp and seeds of pitaya are used in the manufacture of different foods such as ice cream, yogurt, fruit juice, jelly and marmalade [2]. Carohydrates are one of the most important macronutrients found in abundance in the different tissues of pitaya. In recent years, a number of studies have been carried out investigating the properties and levels of carbohydrates obtained in the different tissues of pitaya [35; 36]. Sugars, together with phenolic components, play an important role in the sensory and nutritional quality of the product and may vary according to the cultivar, maturity stages, storage conditions, crop year and fruit development conditions. It has been reported that dried pitaya peels are a rich source of pectin and dietary fiber (60-80%) [37]. Red pitaya fruit is very rich in iron content. Scientists have proven that consuming red pitaya fruit juice drastically increases hemoglobin and erythrocyte levels in pregnant women. Thus, consuming it during pregnancy is an alternative treatment for anemia [38]. [PERSON] et al. [26] analyzed the flesh of the _H. undatus_ and found that the predominant fatty acids were oleic, linoleic, and palmitic acid as 50.8%, 21.5% and 12.6% of the total fatty acid content, respectively. Similarly, [PERSON] et al. [39] analyzed the oil extracted from red and white pitaya seeds and found a high content of essential fatty acids, namely linoleic (~50%) and linoleic (~1%) acid, and other fatty acids such as cis-vaccenic acid (~3.0%), palmitic acid (17.5%), and oleic acid (22.7%). The human health benefits of poly-and monounsaturated fatty acids have been documented and they help to reduce cholesterol and lipoprotein fractions [40; 41]. It has also been reported that linoleic and alpha-linolenic acids are required to maintain cell membranes, brain function, and transmission of nerve impulses [26; 42]. In recent years, pitaya fruits have greatly increased in popularity worldwide due to their attractive colors, sweetness, juicy and pleasant taste. This fruit has been recognized as the most beautiful of the _Catacae_ family [43]. There are many species of the pitaya; however, the _Hylocreens undatus_ is the best known and widely cultivated. Due to having a red-purple color, pitaya is highlighted by global breeders for its rich polyphenol compounds and antioxidant capacities.