Chemical Composition of Mango (Mangifera indica L.) Fruit: Nutritional and Phytochemical Compounds

1This manuscript presents a compilation of updated information on the nutritional composition of different mango varieties ( Figure 1 ), as well as their main phytochemical components, useful for human nutrition, health, and other applications for agricultural, pharmaceutical, and food industries and the changes of these components during development and postharvest. This knowledge should contribute to control fruit deterioration, greater use, and valorization of the fruit.

2The review consists of four parts for better understanding of the reader. The first part corresponds to the description on the nutritional content of mango fruit based on its macronutrients (carbohydrates, lipids and fatty acids, proteins and amino acids, and organic acids) and micronutrients (vitamins and minerals). The second part continues with the analysis of the most relevant phytochemical compounds identified in mango fruit (phenolic acids, flavonoids, and pigments such as chlorophyll and carotenoids) not only in the edible portion of the fruit but also in the seed and skin, in order to show that by-products of the mango fruit can be used with potential benefit for health and industry.

3In the third part, the changes on nutritional and phytochemical composition of mango fruit during the development and ripening are explained. It is well known that chemical components of mango vary according to the region of planting, cultivar, cultural practices, and nutritional conditions of the plant. However, the mango fruit development and ripening involve a series of biochemical, physiological, and structural controlled changes that affect the content of nutrients, phytochemical compounds, and the organoleptic characteristics leading to a soft, ripe, and edible mango fruit with desirable attributes for consumer acceptance.

4Finally, taking into account that mango is a climacteric fruit that continues the ripening processes after detachment from the parent plant, attributed to the increases in the rate of respiration and ethylene production, several postharvest handling processes can reduce their postharvest life and also the fruit composition, leading to losses in terms of quality and quantity, which can be considerably reduced by applying adequate and improved strategies and technologies to prolong the shelf life of mango fruit.

5Mango fruit is an important source of macronutrients such as carbohydrates, lipid and fatty acids, protein and amino acids, and organic acids. Also, mango has micronutrients such as vitamins and minerals and, finally, non-nutrients compound such as phenolic compounds, flavonoids and other polyphenols, chlorophyll, carotenoids, and volatile compounds. The energy value for 100 g of the pulp ranges from 60 to 190 kcal (250–795 kJ), being an important fruit for the human diet ( Table 1 ). The nutritional, non-nutritional, and water contents of mango fruit vary depending of the cultivar and several preharvest and postharvest factors. For example, according to the United States Department of Agriculture (USDA) data of nutrient report, the mature mango pulp of Haden, Kent, Keitt, and/or Tommy Atkins varieties present 83.4 g of water per 100 g of fresh fruit, while the cultivar Azúcar from Colombia contain 79.3 g.

6Ripened mango fruit is a major source of sugars (glucose, fructose, and sucrose) and other carbohydrates such as starch and pectins. All these are significant compounds from a nutritional and flavor aspect. The fruit flesh of ripe mango contains about 15% of total sugars. Fructose is the major monosaccharide during the preclimateric phase, while sucrose is the principal sugar in ripe mango fruit.

7The USDA Nutrient Database reports that the total carbohydrate and sugar contents of Tommy Atkins, Haden, Kent, and Keitt cultivars per 100 g fruit is 14.98 and 13.66 g, respectively (sucrose, 6.97 g; glucose, 2.01; and fructose, 4.68 g), and 1.6 g of dietary fiber/100 g of fruit. The table of food composition from Colombia presented the content of glucose, fructose, sucrose, starch, and pectin in mango pulp (3.9, 1.0, 8.8, 1.8, and 8.2 g/100 g of pulp, respectively) and 2.6 g of dietary fiber. In African mango cultivars, the total sugar content varied between 10.5% and 32.4%, while the interval diminishes to 10–12% in Sudanese varieties. In general, many cultivars of mango contain sucrose, fructose, and glucose in order of highest to lowest.

8Starch is the most important from a quantitative point of view in the unripe mango fruit. During ripening, starch is hydrolyzed to glucose. After phosphorylation, glucose phosphate enters the hexose phosphate pool and fuels a “futile cycle” of sucrose synthesis and degradation that controls the content of glucose, fructose, and sucrose, as it was found in kiwifruit. Thus, during ripening, glucose, fructose, and sucrose generally increase. The increase of these monosaccharides and disaccharides during maturation has been observed in cultivars Baladi, Haden, Alphonso, Dashehari, Keitt, and Tommy Atkins.

9Pectin is a structural carbohydrate abundant in mango pulp and is considered an important component as a gelling sugar. When fruit is unripe, pectin is accumulated, but during ripening, its molecular weight decreases; this is attributed to the activity of hydrolysis of pectin enzymes in this stage.

10Mango, like many fruits, has a low protein content with respect to the other macronutrients; by example, mango pulp from Colombia contributes to 0–0.6% of protein, while in Peru, mango contains 1.5 to 5.5% total protein; in other cultivars like Java, mango has 1–2%, and in India, cultivars present low contents of total protein (0.5–1%).

11The amino acid composition also varies among cultivars and maturation levels. The amino acids alanine, arginine, glycine, serine, leucine, and isoleucine have been detected in considerable amounts in the ripe state, while all other amino acids are present in trace amounts. Table 2 presents the content of amino acids described by the.

12Lipids are nutrients present in small quantities in mango pulp; however, the seed and the peel have been considered a source of fatty acids and are compared with cocoa butter ( Table 3 ). These fatty acids are useful mango by-products and can be used in the pharmaceutical and food industries.

13The prominent fatty acids found in the mango kernel are palmitic, stearic, oleic, and linoleic. Lignoceric, arachidic, linolenic, and behenic acids are present in lower concentrations ( Table 3 ). The content of triglycerides determined in blend of mango seed was 11% to 38.8% of 1,3-dipalmitoyl-2-oleoyl-glycerol (POP), 22.1% to 36.9% of 1,3-distearoyl-2-oleoyl-glycerol (SOS), and 15.4% to 16.2% of 1-palmitoyl-3-stearoyl-2 oleoyl-glycerol (POS). It has been reported that the incorporation of SOS-rich fats in chocolate products increases the solid fat content, leading to the inhibition of fat bloom and reducing the tempering time. Therefore, SOS-rich fractions could be used as an ingredient for the production of temperature-resistant hard butter, which is particularly useful in countries with high temperatures; thus, mango seed fat is a potential cocoa butter alternative.

14The fatty acid content in the peel and pulp has been also studied in different varieties of mango such as Malgoa, Totapuri, Benishan, Sundari, and Neelam and was found to range from 0.75% to 1.7% in the skin and 0.8% to 1.36 in the flesh, with the triglycerides being the major components of the pulp, while monoglycerides and diglycerides are minor components. In the cultivars Alphonso, Pairi, and Kent, 17 different fatty acids were identified and quantified during development and ripening of mango fruit with an increase of unsaturated fatty acids and an omega-6/omega-3 ≤ 1 at the ripe stage, which suggests that mango fruit is a good source of essential fatty acids ( Table 3 ). This increase in fatty acid content during maturation has also been observed in Harumanis, Kalabau, Stam Panjang, African Bush, Fazil, and Kanchamithia varieties.

15showed the association between the intensity of aroma and flavor and determined the ratio of palmitic–palmitoleic acid in ripening mango pulp to apply as an index of aroma and flavor of mangoes. When this ratio is greater or less than 1, the fruit has a mild or strong aroma and flavor, respectively. It has been proposed that fatty acids are probably precursors for the biosynthesis of lactones. These compounds are important in the research on flavor biochemistry of foods.

16Organic acids are characterized by weak acidic properties. These compounds may have low molecular weight such as oxalic and citric acids or too high molecular weight like humic acids with aromatic nuclei composed of carboxylic and phenolic functional substituents. Organic acids are necessary for aerobic metabolism and as flavor constituents that contribute to fruit quality, organoleptic properties, and fruit acidity.

17Organic acid compounds have been identified in different varieties of mango, and the content depends on acid synthesis, degradation, utilization, compartmentation, and external factors such as temperature, light, fertilization, water supply, and other plant management practices.

18Fruit acidity of mango is attributed mainly to the content citric and malic acids, although other common organic acids from the tricarboxylic acid cycle have been reported in mango fruit including citric, oxalic, succinic, malic, and pyruvic as well as tartaric, muconic, galipic, glucuronic, and galacturonic acids; of these, citric is the major organic acid [0.13% to 0.71% fresh weight (FW)]. For example, citric and malic acids are the major organic acids in Keitt mango, whereas α-ketoglutaric, ascorbic, oxalic, and tartaric acids are found in lower concentrations. In mangoes from Badami, citric acid presents the highest concentration, but succinic and malic acids were also detected. A similar profile was described in Fazli variety (pyruvic, citric, succinic, oxalic, and malic acids); in addition to those, tartaric acid was determined in Zardalu mangoes. On the contrary, mango cultivars from Africa present a moderate content of citric acid (0.2% to 1.3%).

19The nutrient database of USDA (National Nutrient Database for Standard Reference) reported the values of water-soluble and fat-soluble vitamins analyzed from Tommy Atkins, Keitt, Kent, and Haden cultivars ( Table 4 ). Vitamin C and vitamin A are dominant, suggesting that regular consumption of mango fruit can provide the necessary dietary requirements of these vitamins.

20Great variations exist in vitamin C content, fluctuating from 9.79 to 186 mg/100 g of mango pulp. The cultivars Kent, Tommy Atkins, and Keitt from Mexico, Peru, Brazil, and Ecuador; Haden from Peru and Mexico; and Ataulfo from Mexico were analyzed by who reported that the average vitamin C level over all harvest locations were 19.3, 24.7, 25.6, 31.0, and 125.4 mg/100 g of pulp in the Tommy Atkins, Keitt, Kent, Haden, and Ataulfo cultivars, respectively. The higher vitamin C concentration in Ataulfo was comparable with the concentrations in Ubá cultivar from Brazil (77.7 mg/100 g FW). analyzed six African varieties (Tommy Atkins, Zill, Peach, Sabre, Rosa, and Phiva) and found that vitamin C content oscillated from 50.71 to 17.01 mg/100 g FW, being significantly higher (P < 0.05) in cv. Sabre and lower (P < 0.05) in cv. Tommy Atkins; and for the Palmer cultivar from Brazil, it was 40.9 mg/100 g FW. These variations are attributed to several different preharvest and postharvest factors, which all can influence the synthesis.

21Vitamin C content changes during ripening; its content is higher in less ripe mango fruit compared with fully ripe mango. Vitamin C decreases quickly 5 to 7 weeks after fruit setting and when ripe fruit is stored at room temperature. The vitamin C decrease may be due to the involvement of different metabolic pathways such as ethylene, oxalate, and tartrate biosynthesis because vitamin C is a coenzyme of their respective enzymes. In the analysis of vitamin C concentration in the pulp of Keitt, Sensation, and Xiangya mango cultivars from China at different stages (green and ripe mangoes), it was observed that the fruit pulp showed an important decrease during ripening (Keitt, 163.94 to 46.87 mg ascorbic acid equivalent (AAE)/100 g; Sensation, 176.03 to 29.34 mg AAE/100 g; and Xiangya, 160.35 to 30.84 mg AAE/100 g).

22The content of vitamin A in the fruit varies from 1,000 to 6,000 IU. Thus, mango consumption is very important, especially for those regions where there is a deficiency of vitamin A. Consumption of a single fruit (around 300 g) would supply 15–69 retinol equivalents (REs)/day depending on the cultivar. This would correspond to 11.5% of REs requirement per day for both teenagers and adults. For example, the consumption of three times per day of Tommy Atkins would provide more than 50% of the daily requirements of women and children aged 3–6 years.

23Similar conclusions were reported by, ) who indicated that intervention strategies with mango improve the vitamin A intake by 50% and serum retinol concentrations by 26% of children (2 to 3 years) in Western Africa, over a 15-week period where mangoes are consumed little or nothing due to low seasonal availability.

24The E and K vitamins are found in minor quantities ( Table 4 ), while vitamin D has not been detected in any cultivars until now. The content of vitamin E is commonly low or moderate in fruit and can occur in tocopherols α-, β-, λ-, and γ-T; its corresponding tocotrienols are α-, β-, λ-, and γ-T3. The most biologically active form is α-tocopherol. In Ataulfo cultivar from Mexico, it was determined that fresh-cut mangoes contain 1.33 mg/100 g FW, which is greater than that informed by the USDA Nutrient Database for Tommy Atkins, Kent, Keitt, and Haden.

25Vitamin E increases from green mature stage to mature stage in Tommy-Kent mangoes, while in Tommy Atkins and Dasherai cultivars, the content of vitamin E is high at the unripe stage but later decreased. These changes in vitamin E content may in part be explained by the fact that vitamin C contributes to the biosynthesis of the oxidized form of vitamin E, tocopheroxyl radical, leading to the production of α-tocopherol. The opposite also occurs; that is, when vitamin C decreases, α-tocopherol content also decreases.

26The vitamin B complex of mango fruit refers to water-soluble enzyme cofactors and their derivatives, which participate in different metabolic processes in plants and in humans. The vitamins included are thiamin (B1); riboflavin (B2); niacin (B3); pantothenic acid (B5); pyridoxine, pyridoxal, and pyridoxamine (B6); biotin (B8); and folate or folic acid (B9), except for biotin all the others vitamins, have been found in mango fruit. All these vitamins B are important for proper human nutrition because humans are not able to synthesize these micronutrients. These vitamins can be also affected by several preharvest and postharvest factors, as well as the maturity stage because vitamin B synthesis is associated with the state of differentiation of cells.

27According to the Recommended Daily Allowance (RDA) recommended levels by the, mango may provide enough amount of essential minerals for human health, such as calcium, iron, magnesium, phosphorus, potassium, sodium, zinc, copper, manganese, and selenium. Table 5 shows the essential mineral contents of Tommy Atkins, Keitt, Kent, and/or Haden and Colombian cultivars. The major essential minerals that mango pulp contributes are K, P and Ca, while the levels of Na, Zn, and Fe were the lowest, and the seeds and peels contain significantly higher levels than does the pulp in the following order: Ca > K > Mg > Na > Fe > Mn > Zn > Cu.

28Phenolic acids are plant secondary metabolites that form part of human diet and are of significant importance because of their biological abilities and health benefits. Mango pulp includes the two major categories of phenolic acids in plants, hydroxybenzoic and hydroxycinnamic acid derivatives. These phenolic acids may be present free or conjugated forms with glucose or quinic acid. The hydroxybenzoic acids that have been detected in the mango pulp are gallic, vanillic, syringic, protocatechuic, and p-hydroxybenzoic acids, while the hydroxycinnamic acid derivatives are p-coumaric, chlorogenic, ferulic, and caffeic acids. The content and characteristics of phenolic acids depend on the cultivar, crop, and ripening stage.

29Different phenolic acids were identified in the flesh and skin of nine mango varieties cultivated in China. The highest phenolic acid in 100 g FW of pulp was ferulic acid (33.75 mg), followed by protocatechuic (0.77 mg), chlorogenic (0.96–6.20 mg), gallic (0.93–2.98 mg), vanillic (0.57–1.63 mg), and caffeic acids (0.25–0.10 mg). Similarly, the major phenolic acids in Ataulfo mango from Mexico were protocatechuic acid (0.48–1.1 mg/100 g dry weight (DW)), vanillic acid (16.9–24.4 mg/100 g DW), gallic acid (94.6–98.7 mg/100 g DW), and chlorogenic acid (28–301 mg/100 g DW). Contrary to these studies, and found that the major phenolic acid in mango pulp of Azúcar and Tommy Atkins varieties was gallic acid; however, these authors were unable to quantify the other well-known phenolic acids (p-hydroxybenzoic, p-coumaric, and ferulic acids) because of low concentration. The peel extracts of the mango cultivars Ataulfo, Keitt, Osteen, and Sensation have been found to have high concentrations of phenolic acids and derivatives such as gallic, syringic, methyl digallate ester, methyl gallate, gallotannins, galloyl glucose, theogallin, protocatechuic, and ferulic acid.

30recently identified tentatively 34 compounds as derivatives of phenolic acids including gallotannins and quercetin derivatives, reporting for first time the detection of rosmarinic acid in mango fruit in different stages of ripeness, both in the peel and in the pulp. All the determinations were done by ultra-performance liquid chromatography in combination with electrospray ionization and quadrupole time-of-flight mass spectrometry (UPLC–ESI–QTOFMS).

31Several authors, using different methods such as high-performance liquid chromatography (HPLC)/ESI–MS and HPLC–photodiode array (PDA)–MS to detect and identify other derivatives of phenolic compounds. have detected in the peel of mango Tommy Atkins 18 gallotannins (1.4 mg/g dry matter (DM) expressed as gallic acid) and five benzophenone derivatives identified tentatively as galloylated maclurin and iriflophenone glucosides, and 21 (15.5 mg/g DM) and eight gallotannins (0.2 mg/g DM) found in the seed and pulp, respectively. Among the gallotannins, some identified derivative compounds were assigned provisionally as iso-penta-O-galloyl-glucose, iso-hexa-O-galloy-glucose, penta-O-galloyl-glucose, tetra-O-galloyl-glucose, and hexa-O-galloy glucose. Some identified derivatives of quercetin were consigned as quercetin-3-O-galactoside and quercetin-3-O-glucoside, quercetin-3-O-xyloside, quercetin-3-O-arabinopyranoside, and quercetin-3-O-arabinofuranoside.

32reported that the peel of Pica cultivar from Chile presented the highest content of total phenolic compounds (66.02 mg/100 g FW) analyzed by HPLC–PDA, and these authors detected 18 compounds present in Pica pulp and 13 in Pica peel more than what was detected in the peel and pulp of Tommy Atkins from Chile. The phenolic compounds identified in these fruits were three procyanidin dimers, seven phenolic acid derivatives, and four xanthones including homomangiferina, mangiferin, and mangiferin gallate in both peel and pulp of Pica and Tommy Atkins cultivars; only dimethyl mangiferin was identified in Tommy pulp.

33Polyphenols are a class of phytochemicals abundant throughout the plant kingdom. These molecules are generally involved in protecting plants from the ultraviolet radiation, aggression by pathogens, and reactive oxygen species (ROS). The most abundantly occurring polyphenols in plants are flavonoids, stilbenes, and lignans, of which flavonoids account for 60% of dietary polyphenols.

34Current interests are the antioxidant, anti-inflammatory, and anticarcinogenic activities of polyphenolic phytochemicals. The relevant polyphenols in the mango fruit related with the antioxidant capacity and/or quantity are the class of flavonoids (catechins, quercetin, kaempferol, rhamnetin, anthocyanins, and tannic acid) and the class of xanthones: mangiferin. In the pulp of mango, the major flavonols are glycosides of quercetin (glucose, galactose, rhamnose, xylose, and arabinose), whereas kaempferol, isorhamnetin, fisetin, and myricetin are present in minor levels.

35The USDA Nutrient Data Laboratory Flavonoid Database (https://www.ars.usda.gov/northeast-area/beltsville-md-bhnrc/beltsville-human-nutrition-research-center/nutrient-data-laboratory/) includes the data for 500 food items and 28 relevant monomeric dietary flavonoids (flavonols, flavones, flavanones, flavan-3-ols, and anthocyanidins). The USDA, through this flavonoid database, has reported that 100 g of edible portion of mango fruit contains anthocyanidins (cyanidin, 0.10 mg; delphinidin 0.02 mg; and pelargonidin, 0.02 mg), the flavan-3-ol (+)-catechin (1.72 mg), traces of the flavones apigenin (0.01 mg) and luteolin (0.02), the flavonols kaempferol (0.05 mg) and myricetin (0.06 mg). In addition, the Nutrient Database of USDA has reported that mango fruit (Tommy Atkins, Kent, Keitt, and Haden) contains isoflavones (0.01 mg), proanthocyanidins dimers (1.8 mg), trimers (1.4), and four to six dimers (7.2 mg). Thus, the main flavonoids that have detected in mango flesh are quercetin and glycosides derivatives; the most relevant is the flavonol glycoside quercetin 3-galactoside (22.1 mg/kg), followed by quercetin 3-glucoside (16.0 mg/kg), quercetin 3-arabinoside (5.0 mg/kg), and quercetin aglycone (3.5 mg/kg). Some mango cultivars were grown in Thailand (Tommy Atkins, Mani, Ngowe, R2E2, Kent, Jose, Mini-mango, Haden, Heidi, and Kaew Mon Duen Gao) has been found to contain glycosides of quercetin between 3.5 and 1,309.1 mg/100 g fruit (diglycoside, 3-O-gal, 3-O-glc, 3-O-xyl, 3-O-arap, 3-O-araf, and 3-O-rha), kaempferol 3-glc (6.7–77.3 mg), rhamnetin-3-O-gal/glc (5.4–734.4 mg), and quercetin (1.7–19.3 mg).

36The seed and peel of mango fruit are also considered promising sources of polyphenols, with a total phenolic content for these residues of 6–8% of DM in Uba cultivar from Brazil, which is 4.6 and 7.3 times higher, respectively, than the content of the pulp, and a similar profile was reported for the flavonoids and xanthones of this variety.

37The xanthones are molecules formed by a C6–C3–C6 backbone structure with hydroxyl, methoxyl, and isoprene units linked to the A and B rings, which mostly occur as ethers or glycosides. Six xanthone derivatives have been identified (mangiferin, dimethyl mangiferin, homomangiferin, mangiferin gallate, isomangiferin, and isomangiferin gallate); among this group mangiferin (C2-b-d-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone), a C-glucosyl xanthone, is broadly distributed in higher plants, with demonstrated pharmacological and antioxidant activities. Mangiferin can be obtained from the bark, fruits, roots, and leaves of Mangifera indica Linn. It has also described that mangiferin is able to activate anticancer, antimicrobial, antiatherosclerotic, antiallergenic, anti-inflammatory, analgesic, and immunomodulatory activities.

38The content of mangiferin and derivatives is higher in the peel from Pica and Tommy Atkins mango fruit (22.15 and 9.68 mg/100 g FW, respectively) than in the pulp, 4.24 and 3.25 mg/100 g FW, respectively. In Uba and Tommy Atkins cultivars from Brazil, mangiferin was detected as 12.4 and 2.9 mg/kg DM, respectively, but it was not detected in Palmer pulp.

39In another analysis of mangiferin of the pulp of 11 cultivars grown in China, only in five of them was mangiferin reported (0.032–3.20 mg/100 g FW), but interestingly, in the pulp of Azúcar cultivar grown in Colombia, it was 11.5 mg/100 g FW (data not shown).

40For the derivative compounds of mangiferin, some characteristic peaks were identified as corresponding to compounds identified provisionally as maclurin-mono-O-galloyl-glucose, maclurin-di-O-galloyl-glucose, iriflophenone di-O-galloyl-glucose, and mangiferin gallate.

41The color of the fruit peel is an important factor of mango maturation indices and quality, which changes from green to orange, yellow, or red flush, depending on the type of cultivar. In mango fruit, the green pigmentation is attributed to the presence of chlorophylls. Two types of chlorophyll have been detected in mango fruit, chlorophylls a (blue-green) and b (yellow-green), in a ratio of 3:1.

42In Tommy Atkins mango fruit, chloroplasts contain between 7 and 10 thylakoids per stack, connected through single intergranular thylakoids. Thylakoid system collapse inside the chloroplast at the beginning of ripening is associated with the loss of chlorophyll. Moreover, the reduction of chlorophyll levels in the peel is correlated with the increase of β-carotene content as ripening advances.

43Chlorophyll and carotenoids are responsible for the color in some fruits. Several studies describe that chlorophyll breakdown is associated with the maturity of some fruits;. When fruit appears green, an abundance of chlorophyll masks the carotenoids. The yellow color of carotenoids is unmasked by chlorophyll degradation during ripening. Taking this into account, the content of chlorophyll could be used as an indicator for the harvest in some fruits but not in others; for example, in their study show that ‘Le Lectier’ pears turned yellow during ripening with concomitant loss of chlorophylls a and b and carotenoids. In contrast, ‘La France’ pears stayed green even when fully ripe, because chlorophyll content did not change significantly.

44demonstrated that the greener color of the fruit is affected according to the position in the tree. The high values of chlorophyll correspond to green color of the peel and the flesh for fruits inside the canopy, whereas low values of chlorophyll are present in the fruits located in the top of the canopy.

45The reduction in the chlorophyll content in the fruit is attributed to ethylene, which up-regulates the de novo synthesis of the enzyme chlorophyllase in the peel during ripening. Besides, chlorophyll can be also degraded by the peroxidase activity able to open the porphyrin ring, producing the loss of color. The peroxidase activity in the peel of unripe and ripe Tongdum Thai mango was lesser than that in Nam Dokmai mango, which can explain the increased content of chlorophyll in Tongdum.

46Mango fruit is rich in carotenoid compounds. These molecules are lipid-soluble stains contributing to yellow-orange colors of mango fruit and red colors when mango is ripe, although the reddish color of peel in several varieties is due to anthocyanins. Carotenoids are located in the chromoplasts, often masked by chlorophyll and non-photosynthetic plant tissues. In the chloroplasts, carotenoids act as an accessory pigment in light harvesting and as antioxidants converting the triplet chlorophyll to the singlet ground state. These compounds are classified in carotenes (α-carotene, β-carotene and γ-carotene), and xanthophylls (auroxanthin, antheraxanthin, neoxanthin, lutein, violaxanthin, and zeaxanthin).

47Sixteen carotenoids have been identified in fully ripe mango fruit, of which β-carotene (all-trans) account for 60% of the total carotenoids in the fruit, while at the green stage, lutein (9- or 9′-cis-lutein) is the most representative, followed by many xanthophylls during the early ripening stage and during late ripening phases.

48The carotenoid levels in fruit are directly affected by the development and the environmental conditions during fruit growth. The variation in total carotenoid content in four different varieties of mango ripe and unripe was analyzed by. They reported that total carotenoids of mango cultivars Bassignac, Green, Julie, and Moussache were between 276.17 (Green) and 2,183 μg (Bassignac) per 100 g FW in the unripe stage. These values increased at the ripe stage, between 603.35 (Moussache) and 4,138.50 μg (Bassignac) of total carotenoids per 100 g FW. A similar profile was observed in the total carotenoid contents of 12 mango varieties from Bangladesh at three stages of development: green (0.003 mg/100 g of pulp), semi-ripe (0.07 mg/100 g of pulp), and ripe (0.25 mg/100 g of pulp), indicating that the carotenoid content increased from green into ripe stage. Another study also compared the total carotenoid levels in the edible portion of the mango, variety Azúcar, at green, semi-ripe, and ripe stages (11.1, 11.8, and 10.7 mg of total carotenoids/100 g FW of edible portion, respectively). A significant difference only was found between the ripe and semi-ripe stages. The total carotenoid contents of the variety Azúcar were similar to those reported for the cultivars Keitt and Kent (10.4 and 12.9 mg/100 g pulp, respectively); higher than those of Tommy Atkins, Tainong No. 1, Irwin, and JinHwang cultivars (4.9, 5.2, 3.7, and 2.6, respectively); but lower than those of Ataulfo mango (26.1 mg) at the ripe stage.

49The total carotenoid content was also analyzed for the cultivars Haden, Tommy Atkins, Ubá, and Palmer from Brazil; this content ranged from 1.91 mg/100 g (Haden) to 2.63 mg/100 g (Palmer). The total carotenoid, β-carotene, accounted for 661.27 (Palmer) to 2.220 µg/100 g (Ubá). These values are higher than those in the Indian cultivars. Comparable results were reported by the Nutrient Database of for β-carotene (640 µg/100 g), α-carotene (9 µg/100 g), β-cryptoxanthin (10 µg/100 g), lutein and zeaxanthin (23 µg/100 g), and lycopene (3 µg/100 g) in Tommy Atkins, Kent, Keitt, and Haden mangoes.

50Although the differences in the composition of carotenoids between different varieties may be due to environmental and genetic factors, state of maturation, production, and postharvest handling techniques, they can also be attributed to the analytical methods employed and to the unstable nature of carotenoids. More than 25 carotenoids (free form, butyrates, and esterified), have been identified, but the major carotenoids in mango flesh seem to be all-trans-β-carotene, and all-trans- and 9-cis-violaxanthin.

51The analysis of seven ripe mango cultivars (Ataulfo, Manila, Criollo, Paraíso, Haden, Kent, and Tommy Atkins) by HPLC coupled to a C30 stationary phase and diode array, fluorescence, and mass detectors showed that the highest content of carotenoid was contributed by all-trans-β-carotene (0.4 and 2.8 mg/100 g FW), with mangoes Haden and Ataulfo having the highest concentration, followed by all-trans-violaxanthin (0.5–2.8 mg/100 g FW) and 9-cis-violaxanthin (0.4–2.0 mg/100 g FW). In a mango cultivar from Brazil, it was identified by HPLC and MS that all-trans-violaxanthin (2.1 mg/100 g FW) was the major carotenoid, followed by all-trans-β-carotene (1.5 mg/100 g FW) and 9-cis-violaxanthin (1.0 mg/100 g FW).

52A study of five mango varieties harvested at different times [Tommy Atkins (México, Brazil, and Ecuador), Kent and Keitt (Mexico), and Haden (Peru)] was performed to compare the β-carotene content over 1 year of harvest. This study showed that the concentration of β-carotene ranged from 5 (Tommy Atkins) to 30 mg/kg FW (Ataulfo) among the five varieties, indicating that the type of cultivar had a greater influence on the levels of β-carotene but not the country of origin or harvest date.

53The volatile compounds of mango are characterized by having low molecular weight (<400 Da), and in a wide range of functional groups, they can be in free or glycoside form. Also, they have a high vapor pressure that allows them to disperse easily and quickly in air, water, and soil. This group of compounds that determine the characteristic aroma of the fruit is commonly present in small quantities, approximately 50 ppm or less, which comprises mixtures of monoterpenes, sesquiterpenes, and volatile oxygenates (monoterpenes, sesquiterpenes, esters, lactones, alcohols, aldehydes, ketones, volatile fatty acids, some degradation product of phenols, and some carotenoids). They have a heterogeneous distribution quantitatively and qualitatively among cultivars, maturity stage, and tissues of the fruit. analyzed more than 285 different volatile compounds in mango fruit including 7 acids, 55 alcohols, 31 aldehydes, 26 ketones, 14 lactones, 74 esters, 69 terpene hydrocarbons, and 9 other compounds. The most abundant volatile components in mango germplasms from China, the Americas, Thailand, India, Cuba, Indonesia, and the Philippines are monoterpenes.

54The content of these molecules can vary according to the method used for their extraction and identification and quantification, such as solid-phase microextraction (SPME), liquid–liquid extraction, simultaneous distillation–extraction, static or dynamic headspace, and solid-phase extraction.

55analyzed the volatile compounds of 20 mango cultivars from the National Botanic Garden in Havana, Cuba, using simultaneously distillation–extraction, gas chromatography (GC), and GC coupled to MS (GC–MS). They reported 180 volatile compounds from 372 identified with a concentration ranging from 18 to 123 mg/kg of fresh fruit. In these cultivars, the major volatile compounds were terpene hydrocarbons such as delta-3-carene, a dominant compound present in other mango cultivar grown in Venezuela extracted by similar methods; followed by limonene also present in cultivars Baladi, Carlota, and Bacuri; terpinolene characteristics of Sri Lanka; and cultivars grown in Australia. The following quantitative important class of volatile compounds in mango grown in Cuba was 90 aliphatic, 16 aromatics, and 8 terpene esters found, with ethyl acetate and ethyl butanoate as the major esters; lactones were also detected.

56Some other examples of volatile constituents detected in the pulp of Tommy Atkins mangoes are pinene, limonene, α-terpinolene, d-carvone, β-elemene, α-bourbonene, β-cubebene, α-cubebene, aromadendrene, α-humulene, germacrene D, and cis-caryophyllene. Some of the compounds found in the variety Bowen grown in Australia include ethyl butanoate, thujene, ethyl decanoate, β-caryophyllene, 3-carene, myrcene, ethyl butenaonate, and β-phellandrene. Some of the compounds found in the sap of seven mango varieties grown in India include β-myrcene, trans-/cis-ocimene, and limonene.

57Some of the compounds detected in the mango sap from nine cultivars grown in Pakistan included (+)-3-carene, sabinene, α-phellandrene, α-humulene, γ-terpinene, α-pinene, and (−)-trans-caryophyllene. The 3-carene is reported as the most abundant for the varieties Bizcochuelo, S. Hayden, Tommy Atkins, Kent, Keitt, M. Bingué, Tête de chat, Palmer, and Irwin. In the varieties Bizcochuelo, S. Hayden, and Amelie, the caryophyllene is abundant, while α-terpinolene, a representative volatile compound, is in the cultivars Palmer, Kensington Pride, Tainong No. 1, JinHwang, and Keitt.

58Volatiles in Tommy Atkins mangoes grown in Mexico were identified using SPME and GC–MS, which included pinene, limonene, α-terpinolene, d-carvone, β-elemene, α-bourbonene, β-cubebene, α-cubebene, aromadendrene, α-humulene, germacrene D, and cis-caryophyllene. It has also been observed that mango fruit grown in the American continent commonly contains terpinene, sabinene, α-copaene, ethyl dodecanoate, and benzaldehyde, whereas the following terpenes were found in all the varieties studied: limonene, α-pinene, β-pinene, 3-carene, α-terpinolene, and α-humulene.

59The beneficial effects of the mango components in human health due to their dietary, nutritional, and biological properties are affected by fruit development, ripening, and senescence. The maturity stage is a significant aspect that affects the compositional quality of fruit including nutritional factors, since during fruit ripening occur important biochemical, physiological, and structural changes.

60The development of mango fruit occurs in four phases: 1) the juvenile until 21 days from fruit setting, when a rapid cellular growth occurs; 2) phase of maximum growth between 21 and 49 days from fruit setting, involving cell enlargement and initiation of maturation; 3) maturation and ripening stage between 49 and 77 days from fruit set, when the respiration climacteric and ripening process occur; and 4) senescence stage from day 77 from fruit set onwards, considered as the post-ripening stage, which is susceptible to microbial attack followed by decay and death.

61During the growth and ripening processes of mango fruit, changes in chemical composition occur ( Figure 2 ), including decrease in ash level with some rise when nearing maturity, fiber remaining more or less constant, increase in the content of alcohol-insoluble solids due to starch accumulation, change of structural polysaccharides, and hydrolysis of starch into sugars, followed by fruit softening, biosynthesis of volatile compounds, chloroplast degradation, and chromoplast and carotenoid biosynthesis. All these changes are the consequence of physiological and biochemical events controlled during ripening of fruit involving the fruit softening that affects the eating quality.

62The increased activity of some enzymes through ripening may favor internal physiological disorders referred to as the internal flesh breakdowns such as a soft nose, jelly seed, and spongy tissue. The occurrence and intensity of the alterations mentioned above depend on climate, geographical localization, and varieties; and the symptoms exhibit at the final step of fruit growth and maturation. Biochemical studies showed increasing activity of the enzyme amylase through fruit growth, and this activity decreases towards the maturity stage.

63It is important to note that depending on the variety of mango, the maturity process occurs starting in the skin towards the seed, as in the case of the Alphonso variety, while other varieties mature in the opposite direction such as in Haden, Kent, and Tommy Atkins.

64The development of the fruit and the maturation process entail changes at the transcriptional level as demonstrated in the Alphonso variety, where it was observed that 4,611 transcripts correspond to different enzymes (oxidoreductase, transferase, hydrolase, ligase, lyase, and isomerase) and in which transferase enzymes were abundant followed by hydrolases in the tissues analyzed: flower, whole fruit 30 and 60 days after pollination, mature raw fruit, and pulp (green, mid-ripe, and ripe fruit). This study identified genes encoding enzymes involved in 142 metabolic pathways of primary and secondary metabolites. Novel transcripts involved in the biosynthesis of monoterpenes, sesquiterpenes, diterpenes, lactones, and furanones related with flavor have been also identified in Ataulfo mangoes, which are differentially regulated during fruit development; in addition, 79 novel transcripts of inhibitors of cell wall-modifying enzymes were also identified, which suggests that the activity of enzymes can be controlled.

65Starch exhibits a rapid rate of accumulation at the beginning of fruit development and decreases later, but it continues increasing until maturity. For example, Alphonso mango shows a rise from 1% to 14% in starch content throughout development. A similar profile was observed in JinHwang mango grown in Taiwan. At the end of the maturity stage, reducing and non-reducing sugars are found to be increasing. During Tommy Atkins mango ripening, starch is hydrolyzed during the first week of harvest, but as the fruit becomes over-ripe, the content of starch and amylase activity is substantially reduced.

66Several studies showed many compositional and metabolic differences between the healthy and damaged tissues. de Oliveira Lima et al. showed that sugars in the spongy pulp tissue (disease of fruit) are a consequence of the presence of starch that has not been hydrolyzed because of low activity of amylase enzyme during ripening in this disorder.

67The last ones are responsible for the hydrolysis of sucrose. The accumulation of sucrose in Irwin mango was associated with the decrease of sucrose phosphate synthase activity, whereas the activities of acid invertase, neutral invertase, and sucrose synthase decreased at five developmental stages (50, 70, 90, 110, and 130 days after anthesis). A similar result was observed in JinHwang mango 110 days after anthesis; moreover, the acid invertase activity was the dominant enzyme in sugar accumulation and quality of mango fruit, which propose that mango fruit of Irwin and JinHwang cultivars should be harvested after physiological maturity at 110 days after anthesis. During the initial stages of fruit development, sucrose phosphate synthase activity was higher than sucrose synthase activity and then decreased during the advances of the development of the fruit; in contrast, sucrose synthase activity increased from 0.27 U sucrose/min/g FW at 50 days after anthesis to 2.32 U sucrose/min/g FW at 130 days after anthesis. During ripening, sucrose increased from 5.8% to 14.2% FW, while the pH changed from 3.0 to 5.2, whereas in the post-climacteric stage, the total acidity ranged from 0.13% to 0.71%, and the level of non-reducing sugars diminishes to 0.6%.

68Pectins are responsible for fruit texture. Pectin rises in the fifth week of mango fruit setting until the stone is formed, and then the pectin content decreases, leading to the fruit softening because of enzymatic degradation and solubilization of protopectin. Mango fruit pulp is composed of parenchymatous tissues that consist of calcium salts of pectin located in the cell wall during the early stages of cell growth. The deesterification of pectins and losses of calcium ions are characteristic of ripening fruit because of cell wall breakdown and dissolution of middle lamella. When mango cell walls are degraded during ripening, monosaccharides of the pectin complex are released, and the resulting water-soluble pectic materials in the cell walls lose arabinose and galactose accounting for the galacturonan-rich polysaccharides in the mesocarp.

69Moisture content was observed to range from 780.78 to 790.78 g/kg FW in green Tommy-Kent and Tommy Atkins mangoes and increased significantly in the mature stage (835.55 to 849.04 g/kg FW), which can be attributed to the catabolism or modifications of cell wall fibers and, therefore, to water liberation.

70A reduction in the soluble protein content happens up to 44 days after fruit setting and rises until 96 days. At maturity, the amino acids alanine–arginine, glycine–serine, and leucine–isoleucine are predominant but decrease during ripening, with the exception of alanine. reported that protein content in immature Tommy-Kent and Tommy Atkins mangoes was 40.45 and 37.02 g/kg FW, respectively, higher than in mature stage (12.10 and 13.87 g/kg FW, respectively); this is because there is an increase of metabolic enzymes required in the maturation and ripening process, while at the senescence stage, enzymes decrease.

71With respect to fatty acid content during mango ripening, it has been reported that there is an increase in triglyceride content in Alphonso mango fruit pulp, followed by modifications in the composition of fatty acid of the pulp. Similar patterns have been also observed in mango cultivars from India. During the ripening, an equal distribution of palmitic acid and palmitoleic acid it has observed, as well as a reduction in linoleic acid content and an increase in linolenic acid content. The palmitic acid is incorporated to hydroxy fatty acids that are precursors of lactones; thus, a correlation between the aroma and flavor was observed using the ratio of palmitic acid to palmitoleic acid. During the preclimateric and climateric stages, the mitochondria increase its capacity to oxidize fatty acids such as stearic and oleic acids, producing precursors for the synthesis of carotenoids and terpenoid volatiles.

72Organic acid content decreases as the mango fruit ripens, and consequently, the titratable acidity declines. It has been reported that the enzyme activities involved in the Krebs cycle of mango fruit change during ripening. For example, the citrate synthase activity is drastically decreased, the activities of isocitrate and succinate dehydrogenases increase, and malic enzyme in mango pulp presents the highest activity just before the climacteric peak. Citrate synthase activity decreases during ripening, while isocitrate dehydrogenase and succinate dehydrogenase activities increase.

73Vitamin C contents in the pulp decrease during mango fruit ripening and are maximum in the early stages of growth; in spite of that, the ripe mango is an important source of vitamin C. In addition, the amount of loss varied by species. One of the first studies on vitamin C developmental patterns in different mango cultivars (Amini, Mullgoa, Pico, and Turpentine) reported a reduction in the levels of the flesh 5 weeks after fruit setting until maturity, and smaller fruits with average age of about 5 weeks had an average vitamin C value of 88 mg/100 g of flesh mango fresh, but at maturity (16 weeks), these same changes were around only 22 mg/100 g. A similar pattern has been reported for Tommy Atkins, Keitt, and Kent mangoes. Moreover, Keitt mango showed significantly higher vitamin C content than did the other two varieties in the ripe phases, because of its direct inhibition of polyphenol oxidase (PPO) that probably confers better color and flavor retention during handling and processing. This reduction in vitamin C levels has been also explained based on the coenzyme function for the ACC-oxidase involved for ethylene synthesis, or as a substrate for the oxalate and tartrate biosynthesis. In spite of this, the consumption of 300 g of mature Kent and Tommy Atkins mangoes contains 645 and 1,410 mg vitamin C/kg FW, respectively, which exceeds the dietary recommendations of 75–90 mg/day.

74The content of vitamin E also changes through the ripening of mango fruit. reported that the content of this vitamin is highest at the immature stage (cv. Tommy-Atkins 91 mg/kg FW); however, when the fruit is ripened, the values were lower (65.81 mg/kg FW). On the other hand, Tommy-Kent mango presented an increase in vitamin E from the immature to mature stage (51.96 to 77.50 mg/kg).

75The content of the group of B vitamins changed significantly at the mature stage compared with the immature stage. Niacin increased by 3.0- and 1.75-folds, pyridone increased by 2.8- and 3.4-folds, riboflavin increased by 3.1- and 2.9-folds, and thiamine increased by 2.2- and 2.5-folds in mature Tommy-Kent and Tommy Atkins mangoes, respectively.

76The content of phenolic compounds (polyphenols and phenolic acids) changes during development until maturity due to their capacity for neutralizing free radicals, which are naturally produced during ripening processes or senescence. Total polyphenol contents in the immature stage in Kent and Tommy Atkins mango fruit were 4.81 and 4.42 g/kg, respectively, while in the mature stage, they were 5.24 and 4.18 g/kg, respectively. Flavonoids were low during mango ripening because of low expression of flavonol synthase as observed in Ataulfo mango; ). A similar profile was observed in Keitt and Xiangya mangoes grown in China for the content of total polyphenols in the pulp and peel, where a decrease was observed during ripening [in Keitt, 97.59 to 59.43 and 1,207.02 to 641.90 mg gallic acid equivalent (GAE)/100 g FW; in Xiangya, 96.15 to 45.15 and 723.67 to 358.62 mg GAE/100 g FW], and flavonoids in green mango were 45% more than those in mature mango.

77Several phenolic compounds have been identified in four ripening stages selected according to the percentage of yellow color in the peel of Ataulfo mango, including gallic, chlorogenic, protocatechuic, and vanillic acids. Chlorogenic acid in Ataulfo mango showed a content of 28 mg/100 g DW in the ripening stage 1 (0–10% yellow surface) and increased to 301 mg/100 g DW in the ripening stage 4 (71–100% yellow surface), whereas gallic acid content in the first ripening stage (0–10% yellow surface) was 94.6 mg/100 g DW, without significant differences with respect to ripening stages 2 and 3 (11–40% and 41–70%, yellow surface, respectively), but in ripening stage 4, it reached 98.7 mg/100 g DW. A similar profile was reported for vanillic acid (16.9 mg/100 g DW) in the first ripening stage to 24.4 mg/100 g DW in ripening stage 4; and the protocatechuic acid had a concentration of 0.48 mg/100 g DW in the first ripening stage and increased to 1.1 mg/100 g DW in the last ripening stage.

78The pigmentation of the pulp in mango fruit occurs from the seed outwards. The chlorophyll present in the unripe stage is degraded during mango ripening, and earlier present pigments and biosynthesis of anthocyanins and carotenoids are uncovered. Mature green mango contains three times more chlorophyll and marginally more β-carotene in the peel, where the enzyme activities of chlorophyllase and peroxidase are about half those of the ripe yellow fruit. The activity of these enzymes leads to a complete reduction of peel chlorophyll a during ripening from 2.2 in unripe fruit to 0.8 µg/cm2 in ripe fruit.

79On the other hand, the total carotenoid content of the peel increases approximately fivefold during ripening, probably due to carotenoid synthesis, in addition to underlying pulp carotenoids. The increase in total carotenoids during maturity has been considered as ripening index and harvest indicator; that is, the cultivars Sensation and Xiangya grown in China showed significantly higher total carotenoid content values in peels than in pulp; on the contrary, the variety Keitt also grown in China exhibited an adverse result. reported that total carotenoid content was fourfold to eightfold greater in ripe mango peel than in unripe mango peel, whereas the research of showed around three to eight times higher content in ripe mango peel.

80The accumulation of anthocyanins, which contribute to the red coloration of the mango peel, is dependent on the level of sun exposure. For example, Saengnil and co-workers showed that mangoes (cv. Kent) that were covered with brown paper bags had lower levels of anthocyanins and less redness in the peel than were mangoes not covered. The accumulation of anthocyanins and flavonoids in the peel of mango fruit protects against the chilling injury and pathogen infection, probably because of the antioxidant capacity of these polyphenols inhibiting lipid peroxidation and reduction of decay incidence. These findings may lead to new strategies as selection of the resistant red fruit or technical methodologies that would increase the content of anthocyanins and flavonoids in mango fruit peel for improving postharvest traits and for improving diminishing losses.

81The synthesis of a mixture of volatile compounds is associated with the flavor and aroma during fruit ripening as mentioned in a previous section. This is a consequence of ethylene production as volatile components accumulate from skin and pulp, improving fruit aroma and flavor. The skin of Alphonso mango has an important terpene content, while the pulp is rich in lactone. A similar profile of the volatile composition of skin and pulp of green Khieosawoei mango grown in Thailand and Kensington Pride mangoes was observed. The major volatile components present in ripe mango fruit are terpenes, while some other hydrocarbons, esters, and alcohols have also been detected in this stage.

82After harvest of mango fruit, losses in quantity and quality occur, affecting the content of nutritional and phytochemical components at different points in the handling chain. This is very important because consumers are interested not only in visual quality but also in health components and fruit safety. There is limited information about how postharvest handling practices influence nutrient and phytochemical levels in mango fruit.

83Postharvest activities include all those that are carried out with the fresh product, which can be done in the field after harvest, in collection centers, packing plant, during transport, during storage, or during marketing. Some of the postharvest practices used for mango include i) trimming, ii) delatexing/desapping, iii) sorting/grading, iv) disease control, and v) procedures for extending shelf life of mangoes, such as packaging and transport.

84Trimming is the cutting of stem resulting in latex or sap stains deposited on the fruit surface, since the sap stored in the fruit ducts is under significant pressure, and after pedicel abscission, the sap falls on the peel of mango fruit. The main cause of mango sap burn is attributed to a deposit of volatile compounds as terpinolene and car-3-ene through the lenticels, producing a tissue damage and the enzymatic browning. The development of these pigmented lesions is a response associated with stress indicators and the successive release of PPO that results in membrane damage with liberation of phenolic compounds deposited into the cell wall.

85The contact of sap or latex with the skin of mango induces lenticel discoloration, a red pigmentation described as red spots on the fruit surface caused by the synthesis of anthocyanins, flavonoids and phenylpropanoid derivatives. However, this lenticel spotting can be induced at storage temperatures below 10–12°C, accelerating the occurrence of red spots related with chilling injury.

86compared the effect of manual and mechanical harvesting practices on total soluble solids (TSS), total carotenoids, and antioxidant activity in four Indian commercial mango cultivars grown in India. Amrapali, Chausa, Dushehari, and Langra were stored at room temperature [25 ± 4°C and 65 ± 5% relative humidity (RH)]. reported that independent of storage days and cultivar, no significant difference was observed in TSS between the manually harvested [20.4°B (Brix)] and mechanically harvested (20.6°B) fruit. Amrapali mangoes had the highest TSS when harvested manually and mechanically (22.1°B and 22.6°B, respectively). These differing results might be due to the fact that mechanically harvested fruit continues to ripen after harvesting, allowing for high accumulation of TSS, while manually harvested fruit does not ripen post-harvesting. In relation to total carotenoid content, reported that independent of storage days and varieties analyzed, an overall slight increase was observed in total carotenoid content when fruits were mechanically harvested (5.4 mg/100 g FW) compared with the mangoes harvested manually (5.3 mg/100 g FW). This slight increase could be due to the effect of mechanical harvesting technique on proper attainment of ripening throughout the shelf life of mango fruit, but also subjected to varietal morphology of mango fruit. However, significant differences were found for total antioxidant activity in both manually and mechanically harvested mangoes. A slight increase of antioxidant activity was observed in fruit harvested mechanically (3.00 μmol Trolox eq/g FW) than that of manually harvested fruit (2.98 μmol Trolox eq/g FW). This difference was even more obvious at the ninth day of storage, as fruit harvested mechanically had an antioxidant activity of 4.29 μmol Trolox eq/g FW compared with 4.23 μmol Trolox eq/g FW in manually harvested fruit. These results were attributed to the extent of physical abrasion, a physical damage that directly affects antioxidants such as vitamin C present inside the fruit, because this component is used up by the fruit for combating external stresses.

87Postharvest disease control measures such as for Anthracnose are an important aspect of postharvest practices that affect the content of mango phytochemical components. At the green stage, anthracnose cannot be perceived, and the symptoms of infection are obvious when the mango ripens; this disease is caused by the Colletotrichum gloeosporioides (Penz) fungi that produce the enzymes polygalacturonase and pectolyase, able to degrade the cell wall, favoring the oxidation of phenol compounds catalyzed by the enzyme PPO-producing quinones that are polymerized and form the characteristic brown spots. On the contrary, when the tissues of the mango fruit are healthy and intact, the PPO enzyme is located in chloroplasts and the phenolic compounds in vacuoles, both separated, and thus, the reaction is avoided.

88analyzed the content of total phenols in ‘Super Haden’ mangos grown in Cuba that are damaged and treated after harvest, to establish their relationship with the defense mechanisms against the infection. In the skin of Super Haden mangoes affected by anthracnose, a reduction in the total phenol content levels was observed (59.25, 58.63, and 56.52 mg GAE/g FW) at different degrees of infection (mild, moderate, and severe damage, respectively), whereas the total phenol content in healthy fruit was 60.5 mg GAE/g FW.

89Postharvest disease control is carried out by hydrothermal and/or chemical methods. compared a treatment using hot water (53°C for 5 min) with polyethylene wax [10% Total solids (ST)] and imazalil (800 mg/L), and other with polyethylene wax (10% ST) plus imazalil (800 mg/L) on Super Haden mango fruit infected with anthracnose (mild, moderate, and severe levels); they observed that the total phenol compound content of mango peel increased after treatments. On the other hand, by using hot water with polyethylene wax plus imazalil and two bags of Conserver 21 (an ethylene absorber product), the total phenol content was 37.58 and 37.11 mg GAE/g FW, respectively, compared with the control value (33.94 mg GAE/g FW). These results also indicated a correspondence with a lower disease occurrence, because this treatment disinfects the fruit by eliminating or destroying the spores or fungal mycelium. Treatment with hot water also induces the expression of the protein of polygalacturonase that can inhibit fungal endopolygalacturonase, considered as an important factor for the resistance of plants to phytopathogenic fungi.

90A similar result was reported by in fresh, mature, green mangoes to inhibit anthracnose. Hot water treatment (46.1°C, 75 min) combined with controlled atmosphere (3 kPa of O2 + 97 kPa of N2, or 3 kPa of O2 + 10 kPa of CO2 + 87 kPa of N2) after 2 weeks of storage at 10°C and ripening in air at 25°C did not affect the content of gallic acid and hydrolysable tannins, while total polyphenols decreased naturally during ripening, regardless of hot water treatment or controlled atmosphere.

91On the other hand, imazalil is a fungicide that inhibits the biosynthesis of ergosterol, an inhibitor of cytochrome P-450 enzyme that demethylates ergosterol. Imazalil acts directly on the fungus, affecting its cellular permeability and lipid biosynthesis reduces spore germination and the inflammation of the germ tube distortion and cytoplasm loss in germinated cells. In addition, the application of essential oil (a mix of eugenol, menthol, and carvacrol), decreases cellular respiration in the fruit and the production of ethylene.

92Although thermal-processing techniques inactivate microorganisms and spoil enzymes, inadequate handling of heat-processing methods may induce several chemical changes in the fruit and reduces not only the content or bioavailability of some phytochemical compounds but also the organoleptic properties.

93For example, showed that blanching at 80°C for 5 min of mango fruit produces loss of carotenoids. also evidenced that total soluble phenolics, gallic acid, and gallotannins of mango fruit diminished as a result of prolonged hot water treatment (46°C for 70 to 110 min).

94On the contrary, Keitt mango fruit treated with hot water dipping at 50°C for 30 min had slightly lower content of TSS until 6 days of storage, but after 9 days of storage, the final value of TSS was higher than at the beginning of the experiment, and the acidity was not significantly affected by the heat treatment. Hot water dipping at 50°C for 30 min and 46°C for 75 min maintained the contents of vitamin C until 3 days of storage, whereas at 46°C for 30 min and 50°C for 75 min, the content of vitamin C quickly decreased. These results suggest that with a proper time–temperature combination, these losses can be diminished, and fresh-cut products can still contain important levels of vitamin C during storage. Finally, the carotenoid content of Keitt mango treated with hot water (46°C/75 min, 50°C/30 min, and 50°C/75 min) increased because of disruption of cell membrane induced by heat treatments, and extraction enhanced and chemically enhanced extraction of carotenoids; moreover, during storage, total carotenoid contents remained stable compared with those in non-treated fruit, which could increase the antioxidant capacity.

95Currently, the methods employed to extend the shelf life of mangoes include physical and chemical treatments to reduce respiration and ethylene production, but the storage techniques are expensive and not fully satisfactory and may lead to the development of off-flavor if temperatures used are lower than the optimum.

96Treatment with plant hormones, such as methyl jasmonate, and their synthetic derivatives are used to improve mango fruit quality, to enhance color uniformity, to increase the activity of phenylalanine ammonia lyase, and to increase the content of total phenolic compounds including anthocyanins. They also improve β-carotene, vitamin C, glucose, fructose, and sucrose contents and the ratio of soluble solids/titratable acidity, increase firmness, and reduce weight loss. Other treatments such as 1-methylcyclopropene (1-MCP) are used commercially to retard ripening, while ethrel is used to accelerate. 1-MCP treatment decreases lipid peroxidation and increases activities and isozymes of catalase and superoxide dismutase in Dashehari mango, while ethrel treatment has opposite effects. It was observed that the use of 1-MCP in Kensington Pride cultivar at higher concentrations (10 and 25 μl/L) affect the production of monoterpenes, esters, aldehydes, and aroma volatile compounds, whereas application of low concentrations of 1-MCP (1 μl/L) has less effect on the aroma profiles of this mango cultivar. In relation to chemical treatments to slow fruit softening, the addition of divalent calcium ions solutions promotes the formation of calcium bridges between the pectic polysaccharide chains.

97The non-thermal-processing technologies such as irradiation has been used as treatments for preservation, causing minimal modifications to the quality attributes of food, but might affect levels of nutrients and phytochemical compounds conditioned to the dose and radiation source used (i.e., gamma, X-ray, UV, and electron beam). evaluated the effect on the total phenolic, carotenoids, and vitamin C content of Tommy Atkins mango after electron-beam ionizing radiation in a dose range of 1–3.1 Gy and storage. They observed that flavonols after 18 days in storage (3.1 Gy) increased, total phenolics were not affected, but vitamin C decreased around 50–54% during storage (≥1.5 kGy), but no important alterations in carotenoid content were reported, indicating a retardation in ripening of treated mangoes (1–3.1 kGy) compared with non-irradiated fruits. However, at the lowest dose (≥1.5 kGy), flesh pitting was observed, indicating presence of death tissue due to the induced oxidative stress. compared the effect of irradiation at 0.4 and 1.0 kGy with the hot water dipping treatment (46°C for 90 min) on organic acid content, among other attributes of Tommy Atkins mangoes from Brazil for export stored for 14 days at 11°C and then 23°C until the end of the study. They reported that the higher levels of citric and succinic acids were present in the control group (untreated fruit) on the last day of the study. In addition, no significant differences in the total sugar content were observed between groups (control vs. treated); finally, gamma radiation does not seem to negatively affect the quality attributes of mangoes.

98At present, molecular biology techniques are good options for the control of ripening, like the antisense RNA technology, which signifies a single type of DNA transcript of 19–23 nucleotides and is complementary to mRNA. This RNA technology has been used to regulate gene expressions during the replication, transcription, and translation. For example, antisense RNA of 1-aminocyclopropane-1-carboxylate oxidase inhibits the expression of rate-limiting enzymes involved in the biosynthesis of ethylene in tomatoes, delaying its maturation. At present, ongoing studies have been applied to mangoes, among other fruits.

99Mango is a valuable fruit from a nutritional point of view, providing fiber, micronutrients as carbohydrates (10–32% in ripe pulp), proteins (0–5%), amino acids (alanine, arginine, glycine, serine, leucine, and isoleucine), lipids (0.75% to 1.7%), and organic acids (citric is the major organic acid, 0.13% to 0.71% FW).

100Mango fruit also provides macronutrients such as vitamins (vitamin C, from 9.79 to 186 mg/100 g of mango pulp; vitamin A, from 1,000 to 6,000 IU; E and K vitamins are found in minor quantities; D vitamin has not been detected in any cultivars until now). Except for biotin, all the other B vitamins have been found in mango fruit. In addition, mango fruit is an important source of polyphenols (catechins, quercetin, kaempferol, rhamnetin, anthocyanins, tannic acid, and mangiferin; carotenoids, organic acids, and volatile compounds), useful for medicinal applications and also as indicators of fruit quality. All these concentrations depend on ripe state of the mango pulp and peel.

101This review shows changes in nutritional and phytochemical components during postharvest handling practices, such as trimming, delatexing/desapping, sorting/grading, and disease control. Knowing and understanding the changes in the chemical composition in mango fruit during its development will allow producers to better characterize their cultivars and select those that have phytochemical characteristics that give added value to the fruit, for example, enhancing fruit color, delaying the maturation process, selecting fruit with a greater contribution of certain nutrients, increasing antioxidant components, and improving fruit characteristics for export purposes or greater use for agro-industry and processing.

102MEM-C and EY collected the literature; wrote the sections related to nutritional composition, phenolic and pigments compounds, and the changes of nutritional and phytochemical components during the postharvest process of the fruit; made critical edits; and reviewed the whole manuscript before submission. RB collected the literature, wrote the section on carbohydrates, and prepared the figures presented. PL and JCGO collected the literature and wrote the sections related to volatile compounds and organic acids. BR collected the literature and contributed to the section on phenolic compounds. NL and JA collected the literature and wrote the sections related to changes of the nutritional and phytochemical compositions during growth and ripening.

103This work was funded by the Francisco José de Caldas Institute for the Development of Science and Technology (COLCIENCIAS), Ecosistema Científico Convocatoria 778 de 2017 (grant number FP44842-211-2018), Estrategia de Sostenibilidad de Grupos 2018-2020 de la Escuela de Nutrición y dietética from Universidad de Antioquia (Colombia), and the Consejo Nacional de Ciencias y Tecnología (CONACyT) de México.

104The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.