Evolution of bioactive compounds of three mango cultivars (Mangifera indica L.) at different maturation stages analyzed by HPLC-DAD-q-TOF-MS

Food Research International 125 (2019) 108526

Contents lists available at ScienceDirect

Food Research International journal homepage: www.elsevier.com/locate/foodres

Evolution of bioactive compounds of three mango cultivars (Mangifera indica L.) at different maturation stages analyzed by HPLC-DAD-q-TOF-MS

T

⁎

M. Elena Alañóna,b,c, , Rodrigo Oliver-Simancasb, Ana M. Gómez-Caravacaa, ⁎ David Arráez-Romána,c, , Antonio Segura-Carreteroa,c a

Department of Analytical Chemistry, Faculty of Sciences, University of Granada, C/Fuentenueva s/n, 18071 Granada, Spain Area of Food Technology, Regional Institute for Applied Scientific Research (IRICA), University of Castilla-La Mancha, Avda. Camilo José Cela, 10, 13071 Ciudad Real, Spain c Research and Development of Functional Food Centre (CIDAF), PTS Granada, Avda. Del Conocimiento 37, Bioregión Building, 18016 Granada, Spain b

A R T I C LE I N FO

A B S T R A C T

Keywords: Mango Phenolic compounds Variety Maturation stage Functional properties

Mango is an important natural source of bioactive compounds with functional properties. However, factors such as variety and maturation stage can have a great influence on the bioactive composition. In this sense, a comprehensive study of chemical composition of three spanish mango varieties (Keitt, Kent and Osteen) at five ripening stages was conducted. The analysis by HPLC-DAD-q-TOF-MS revealed the presence of more than seventy compounds from different chemical families. Subsequently, PCA evidenced that ripening process entailed an important decrease on phenolic compounds which was being more accentuated in Keitt variety. On the other hand, Osteen was revealed as the poorest variety on phenolic compounds meanwhile mangoes from Keitt variety exhibited the major quantities of gallotannins and mono and di-galloyl species at the earliest maturation stages. Therefore, from a functional point of view, unripe mango from Keitt variety seems to be an excellent natural source of bioactive compounds.

1. Introduction

Makare, Bodhankar, & Rangari, 2001). Phenolic compounds from mango seem to be the biologically active compounds responsible for these health-promoting evidence. Compounds such as gallotanins, gallic acid and its derivatives, mangiferin, flavonoids, catechin and phenolic acids are pointed out as the main bioactive compounds. However, phenolic composition of mango is influenced by multiple factors such as cultivar (López-Cobo et al., 2017; Ribeiro, Barbosa, Queiroz, Knödler, & Schieber, 2008), storage conditions (Vithana, Singh, & Johnson, 2018a) or the pre-harvest spray application of chemicals (Vithana, Singh, & Johnson, 2018b). But maybe, the most influential factor on the accumulation of bioactive compounds of any fruit is the maturation stage since this process involves various physiological, biochemical and molecular changes include degradation or synthesis of phenolics among other compounds (Tiwari & Cummins, 2013). Usually, mango is consumed at an optimal ripened stage based on sensorial properties; however, its bioactive potential could differ as a consequence of maturation process. Therefore, if the purpose is to use mango as a functional food for improving health beneficial effects or as an ingredient for food or nutraceutical industry, the knowledge of changes on bioactive compounds during maturation is

One of the main group substances widely recognized as bioactive components due to their antioxidant properties and potential beneficial health effects are phenolic compounds. Indeed, there is increasing evidence that consumption of a variety of phenolic compounds present in foods, mainly vegetables and fruits, may lower the risk of health disorders (Halliwell, 2007; Shahidi & Ambigaipalan, 2015; Young & Woodside, 2001). However, it is important to take into account that health implications of dietary phenolic compounds are dependent on the composition of diet components and the bioavailability of the individual compounds (Scalbert & Williamson, 2000). Mango (Magnifera indica L.) is a tropical fruit with prominent recognition and consumption by consumers due to its sensorial features. On the other hand, the consumption of mango on a regular diet provides some health benefits. Mango has been postulated as functional food to prevent and combat metabolic disorders, obesity-related chronic diseases, hepatic steatosis and other comorbidities (Evans et al., 2014; Fang, Kim, Noratto, Sun, Talcott, & Mertens-Talcott, 2018; Fang, Kim, Barnes, Talcott, & Mertens-Talcott, 2018; Natal et al., 2016;

⁎ Corresponding authors at: Research and Development of Functional Food Centre (CIDAF), PTS Granada, Avda. Del Conocimiento 37, Bioregión Building, 18016 Granada, Spain. E-mail addresses: [email protected] (M.E. Alañón), [email protected] (D. Arráez-Román).

https://doi.org/10.1016/j.foodres.2019.108526 Received 19 February 2019; Received in revised form 22 May 2019; Accepted 21 June 2019 Available online 25 June 2019 0963-9969/ © 2019 Elsevier Ltd. All rights reserved.

Food Research International 125 (2019) 108526

M.E. Alañón, et al.

Column was equilibrated for 3 min after each run. Sample volume injected was 10 μL and flow rate used was 0.8 mL/min. UV spectra were recorded from 200 to 600 nm and chromatograms were registrated at 240, 280 and 330 nm. MS analysis were carried out using a 6540 Agilent Ultra-HighDefinition Accurate-Mass q-TOF-MS coupled to the HPLC, equipped with an Agilent Dual Jet Stream electrospray ionization (Dual AJS ESI) interface in negative ionization mode at the following conditions: drying gas flow (N2),12.0 L/min; nebulizer pressure, 50 psi; gas drying temperature, 370 °C; capillary voltage, 3500 V; fragmentor voltage,and scan range were 3500 V and m/z 50–1500, respectively.Automatic MS/ MS experiments were carried out using the following collision energy values: m/z 100, 30 eV; m/z 500,35 eV; m/z 1000, 40 eV; and m/z 1500, 45 eV. Peak identification was performed on basis of their relative retention time values, their UV–Vis spectra and mass spectra obtained using qTOF-MS (Mass Hunter Workstation software, Agilent Technologies) together with information previously reported in the literature. The idenfified compounds are summarized in Supplementary Table S1 including retention time (min), experimental and calculated m/z, molecular formula, error (ppm) and score. All identifications were assigned with an error ranged between 0.05 and 7.83 ppm and an average score of 92.63%. Quantification was carried out by means of calibration curves made with MS data of gallic acid, coumaric acid, ferulic acid, vanillic acid, catechin, quercetin, quinic acid, citric acid, ellagic acid and mangiferin as standards (Sigma Aldrich, St. Louis, MO, USA) from 0.39 to 100 μg/mL. The calibration curve of gallic acid was used to quantify gallates and gallotannins. Meanwhile, the calibration curve of coumaric acid, ferulic acid, vanillic acid and quercetin were used for coumaric derivatives, ferulic derivatives, vanillic derivatives and quercetin derivatives respectively (Table S1). Integration and data processing were performed using Mass Hunter Workstation software (Agilent Technologies).

essential to select the most suitable ripening stage. Asia, Sudamerica and Africa are the main producers of mango. However, the overall quality of the Spanish mango, cultivated in regions of Malaga and Granada (Tropical Coast), is regarded as superior in the European market since it remains in the tree longer time for its maturation before being exported to European countries due to its proximity. Despite this fact, scarce works reported in bibliography address the study of chemical composition of Spanish mango (GómezCaravaca, López-Cobo, Verardo, Segura-Carretero, & FernándezGutiérrez, 2016; López-Cobo et al., 2017). Therefore, it is thought to be of interest a comprehensive study about the evolution of phenolic compounds with health-promoting activities of Spanish mango during the whole maturation process. For that purpose, the aim of this study is to compare five ripening stages of three mango cultivars (Keitt, Kent and Osteen) through the phenolic composition and assess the best maturation stage according to the evolution of bioactive compounds to maximize the functional potential of mango to produce high-quality functional and nutraceutical products or as natural source of bioactive compounds. 2. Materials and methods 2.1. Fruit materials and sample preparation About 60 kg of mango from each cultivar (Keitt, Kent and Osteen) cultivated in Tropical Coast at different ripening stages were provided by Miguel García Sánchez e Hijos S.A. (Motril, Spain) in October 2016. Samples were cleaned and classified into five ripening stages according to their °Brix as follows: stage 1, ˂10.0°Brix; stage 2, 10.0–13.0°Brix; stage 3, 13.1–16.0°Brix; stage 4, 16.1–19.0°Brix; stage 5, ˃19.0°Brix. After classification, mango pulp were manually separated from the rest of non-edible parts and cut into small pieces. A total of 15 batches of 4 kg each one were resulted. Subsequently, samples made up each batch freeze dried, moisture content ˂7% (Advantage Plus EL-85 freeze dryer, SP Scientific, Ipswich, Suffolk, UK), milled (IKA M20-IKAWERKE GmbH & Co. KG, Staufen, Germany), homogenized and stored at −18 °C prior to their analysis.

2.4. Statistical analysis Statistical analysis was carried out by using the IBM SPSS statistics v.22.0 for Windows statistical package. Chemical data set was submitted to the Student-Newman-Keuls test in order to find significant differences, as well as a principal component analysis (PCA) with the aim of highlighting the main contributors to the variance among samples of different cultivars and ripening stages.

2.2. Extraction of phenolic compounds from mango samples For each representative batch, 0.5 g of freeze-dried powder were dissolved in 10 mL of a solution of methanol/water (80:20 v/v). The mixture was sonicated in an ultrasonic bath for 15 min. After the extraction process, mixture was centrifuged for 15 min at 10000 rpm under 4 °C. The supernatant was removed and the extraction step was repeated twice more (Gómez-Caravaca et al., 2016). Finally, all supernatants were collected, evaporated to dryness and reconstituted in 3 mL of methanol/water (80:20 v/v). The final extracts were filtered with regenerated cellulose filters 0.2 μm (Millipore, Bedford, MA, USA) and stored at −18 °C until their chromatographic analysis. All extractions were performed in duplicate.

3. Results and discussion Mango samples contained a congregation of several bioactive compounds. Phenolic composition of the three cultivars “Keitt”, “Kent” and “Osteen” during five maturation stages considered is compiled in supplementary information (Supplementary Table S2, S3 and S4). As shown, more than seventy compounds belonged to different families were characterized based on their relative retention time, their UV–Vis spectra and mass spectra obtained using q-TOF-MS together with information previously reported in literature (Gómez-Caravaca et al., 2016; López-Cobo et al., 2017). Among chemical families, organic acids were identified such as quinic and citric acid, being the latter one the major compound found in all samples tested decreasing with the maturation degree. Several phenolic compounds with bioactive properties were also detected in mango samples (Asif et al., 2016; Masibo & He, 2008). Thus, a large number of phenolic acids were also found, almost all of them esterified with glucose. Gallic acid and its derivatives were acknowledged as the most numerous family detected in mango samples. Several monogalloyl derivatives were found but also digalloyl derivatives as consequence of the esterification reaction between a hydroxyl group and a carboxylic acid group from gallic acid. Other phenolic acids esterified were detected such as vanillic, ferulic, sinapic and benzoic derivatives acids.

2.3. Analysis of phenolic composition by HPLC-DAD-q-TOF-MS Phenolic extracts from mango samples of tree cultivars at five ripening stages were analyzed by HPLC-DAD-q-TOF-MS. An Agilent 1200 series HPLC (Agilent Technologies, Palo Alto, CA, USA) equipped with a vacuum degasser, autosampler, binary pump and DAD was used for the chromatographic determination. The chromatographic separation was done in a column Poroshell 120 EC-C18(4.6 × 100 mm, particle size 2.7 μm) from Agilent Technologies. The method followed was that previously proposed by Gómez-Caravaca et al., 2016. Temperature was set at 25 °C and mobile phase consisted on 1% acetic acid as solvent A and ACN as solvent system B with the following gradient elution: 0 min, 0.8% B; 5.5 min, 6.8% B; 16 min, 20% B; 20 min, 25% B; 25 min, 35% B; 29 min, 100% B; 32 min, 100% B; 34 min, 0.8% B; 36 min, 0.8% B. 2

Food Research International 125 (2019) 108526

M.E. Alañón, et al.

The presence of flavonols glycosides derivatives as well as benzophenone derivatives and ellagic acid in mango were also confirmed. As xanthones, mangiferin was only found in ripening mango from Keitt cultivar. This fact supported that the presence of mangiferin in mango pulp seems to be restricted to certain varieties (Asif et al., 2016; GómezCaravaca et al., 2016; López-Cobo et al., 2017; Pierson et al., 2014; Ribeiro et al., 2008). Another large chemical family detected was hydrolyzable tannins such as gallotannins. According to other authors, ripening process seemed to be involved in various physiological, biochemical and molecular changes resulted in the degradation or synthesis and accumulation of bioactive compounds such as phenolic compounds, vitamin C and carotenoids (Ibarra-Garza, Ramos-Parra, Hernández-Brenes, & Jacobo-Velázquez, 2015; Siriamornpun & Kaewseejan, 2017; Tiwari & Cummins, 2013). For example, in green olives, oleuropein and the total phenol content in general as well as antioxidant activity dropped during maturation (Sousa, Malheiro, Casal, Bento, & Pereira, 2014). Greater phenolic and flavonoid contents and antioxidant activities were detected in green climacteric fruits compared to the ripe ones despite of some increasing levels of certain individual phenolic acids (Siriamornpun & Kaewseejan, 2017; Siriamornpun, Weerapreeyakul, & Barusrux, 2015). On the other hand, the highest content of vitamin C was found in green stage of climacteric fruits, while β-carotene was observed in the ripe stage (Siriamornpun & Kaewseejan, 2017). Physiologically, the ripening process also resulted in statistically increased of total soluble solids and the reductions of crude fiber, hardness, firmness and crispness (Siriamornpun & Kaewseejan, 2017). Based on our results, a significant decrease on the content of most phenolic compounds was evidenced in mango pulp according to the ripening degree in all cultivars evaluated (Supplementary Tables S2, S3, S4). Samples from the earliest maturation stages were richer in phenolic compounds such as gallic derivatives, phenolic acids, flavonols and benzophenone derivatives. This fact seemed to be in good agreement with those reported by other authors who stated the major content of total phenols and antioxidant capacity for green climacteric fruits than those observed for ripe ones (Ibarra-Garza et al., 2015; Siriamornpun & Kaewseejan, 2017). Among them, diverse mango cultivars from Thailand such as Nam Dokmai and Khiew Sawoey and Keitt variety from Mexico conducted a dramatic decrease in phenolic acids and flavonoids during ripening. Contrary, other authors reported a higher amount of phenolic compounds at further maturation stages (16.5 ± 1.5°Brix) in Ubá mangoes from Brazil (Oliveira et al., 2016). With the aim to highlight the main differences in phenolic composition according to maturation stage and cultivar effect, all chemical data were submitted to a principal component analysis (PCA). The three principal components accounted for 70% of the total variance. The phenolic compounds that displayed the best correlation with each principal component (loading ≥0.90) are exposed in Table 1 with their correlation coefficients and percentages of partial and total variance. Gallic acid derivatives were the largest family found in all mango samples which is in consonance with the dominant gallic acid content of mango reported in comparison with another climacteric exotic fruit (Siriamornpun & Kaewseejan, 2017). The potential significance to human health of gallic acid and its derivatives presented in mango has already been reported (Masibo & He, 2008). The most discriminant compounds were gallotannins which are hydrolysable tannins to which several pharmacological effects are attributed (Smeriglio, Barreca, Bellocco, & Trombetta, 2017). Gallotannins contain gallic acid substituents esterified with glucose whose galloylation reaction yields tri-, tetra-, penta-, hexa-, and hetpagalloylglucoses. Mango is recognized as one of the fruit with the major content of gallotannins (Smeriglio et al., 2017). Amounts of some tetra-, hexa- and heptagalloyl glucose isomers appeared to be influenced by both cultivar and ripening stage (Table 2). Thus, Keitt variety exhibited the major content of gallotannins at the first three maturation stages in comparison with the rest of varieties. Decreasing of gallotannins according to the maturation was a general

Table 1 Result of principal component analysis applied to chemical data obtained from mango pulp of three cultivars at five maturation stages. Principal component

% Partial variance

% Total variance

Compounds

Loadings

PC1

42.1

42.1

Heptagalloylglucose Hexagalloyl glucose I Heptagalloylglucose isomer III Heptagalloyl glucose isomer I Hexagalloyl glucose isomer II Galloylglucose isomer I Tetragalloyl glucose isomer II Methylgallate isomer I Methyl-digallate ester Hexagalloyl glucose isomer III Heptagalloylglucoseisomer II Digalloylglucose Methyl-digallate ester isomer II Hydorxybenzoyl galloyl glucoside Hexagalloylglucose Vanillic acid glucoside isomer I Methyl-digallate ester isomer I Heptagalloylglucose isomer IV Methyl-digallate ester isomer III Galloylglucose Methylgallate isomer II Methylgallate Vanillic acid glucoside isomer III Galloyl diglucoside Galloyl diglucosidei isomer I Galloyl diglucoside isomer II Coumaric acid glucoside Quercetin galactoside Vanillic acid glucoside isomer IV Vanillic acid glucoside isomer V Iriflophenone glucoside

0.99 0.99 0.98

PC2

15.3

57.4

PC3

12.3

69.7

0.98 0.98 0.98 0.97 0.97 0.96 0.96 0.96 0.96 0.95 0.94 0.93 0.93 0.93 0.93 0.92 0.92 0.91 0.91 0.90 0.94 0.93 0.92 0.90 0.90 0.96 0.92 0.90

tendency for all varieties. In particular, in the Keitt cultivar, a slight diminishing was detected up to the third stage but, for further maturation points, a prominent decrease of gallotannins was observed which conducted to a disappearance of almost all gallotannis isomers. However, although the initial content of gallotannins was lower in mangoes from Kent cultivar, its decreasing along maturation process was less drastically. Consequently, at the longest ripening stages, the content of gallotannins seems to be higher for mangoes belonged to Kent variety than those belonging to Keitt one. On the other hand, Osteen was revealed as a mango cultivar poor on gallotannins since hardly small quantities of these compounds were detected at the first ripening stages. On the other hand, numerous gallic acid derivatives, monogalloylated and digalloylated species, were also pointed out as discriminant bioactive compounds for variety and maturation state factors. As can be observed in Table 3, the most abundant compound was galloylglucose which concentrations ranged from 23.93 ± 1.06 to 7.75 ± 0.14 mg per 100 g of mango pulp expressed as dry matter. Keitt variety exhibited the highest amounts of galloylglucose and its isomer I in comparison with the other two varieties at the earliest maturation stages. However, despite their generalized decrease over the course of maturation, a dramatic diminution of galloylglucose and its isomer I was observed at the last two maturation stages in Keitt variety. Thus, a 65.7 and 81.5% reduction was observed for galloylglucose and its

3

4

1 2 3 4 5

1 2 3 4 5

1 2 3 4 5

Maturation stage

ND ND ND ND ND

0.30 0.09 0.14 0.12 0.05

± ± ± ± ±

0.01d 0.00b,c 0.0c 0.0c 0.0a,b

0.64 ± 0.09f 0.46 ± 0.04e 0.31 ± 0.01d ND ND

Isomer II

Tetragalloyl glucose

0.33 0.18 0.08 0.05 0.01

3.04 1.43 2.04 1.60 1.28

2.92 2.50 2.02 0.34 0.39

± ± ± ± ±

± ± ± ± ±

± ± ± ± ±

0.11b 0.00a,b 0.02a 0.01a 0.01a

0.03g 0.01c 0.01e 0.12d 0.02c

0.21g 0.09f 0.01e 0.03b 0.01b

Hexagalloyl glucose

ND ND ND ND ND

1.02 0.32 0.71 0.67 0.39

± ± ± ± ±

0.00c 0.00a 0.01b 0.07b 0.02a

1.40 ± 0.16e 1.24 ± 0.04d 0.94 ± 0.00c ND ND

Isomer I

ND ND ND ND ND

0.63 0.16 0.38 0.27 0.15

± ± ± ± ±

0.02e 0.02a 0.00c 0.04b 0.01a

0.87 ± 0.01f 0.67 ± 0.05e 0.46 ± 0.05d ND ND

Isomer II

ND ND ND ND ND

0.69 0.12 0.38 0.35 0.20

± ± ± ± ±

0.01e 0.01a 0.02c 0.05c 0.00b

0.72 ± 0.07e 0.66 ± 0.06e 0.47 ± 0.03d ND ND

Isomer III

matter

(n = 2).

± ± ± ± ±

± ± ± ± ± 0.05e 0.02b 0.01d 0.09d 0.00c

0.12g 0.06f 0.01e 0.01a 0.01a

0.02 ± 0.01a ND ND ND ND

1.11 0.31 0.73 0.71 0.50

1.74 1.38 1.10 0.02 0.01

ND ND ND ND ND

1.22 0.37 0.82 0.80 0.55

1.62 1.33 1.05 0.02 0.01 ± ± ± ± ±

± ± ± ± ±

Isomer I

Heptagalloyl glucose

0.02f 0.03b 0.00d 0.09d 0.01c

0.15g 0.15f 0.01e 0.01a 0.01a

± ± ± ± ±

± ± ± ± ±

0.07f 0.03b 0.01d 0.07d 0.01c

0.06g 0.05f 0.01e 0.00a 0.00a

0.02 ± 0.01a ND ND ND ND

1.07 0.34 0.66 0.67 0.50

1.20 1.02 0.81 0.02 0.03

Isomer II

ND ND ND ND ND

0.53 0.11 0.36 0.33 0.22

± ± ± ± ±

0.03d 0.00a 0.02c 0.04c 0.00b

0.76 ± 0.08e 0.55 ± 0.06d 0.48 ± 0.01d ND ND

Isomer III

ND ND ND ND ND

0.23 0.16 0.10 0.08 0.05

± ± ± ± ±

0.01c 0.02b 0.01a,b 0.02a,b 0.00a

0.35 ± 0.10d 0.24 ± 0.04c 0.14 ± 0.01b ND ND

Isomer IV

Values with different superscripts in the same column denoted significant differences according to the Student-Newman-Keuls test at p < 0.05. Maturation stage was defined according to their °Brix as follows: stage 1, ˂ 10.0°Brix; stage 2, 10.0–13.0°Brix; stage 3, 13.1–16.0°Brix; stage 4, 16.1–19.0°Brix; stage 5, ˃19.0°Brix.

OSTEEN

KENT

KEITT

Variety

Table 2 Concentrations of discriminant gallotannins from mango pulp of three cultivars at five maturation stages expressed as mg/100 gdry

M.E. Alañón, et al.

Food Research International 125 (2019) 108526

5

1 2 3 4 5

1 2 3 4 5

1 2 3 4 5

Maturation stage

± ± ± ± ±

0.15d,e 1.10c 0.19c 0.59c 0.35b

13.31 ± 0.77b 13.85 ± 0.58b 13.80 ± 0.15b 8.92 ± 0.34a 7.75 ± 0.14a

21.20 16.45 17.58 16.39 14.11

23.93 ± 1.06f 22.26 ± 0.45e 20.46 ± 0.17d 9.15 ± 0.33a 8.20 ± 0.09a

Galloylglucose

0.28 0.32 0.23 0.21 0.18

0.87 0.43 0.62 0.44 0.43

1.08 0.92 0.98 0.26 0.20

± ± ± ± ±

± ± ± ± ±

± ± ± ± ±

Isomer I

0.01b,c 0.03c 0.01a,b 0.04a,b 0.00a

0.01f 0.04d 0.02e 0.02d 0.01d

0.06h 0.01f 0.17g 0.33a,b,c 0.09a,b ± ± ± ± ±

0.01f 0.02d 0.00e 0.01d 0.00b

ND ND ND 0.08 ± 0.01c 0.07 ± 0.01c

0.50 0.11 0.22 0.11 0.04

ND ND 0.02 ± 0.00a 0.04 ± 0.00b 0.04 ± 0.00b

Galloyl diglucoside

± ± ± ± ±

0.01h 0.01e 0.00g 0.01f 0.01d

ND ND ND 0.03 ± 0.00b 0.05 ± 0.00c

0.28 0.10 0.19 0.13 0.06

ND ND 0.01 ± 0.00a 0.03 ± 0.01b 0.06 ± 0.00d

Isomer I

0.02 0.06 0.06 0.17 0.16

0.66 0.26 0.48 0.31 0.16

0.02 0.02 0.06 0.06 0.19

± ± ± ± ±

± ± ± ± ±

± ± ± ± ±

0.01a 0.01b 0.00b 0.01c 0.01c

0.03g 0.02d 0.01f 0.00e 0.00c

0.01a 0.01a 0.01b 0.02b 0.01c

Isomer II

1.43 1.52 0.80 0.69 1.64

4.35 2.91 3.32 3.41 2.82

4.50 4.17 3.18 1.16 1.09

± ± ± ± ±

± ± ± ± ±

± ± ± ± ±

0.25c,d 0.03d 0.07a,b 0.02a 0.02d

0.05h 0.15e,f 0.09g 0.00g 0.16e

0.09h 0.17h 0.34f,g 0.06c 0.01b,c

Methylgallate

0.13 0.10 0.05 0.02 0.11

0.88 0.48 0.77 0.80 0.62

1.25 1.30 0.84 0.17 0.14

± ± ± ± ±

± ± ± ± ±

± ± ± ± ±

0.00a,b,c 0.01a,b,c 0.01a,b 0.01a 0.01a,b,c

0.04f,g 0.02d 0.00f 0.05f,g 0.05e

0.08h 0.01h 0.06f,g 0.00c 0.01b,c

(n = 2).

Isomer I

matter

0.23 0.19 0.11 0.09 0.38

1.43 0.99 1.44 1.42 1.13

1.69 1.85 1.39 0.46 0.42

± ± ± ± ±

± ± ± ± ±

± ± ± ± ±

0.05b 0.01a,b 0.01a 0.02a 0.00c

0.02f 0.02d 0.01f 0.04f 0.02e

0.02g 0.10h 0.08f 0.05c 0.02c

Isomer II

ND ND ND ND ND

0.20 0.09 0.19 0.02 0.02

0.45 0.53 0.26 0.02 0.03

± ± ± ± ±

± ± ± ± ±

0.00c 0.01b 0.00c 0.01a 0.00a

0.06e 0.04f 0.00d 0.00a 0.01a

Hydroxybenzoyl galloyl glucoside

Values with different superscripts in the same column denoted significant differences according to the Student-Newman-Keuls test at p < 0.05. Maturation stage was defined according to their °Brix as follows: stage 1, ˂10.0°Brix; stage 2, 10.0–13.0°Brix; stage 3, 13.1–16.0°Brix; stage 4, 16.1–19.0°Brix; stage 5, ˃19.0°Brix.

OSTEEN

KENT

KEITT

Variety

Table 3 Concentrations of discriminant monogalloyl compounds from mango pulp of three cultivars at five maturation stages expressed as mg/100 gdry

M.E. Alañón, et al.

Food Research International 125 (2019) 108526

Food Research International 125 (2019) 108526

M.E. Alañón, et al.

seems to catalyze the decarboxylation of gallic acid to pyrogallol, which can be later converted to other compounds (Mingshu et al., 2006). The biodegradation metabolic pathway of gallotannins and gallic acid derivatives is presented in Fig. 1. Therefore, based on the results seems that the enzymatic mechanisms of mango are more intense in the last maturation stages, especially in Keitt variety. Finally, the presence of other phenolic acids derived from vanillic and coumaric acid was also remarkable on the differentiation among samples (Table 5). Their concentrations were perceptibly influenced not only by the variety factor but also by the maturation process. In this sense, mango samples from Keitt cultivar exhibited major amounts of vanillic acid glucoside spices than coumaric acid glucoside, contrary to Kent variety whose concentrations of coumaric acid glucoside were higher than vanillic acid derivatives. Meanwhile, similar quantities of vanillic and coumaric acid glucosylated were detected for Osteen variety. Both, vanillic acid and coumaric acid derivatives have undergone a significant decrease in all samples over the course of ripening process. On the other hand, quercetin galactoside and iriflophenone glucoside were regarded also as discriminant variables. Despite higher concentrations usually found in mango by-products such as peel or seed (Gómez-Caravaca et al., 2016; López-Cobo et al., 2017), only small quantities of quercetin galactoside and iriflophenone glucoside were detected in pulp from Kent and Osteen cultivars respectively, decreasing along the ripening. With the aim to illustrate the discrimination of mango samples graphically, a distribution in the space formed by principal component 1 and 2 (PC1, PC2) is shown in Fig. 2. As data shows, the chemical composition on phenolic compounds from mango was deeply influenced by the combination of variety and maturation factor. Thus, the earliest three maturation stages of mango from Keitt variety were concentrated in the region defined by the positive side of PC1 and the negative side of PC2. This differentiation responded to the highest concentrations of gallotannins, galloylglucose, methylgallate, methyl digallate ester, digalloylglucose and vanillic acid glucoside joint the low content of galloyl diglucoside species and coumaric acid glucoside and the absence of quercetin glucoside. Almost all mango samples from Kent variety with the exception of the longest ripening stage were mainly correlated with PC2 due to the highest quantities of galloyl diglucoside species, coumaric acid glucoside and quercetin galactoside. On the other hand, all mango samples from Osteen variety were grouped in the fourth quadrant defined by the negative values of “x” and “y” axis

isomer I respectively at the last ripening stage of Keitt variety, meanwhile lower decreases ranged from 33.4 to 50.6% were detected in case of Kent and Osteen varieties at the same maturation point. Indeed, despite being revealed as variety rich in galloylglucose content, Keitt variety did not show significant differences on quantities of galloylglucose and its isomer I at the two last stages with those mangoes from Osteen variety that, is regarded as the poorest variety on galloylglucose content in particular and galloylated compounds in general. Galloyl diglucoside and its isomers I and II were not detected until the latest maturation stages in Keitt and Osteen mango varieties where small quantities were found. The contrary behavior was exhibited by mangoes belonged to Kent variety whose concentrations of galloyl diglucoside decreased according to the ripening evolution. Methylgallate species shared the same tendency found for galloylglucose and its isomer. The highest quantities of methylgallate species were found in mangoes from Keitt variety at green stages. However, the ripening process produced a greater decrease on methylgallate and its isomers content than those resulted in Kent and Osteen varieties. Mangoes from Osteen cultivar showed the lowest values of methylgallate species, despite the rebound of their concentrations at the longest ripening stage. Apart from monogalloyl species, digalloyl compounds were also detected, whose presence in mango pulp has already been reported recently by other authors (Gómez-Caravaca et al., 2016; López-Cobo et al., 2017). Certain digalloyl compounds such as digalloyl glucose, methyl-digallate ester and its isomer I, II, and III resulted to be discriminant factors among mango samples from different varieties at diverse maturation states (Table 4). As far as these digalloyl compounds concerns, their abundances were the lowest in those mangoes from Osteen variety and remained practically constant during ripening process. Meanwhile, the major content of digalloyl compounds was found in Keitt samples at the first two maturation points. Regarding digalloyl glucose, a clear tendency to decrease over the maturation process was observed for Keitt and Kent cultivars, which was considerable more attenuated in case of Kent samples. The remarkable degradation of hydrolysable gallotannins and the other gallic acid derivatives observed over maturation process could be driven by enzymatic actions. Some of the enzymes involved in degradation of gallotannins and gallic acid derivatives are tannase and gallic acid decarboxylase (Mingshu, Kai, Qiang, & Dongying, 2006). Tannase acts on gallotannins breaking only ester bonds without affecting the carbon‑carbon bonds meanwhile gallic acid decarbosylase

Table 4 Concentrations of discriminant digalloyl compounds from mango pulp of three cultivars at five maturation stages expressed as mg/100 gdry Isomer I

Isomer II

Isomer III

matter

(n = 2).

Digalloyl glucose Isomer I

Isomer II

Isomer III

KEITT 1 2 3 4 5

4.01 4.26 2.77 0.62 0.57

± ± ± ± ±

0.24d 0.38d 0.39c 0.01a 0.05a

8.38 8.81 6.71 2.44 2.15

± ± ± ± ±

0.57g 0.48g 0.65f 0.10c 0.13c

0.15 ± 0.01e 0.19 ± 0.02f 0.08 ± 0.01c ND ND

0.61 0.70 0.47 0.09 0.03

± ± ± ± ±

0.01f 0.06e 0.04e 0.00a 0.01a

7.88 5.88 4.17 0.92 0.98

± ± ± ± ±

0.22i 0.26h 0.02g 0.03c 0.03c

1 2 3 4 5

2.82 1.68 2.53 2.62 1.99

± ± ± ± ±

0.19c 0.05b 0.10c 0.07c 0.04b

7.31 4.83 6.80 6.71 5.69

± ± ± ± ±

0.23f 0.21d 0.33f 0.24f 0.27e

0.12 0.02 0.09 0.08 0.04

0.00d 0.01a 0.02c 0.01c 0.02b

0.58 0.26 0.50 0.49 0.35

± ± ± ± ±

0.00e 0.02b 0.01d 0.03d 0.00c

5.91 3.63 3.54 2.60 2.12

± ± ± ± ±

0.04h 0.27f 0.01f 0.04e 0.01d

1 2 3 4 5

0.41 0.45 0.25 0.18 0.47

± ± ± ± ±

0.04a 0.01a 0.02a 0.04a 0.00a

1.87 1.85 1.06 0.98 2.12

± ± ± ± ±

0.40b,c 0.01b,c 0.14a,b 0.06a,b 0.08c

ND ND ND ND ND

0.51 0.41 0.48 0.73 0.20

± ± ± ± ±

0.07a,b 0.05a,b 0.02a 0.05b,c 0.01a

KENT ± ± ± ± ±

OSTEEN ND ND ND ND ND

Values with different superscripts in the same column denoted significant differences according to the Student-Newman-Keuls test at p < 0.05. Maturation stage was defined according to their °Brix as follows: stage 1, ˂10.0°Brix; stage 2, 10.0–13.0°Brix; stage 3, 13.1–16.0°Brix; stage 4, 16.1–19.0°Brix; stage 5, ˃19.0°Brix. 6

Food Research International 125 (2019) 108526

M.E. Alañón, et al.

Fig. 1. Pathways for the biodegradation of gallotannins and gallic acid derivatives (Mingshu et al., 2006). Table 5 Concentrations of discriminant phenolic acids, flavonols and benzophenone derivatives from mango pulp of three cultivars at five maturation stages expressed as mg/ 100 gdry matter (n = 2). Variety

Maturation stage

Vanillic acid glucoside

Coumaric acid glucoside

Quercetin galactoside

Iriflophenone glucoside

ND ND ND ND ND

Isomer I

Isomer III

Isomer IV

Isomer V

1 2 3 4 5

0.27 ± 0.00e 0.19 ± 0.01d 0.30 ± 0.04f ND ND

0.96 ± 0.08e 0.88 ± 0.02d 0.87 ± 0.07d ND ND

0.02 ± 0.00a ND ND ND ND

0.37 0.28 0.24 0.10 0.09

± ± ± ± ±

0.03e 0.04d 0.01b,c,d 0.00a 0.00a

0.06 0.06 0.07 0.27 ND

± ± ± ±

0.01a,b 0.00a,b 0.00a,b 0.01d

ND ND ND ND ND

1 2 3 4 5

0.12 0.06 0.09 0.05 0.04

ND ND ND ND ND

0.29 0.30 0.19 0.18 0.18

± ± ± ± ±

0.00d 0.01d 0.00b 0.01b 0.02b

2.62 1.75 1.24 1.12 1.23

± ± ± ± ±

0.03k 0.08j 0.01i 0.02h 0.03i

0.33 0.16 0.12 0.12 0.18

1 2 3 4 5

ND ND ND ND ND

0.08 ± 0.01b 0.11 ± 0.01c 0.02 ± 0.00a ND ND

0.82 0.70 0.41 0.26 0.21

± ± ± ± ±

0.06g 0.01f 0.01e 0.00c,d 0.01b,c

0.93 0.60 0.47 0.13 0.17

± ± ± ± ±

0.08g 0.03f 0.02e 0.02b,c 0.01c

ND ND ND ND ND

KEITT

KENT ± ± ± ± ±

0.01c 0.00a 0.00b 0.00a 0.01a

0.74 0.81 0.53 0.23 0.26

± ± ± ± ±

0.01c 0.01c,d 0.07b 0.03a 0.04a

± ± ± ± ±

0.06c 0.01a,b 0.00a 0.01a 0.00b

ND ND ND ND ND

OSTEEN ND ND ND ND ND

0.08 ± 0.03b 0.08 ± 0.01b 0.02 ± 0.01a ND ND

Values with different superscripts in the same column denoted significant differences according to the Student-Newman-Keuls test at p < 0.05. Maturation stage was defined according to their °Brix as follows: stage 1, ˂10.0°Brix; stage 2, 10.0–13.0°Brix; stage 3, 13.1–16.0°Brix; stage 4, 16.1–19.0°Brix; stage 5, ˃19.0°Brix.

4. Conclusions

related to the lowest concentrations of phenolic compounds in comparison with the other two varieties. Furthermore, the longest ripening samples from Keitt and Kent varieties were also located in the fourth quadrant due to the significant decrease in phenolic compounds entailed by the maturation process as consequence of the enzymatically degradation.

The comprehensive study of phenolic compounds present in Spanish mangoes from different cultivars at five-maturation stages highlighted the influence of both factors on chemical composition. Based on the results, in general terms, Keitt variety showed the highest content of bioactive compounds, especially those derived from gallic acid and gallotannins at the earliest maturation stages, while Osteen was

7

Food Research International 125 (2019) 108526

M.E. Alañón, et al.

Fig. 2. Plot of mango pulp from different varieties at five ripening stages in the space defined by principal component (PC1 and PC2) with regards to significant bioactive compounds analyzed by HPLC-DAD-q-TOF-MS.

revealed as the poorest variety on these bioactive compounds. On the other hand, the decreasing of phenolic compounds underwent over the course of maturation was another main outcome of the study. Especially noteworthy was the remarkable decrease of phenolic compounds of mangoes from Keitt variety at the longest ripening points. Therefore, cultivar selection and maturity at harvest are revealed as critical factors on bioactive composition. Consequently, both variables should be selected in order to optimize the highest amount of specific phenolic compounds linking to functional properties, which could be of interest to functional food, nutraceutical or cosmeceutical industries.

Evans, S. F., Meister, M., Mahmood, M., Eldoumi, H., Peterson, S., Perkins-Veazie, P., ... Lucas, E. A. (2014). Mango supplementation improves blood glucose in obese individuals. Nutrition and metabolic insights, 7, 77–84. Fang, C., Kim, H., Barnes, R. C., Talcott, S. T., & Mertens-Talcott, S. U. (2018). Obesityassociated diseases biomarkers are differently modulated in lean and obese individuals and inversely correlated to plasma Polyphenolic metabolites after 6 weeks of mango (Mangifera Indica L.) consumption. Molecular Nutrition & Food Research, 62, 1800129. Fang, C., Kim, H., Noratto, G., Sun, Y., Talcott, S. T., & Mertens-Talcott, S. U. (2018). Gallotanin derivatives from mango (Mangifera Indica L.) suppress adipogenesis and increase thermogenesis in 3T3-L1 adipocytes in part through the AMPK pathway. Journal of Fuctional Foods, 46, 101–109. Gómez-Caravaca, A. M., López-Cobo, A., Verardo, V., Segura-Carretero, A., & FernándezGutiérrez, A. (2016). HPLC-DAD-q-TOF-MS as a powerful platform for the determination of phenolic and other polar compounds in the edible part of mango and its byproducts (peel, seed, and seed husk). Electrophoresis, 37, 1072–1084. Halliwell, B. (2007). Dietary polyphenols: Good, bad, or indifferent for your health? Cardiovascular Research, 73(2), 341–347. Ibarra-Garza, I. P., Ramos-Parra, P. A., Hernández-Brenes, C., & Jacobo-Velázquez, D. A. (2015). Effects of postharvest ripening on the nutraceutical and physicochemical properties of mango (Mangifera indica L. cv Keitt). Postharvest Biology and Technology, 103, 45–54. López-Cobo, A., Verardo, V., Díaz de Cerio, E., Segura-Carretero, A., Fernández-Gutiérrez, A., & Gómez-Caravaca, A. M. (2017). Use of HPLC- and GC-QTOF to determine hydrophilic and lipophilic phenols in mango fruit (Mangifera indica L.) and its by-productos. Food Research International, 100, 432–434. Makare, N., Bodhankar, A., & Rangari, V. (2001). Immunomodurlatory activity of alcoholic extract of Mangifera indica L. in mice. Journal of Ethnopharmacology, 78, 133–137. Masibo, M., & He, Q. (2008). Major mango polyphenols and their potential significance to human health. Comprehensive Reviews in Food Science and Food Safety, 7, 309–319. Mingshu, L., Kai, Y., Qiang, H., & Dongying, J. (2006). Biodegradation of gallotannins and ellagitannins. Journal of Basic Microbiology, 46, 68–84. Natal, D. I. G., de Castro Moreira, M. E., Milião, M. S., dos Anjos Benjamin, L., de Souza Dantas, M. I., Ribeiro, S. M. R., & Martino, H. S. D. (2016). Ubá mango juices intake decreases adiposity and inflammation in high-fat diet-induced obese Wistar rats. Nutrition, 32(9), 1011–1018. Oliveira, B. G., Costa, H. B., Ventura, J. A., Kondratyuk, T. P., Barroso, M. E. S., Correia, R. M., ... Romão, W. (2016). Chemical profile of mango (Mangifera indica L.) using electrospray ionization mass spectrometry (ESI-MS). Food Chemistry, 204, 37–45. Pierson, J. T., Monteith, G. R., Roberts-Thomson, S. J., Dietzgen, R. G., Gridley, M. J., & Shaw, P. N. (2014). Phytochemical extraction, characterization and comparative distribution across four mango (Mangifera indica L.) fruit varieties. Food Chemistry, 149, 253–263.

Acknowledgements Authors thank to the financial support of projects from program of aid for R + D + i of the Andalusian plan for research, development and innovation (PAIDI 2020) of the Junta de Andalucía and Junta de Comunidades de Castilla-La Mancha (SBPLY/17/180501/000509). M. Elena Alañón thanks to University of Castilla-La Mancha for the postdoctoral contract: Access to the Spanish System of Science, Technology and Innovation (SECTI) and to the CYTEMA grant. Authors are also grateful to the Company “Grupo Empresarial La Caña” for the mangoes traceability assurance and for its compromise with the research group and I + D + i. Appendix A. Supplementary data Supplementary data to this article can be found online at https:// doi.org/10.1016/j.foodres.2019.108526. References Asif, A., Farooq, U., Akram, K., Hayat, Z., Shafi, A., Sarfraz, F., ... Aftab, S. (2016). Therapeutic potentials of bioactive compounds from mango fruit wastes. Trends in Food Science and Technology, 53, 102–112.

8

Food Research International 125 (2019) 108526

M.E. Alañón, et al.

Sousa, A., Malheiro, R., Casal, S., Bento, A., & Pereira, J. A. (2014). Antioxidant activity and phenolic composition of cv. Cobrançosa olives affected through the maturation process. Journal of Functional Foods, 11, 20–29. Tiwari, U., & Cummins, E. (2013). Factors influencing levels of phytochemicals in selected fruit and vegetables during pre- and post-harvest food processing operations. Food Research International, 50, 497–506. Vithana, M. D. K., Singh, Z., & Johnson, S. K. (2018a). Cold storage temperatures and durations affect the concentrations of lupeol, mangiferin, phenolic acids and other health-promoting compounds in the pulp and peel of ripe mango fruit. Postharvest Biology and Technology, 139, 91–98. Vithana, M. D. K., Singh, Z., & Johnson, S. K. (2018b). Levels of terpenoids, mangiferin and phenolic acids in the pulp and peel of ripe mango fruit influenced by pre-harvest spray application of FeSO4 (Fe2+), MgSO4 (Mg2+) and MnSO4 (Mn2+). Food Chemistry, 256, 71–76. Young, I. S., & Woodside, J. V. (2001). Antioxidants in health and disease. Journal of Clinical Pathology, 54, 176–186.

Ribeiro, S. M. R., Barbosa, L. C. A., Queiroz, J. H., Knödler, M., & Schieber, A. (2008). Phenolic compounds and antioxidant capacity of Brazilian mango (Mangifera indica L.) varieties. Food Chemistry, 110, 620–626. Scalbert, A., & Williamson, G. (2000). Dietary intake and bioavailability of polyphenols. Journal of Nutrition, 130, 2073S–2085S. Shahidi, F., & Ambigaipalan, P. (2015). Phenolics and polyphenolics in foods, beverages and spices: Antioxidant activity and health effects – A review. Journal of Functional Foods, 18, 820–897. Siriamornpun, S., & Kaewseejan, N. (2017). Quality, bioactive compounds and antioxidant capacity of selected climacteric fruits with relation to their maturity. Scientia Horticulturae, 221, 33–42. Siriamornpun, S., Weerapreeyakul, N., & Barusrux, S. (2015). Bioactive compounds and health implications are better for green jujube fruit than for ripe fruit. Journal of Functional Foods, 12, 246–255. Smeriglio, A., Barreca, D., Bellocco, E., & Trombetta, D. (2017). Proanthocyanidins and hydrolysable tannins: Occurence, dietary intake and pharamacological effects. Brithish Journal of Pharmacology, 174, 1244–1262.

9