Food Chemistry 122 (2010) 167–172

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Food Chemistry

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Screening of vegetables and fruits from Panama for rich sourcesof lutein and zeaxanthin

Enrique Murillo a, Antonio J. Meléndez-Martínez b,*, Falcón Portugal a

a Departamento de Bioquímica, Facultad de Ciencias Naturales Exactas y Tecnología, Universidad de Panamá, Panamab Food Colour and Quality Lab., Dept. Nutrition and Food Science, Universidad de Sevilla, Facultad de Farmacia, 41012 Sevilla, Spain

a r t i c l e i n f o

Article history:Received 18 November 2009Received in revised form 5 January 2010Accepted 15 February 2010

Keywords:Age-related macular degenerationCarotenoidsEye healthLuteinPhytochemicalsPigmentsTropical fruitsXanthophyllsZeaxanthin

0308-8146/$ - see front matter � 2010 Elsevier Ltd. Adoi:10.1016/j.foodchem.2010.02.034

* Corresponding author. Tel./fax: +34 954557017.E-mail address: ajmelendez@us.es (A.J. Meléndez-

a b s t r a c t

In this study we present the results of a screening for good sources of the carotenoid pigments lutein andzeaxanthin, which are related to the eye health. Seventy-four fruits and vegetables available in Panama,including 20 for which there were not previous reports on their carotenoid content have been analysed.The results obtained have revealed the existence of 7 sources with high content (5–20 lg/g) and 8 withvery high content (>20 lg/g) of lutein. More importantly, we found 4 sources with high content and 5with very high content of zeaxanthin, for which only a few good sources were known so far. These resultscan be useful for the update of carotenoid composition tables, the domestication of some species, thedevelopment of ingredients for functional foods, the study of the molecular basis underlying high-zea-xanthin phenotypes, etc.

� 2010 Elsevier Ltd. All rights reserved.

1. Introduction

Carotenoids are isoprenoid compounds that continue to attractthe interest of scientists, since their discovery in the 19th century.For many years, the interest in these compounds was mainly dueto the fact that they are pigments that account for the colour ofmany eye-catching structures (fruits, petals, feathers, the exoskel-eton of some animals, etc.) and have been consequently attributedimportance in relation to, pollination, seed dispersal and signallingin general, food acceptability, etc. However, carotenoids are muchmore than just pigments. For instance, they play roles of para-mount importance in photosynthesis that makes them essentialcompounds for life as we know it. Moreover, many aroma com-pounds and the plant hormone, abscisic acid, are formed as a resultof the cleavage of carotenoids. Some carotenoids (around 50) arealso provitamin A, hence they have been long attributed impor-tance in human nutrition. However, the interest in these com-pounds from a nutritional standpoint has expanded considerablyin the last three decades. This fact has been mainly due to accumu-lating evidence that these compounds can protect us against theharmful effect of free radicals and have beneficial effects in the pre-vention and/or alleviation of human disorders, like cardiovascular

ll rights reserved.

Martínez).

disease, diverse forms of cancer, eye disorders, light-inducederythemas, etc. (Britton, Liaaen-Jensen, & Pfander, 1995; Krinsky,Mayne, & Sies, 2004; Rodriguez-Amaya, 2001) (Britton, Liaaen-Jensen, & Pfander, 2008).

Within the group of carotenoids commonly found in diet ofhumans, the interest in the possible health benefits associated tolutein (b,e-carotene-3,30-diol) and zeaxanthin (b,b-carotene-3,30-diol) (Fig. 1) has grown considerably during the last years (Grana-do, Olmedilla, & Blanco, 2003). Although it has been reported thatthey can act as antioxidant and be beneficial for the prevention ofcertain cancers and cardiovascular disorders (reviewed in Calvo(2005)), their role in eye health has been better established. Thus,it has been demonstrated that both lutein and zeaxanthin areselectively deposited in the retina and that they prevent againstage-related macular degeneration, the main cause of blindness inhumans over 60 years old. Likewise, it has been reported that theratio zeaxanthin/lutein increases towards the centre of the macula,which may indicate that zeaxanthin serves special roles in vision(Krinsky, Landrum, & Bone, 2003). Consequently, the content ofboth carotenoids have been determined in several common foodsand dietary supplements in the current decade (Breithaupt &Schlatterer, 2005; Humphries & Khachik, 2003; Liu, Perera, &Suresh, 2007) and studies on their bioaccessibility and bioavail-ability have been conducted (Granado-Lorencio et al., 2009;Lakshminarayana, Raju, Krishnakantha, & Baskaran, 2007). It is

Fig. 1. Chemical structures of lutein and zeaxanthin.

168 E. Murillo et al. / Food Chemistry 122 (2010) 167–172

therefore well-known that green vegetables, pumpkins, other veg-etables and egg yolk are rich in lutein, although apart from somegenotypes of pepper, the fruits of the Chinese wolfberry (Lyciumbarbarum) and buriti (Mauritia vinifera), there are very few knowngood sources of zeaxanthin (Britton & Khachik, 2009; Inbaraj et al.,2008; Sommerburg, Keunen, Bird, & van Kuijk, 1998).

Panama possesses a great plant biodiversity, which has beenhowever little studied with a view to find new interesting sourcesof carotenoids and other micronutrients. In this study we presentthe results of a comprehensive screening for good sources of totalcarotenoids, lutein and zeaxanthin in which 74 fruits and vegeta-bles available in Panama have been analysed. Amongst the foodsstudied there are 20 for which there are not previous reports ontheir carotenoid content to the best of our knowledge. Within thisgroup there are 11 wild fruits little known by most of the popula-tion but very consumed by farmers and aborigines.

2. Materials and methods

2.1. Samples

Known carotenoid-containing foods and other fruits and vege-tables whose edible portion exhibited greenish, yellowish, orangeor reddish colours, and that may therefore be potential sourcesof these pigments, were chosen for the study. Most of the sampleswere procured from retailers based on Panama City. Other fruits,such as yellow mombin (Spondias mombin), red mamey (Pouteriasapota), purple mombin (Spondias purpurea), ‘‘guanabana toreta”(Annona purpurea), Chinese passion fruit (Cionosicyos macranthus),hill cherry (Bunchosia nitida), corozo (Aiphanes aculeata), membrillo(Gustavia superba), Chinese rose (Pereskia bleo), canistel (Pouteriacampechiana), sastra (Garcinia intermedia), black palm (Astrocaryumstandleyaum) and nance (Birsominia crassiflora), were collected di-rectly from the trees. Four samples of every fruit or vegetable wereanalysed. The samples were collected at different times during theperiod February 2004 through May 2006.

2.2. Extraction and saponification of carotenoids

The carotenoid pigments were extracted and saponified accord-ing to recommended procedures (Rodriguez-Amaya, 2001).Depending on their colour intensity, between 2 and 10 grams ofthe edible portion of the samples were accurately weighed, andthen mixed with 0.2–1.0 g of sodium bicarbonate and extractedto colour exhaustion with acetone. The acetonic extract (25 ml)was concentrated to dryness (in a rotary evaporator at temperaturebelow 40 �C) and then equal volumes of a mixture of ether andhexane (1:1) and water were added to remove traces of acetone,which may promote the formation of artifacts of carotenoids with

carbonylic groups in alkaline conditions. The epiphase was concen-trated to dryness (in a rotary evaporator at temperature below40 �C) and the residue re-dissolved in equal volumes of diethylether and methanolic KOH (5%). The saponification was carriedout under an atmosphere of nitrogen for 2 h. Finally, the mixturewas washed several times with saline to remove all the alkaliand was split into two aliquots. One of the aliquots was used forthe spectrophotometric estimation of the total carotenoids andthe other for the HPLC analysis.

2.3. Estimation of the total carotenoid content

Orientative assessments of the total carotenoid content of thesamples analysed were carried out by spectrophotometry as rec-ommended anywhere else (Rodriguez-Amaya, 2001). In brief, oneof the saponified aliquots was dried out and re-dissolved in anappropriate volume of hexane depending on its colour intensity,after which the absorbance reading at 450 nm was taken. The totalcarotenoid content was expressed as b-carotene equivalents.

2.4. HPLC

A model 1050 Hewlett Packard HPLC system fitted with a qua-ternary pump, an automated injector and a diode-array detectorwas used for the HPLC analyses. The chromatograms were regis-tered using ChemStation software (Agilent Technologies, Palo Alto,CA). A Spherisorb ODS2 column (5 lm, 250 � 4.6 mm) was used asstationary phase. The compounds were elute isocratically using themixture acetonitrile:dichloromethane:methanol (82:13:5) at1.5 ml/min. The volume of injection was 30 ll. Lutein and zeaxan-thin were identified by comparison of their retention times and on-line UV–Vis spectra with those of standards.

2.5. Lutein and zeaxanthin standards

The lutein standard was isolated from spinach leaves (Spinaceaoleracea) and the zeaxanthin standard from orange peppers (Capsi-cum annuum) by column chromatography according to Rodriguez-Amaya (2001). Their identity was confirmed by the study of theirUV–Vis spectra in methanol (recorded on a UV-1203 Shimatzuspectrophotometer) and by HPLC–APCI-MS, using an Agilent1100 HPLC system (Agilent Technologies, Palo Alto, CA) coupledwith a JEOL MS LCmate detector (JEOL Ltd., Peabody, MA).

The quantification of lutein and zeaxanthin in the samples wascarried out by external calibration. For this purpose dose–responsecurves were obtained from the standards according to recom-mended procedures (Rodriguez-Amaya, 2001).

3. Results and discussion

3.1. Separation, identification and quantification of carotenoids

Lutein and zeaxanthin are dihydroxycarotenoids differing in theposition of one of their endocyclic double bonds (Fig. 1). Theirpolarity is therefore very similar, which makes difficult their base-line separation with certain stationary phases and under certainchromatographic conditions. Although the development of newstationary phases made possible the baseline separation of bothpigments, their quantification was impaired for many years tothe extent that in some composition tables the levels of bothcarotenoids are expressed as lutein or lutein + zeaxanthin (E-Siong,Ah-Heng, & Swan-Choo, 1995; Holden et al., 1999; O’Neill et al.,2001), but not individually.

Fig. 2 depicts a chromatogram corresponding to a carotenoidextract from the tree tomato. This chromatogram serves to illus-

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Fig. 2. Chromatogram at 450 nm of a carotenoid extract from the tree tomato (Cyphomandra betaceae) and online spectra of lutein (left) and zeaxanthin (right). Peakidentification: 1, violaxanthin; 2, cis-violaxanthin isomer; 3, cis-antheraxanthin; 4, antheraxanthin; 5, lutein; 6, zeaxanthin; 7, cis-zeaxanthin isomer; 8-cis-b-cryptoxanthin;9, b-cryptoxanthin; 10, b-carotene.

Table 1Total carotenoid content and lutein and zeaxanthin levels in Panamaian wild fruits (lg/g). Entries listed in decreasing order according to their total carotenoid content.

No. Fruit Scientific name Total Lutein Zeaxanthin

1 Hill cherry Bunchosia nitida 513 ± 36.2 7.5 ± 0.6 ND2 Membrillo Gustavia superba 320 ± 3.9 6.7 ± 0.5 37.6 ± 4.03 Black palm Astrocaryum standleyaum 246 ± 13.6 4.4 ± 0.3 ND4 Canistel Pouteria campechiana 225 ± 30.5 ND 19.7 ± 1.65 Chinese passion fruit Cionosicyos macranthus 204 ± 18.3 ND 2.8 ± 0.26 Sastra Garcinia intermedia 194 ± 15.4 36.8 ± 2.9 84.7 ± 7.57 Yellow mombin Spondias mombin 45.8 ± 5.2 8.6 ± 0.7 1.2 ± 0.28 Guanabana toreta Annona purpurea 41.0 ± 3.6 2.3 ± 0.2 6.8 ± 0.99 Purple mombin Spondias purpurea 18.2 ± 2.4 6.3 ± 0.5 0.8 ± 0.110 Chinese rose Pereskia bleo 13.3 ± 1.9 8.3 ± 1.0 0.8 ± 0.111 Nance Birsominia crassiflora 1.8 ± 0.3 0.7 ± 0.1 0.2 ± 0.1

ND = not detectable, less than 0.1 lg/g.

E. Murillo et al. / Food Chemistry 122 (2010) 167–172 169

trate the baseline separation of lutein and zeaxanthin (peaks 5 and6, respectively) achieved with our chromatographic conditions.The online UV–Vis spectra of both carotenoids are also shown. Boththe retention times and the spectroscopic features of the peaks cor-responding to lutein and zeaxanthin matched those of thestandards.

Concerning the spectrophotometric assessment of the totalcarotenoid content of the samples, it is to be taken into accountthat the data have to be considered as orientative, as an arbitraryextinction coefficient is used (Britton & Young, 1993). Althoughthe accuracy is obviously not has high as that obtained by sum-ming the levels of the individual carotenoids quantified by HPLC,the values obtained are very useful for a rapid comparison of therelative carotenoid content between different sources.

3.2. Wild fruits

Information concerning the total carotenoid contents and indi-vidual lutein and zeaxanthin levels of the wild fruits surveyed issummarised in Table 1. To the best of our understanding, no previ-ous reports on the carotenoid content of these fruits have beenpublished.

The highest total carotenoid contents of all of the samples ana-lysed in the study were found in this group, the one correspondingto the hill cherry (over 500 lg/g) being outstanding. The fruit of thesastra (G. intermedia) was the sample with the highest levels of

both zeaxanthin and lutein (84.7 and 36.8 lg/g, respectively) inthis group, the levels of zeaxanthin being the highest found in allthe samples surveyed in the study. Indeed, the levels found ex-ceeded those reported by other authors in other foods, like orangepepper, maize and egg yolk (Holden et al., 1999; Sommerburget al., 1998). In Panama, the sastra (also known as monkey fruit)grows on the banks of the rivers and is neither cultivated nor mar-keted, despite it is very appreciated by the farmers and aboriginesdue to its nice sour taste (Mendoza, 1979). This data may be usefulto study the viability of its domestication and acceptability by con-sumers. In this regard, it is interesting to note that the sastra growswell in tropical regions of America, being found from Mexico toEcuador (Chizmar, 2009).

Other wild fruits with remarkable levels of zeaxanthin were themembrillo (G. superba) and the canistel (P. campechiana) (37.6 and19.7 lg/g, respectively). Taking into consideration the referencevalues suggested by Britton and Khachik to classify the levels ofindividual carotenoids as high (0.5–2 mg/100 g, that is, 5–20 lg/g) or very high (>2 mg/100 g, that is, >20 lg/g) it can be stated thatwithin this group there were 5 good sources of lutein (yellowmombin, Chinese rose, hill cherry, membrillo and purple mombin,in decreasing order of lutein content) and one very good source(sastra). More importantly due to the scarcity of good sources ofzeaxanthin, two good sources of this pigment were found (canisteland guanabana toreta, in decreasing order of zeaxanthin content).Strikingly, two fruits with zeaxanthin contents clearly over the

170 E. Murillo et al. / Food Chemistry 122 (2010) 167–172

reference value of 20 lg/g (sastra and membrillo, that exceededthe reference value by 4- and 2-fold, respectively) were also found.

3.3. Cultivated fruits

Data on the total carotenoid contents and individual lutein andzeaxanthin concentrations of fruits surveyed within this group aresummarised in Table 2. The total carotenoid content of the red ma-mey and the corozo (around 250 lg/g) were noteworthy, althoughthe former did not contain appreciable levels of lutein orzeaxanthin.

The highest levels of zeaxanthin within this group were foundin the corozo (79.2 lg/g). A previous report (Balick & Gershoff,1990) concluded that the corozo was rich in b-carotene (b,b-caro-tene) and therefore a good source of vitamin A, although HPLCanalysis was not carried out, so data on other carotenoids werenot supplied. The palm bearing the corozo, is native from the An-dean region and can be a very good source of zeaxanthin for coun-tries like Venezuela, Peru, Colombia and Bolivia. In Panama thispalm is cultivated for ornamental purposes, although the data pro-vided in this study indicate that its cultivation should be promotedfor the consumption of its fruit.

The very high-zeaxanthin content of South American sapote(Quararibea cordata) was also noteworthy. Considering the spectro-photometric estimation of the total carotenoid content as refer-ence, zeaxanthin accounted for ca. 50% of the carotenoid contentin the pulp of this fruit. The South American sapote has a goodacceptability in Panama due to its nice taste similar to that of themango. Furthermore, this fruit is also commonly consumed inother American countries like Colombia, Venezuela, Ecuador, Peruand Brazil. In the latter country the fruit is known as Sapota-do-Solimoes, and its chemical composition was the subject of a study,although no data on its carotenoid content were reported (Bragaet al., 2003). In this sense, this study seems to be the first that re-

Table 2Total carotenoid content and lutein and zeaxanthin levels in fruits cultivated in Panama (

No. Fruit Scientific name

1 Red mamey Pouteria sapota2 Corozo Aiphanes aculeata3 South American sapote Quararibea cordata4 Red guava Psidium guajava5 Orange mamey Pouteria sapota6 Watermelon Citrullus vulgaris7 Passion fruit Pasiflora edulis8 Tree tomato Cyphomandra betacea9 Mango Mangifera indica10 Mandarin Citrus reticulata11 Melo Cucumis melo12 Cassabanana Sicana odorífera13 Red tree tomato Cyphomandra betecea14 Red papaya Carica papaya15 Grafted orange Citrus sinensis16 Mandarin juice Citrus reticulata17 Yellow papaya Carica papaya18 Pineapple Ananas comosus19 Cashew Anacardium occidentale20 Aguacate Persea americana21 Grafted orange (juice) Citrus sinensis22 Red grapefruit Citrus grandis23 Red cashew Anacardium occidentale24 Naranjilla Solanum quitoense25 Orange Citrus sinensis26 Tahitian apple Spondias dulces27 Cocona Solanum sessiliflorum28 Yellow guava Psidium guajava29 Roselle Hibiscus sabdariffa30 Orange juice Citrus simensis31 Plantain Musa paradisiaca

ND = not detectable, less than 0.1 lg/g.

ports data on levels of these pigments in the South Americansapote.

According to the data displayed in Table 2, Panamaian orangesand mandarins and their juices are modest sources of lutein andzeaxanthin, although due to their availability all year round andtheir high consumption they are important contributors of carote-noids to the diet. When comparing the carotenoid contents in thepulps and in the juices, it can be seen that they are higher in theformer, which is owed to that the juice extraction procedures donot extract all the carotenoids. However, the fact that the pulpscontain more carotenoids than the juices does not imply necessar-ily that the former lead to higher bioavailabilities than the latter. Infact, many studies reveal that carotenoids are more bioavailablefrom processed foods than from raw ones, since the processingcan help release them from the cell (Yeun & Russell, 2002).

In summary, it can be stated that within this group sources withhigh or very high lutein contents were not found, but two fruitswith very high-zeaxanthin content (corozo and South American sa-pote) were determined.

3.4. Foliar vegetables

With some exceptions (such as leaves from the genus Lactuca),the carotenoid profile of green leaves is constant, the main profilesbeing lutein, b-carotene, (90Z)-neoxanthin ((90Z)-50,60-epoxy-6,7-didehydro-5,6,50,60-tetrahydro-b,b-carotene-3,5,30-triol) and viola-xanthin (5,6:50,60-diepoxy-5,6,50,60-tetrahydro-b,b-carotene-3,30-diol) (Britton et al., 1995). In this sense, it is well-known that thesevegetables are poor sources of zeaxanthin and very good sources oflutein, although the bioavailability of carotenoids from leafy vege-table is lower as compared to other foods (O’Connell, Ryan &O’Brien, 2007).

The levels of lutein and zeaxanthin found in the samples ana-lysed within this group are summarised in Table 3, in which it

lg/g). Entries listed in decreasing order according to their total carotenoid content.

Total Lutein Zeaxanthin

250 ± 35.2 ND ND240 ± 13.6 ND 79.2 ± 10.3

95.4 ± 14.5 2.2 ± 0.2 46.2 ± 6.265.0 ± 7.2 1.2 ± 0.2 ND60.2 ± 9.7 ND ND38.6 ± 4.6 ND ND35.5 ± 3.7 0.1 ± 0.1 0.2 ± 0.134.5 ± 2.7 1.9 ± 0.1 1.7 ± 0.233.9 ± 3.8 0.6 ± 0.1 0.5 ± 0.130.5 ± 3.6 2.0 ± 0.3 2.1 ± 0.229.8 ± 1.8 0.3 ± 0.1 0.1 ± 0.128.9 ± 2.5 0.1 ± 0.1 0.4 ± 0.126.6 ± 1.8 1.7 ± 0.2 2.4 ± 0.221.2 ± 1.6 0.2 ± 0.1 0.6 ± 0.121.0 ± 2.5 0.7 ± 0.2 1.1 ± 0.219.8 ± 2.6 1.6 ± 0.2 1.7 ± 0.317.1 ± 2.9 0.1 ± 0.1 ND13.5 ± 1.0 0.1 ± 0.1 0.1 ± 0.110.1 ± 0.8 0.4 ± 0.1 0.1 ± 0.1

9.8 ± 1.3 3.2 ± 0.4 ND9.7 ± 1.9 0.5 ± 0.1 0.6 ± 0.18.9 ± 1.3 0.2 ± 0.1 0.2 ± 0.18.5 ± 0.9 0.2 ± 0.1 0.1 ± 0.18.5 ± 1.2 1.9 ± 0.3 ND7.7 ± 1.0 0.3 ± 0.1 0.3 ± 0.16.7 ± 1.4 0.5 ± 0.2 0.1 ± 0.16.2 ± 1.8 0.4 ± 0.2 ND5.3 ± 0.7 0.4 ± 0.1 0.2 ± 0.12.3 ± 0.1 ND 0.8 ± 0.32.1 ± 0.3 0.1 ± 0.1 0.1 ± 0.11.2 ± 0.4 0.4 ± 0.2 ND

Table 3Total carotenoid content and lutein and zeaxanthin levels in foliar vegetables (lg/g). Entries listed in decreasing order according to their total carotenoid content.

No. Fruit Scientific name Total Lutein Zeaxanthin

1 India mustard Brassica juncea 135 ± 10.8 53.8 ± 4.2 0.8 ± 0.12 Beet Beta vulgaris 130 ± 11.2 53.1 ± 6.1 0.7 ± 0.13 Espinach Spinacea juncea 124 ± 8.7 43.7 ± 3.8 0.7 ± 0.14 Watercress Nasturitum officinale 97.7 ± 10.5 42.8 ± 4.1 0.4 ± 0.15 Endive Cichorium endivia 97.2 ± 12.6 34.2 ± 4.0 0.5 ± 0.16 Romaine lettuce Lactuca sativa (longifolia) 92.8 ± 9.1 21.1 ± 1.4 0.7 ± 0.17 Lettuce Lactuca sativa 9.9 ± 1.2 2.0 ± 0.1 0.1 ± 0.18 Cabbage Brassica oleracea (viridis) 8.5 ± 0.7 2.5 ± 0.1 0.1 ± 0.1

ND = not detectable, less than 0.1 lg/g.

E. Murillo et al. / Food Chemistry 122 (2010) 167–172 171

can be seen that 6 of the 8 samples analysed (India mustard, beet,spinach, watercress, endive, Romaine lettuce) contained very highlevels of lutein (>20 lg/g). These dark green foliar vegetables aremainly consumed by people from Asian origin. Paradoxically, light-er green vegetables like lettuce and cabbage, which contain muchlower levels of carotenoids, are the ones preferred by Panamaianpeople.

3.5. Miscellaneous vegetables

The food with the highest carotenoid content within this group(Table 4) was the squash (173.0 lg/g), which also had the highestcontent of lutein (81.7 lg/g). In Panama, the squash is widely con-sumed, commonly as puree or in pieces as ingredients of soups andsalads, so it is one of the main dietary sources of lutein. The levelsof carotenoids in squashes and pumpkins have been the subject ofother studies in the last years, which have revealed that there aredifferences amongst them as a consequence of factors like thegenotype or the stage of maturity, (Azevedo-Meleiro & Rodri-guez-Amaya, 2007; Murkovic, Mülleder, & Neunteufl, 2002).

Regarding the levels of zeaxanthin, the orange pepper was thebest source of this pigment amongst the foods analysed within this

Table 4Total carotenoid content and lutein and zeaxanthin levels in miscellaneous vegetables (lg

No. Fruit Scientific name

1 Squash Cucurbita maxima2 Red pepper Capsium annumm3 Orange pepper Capsium annuum4 Carrot Daucus carota5 Tomato Solanum lycopersicum6 Yellow pepper Capsiuum annumm7 Broccoli Brassica oleracea (italica)8 Kidney been Phaseolus vulgaris9 Green pepper Capsium annuum10 Okra Abelmoschus esculentus

ND = not detectable, less than 0.1 lg/g.

Table 5Total carotenoid content and lutein and zeaxanthin levels in starchy vegetables (lg/g). En

No. Fruit Scientific name

1 Red peach palm Bactris gasipaes2 Orange peach palm Bactris gasipaes3 Sweetpotato Ipomoea batatas4 Corn flour Zea mays5 Yellow peach palm Bactris gasipaes6 Green French plantain Musa paradisiaca (AAB)7 Ripe French plantain Musa paradisiaca (AAB)8 Boiled corn Zea mays9 Potato Solanum tuberosum10 Yellow potato Solanum tuberosum

ND = not detectable, less than 0.1 lg/g.

group (62 lg/g, roughly 60% of the total carotenoid content). De-spite these peppers can be therefore considered as very goodsources of zeaxanthin, they are not widely consumed by the popu-lation, so their relevance as dietary source of carotenoids is lowerthan that of pumpkins. Moreover, when they are consumed theyare taken in small portions, for instance, ingredients of salads oras condiments for stews.

3.6. Starchy vegetables

Within this group, yellow-orange foods containing over 70% ofstarch on a dry weight basis were analysed (the results are summa-rised in Table 5). The samples with the highest total carotenoidcontents were those of the red peach palm (ca. 150 lg/g), althoughtheir content of lutein was very low and zeaxanthin was not de-tected. The best sources of both pigments were products derivedfrom the yellow corn, specifically corn flour and boiled corn. Thisinformation is valuable, since the yellow corn is the third foodmost consumed in Panama, only to rice and French plantain (Direc-ción Nacional de Estadística y Censo, 2006). In fact, despite its con-tent in zeaxanthin is not excessively high, this kind of corn is verylikely to be the main dietary source of this carotenoid in Panama,

/g). Entries listed in decreasing order according to their total carotenoid content.

Total Lutein Zeaxanthin

173 ± 35.2 81.7 ± 15.1 1.9 ± 0.3140 ± 18.6 2.2 ± 0.4 4.4 ± 0.4103 ± 13.4 7.9 ± 0.6 62.0 ± 8.891.0 ± 8.3 3.6 ± 0.5 ND64.4 ± 7.5 3.4 ± 0.6 1.3 ± 0.251.2 ± 4.7 2.2 ± 0.2 4.4 ± 0.615.7 ± 2.1 1.4 ± 0.2 ND14.2 ± 1.7 4.3 ± 0.5 0.1 ± 0.112.1 ± 0.8 3.9 ± 0.4 ND11.4 ± 0.7 5.2 ± 0.3 0.1 ± 0.1

tries listed in decreasing order according to their total carotenoid content.

Total Lutein Zeaxanthin

148 ± 18.3 1.2 ± 0.2 ND60.1 ± 8.5 0.9 ± 0.2 ND56.8 ± 4.6 0.9 ± 0.1 0.3 ± 0.125.9 ± 1.8 2.1 ± 0.2 9.4 ± 0.725.0 ± 3.2 3.1 ± 0.6 ND17.2 ± 1.4 0.4 ± 0.1 ND16.8 ± 1.9 1.5 ± 0.2 ND12.7 ± 1.8 2.8 ± 0.4 3.7 ± 0.510.8 ± 1.6 0.7 ± 0.1 7.7 ± 0.6

2.9 ± 0.2 0.7 ± 0.1 0.5 ± 0.1

Table 6Total carotenoid content and lutein and zeaxanthin levels in imported fruits (lg/g). Entries listed in decreasing order according to their total carotenoid content.

No. Fruit Scientific name Total Lutein Zeaxanthin

1 Apricot Prunus armeniaca 31.0 ± 2.7 0.6 ± 0.1 0.3 ± 0.12 Peruvian groundcherry Physalis peruviana 29.9 ± 1.8 2.5 ± 0.2 0.4 ± 0.13 Nectarin Prunus persica 6.6 ± 0.5 0.3 ± 0.1 0.2 ± 0.14 European plum Prunus domestica 4.7 ± 0.4 0.9 ± 0.2 0.1 ± 0.15 Kiwi Actinidia deliciosa 1.8 ± 0.3 0.7 ± 0.1 ND

ND = not detectable, less than 0.1 lg/g.

172 E. Murillo et al. / Food Chemistry 122 (2010) 167–172

since it is consumed in several different ways, like tortilla (boiledand fried dough), bollo (boiled dough), tamal (dough with meatand condiments) and creams. At this point it is important to notethat in Central America and Mexico, the corn accounts for threequarters of the total consumption of cereals, although the whitecorn, whose carotenoid content is very low, is the most widely con-sumed (Organización de las Naciones Unidas para la Agricultura yla Alimentación (FAO), 1990).

3.7. Imported fruits

The total carotenoid content and the individual levels of bothlutein and zeaxanthin were very low in the samples analysed with-in this group (Table 6). The carotenoid levels reported for apricot,nectarin, European plum and kiwi, agreed well with those reportedanywhere else (Olmedilla, Granado, Blanco, Martinez, & Hidalgo,1998). As for the Peruvian groundcherry, a fruit native of Andeanregions, no previous report on their carotenoid content has beenreported previously to the best of our knowledge.

4. Conclusions

A comprehensive screening of 74 fruits and vegetables com-monly consumed in Panama has revealed the existence of 7sources with high content (5–20 lg/g) and 8 with very high con-tent (>20 lg/g) of lutein. More importantly due to the scarce num-ber of good sources of zeaxanthin, we have found 4 sources withhigh content of this pigment and 5 with very high content. Addi-tionally, data on the carotenoid content of several products forwhich there were not previous reports including 11 wild fruits lit-tle known by most of the population but highly consumed by Pan-amaian farmers and aborigines have been provided. Although theanalyses were carried out in products collected or purchased inPanama, many of them are readily available in other tropical re-gions of America. This information can be of great value from dif-ferent perspectives, like the update of carotenoid compositiontables, the promotion of the introduction and/or domestication ofsome of the products in other regions, the development of ingredi-ents for functional foods, the study of the molecular mechanismsresulting in the high-zeaxanthin phenotypes for the design ofnew carotenoid transgenics, etc.

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