Phenolic compounds, antioxidant activity, and ...

International Journal of Food Properties

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Phenolic compounds, antioxidant activity, and medium chain fatty acids profiles of coconut water and meat at different maturity stages Busarakorn Mahayothee, Intira Koomyart, Pramote Khuwijitjaru, Prasong Siriwongwilaichat, Marcus Nagle & Joachim Müller To cite this article: Busarakorn Mahayothee, Intira Koomyart, Pramote Khuwijitjaru, Prasong Siriwongwilaichat, Marcus Nagle & Joachim Müller (2015): Phenolic compounds, antioxidant activity, and medium chain fatty acids profiles of coconut water and meat at different maturity stages, International Journal of Food Properties, DOI: 10.1080/10942912.2015.1099042 To link to this article: http://dx.doi.org/10.1080/10942912.2015.1099042

Accepted author version posted online: 14 Oct 2015.

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Date: 26 October 2015, At: 03:40

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Busarakorn Mahayothee1*, Intira Koomyart1, Pramote Khuwijitjaru1, Prasong Siriwongwilaichat1, Marcus Nagle2, Joachim Müller 2

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Silpakorn University, Faculty of Engineering and Industrial Technology, Department of Food Technology, Nakhon Pathom, Thailand 73000 P

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Universität Hohenheim (440e), Institute of Agricultural Engineering, Tropics and Subtropics Group, Stuttgart, Germany 70599 P

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*Corresponding author: B. Mahayothee E-mail address: [email protected], [email protected]

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Properties of coconut water and meat at different maturity stages

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ABSTRACT

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Coconut is grown in tropical and subtropical areas worldwide. The endosperm (water and meat)

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is consumed and processed in different forms. This study investigated the antioxidant activities

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and identified the phenolic compounds existing in the water and meat of coconut fruits at 3

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different maturity stages, i.e., 180, 190, and 225 days after pollination (DAP) from two planting

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areas in Thailand. Total phenolic content and antioxidant activity indices increased as the

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coconut matured from 180 to 190 DAP and then decreased or remained unchanged at 225 DAP.

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Catechin and salicylic acid were the major phenolic compounds found in the water, while gallic,

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Phenolic compounds, antioxidant activity, and medium chain fatty acids profiles of coconut water and meat at different maturity stages

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caffeic, salicylic, and p-coumaric acids were found in the meat. Fat content of the meat increased

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significantly with maturity stage. Medium chain fatty acids profiles were also analyzed. The

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results are important for producers, processors and consumers to realize an optimal quality and

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functionality of coconut water and meat when used for specific purposes.

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Keywords: Cocos nucifera; Total phenolic content; DPPH; ABTS; MCT

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INTRODUCTION

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Coconut (Cocos nucifera Linn.) is produced worldwide, with a global production of about 56

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MT per year and is one of the important agricultural commodities in Thailand with an annual

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production of 1.1 MT.

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Thailand exportation. It is favourite for a pleasure scent and sweet smell from various fruit parts

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such as coconut water and meat.[2] It is used at different maturity stages for different commercial

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purposes. Young coconut or green coconut with tender meat is usually consumed as fresh and

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processed into burnt aromatic coconut, coconut water, young coconut in jelly and coconut ice

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cream, while mature meat is used for an extraction of virgin coconut oil and a production of

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dehydrated coconut. Fresh coconut water is a traditional, refreshing drink in Southeast Asia and

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Latin American countries, and recent reports indicate that packaged ready-to-drink coconut water

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is gaining much interest from consumers in other countries as a natural drink for hydration

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even though scientific data for its effectiveness is scarce. [4] Main composition, mineral contents

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and aromatic compounds of coconut water from several cultivars have been reviewed.

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Normally, coconut water contains about 5 − 8 % of total soluble solids, of which the majority are

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The aromatic coconut cv. Nam Hom is of the utmost importance to

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sugars (3 − 7 %). Other minor components are amino acids and minerals. Recently, various

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health benefits of coconut water were reported. Young coconut water (6 months) which contains

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estrogen-like compounds might be used to prevent Alzheimer's disease in menopausal women. [7]

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Mature coconut water (12 months) also showed hypoglycemic effect and reduced oxidative

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stress in rats. [8]

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Phenolic compounds are important phytochemicals that exhibit several bioactive

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properties including antioxidant activitiy. Quantification and identification of phenolic

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compounds in different kinds of fruits and vegetables and their processed products have been

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reported in many studies. Also, determination of total phenolic content (TPC) by Folin-

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Ciocalteu’s reagent was widely performed for preliminary screening of potential high antioxidant

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sources. Antioxidant activity of coconut water, however, has been reported by only a few

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studies. [9, 10] Identification of phenolic containing compounds was only reported. [11] For coconut

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meat, fat components are of interest for food scientists and industries. It is well-known that

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triacylglycerols present in coconut contain mainly lauric and other medium chain fatty acids.[12]

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These medium chain triacylglycerols (MCT) show a potential use as a functional food

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ingredient. [13, 14]

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To date, the TPC, antioxidant activities, and medium chain fatty acids profiles of coconut

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water and meat have been underreported in literature, especially with respect to different

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maturity stages. This information can be useful for selecting appropriate harvesting period of

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coconut crops for specific purposes. Therefore, the present study provides results focused on

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these analyses for a well-known aromatic coconut crop variety ‘Nam Hom’ grown in Thailand.

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MATERIALS AND METHODS

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Chemicals and reagents

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Gallic acid, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), 2,2-azino-bis(3-

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ethylbenzothiazoline-6-sulfonic acid) diammonium (ABTS), 1,1-diphenyl-2-picrylhydrazyl

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(DPPH),

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(caprylate, caprate, laurate, myristate, and palmitate), standard phenolic compounds (salicylic, 4-

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hydroxybenzoic, syringic, m-coumaric, p-coumaric, gallic, and caffeic acids, and catechin), N,O-

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bis(trimethylsilyl) acetamide (BSA), trimethylchlorosilane (TMCS), and pyridine were

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purchased from Sigma-Aldrich (St. Louis, MO, USA). HPLC grade methanol and isopropanol

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were purchased from Merck (Darmstadt, Germany). Chloroform was purchased from RCI

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Labscan (Bangkok, Thailand). Acetic acid and hexane were purchased from Mallinckrodt Baker

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(Phillipsburg, NJ, USA). Sodium carbonate, potassium persulfate, and potassium chloride were

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obtained from Ajax Chemicals (NSW, Australia).

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Sample preparation

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Thai aromatic coconuts cv. Nam Hom of three different maturity stages, i.e. 180, 190 and 225

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Folin-Ciocalteu’s reagent, sodium methoxide, standard fatty acid methyl esters

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days after pollination (DAP), were purchased from the same areas and same local producers in

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two major planting areas in Thailand, i.e. Ban Phaeo, Samut Sakhon province (13° 35′ 26″ N,

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100° 6′ 28″ E) and Damnoen Saduak, Ratchaburi province (13° 31′ 6″ N, 99° 57′ 18″ E). Those

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three selected maturity stages are covered the harvesting maturity for commercial uses of

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aromatic coconut (approximately 6-7 months). The coconuts at 180 DAP contained jelly-like

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meat with transparent characteristic and a thin layer on the soft eye, whereas at 190 DAP, the

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meat of the whole fruit became rather thick, more tender with light cream colour whereas that

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near the stem end has a small portion of transparent pulp which corresponds to the most

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preferable stage for fresh consumption. The last maturity stage of aromatic coconut used in this

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study was 225 DAP, at which point the meat was thick and hard without transparent pulp. The

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two selected planting areas are similar in type of soil (sandy loam), irrigation method (furrow

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irrigation) and amount of rainfall. The distance between the two areas are about 34 km.

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Thirty fruits from each planting area and maturity stage were harvested in October 2008, January

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2009, and July 2009. For each lot, all coconuts were manually dehusked after which the coconut

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water and meat were separated. The coconut water and meat from 30 fruits were pooled and

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stored at −18oC for subsequent analyses. Chemical properties of the water were analyzed using

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pH meter (PHM 210, Radiometer Analytical, Villeurbanne cedex, France) for pH, hand

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refractometer (2110-W06, Atago, Tokyo, Japan) for total soluble solids (TSS), and titration with

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0.1 N NaOH for titratable acidity. The meat thickness was measured by a vernier calliper.

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Moisture, crude protein, crude fat, crude fiber, and ash contents of the meat were determined

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using hot air oven drying, Kjeldahl method, soxhlet method, acid-base hydrolysis, and dry ashing,

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respectively according to the AOAC methods. [15]

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TPC, antioxidant activities, and GC-MS analysis

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Extraction: Extraction of the phenolic compounds from the coconut meat was performed

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according to Maisuthisakul et al. [16] with some modifications. Thawed coconut meat (20 g) was

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ground in a food processor. The ground sample was combined with methanol (100 mL) and the

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mixture was shaken at room temperature for 3 h using an orbital shaker at 90 rpm. The mixture

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was filtered through Whatman no. 4 paper and the liquid extract was evaporated under vacuum at

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50°C using a rotary evaporator (Rotavapor R−114, Buchi, Switzerland). The concentrated extract

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was volumetrically adjusted with methanol to 10 mL in a volumetric flask for further analyses.

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Similarly for coconut water, the liquid was thawed and was mixed with methanol (1: 5 v/v) and

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the extraction steps were followed as described above. All extractions were performed in

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triplicate.

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TPC determination: The methanolic extracts of coconut meat and water were determined for

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TPC using Folin−Ciocalteu’s reagent.

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Ciocalteu’s reagent (1 mL) and allowed to react for 3 min. Sodium carbonate (7.5 % w/v, 0.8

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mL) was added to the mixture and allowed to react at room temperature for 2 h. The absorbance

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at 765 nm was measured using a spectrophotometer (Genesys 20, Spectronic, USA). Gallic acid

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was used for standard calibration and TPC were expressed as mg gallic acid equivalents (GAE)

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per 100 g fresh meat or 100 mL water.

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DPPH assay: DPPH assay was performed as described by Brand-Williams et al.

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extract (0.1 mL) was mixed with 6 × 10−5 M DPPH in methanol (3.9 mL). The mixture was kept

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The extract (0.2 mL) was mixed with 10% v/v Folin-

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Diluted

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at room temperature in the dark for 2 h. Absorbance was measured at 515 nm and the DPPH

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radical scavenging activity was calculated as:

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DPPH radical scavenging activity (%) = (A 0 − A s / A 0 ) × 100

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where A s and A 0 are the absorbance of DPPH solutions with and without the sample,

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respectively.

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ABTS assay: ABTS assay was performed according to Re et al. [19] The ABTS reagent (7.0 mM)

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was mixed with potassium persulfate (2.45 mM) in the ratio of 2:1 v/v and kept in the dark at

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room temperature for 12 h. Before the analysis, the reagent was diluted with 95% ethanol to

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adjust the absorbance at 734 nm to 0.7 ± 0.02. The ABTS+ reagent (4 mL) and the extract (40

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µL) were mixed. Absorbance at 734 nm was recorded after 6 min. Trolox solution (1 mM) was

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used for calculating the Trolox equivalent antioxidant capacity (TEAC) from:

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TEAC (mM TE/mL or g FW) =

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inhibition by test sample (%) inhibition by 1 mM Trolox (%) × g or mL of sample

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GC-MS analysis of phenolic compounds

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Phenolic compounds were converted to trimethylsilyl derivatives with BSA for GC-MS

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Five millilitres of the methanolic extract was mixed with 50 µL of pyridine at 60°C

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analysis.

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for 10 min. The mixture was combined with BSA (500 µL) and TCMS (200 µL) and kept for

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another 60 min. GC-MS analysis was performed using a HP 6890 GC with a HP 5973 MS

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(Agilent, Santa Clara, CA, USA). Separation was accomplished on HP5 column (30 m × 0.25

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mm i.d., 0.25 µm film thickness) using helium at 1.5 mL/min as the carrier gas. The injector

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temperature was set at 240°C, whereas column temperature was 90°C for 1 min, then increased

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to 240 at 20°C/min, kept constant for 10 min, then increased to 280 at 20°C/min and finally kept

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constant for 5 min. Samples (1 µL) were injected using a splitless mode. Authentic standards of

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phenolic compounds were used for peak identification.

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Medium chain fatty acids (MCFA) profile of coconut meat

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Oil extraction and purification: Coconut oil extraction was conducted using the modified

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Folch procedure as described by Christie.

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chloroform-methanol (2:1 v/v) in a continuous shaker at 90 rpm for 12 h. Coconut residue was

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separated by filtration through Whatman no.4 paper and the solvent was then removed using a

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rotary evaporator under vacuum at 50°C. The oil residue at this point was considered as crude

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oil.

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The coconut crude oil was purified by the procedure of Christie.

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chloroform-methanol (2:1 v/v, 30 mL) and shaken continuously for 3 min. The mixture was

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washed with 8 mL of potassium chloride solution (0.88% w/v) in a measuring cylinder. The

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mixture was shaken thoroughly before allowing to settle. The upper aqueous layer was drawn off

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Coconut meat (10 g) was dissolved with

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Crude oil was mixed with

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by pipette. Methanol- potassium chloride solution (1:1 v/v, 10 mL) was added twice to the lower

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layer for washing. The mixture was filtered before the solvent was removed using a rotary

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evaporator. The purified oil was stored at -18°C for fatty acids methylation.

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Fatty acids methylation: The purified oil (10 mg) was dissolved with hexane (5 mL) in a

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capped test tube and sodium methoxide in methanol (0.5 M, 0.1 mL) was added. The mixture

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was shaken for 5 min at room temperature. Glacial acetic acid (10 µL) and anhydrous calcium

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chloride (2 g) were added to the mixture. After 1 h, the mixture was centrifuged at 5000 rpm for

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5 min to precipitate the drying agent. The supernatant was taken for subsequent GC analysis.

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GC-FID: The fatty acid methyl esters (FAMEs) were analyzed by a Shimadzu GC 2010 (Kyoto,

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Japan) equipped with a flame ionization detector (FID). The esters were chromatographically

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separated in an Alltech AT-WAX capillary column (50 m × 0.25 mm i.d., 0.2 µm film thickness)

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(Grace, Deerfield, IL, USA). The oven temperature was kept at 120°C for 3 min, followed by an

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increase at 5°C/min to 210°C that was held for 15 min. Helium was used as the carrier gas at a

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flow rate of 0.4 mL/min. The injector and detector temperatures were maintained at 210°C. Ten

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microliters of sample was injected in a split mode (1:10). A comparison of the retention time of

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FAMEs with authentic standards was made to facilitate identification.

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Statistical analyses

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To evaluate effects of maturity stage and origin of coconut, analysis of variance (ANOVA) for 3

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× 2 factorial in randomized complete block design (RCBD) using 3 different harvesting dates of

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samples as blocks, followed by the least significant difference (LSD) test were performed using

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PASW Statistics 18 (IBM, NY, USA). Simple main effects were analyzed if significant

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interaction between the two factors was observed. [22] P

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RESULTS AND DISCUSSION

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Chemical compositions and physical properties

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Some basic chemical compositions and physical properties of coconut water and meat from the

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two planting areas are shown in Table 1. TSS and TA of the coconut water slightly decreased at

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225 DAP. These were in agreement with previously reported values in literature.

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coconut meat, thickness and fat content increased significantly with the maturity stages. Data in

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Table 1 are important for selection the proper maturity for different commercial coconut

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utilizations. For example, coconut water is usually consumed as natural beverage, therefore, the

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coconut water at 190 DAP would give moderate acidity and adequate sweetness while the meat

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from 225 DAP is suitable for producing coconut virgin oil because of considerable high amount

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of fat compared to other maturities.

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TPC and antioxidant activity

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TPC and two antioxidant activity indices (DPPH and ABTS) for coconut water and meat are

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shown in Table 2. Aromatic coconuts from these two important planting areas of Thailand

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showed no significant differences in antioxidant activities (p > 0.05), while significant

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differences could be found for the TPC depending on the maturity, both in the water and meat.

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Overall, the coconut meat contained higher TPC and antioxidant activities wet basis than the

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water. Leong and Shui [10] also reported that the ABTS radical scavenging activity (per g FW) of

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meat was about 4 times higher than that of water for coconut samples purchased from local

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market in Malaysia. In this study, it was found that during the maturation of fruit, TPC

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significantly increased at 190 DAP and then slightly decreased at 225 DAP. The TPC values

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were in ranges of 5.18-7.17 mg GAE/100 mL and 6.28 – 10.01 mg GAE/100 g for the water and

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meat, respectively. These values were in agreement with data from a recent report

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though they were relatively low compared with those from other well-known high phenolic

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content fruit juices, for example, pomegranate (400 -1600 mg GAE /100 mL)

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GAE/100 g)

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mL). [26]

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Both free radical scavenging activity indices increased until 190 DAP and remained unchanged

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at 225 DAP. The TEAC values were in ranges of 2.98 – 4.55 µM TE/mL and 4.00 – 7.69 µM

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TE/g FW for the water and meat, respectively. These values were also lower than those of some

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other fruits, for example, blueberry fruits (~ 30 µM TE/g), and juice (~ 10 µM TE/mL).[27] Leong

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and Shui [10] reported that the antioxidant activities of coconut water and meat were classified as

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“low” based on ABTS values.

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Phenolic compounds

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Identification of phenolic compounds in coconut water and meat is presented in Figure 1. Based

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, even P

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, and white and red grapes (25.4 – 38.9 and 140.7 to 224.6 mg GAE /100 P

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on the chromatographic peaks of 8 identified compounds, the phenolic components found in the

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water samples were catechin and salicylic acid, while gallic, caffeic, salicylic and p-coumaric

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acids were the main phenolic compounds found in the meat (Table 2). Overall, the amounts of

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the phenolic compounds found in the water were less than in those of the meat, which was in

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agreement with the TPC and antioxidant activities described earlier. Identification of phenolic

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compound in coconut water was scarcely reported. The presence of (+)-catechin and (−)-

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epicatechin in coconut water with concentrations of 0.344 and 0.242 μg/mL, respectively was

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recently reported by Chang and Wu.

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methanolic extract of coconut oil. Seneviratne et al. [28] found only gallic, syringic acids, and (−)-

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epigallocatechin in coconut oil extracted under cold conditions, while gallic, caffeic, syringic, p-

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hydroxybenzoic, ferulic acids, (−)-epigallocatechin, (+)-epicatechin, and (+)-catechin were found

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in coconut oil extracted under heated conditions. Gallic and caffeic acids as well as catechin are

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phenolic compounds with relatively high antioxidant properties

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vegetables. These compounds should contribute considerably to the antioxidant activities of

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coconut water and meat. Other major antioxidants in coconut water and meat were not reported

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in literature. Leong and Shui

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coconut water and meat (0.7 and 0.9 mg/100 g, respectively). Salicylic acid was also detected in

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the water. It is considered as a phytohormone found in coconut water. [30]

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Fat content and medium chain fatty acids (MCFA) profile of coconut

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meat

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Because the water and meat are part of the endosperm tissues of the fruit, accumulation of the fat

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Similar phenolic compounds were identified from a P

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found in many fruits and

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reported that only small amount of ascorbic acid was found in

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during maturation of coconut is expected. The crude fat contents of coconut meat increased with

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the maturity as shown in Table 1. Since the fat content in coconut water is generally low,

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therefore, no attempt was made to analyze the value in this study. However, increase in fat

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content in coconut water was reported by Jackson et al. [31] for some varieties in Jamaica, which

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were in the range of 1 – 2 % during maturity stages of 7 – 10 months.

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Even though there is some disagreement about the consumption of coconut oil due to its high

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content of saturated fatty acids, several recent reports on the health beneficial of this oil,

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specifically virgin coconut oil, have been published in the last decade.

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be noted that coconut meat and coconut milk are used in many tradition cuisines for people in

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South and Southeast Asia. Lately, MCT as functional ingredients have received more interest

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from nutritionists. A typical GC-FID chromatogram of FAMEs found in coconut meat is shown

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in Figure 2. The major fatty acids in coconut were lauric, myristic and palmitic acids (Table 3).

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The percentages of these fatty acids were in agreement with those present in extracted coconut

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oil. [13] The content of all fatty acids also increased in later maturity stages.

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CONCLUSIONS

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This study reported several chemical changes during the maturation of coconut which should be

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important for producers, manufacturers and consumers to select an appropriate quality and

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functionality of coconut water and meat for specific purposes.

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In addition, it should

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ACKNOWLEDGEMENTS

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This research was supported by the Research and Development Institute, Silpakorn University,

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Thailand (SURDI 53/02/03). B. Mahayothee gratefully acknowledges the Invitation

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Professorship from the Food Security Center, Universität Hohenheim, Germany supported by

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German Academic Exchange Service (DAAD) and Federal Ministry for Economic Cooperation

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and Development (BMZ).

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REFERENCES

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Brand-Williams, W.; Cuvelier, M. E.; Berset, C., Use of a free radical method to evaluate

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Re, R.; Pellegrini, N.; Proteggente, A.; Pannala, A.; Yang, M.; Rice-Evans, C.,

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Zadernowski, R.; Naczk, M.; Nesterowicz, J., Phenolic acid profiles in some small

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Christie, W. W., Gas Chromatography and Lipids: A Practical Guide. The Oily Press:

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Tan, T.-C.; Cheng, L.-H.; Bhat, R.; Rusul, G.; Easa, A. M., Composition,

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Thermosonication as a potential quality enhancement technique of apple juice. Ultrasonics

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Bosanek, C. A.; Silliman, K.; Kirk, L. L.; Frankel, E. N., Total Phenolic Content And

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Seneviratne, K. N.; HapuarachchI, C. D.; Ekanayake, S., Comparison of the phenolic-

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340

31.

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composition of coconut (Cocos nucifera) water during maturation of the fruit. Journal of the

342

Science of Food and Agriculture 2004, 84, 1049-1052.

us

343

cr ip

t

Jackson, J. C.; Gordon, A.; Wizzard, G.; McCook, K.; Rolle, R., Changes in chemical

Table 1 Chemical and physical properties of coconut water and meat at different maturity stages (n = 3).

M an

344 345

Samut Sakhon

± 5.56

4.84

ce

P

225 DAP

180 DAP

pt

Water

pH2

190 DAP

Ratchaburi

190 DAP

225 DAP

ed

180 DAP

0.02a P

Ac


18

TSS (ºBrix)2

7.7 ±0.10b

Titratable

0.07

P

P

± 5.84

± 4.95

0.22c

0.10a

0.14b P

P

7.9 ± 0.12b

± 0.06

P

± 5.25 0.31b

P

7.2 ± 0.12a P

± 0.05

18

P

P

7.9 ± 0.12b

± 0.07

±

0.12c

P

7.8 ± 0.31b

± 0.08

± 5.58

P

7.6 ± 0.21a

± 0.05

P

±

19

acidity, as malic 0.01b

0.02b

P

0.01a

P

0.02b

P

0.04b

P

0.01a

P

P

acid (%)2 P

(mm)2

0.60a

Moisture

74.7

content2

2.81c

± 67.3

± 2.99

0.78a

0.33a

P

± 4.19

0.17b P

± 10.17

pt

± 24.22

0.13a

1.21b* P

ce

P

Crude fiber1 P

± 1.22

1.33

Ac

0.09a*

Ash2 P

P

P

P

0.25a* P

P

± 2.04

1.43 0.71a P

P

± 4.49 0.27b

11.15

± 23.25

P

P

P

± 0.92

0.05b*

P

P

± 1.59

0.04b

P

19

0.12B* P

P

P

P

±

0.11C* P

P

± 2.20

0.42b P

±

0.49C*

± 4.84

± 2.23

0.06a

P

P

± 1.75

0.23A*

P

± P

0.08B*

± 2.00

0.19b

P

0.40a

P

P

1.15a

P

0.91a

± 4.7 ± 0.54A

± 6.51

±

± 3.11

0.05c* P

2.84b

± 57.4

± 2.67 P

ed

P

P

± 66.4

74.2

±

0.72c

P

3.09c

P

2.71

5.04

P

P

± 5.97

0.41b

P

a ± 55.2 4.02

1.12b

P

Crude fat1

0.40a

P

± 4.81

M an

P

0.65c

P

P

Crude protein2

± 3.85

0.37b

P

P

± 6.04

us

3.67

P


± 4.64

Thickness

cr ip

t

Meat

±

0.36b P

20

Carbohydrate2,3 P

14.84

± 16.27

± 7.84

± 15.85

± 15.37

± 10.20

2.98b

0.10b

3.84a

4.50b

3.53b

2.79a

P

P

P

P

P

346

1

347

indicated by different letters. Significant differences within the same DAP are indicated by *.

348

2

349

3

350 351

able 2 Total phenolic content and antioxidant capacity as measured by DPPH and ABTS assays (n = 3).

t

Significant interaction (p < 0.05). Significant differences within the same planting area are P

cr ip

P

Non-significant interaction (p > 0.05). Significant differences are indicated by different letters. By difference. P

M an

P

P

us

P

352

DA

area

P

Water

Meat

ce

pt

ed

Planting

Ac


P

±

TPC

DPPH

(mg

(%

ABTS (µM

TPC

Trolox/mL

(mg

P

0 mL) P

1

(µM

GAE/10

inhibition )

ABTS

(% )2

GAE/10

DPPH

Trolox/ inhibition

0g

2

FW)1 P

20

g FW)2 P

)

P

P

2

21

18.92 ±

3.09 ±

8.41 ±

57.77 ±

4.97 ±

0.51c*

2.56b

0.48b

0.29b*

9.86b

0.93b

7.08 ±

27.30 ±

3.89 ±

9.84 ±

77.54 ±

7.54 ±

0.19a

5.98a

0.73a

5.80 ±

19.87 ±

3.54 ±

0.11b*

2.99b

0.69b

P

190

P

P

P

P

Ratchabu

180

ri

P

6.22 ±

P

P

P

0.56a

3.51a

0.31a

6.28 ±

73.95 ±

7.39 ±

0.23c

5.13a

1.92a

P

P

P

P

P

P

6.85 ±

58.87 ±

4.00 ±

0.24C*

2.49b

0.94b

0.77B*

6.53b

0.28b

7.17 ±

22.05 ±

4.55 ±

10.01 ±

71.72 ±

7.69 ±

0.03A

4.97a

0.73a

0.15A

3.87a

0.34a

6.68 ±

20.56 ±

4.40 ±

6.82 ±

69.66 ±

6.46 ±

0.13B*

3.88b

0.37b

0.03B

4.25a

0.20a

P

ed

P

pt P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

Ac

ce

P

2.98 ±

P

225

P

P

15.89 ±

P

190

P

P

M an


225

P

t

Sakhon

5.18 ±

cr ip

180

us

Samut

353

354

1

355


P


21

22

356 P

2 P

Non-significant interaction (p > 0.05). Significant differences are indicated by different letters.

357

cr ip us M an ed pt ce Ac


t

358

22

23

359 360

Table 3 Phenolic compounds of coconut meat and water at different maturity stages from Samut Sakhon (n = 3).

361

t

Peak area (× 107)1

Phenolic compounds

P

P

cr ip

P

us 190

225

M an

180

Coconut wat

180

190

3.09±0.45ns

2.84±0.23ns

2.81±0.10ns

1.15±0.51 ns

1.12±0.14 n

1.62±0.29b

2.67±0.20a

3.22±0.34a

0.51±0.32 ns

0.78±0.47 n

1.19±0.08 ns

1.24±0.16 ns

0.89±0.11 ns

0.49±0.09 a

0.22±0.26

0.91±0.19b

1.44±0.07a

0.41±0.09c

0.45±0.16 ns

0.61±0.19 n

2.74±0.36 ns

2.81±0.34 ns

2.24±0.17 ns

0.39±0.23 ns

0.31±0.09 n

gallic acid

3.22±0.55 ns

3.64±0.46 ns

2.59±0.15 ns

-

-

caffeic acid

3.45±0.11 ns

3.72±0.16 ns

3.01±0.59 ns

0.41±0.27 ns

salicylic acid

P

P

ed

p-hydroxybenzoic acid

pt

syringic acid

ce

m-coumaric acid

p-coumaric acid

Ac


coconut meat

P

P

P

P

P

23

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

P

0.33±0.15 n P

24

2.14±0.40 ns

catechin

P

1.83±0.42 ns P

2.04±0.07 ns P

4.95±0.52 ns P

1 P

Significant differences are indicated by different letters. P

us M an ed pt ce Ac


364

cr ip

363

t

362

24

4.02±0.31 n P

25

365 366

Table 4. Medium-chain fatty acids (MCFAs) contents of coconut meat at different maturity stages (n = 3).

367

t

Fatty acids content (mg/100 g coconut meat)1

Planting area

DAP Capric acid

Lauric acid

Myristic acid

180

286.76±1.64a*

289.63±7.44a*

1309.67±54.00a*

832.82±60.033a

190

451.32±16.89b

408.37±10.09b

2258.27±90.23b*

675.49±95.59b*

434.42±28.06b*

2568.50±147.45c*

648.65±20.06b*

353.20±6.62A*

334.27±13.65A* 1530.13±88.82A*

799.30±95.06A

190

410.11±14.53B

372.09±23.11A

225

649.21±45.70C* 548.16±42.23B* 3217.63±162.31C* 1365.80±121.01B*

ed

Samut Sakhon

M an

us


Caprylic acid

cr ip

P

500.48±54.48b*

pt

225

ce

180

Ac

Ratchaburi

1913.98±123.06B* 966.07±162.31A*

368

1

369


P


25

M

(

c

ed

pt

ce

Ac

t

cr ip

us

M an


26

370 P

2 P

Sum of caprylic, capric, lauric and myristic acids.

371

26

27

5 8

3 2 1

1

2 0 5

7

3 45

10 15 Retention time (min)

20

25

us

5

4 signal × 107

M an

7

3

6

2

1

5 8

2

3

1

4

ed

0

0

Figure 1 Mahayothee et al.

ce

373

10

15

Retention time (min)

pt

372

5

Ac


0

cr ip

t

Signal × 107

4

27

20

25

375

374

ed

pt

ce

Ac


C8:0 C10:0

0 5 C16:0

C14:0

10 15 20 Retention time (min)

28

t

cr ip

us

M an

28

C12:0

25

ed

pt

ce

Ac

t

cr ip

us

M an


29

376 Figure 2 Mahayothee et al.

377

378

29