Composition of Coconut Testa, Coconut Kernel and its Oil

Abstract

Testa, a by-product from the coconut processing industry is getting wasted. A study was carried out to utilize testa as a source of edible oil. The composition of the oils from testa of wet coconut (WCT) and copra (CT) were evaluated and compared with wet coconut whole, copra whole, wet coconut white kernel and copra white kernel. The samples had fat as a major component ranging from 34 to 63 %. Oils had 90–98.2 % triacylglycerols, 1–8 % diacylglycerols and 0.4–2 % monoacylglycerols. The triacylglycerol composition of oil from WCT had decreased trilaurin and increased triolein. Lauric acid content of CT was 40.9 % and WCT was 32.4 % whereas other oils were 50–53 %. Oils from testa were richer in monounsaturates and polyunsaturates than other coconut oil samples. The phenolics and phytosterols content were 0.2–1.9 % and 31–51 mg%, respectively. The total phenolic acids and tocopherol content of oils from CT (313.9 μg%, 22.3 mg%) and WCT (389.0 μg%, 100.1 mg%) were higher than other samples (94.8–291.4 μg%, 2.5–6.7 mg%). These studies indicated that the oil from coconut testa contained more of natural antioxidants such as tocopherols, tocotrienols and phenolics compared to coconut kernel oil and may confer health benefits.

Full text

ORIGINAL PAPER
Composition of Coconut Testa, Coconut Kernel and its Oil
Prakruthi Appaiah •L. Sunil •P. K. Prasanth Kumar •
A. G. Gopala Krishna
Received: 1 July 2013 / Revised: 17 January 2014 / Accepted: 28 February 2014 / Published online: 22 March 2014
ÓAOCS 2014
Abstract Testa, a by-product from the coconut processing
industry is getting wasted. A study was carried out to utilize
testa as a source of edible oil. The composition of the oils
from testa of wet coconut (WCT) and copra (CT) were
evaluated and compared with wet coconut whole, copra
whole, wet coconut white kernel and copra white kernel.
The samples had fat as a major component ranging from 34
to 63 %. Oils had 90–98.2 % triacylglycerols, 1–8 % dia-
cylglycerols and 0.4–2 % monoacylglycerols. The triacyl-
glycerol composition of oil from WCT had decreased
trilaurin and increased triolein. Lauric acid content of CT
was 40.9 % and WCT was 32.4 % whereas other oils were
50–53 %. Oils from testa were richer in monounsaturates
and polyunsaturates than other coconut oil samples. The
phenolics and phytosterols content were 0.2–1.9 % and
31–51 mg%, respectively. The total phenolic acids and
tocopherol content of oils from CT (313.9 lg%, 22.3 mg%)
and WCT (389.0 lg%, 100.1 mg%) were higher than other
samples (94.8–291.4 lg%, 2.5–6.7 mg%). These studies
indicated that the oil from coconut testa contained more of
natural antioxidants such as tocopherols, tocotrienols and
phenolics compared to coconut kernel oil and may confer
health benefits.
Keywords Acylglycerols Coconut kernel Coconut
testa Copra Fatty acids Oil Phenolics Phytosterols 
Tocopherols Triacylglycerols
Abbreviations
WCW Wet coconut whole
WCWK Wet coconut white kernel
WCT Wet coconut testa
CW Copra whole
CWK Copra white kernel
CT Copra testa
K Potassium
Na Sodium
Ca Calcium
Fe Iron
Zn Zinc
TPC Total phenolics content
TAG Triacylglycerols
DAG Diacylglycerols
MAG Monoacylglycerols
Introduction
Coconut is a tropical fruit of coconut palm, Cocos nucifera,
and is largely consumed in many countries. Coconut oil is
derived from the dried fruit (endosperm) which undergoes
refining steps of alkali treatment, bleaching and deodor-
ization while the virgin coconut oil is produced without any
of these chemical processes [1]. It is known to impart many
health benefits [1].
Coconut oil contains mainly saturated fatty acids (SFA)
(&93 %) with lauric acid (C
12:0
)(&50–55 %) being the
most prevalent fatty acid present [2]. It also contains
medium chain fatty acids (MCFAs) consisting of caproic
acid (C
6:0
), caprylic acid (C
8:0
), capric acid (C
10:0
) and
lauric acid (C
12:0
) that can be easily burned for energy
P. Appaiah L. Sunil P. K. Prasanth Kumar 
A. G. Gopala Krishna (&)
Department of Lipid Science and Traditional Foods, CSIR-
Central Food Technological Research Institute, Mysore 570020,
India
e-mail: aggk_55@yahoo.com
123
J Am Oil Chem Soc (2014) 91:917–924
DOI 10.1007/s11746-014-2447-9

rather than being stored in the body [2]. Coconut oil pos-
sesses antiviral, antibacterial and antiprotozoal properties
due to the presence of C
12:0
and C
10:0
fatty acids [3].
Monounsaturated and polyunsaturated fatty acids are less
in coconut oil (&7–8 %) and, hence, it is highly stable
towards oxidation and eventually provides longer shelf-life
for the food products prepared in it [4].
Coconut oil contains minor components like tocophe-
rols, tocotrienols, phytosterols and phenolics which are the
natural antioxidants. Polyphenols are ubiquitous in food
and are found to act as antioxidants, free radical scavengers
and peroxidation inhibitors [5]. It also acts as an anti-car-
cinogenic and reduces cardiovascular diseases [6–8]. Phy-
tosterols are present predominantly in oilseed plants. In
addition to nuts, they are found in legumes, vegetables and
unrefined vegetable oils [9]. Tocopherols are fat soluble
antioxidants having vitamin E activity. Tocotrienols are
present in coconut oil, palm oil and oil from bran sources
such as rice bran and wheat bran. No other vegetable oils
contain tocotrienols in significant amounts. They act
against the membrane lipid peroxidation of polyunsatu-
rated fatty acids [10].
Testa is the brown part covering coconut kernel, i.e.,
brown skin. It is obtained from coconut processing indus-
tries as a by-product through paring of wet coconut during
the preparation of products like desiccated coconut, coco-
nut milk and virgin coconut oil. Testa is used as animal
feed. Consumption of coconut kernel provides the benefi-
cial effect on human health but the coconut testa is getting
wasted.
Nevin and Rajamohan [11] have reported that the pre-
sence of phenolic compounds is mainly responsible for the
antioxidant properties of virgin coconut oil. Seneviratne
et al. [12] have reported that the final phenolics content of
coconut oil depends on the components of the endosperm.
Information on the components of coconut testa is rare.
Hence, the study focuses on the evaluation of composition
and minor components including tocopherols, tocotrienols,
phytosterols and phenolics of oil from coconut testa in
comparison with coconut whole and coconut white kernel.
Materials and Methods
Wet coconut whole (WCW) and copra whole (CW) were
purchased from the local market. The white kernel and
testa of wet coconut and copra were separated manually to
get wet coconut white kernel (WCWK) and wet coconut
testa (WCT); copra white kernel (CWK) and copra testa
(CT). Standard gallic acid, cholesterol, FAME mix, toc-
opherols, hydroxybenzoic acid, chlorogenic acid, vanillic
acid, syringic acid, coumaric acid, caffeic acid, ferulic acid
and cinnamic acid were procured from Sigma Chemicals
Co., St. Louis, USA. All reagents and chemicals used were
of analytical grade.
Proximate Composition of Starting Materials
The moisture content of the coconut samples was deter-
mined according to the AOCS method Ac 2–41 [13]. Fat
was extracted from dried coconut samples by using hexane
in a Soxhlet apparatus according to AOCS O.M.No. Ac
3–44 [13]. The micro-Kjeldahl method was used to deter-
mine total proteins described by the AOAC Official
Method 950.48 [14]. The method described by the AOAC
Official Method 950.02 [14] was used for crude fiber
determination. Ash content of the dried and defatted
coconut samples was determined gravimetrically according
to AOCS O.M.No. Ba 5a-49 [13]. The iron, zinc, sodium,
potassium and calcium content of coconut samples were
analyzed by atomic absorption spectroscopy (AAS) [15].
Acylglyerol Content of the Oil Samples by Column
Chromatography
The TAG, DAG and MAG fractions from oil samples were
separated according to the AOCS Official Method No. Cd
11c-93 [13].
Fatty Acid Composition of Oil Samples by GC
The fatty acid methyl esters of the fat extracted from the
coconut kernels and coconut testa were prepared by
transesterification according to the AOCS Method [13].
Analysis was carried out using a gas chromatograph
(model-GC-15A, Shimadzu Corporation, Kyoto, Japan)
equipped with a FID detector and a stainless steel column
of 3 m length 90.5 mm ID, coated with 15 % diethylene
glycol succinate on 60–80 mesh chromosorb WAW. The
operating conditions were as follows: nitrogen flow 40 ml/
min, hydrogen flow 40 ml/min, air flow 300 ml/min, col-
umn temperature 180 °C, injector temperature 220 °C and
detector temperature 230 °C. A reference standard FAME
mix (Supelco Inc., Bellefonte, PA, USA) was analyzed
under the same operating conditions to determine the peak
identity. The FAMEs were expressed as relative area %.
Triacylglycerols Composition of Oil Samples by HPLC
Triacylglycerols composition was determined according to
Swe et al. [16]. The HPLC system used was equipped with
a Shimadzu LC-10A liquid chromatograph with a Refrac-
tive Index (RI) detector. The column used was a C18
Discovery column (Supelco, Bellefonte, USA) with a
mobile phase acetone/acetonitrile (70:30, v/v) at the flow
rate of 1 ml/min. The oil samples were dissolved in
918 J Am Oil Chem Soc (2014) 91:917–924
123

acetone. TAG peaks were identified based on the retention
time of the TAG standards.
Phenolics Extraction from Oil Samples
The phenolics extraction from the samples was carried out
according to Seneviratne and Dissanayake [17]. The
phenolics were extracted using methanol: water (80:20
v/v). About 5 g of the oil sample was mixed with 1 ml of
80 % methanol and vortexed for 2 min (twice). The sam-
ples were centrifuged at 2,500 rpm for 10 min at room
temperature. The methanol: water layer was collected in
another tube. This step was repeated four times and the
extracts pooled were made up to 4 ml with 80 % methanol.
Determination of Total Phenolics Content (TPC) of Oil
Samples by the Colorimetric Method
The total phenolics content (TPC) was determined using
the Folin–Ciocalteu reagent. Different aliquots were mixed
with 0.2 ml of Folin–Ciocalteu reagent and were kept for
3 min. About 1 ml of 15 % Na
2
CO
3
solution was added
and made up to 7 ml with distilled water. The tubes were
incubated for 45 min and centrifuged at 2,000 rpm for
10 min at room temperature. The absorbance was read at
765 nm using a UV–Visible spectrophotometer (Shimadzu
corporation, Kyoto, Japan, model UV—1601). The TPC
(mg/100 g) was calculated using gallic acid as standard
compound [18].
Determination of Total Phytosterols Content of Oil
Samples by the Colorimetric Method
Total phytosterols content was analyzed by using the Lie-
bermann-Burchard method. About 0.3 g of oil sample was
dissolved with 1.2 ml of chloroform and 2 ml of the Lie-
bermann–Burchard reagent (0.5 ml of sulphuric acid dis-
solved in 10 ml of acetic anhydride, covered and kept in an
ice bucket). Final volume was made up to 7 ml with
chloroform and mixed well. The tubes were kept in the
dark for 15 min and their absorbance was read at 640 nm
using a UV–Visible spectrophotometer (Shimadzu corpo-
ration, Kyoto, Japan, model UV—1601). A blank was
prepared without the sample. The total phytosterols content
was calculated using standard cholesterol [19].
Analysis of Individual Phenolic Acids of Oil Samples
by HPLC
The extraction of phenolic acids from coconut oils for
HPLC analysis was done according to Brenes et al. [20].
The analysis of phenolic acids in the coconut oil was
conducted using a Waters Atlantis C18 (250 mm 9i.d.
4.6 mm, 5 lm) Bondapack column. Isocratic elution was
carried out with a mobile phase consisting of water:
methanol (82:18 v/v) containing 2 % (v/v) acetic acid, at a
flow rate of 1 ml/min. A photo diode array (PDA) detector
was used for detection of phenolic acids and the HPLC
profiles were obtained at 280 and 320 nm. The injection
volume for all samples was 10 ll. Identification of phe-
nolic acids was based on retention times in comparison
with standards [21].
Analysis of Tocopherols and Tocotrienols of Oil
Samples by HPLC
Tocopherols and tocotrienols were estimated in the oil
samples by HPLC according to the AOCS method O.M.No.
Ce 8–89 [13]. The analysis of tocopherols and tocotrienols
was achieved by normal phase HPLC separation on a silica
column (Lichrosorb Si60 5 lm) employing Shimadzu
HPLC system consisting of a LC-10A pump, injector fitted
with a 20 ll loop and fluorescence detector (FLD). The
mobile phase was hexane: isopropyl alcohol (99.5:0.5, v/v)
at the flow rate of 1 ml/min. The excitation wavelength of
290 nm and an emission wavelength of 330 nm were kept
for the fluorescence detection of all the peaks. The toc-
opherols and tocotrienols were identified using standard
tocopherols and expressed as a-tocopherol.
Statistical Analysis
All the analyses were carried out in triplicate and the
average values ±SD are reported. One-way ANOVA was
used to calculate significant differences among the coconut
and oil samples [22]. A two-tailed pvalue was determined
to show the significant differences at a pvalue B0.001.
Results and Discussion
Proximate Composition of Starting Materials
The composition of CW, CWK, CT, WCW, WCWK and
WCT were analyzed and are presented in Table 1. The
composition included moisture content, fat content, protein
content, carbohydrate content, crude fiber content and ash
content. The moisture content was less in copra (3.8, 4.0
and 4.3 %) when compared to the wet coconut (43.5, 32.9
and 42.2 %). WCT contained a lower moisture content
than WCW and WCWK. Solangi et al. [23] had reported
that the moisture content of mature coconut ranges from 38
to 62 % and ash content 0.85–1.26 % for different coconut
varieties. According to Obasi et al. [24], the moisture
content of copra was 7.51 %, crude fiber was 7.70 % and
J Am Oil Chem Soc (2014) 91:917–924 919
123

fat content was 47.80 %. The chief constituent of coconut
kernel was carbohydrate, followed by lipid. On the wet
basis, the fat content of copra was high ranging from 59.8
to 63.4 % and the wet coconut was low ranging from 34.7
to 38.8 %. CT had the same amount of fat when compared
to CW and CWK. The crude fiber content of copra was less
(6.6–11.6 %) and wet coconut was more (11.7–17.2 %).
Both CT (11.6 %) and WCT (17.2 %) had high crude fiber
content. The crude fiber content of healthy coconut kernel
was 13.13 % [25]. The ash content of copra was slightly
higher than that of the wet coconut. CW had an ash content
of 1.4 %, CWK was 2.1 % and CT was 1.4 %. WCW had
an ash content of 1.0 % of which WCWK was 0.9 % and
WCT was 0.7 %. WCT had less ash content when com-
pared to WCW and WCWK. CWK had more ash content
than in CW and CT. Santoso et al. [26] showed that the ash
content of wet coconut and copra (dry matter) was 1.15 and
2.11 %, respectively. The protein content of CW, CWK,
CT, WCW, WCWK and WCT were 10.2, 8.1, 9.3, 7.5, 6.2
and 7.1 % respectively [23,24]. The carbohydrate content
was calculated by difference. The carbohydrate content of
WCT (24.6 %) and CT (26.3 %) was more than other
coconut samples (10.6–24.3 %).
Mineral Composition of Coconut Samples
The mineral composition of coconut samples is presented
in Table 2. The coconut testa and kernel have substantially
more potassium than sodium. CW, CWK, CT, WCW,
WCWK and WCT had 120.3, 124.1, 120.3, 122.1, 123.8
and 107.8 mg of potassium/100 g, respectively. They had
15–29 mg/100 g of sodium, 14–18 mg/100 g of calcium,
1.5–7.9 mg/100 g of iron and 1.6–3 mg/100 g of zinc
content. CT contained 29.8 mg/100 g of sodium content.
CW, CT and WCW contained 7.9, 6.2 and 7.9 mg of iron
content/100 g, respectively. CW (2.9 mg/100 g) and CT
(3.0 mg/100 g) contained slightly high zinc content. CT
(22.4 %) and WCT (29.8 %) had more sodium content than
in other coconut samples. The results are in good agree-
ment with that reported by Solangi et al. [23].
Acylglycerol and Fatty Acid Compositions of Oil
Samples
The acylglycerol and fatty acid compositions of oil samples
are presented in Table 3. CW, CWK, CT, WCW, WCWK
and WCT oils had a TAG content of 90–98.2 %, DAG of
Table 1 Proximate composition of starting material
Sample Moisture (%) Fat (%) Protein (%) Carbohydrates (%) Crude fiber (%) Ash (%)
CW 4.3 ±0.18
a
59.8 ±0.32
a
10.2 ±0.21
a
24.3 ±0.78
a
7.0 ±0.64
a
1.4 ±0.04
a
CWK 3.8 ±0.02
a
63.6 ±0.4
b
8.1 ±0.35
b
22.4 ±0.64
b
6.6 ±0.14
b
2.1 ±0.06
b
CT 4.0 ±0.01
a
59.0 ±0.95
a
9.3 ±0.28
c
26.3 ±0.78
c
11.6 ±0.35
a
1.4 ±0.05
a
WCW 42.2 ±0.18
b
37.0 ±0.22
c
7.5 ±0.35
b
12.3 ±0.28
d
14.3 ±0.57
c
1.0 ±0.04
c
WCWK 43.5 ±0.54
c
38.8 ±0.46
d
6.2 ±0.21
d
10.6 ±0.35
e
11.7 ±0.35
b
0.9 ±0.06
d
WCT 32.9 ±0.21
d
34.7 ±0.5
e
7.1 ±0.42
b
24.6 ±0.85
a
17.2 ±0.42
d
0.7 ±0.03
e
Values are mean ±SD of wet coconut and copra from five individual nuts separately. All analyses carried out in triplicate (n=15 for five
individual nuts). All are expressed on a wet basis. The values with different superscripts in the column are significantly different at p\0.001
CW copra whole, CWK copra white kernel, CT copra testa, WCW wet coconut whole, WCWK wet coconut white kernel, WCT wet coconut testa
Table 2 Mineral composition of coconut kernel and testa
Samples Minerals (mg/100 g)
KNaCaFeZn
CW 120.3 ±1.0
a
15.5 ±0.5
a
14.6 ±0.6
a
7.9 ±0.5
a
2.9 ±0.5
a
CWK 124.1 ±1.0
b
21.0 ±0.6
b
18.1 ±0.2
b
3.2 ±0.1
b
1.6 ±0.2
b
CT 120.3 ±1.3
a,c
22.4 ±0.8
c
17.0 ±1.0
b,c
6.2 ±0.3
c
3.0 ±0.1
a,c
WCW 122.1 ±0.8
a,b,c
21.6 ±0.4
b
18.1 ±0.4
b,c
7.9 ±1.0
a
2.2 ±0.1
b,c
WCWK 123.8 ±0.5
bc
20.3 ±0.2
b
14.0 ±0.3
a
1.5 ±0.3
d
1.8 ±0.4
b,c
WCT 107.8 ±0.6
d
29.8 ±0.9
d
16.7 ±0.6
c
1.9 ±0.3
d
1.6 ±0.1
b,c
Values are mean ±SD of wet coconut and copra from five individual nuts separately. All analyses carried out in triplicate (n=15 for five
individual nuts). All are expressed on a wet basis. The values with different superscripts in the columns are significantly different at p\0.001.
CW copra whole, CWK copra white kernel, CT copra testa, WCW wet coconut whole, WCWK wet coconut white kernel, WCT wet coconut testa.
Kpotassium, Na sodium, Ca calcium, Fe iron, Zn zinc
920 J Am Oil Chem Soc (2014) 91:917–924
123

1–8 % and MAG of 0.4–2 %. CW contain a high amount
of DAG, i.e. 8.4 %, CT oil with 5.3 % and WCT oil with
3.2 %. WCWK oil contained a high amount of TAG
(98.2 %) and CW oil was 90.00 %. Oils from wet coconut
(96.4–97.7 %) contained a slightly high TAG content when
compared to that of copra oils (90–94.1 %). Whereas for
DAG content, it was more in CW oil (8.4 %) and less in
WCWK oil (1.1 %). DAG content was higher in copra
(4.6–8.4 %) than in wet coconut (1.1–3.2 %). MAG con-
tent was also slightly higher in copra (0.6–2.0 %) when
compared to the wet coconut (0.4–0.6 %). DAG is used in
small quantity in foods as an emulsifier [27,28].
The fatty acid compositions of coconut oil samples are
reported in Table 3. Lauric acid is the major fatty acid of
coconut oil [1]. The lauric acid content of CT and WCT
oils was 40.94 and 32.4 %, respectively whereas CW,
CWK, WCW and WCWK oils were 50–53 %. The caprylic
acid (C
8:0
) and capric acid (C
10:0
) content of CT and WCT
oils were slightly less when compared to other oil samples.
Palmitic acid (C
16:0
) content of CT (11.31 %) and WCT
(14.07 %) oils were higher than the other oil samples,
which is varying from 6.8 % for WCW to 7.4 % for
WCWK and CWK oils. MCW (2.3 %) had more linolenic
acid (C
18:0
) followed by CWK (1.9 %), WCWK (1.9 %),
CT (1.6 %), WCT (1.2 %) and CW (1.1 %). CT and WCT
oils contained 12.19 % and 17.82 %, respectively, of oleic
acid (C
18:1
) and 5.32 and 10.6 %, respectively, of linoleic
acid (C
18:2
) content whereas CW, CWK, WCW and
WCWK oils contained 4–6 % of C
18:1
and 1–2 % of C
18:2
.
The oils from CT and WCT were found to be having more
C
18:1
and C
18:2
than other oil samples. The SFA of CT and
WCT oils (82.51–71.59 %) was marginally less when
compared to CW, CWK, WCW and WCWK oils
(92–95 %); MUFA of CT was 12.19 %, WCT oils was
17.82 % and CW, CWK, WCW and WCWK oils were
4–6 %; PUFA of CT and WCT oils was 5.32 % and
10.6 %, respectively, and CW, CWK, WCW and WCWK
oils were 1–2 %. MCFA was less in CT (48.25 %) and
WCT (36.16 %) oils whereas CW, CWK, WCW and
WCWK oils were 64–68 %. The CT and WCT oils have
higher PUFA and MUFA as compared to other coconut oil
samples. The low SFA and MCFA in CT and WCT are
most probably due to the presence of a high amount of
MUFA and PUFA than in other samples. Oils from CT and
WCT were significantly different from other coconut oil
samples in the fatty acids composition. The fatty acids
composition of whole coconut kernel oil was in good
agreement with that reported by Bhatnagar et al. [3].
Triacylglycerol Composition of Oil Samples
The major TAGs in the coconut oils were CCLa, CLaLa,
LaLaLa and LaLaM; these counted for around 50–75 % of
the total TAG composition (Table 4). The sum of these
four TAGs in CW, CWK, CT, WCW, WCWK and WCT
oils were 51.82, 64.96, 50.4, 74.61, 76.67 and 39.97 %,
respectively. WCT oil showed comparatively slightly
higher LaLaO (6.42 %), LaMO (8.04 %), LaMP (8.0 %),
LaSO (3.46 %), MOO (3.48 %), MPO (2.79 %), OOO
(3.35 %), POO (2.22 %) than CWK, CT, CW, WCWK and
WCW oils. CCLa (4.64 %), CLaLa (8.56 %), LaLaLa
(12.34 %) and LaLaM (14.43 %) were less in WCT oil as
Table 3 Acylglycerol and fatty
acid compositions of oils
extracted from coconut kernel
and testa
Values are mean ±SD of wet
coconut and copra from five
individual nuts separately. All
analyses were carried out in
triplicate (n=15 for five
individual nuts). The values
with different superscripts in the
rows are significantly different
at p\0.001.
CW copra whole, CWK copra
white kernel, CT copra testa,
WCW wet coconut whole,
WCWK wet coconut white
kernel, WCT wet coconut testa
CW CWK CT WCW WCWK WCT
Acylglycerol %
TAG 90.0 ±0.7
a
93.4 ±0.4
b
94.1 ±0.8
b
97.7 ±0.8
c
98.2 ±0.8
c,d
96.4 ±0.4
c,e
DAG 8.4 ±0.6
a
4.6 ±0.4
b
5.3 ±0.2
b
1.6 ±0.1
c
1.1 ±0.2
c
3.2 ±0.2
d
MAG 1.7 ±0.1
a
2.0 ±0.2
b
0.6 ±0.0
c
0.6 ±0.1
c
0.7 ±0.1
c,d
0.4 ±0.0
c,e
Fatty acid %
C
8:0
9.6 ±0.2
a
6.7 ±0.0
b
3.9 ±0.1
c
8.1 ±0.1
d
5.6 ±0.3
e
1.6 ±0.3
f
C
10:0
6.4 ±0.3
a
6.2 ±0.4
a
3.8 ±0.2
b
7.8 ±0.3
c
5.8 ±0.6
a
2.2 ±0.5
d
C
12:0
51.5 ±0.5
a
52.6 ±0.2
b
40.9 ±0.1
c
50.5 ±0.3
a
52.8 ±0.4
b
32.4 ±0.9
d
C
14:0
19.1 ±0.1
a
18.9 ±0.4
a
20.9 ±0.8
b
16.1 ±0.1
c
19.2 ±0.6
a,b
20.2 ±0.1
b
C
16:0
6.9 ±0.0
a
7.4 ±0.9
a
11.3 ±0.6
b
6.8 ±0.1
a
7.4 ±0.2
a
14.1 ±0.0
c
C
18:0
1.1 ±0.8
a
1.9 ±0.1
a
1.6 ±0.3
a
2.3 ±0.0
b
1.9 ±0.1
a
1.2 ±0.5
a,b
C
18:1
4.3 ±0.5
a
4.8 ±0.0
a
12.2 ±0.1
b
5.6 ±0.2
c
5.5 ±0.1
c
17.8 ±0.2
d
C
18:2
1.1 ±0.4
a
1.6 ±0.1
a,b
5.3 ±0.2
c
1.8 ±0.0
b
1.0 ±0.3
a,b
10.6 ±0.4
d
SFA 94.6 93.7 82.5 92.6 92.7 71.6
MUFA 4.3 4.8 12.2 5.6 5.5 17.8
PUFA 1.1 1.6 5.3 1.8 1.0 10.6
MCFA 67.5 65.5 48.3 66.3 64.2 36.2
J Am Oil Chem Soc (2014) 91:917–924 921
123

compared to other samples. The trilaurin (LaLaLa) is less
in oils from WCT (12.34 %) and CT (14.30 %) whereas
WCW, CW, CWK, WCWK showed 23.04, 16.23, 20.01
and 22.28 %, respectively. CT oil contained the least
amount of dilaurin (LaLaM) (5.04 %) than CWK
(16.38 %), CW (16.0 %), WCWK (15.93 %), WCT
(14.43 %) and WCW (10.41 %) oils. WCT oil had a low
amount of CCLa (4.64 %) and CLaLa (8.56 %). WCT oil
(8.04 %) and CT oil (6.21 %) showed comparatively
higher LaMO content than oils from CWK (2.93 %), CW
(4.62 %), WCWK (1.33 %) and WCW (1.54 %). CT oil
had 0.29 % and WCT oil had 8.00 % of LaMP content.
MPL was marginally more in CT oil (1.92 %) and very less
in CWK (0.33 %), CW (0.54 %), WCWK (0.20 %), MCT
(0.18 %) and WCW (0.08 %) oils. Triolein content was
more in WCT oil (3.35 %) whereas CT, CW, WCWK and
WCW oils had 0.13, 1.53, 0.14 and 0.53 % respectively.
The TAG composition of wet coconut kernel and copra
were similar to that of what Gopala Krishna et al. [1] had
reported. The TAG composition of oils from testa showed
some differences when compared to other oils.
Composition of Oil Samples
In the coconut industry, the testa is removed during oil
extraction as it gives a yellowish color to oil. The oils
extracted along with the testa gave little higher phenolics
content than the oil extracted without testa. Nutraceuticals
content and compositions of oil samples are presented in
Table 5. The total phytosterols content of CW, CWK, CT,
WCW, WCWK and WCT oil were 49.89, 33.31, 42.52,
50.27, 30.66 and 50.97 mg/100 g respectively. The total
phytosterol content was more in CW (49.89 mg/100 g) and
WCW (50.27 mg/100 g) than in CWK (33.31 mg/100 g)
and WCWK (30.66 mg/100 g). This was may be due to the
presence of testa while extracting the oil. The total phy-
tosterols content of oils from CT and WCT was almost
similar to that of oils from CW and WCW whereas the oils
from CWK and WCW were less when compared to other
coconut oils. Raja Rajan et al. [29] had reported that the
total phytosterols content of whole coconut oils was
87 mg %.
Oil samples showed fewer amounts of phenolics. CW,
CWK, CT, WCW, WCWK and WCT had 1.1, 1.9, 1.4, 0.2,
0.5 and 0.7 mg of TPC/100 g oil, respectively. TPC was
more in the copra than in the wet coconut. Henna et al. [30]
reported that virgin coconut oil contained 0.65 mg of total
phenolics/100 g of oil. All the samples showed the pre-
sence of gallic acid, hydroxybenzoic acid, vanillic acid,
syringic acid, coumaric acid, caffeic acid, ferulic acid and
cinnamic acid in significant amounts. The total phenolic
acids content of oils from WCT and CT (388.9 and
313.1 lg/100 g, respectively) were higher when compared
to that of the WCW, WCWK, CWK and CW oils (291.1,
94.7, 141.8 and 131.1 lg/100 g of oil, respectively).
Among the phenolic acids, coumaric acid content was
found to be more in WCT oil (230.6 lg/100 g) and hy-
droxybenzoic acid content in CT oil (126.4 lg/100 g).
Seneviratne et al. [31] had reported the same phenolic acids
composition in coconut kernel. The results are in agree-
ment with the reports of Seneviratne and Dissananyake
[17]. Marina et al. [32] had reported that the phenolic acids
composition of coconut kernel oil varies with different
extraction methods and contained protocatechuic acid,
vanillic acid, caffeic acid, syringic acid, ferulic acid and p-
coumaric acid. Phenolic acids were found to be more in
mature coconut than in copra. The oils from testa were
found to have higher total phenolic acids than CW and
WCW followed by CWK and WCWK.
Table 4 Triacylglycerol composition of oils from coconut kernel and
testa
Triacylglycerol
%
CW CWK CT WCW WCWK WCT
UI 0.38 0.4 0.13 – – –
UI 0.83 1.61 1.55 1.09 – –
UI 0.77 2.01 0.54 0.04 – 0.32
UI – 1.44 0.64 – – –
CpCC 1.23 1.88 0.75 0.49 0.14 0.19
CpCpLa 1.21 1.42 1.68 1.44 0.95 0.29
CpCLa 2.24 2.91 7.91 5.26 4.17 0.93
CCLa 7.41 12.12 12.20 19.69 16.26 4.64
CLaLa 12.18 16.45 18.76 23.53 20.14 8.56
LaLaLa 16.23 20.01 14.30 23.04 22.28 12.34
LaLaM 16.0 16.38 5.04 10.41 15.93 14.43
LaLaO 3.87 3.07 13.42 1.73 2.37 6.42
LaMM 13.73 9.77 4.91 5.33 8.91 15.9
LaMO 4.62 2.93 6.21 1.54 1.33 8.04
LaMP 6.81 4.86 0.29 2.70 3.85 8.00
MPL 0.54 0.33 1.92 0.08 0.20 0.18
LaCO 0.26 0.60 1.46 0.83 0.84 2.75
LaPP 1.66 0.97 1.43 0.47 1.12 1.15
LaSO 1.45 0.10 1.32 – 0.16 3.46
MOO 1.97 0.54 1.10 0.87 0.19 3.48
MPO 1.26 0.22 0.89 0.56 0.62 2.79
OOO 1.53 – 0.13 0.53 0.14 3.35
POO 1.23 – – 0.20 – 2.22
POP – – – 0.18 – 0.17
UI-unidentified mono and diacylglycerols. Values provided are mean
of triplicate samples and the cv is \1%
CW copra whole, CWK copra white kernel, CT copra testa, WCW wet
coconut whole, WCWK wet coconut white kernel, WCT wet coconut
testa
922 J Am Oil Chem Soc (2014) 91:917–924
123

The coconut kernel oils contained less tocopherols
(T) and tocotrienols (T
3
) content when compared to oils
from testa. The T and T
3
content of CW, CWK, WCW and
WCWK oils were only 2.9, 6.7, 4.4 and 2.5 mg/100 g of
oil, respectively. However, CT and WCT oils had 22.3 and
100.1 mg/100 g oil of T and T
3
content. CW (2.1 mg/
100 g) and CWK (3.7 mg/100 g) oils had more of b?c
tocopherols content whereas WCW (3.6 mg/100 g) and
WCWK (2.5 mg/100 g) oils had more of a-tocopherol
content. Oils from CT and WCT were found to have higher
tocotrienols concentration than other coconut oil samples.
There was 90.2 mg/100 g for WCT oil followed by CT oil,
16.6 mg/100 g. WCT oil contained 2.9 mg/100 g of d-
tocopherol content. CT oil contained 0.7 mg/100 g of d-
tocotrienols content. Raja Rajan et al. [29] had reported
that whole coconut oil contained 1.7–3.1 mg/100 g of total
tocopherols and tocotrienols content.
Conclusion
Coconut testa and kernel samples are rich in potassium
content. The CT and WCT oils have higher PUFA and
MUFA as compared to other coconut oil samples. Oils
extracted from coconut testa were found to be rich in
minor components like tocopherols, phenolics and phy-
tosterols than oil extracted from kernel or whole coconut.
They contained &50 mg of total phytosterols/100 g of
oil. CT and WCT oils contained slightly higher DAG
content than WCWK, WCW and CWK oils. WCT oil
contained more amounts of coumaric acid whereas CT oil
was found to have more of hydroxybenzoic acid than CW,
CWK, WCW and WCWK oils. The oil from WCT had
less trilaurin content and slightly higher triolein content
when compared with other coconut oil samples. To our
knowledge, reports on composition and natural antioxi-
dants/minor components of oil from coconut testa have
not been reported so far. Dried CT and WCT yield same
amount of fat like copra and dry coconut kernel; there-
fore, they can also be used as a good oil source. Oils
extracted from WCT and CT could be used for regular
consumption as they contain a similar fatty acid compo-
sition, acylglycerol and triacylglycerol profile, minor
components like phenolics, phytosterols, tocopherols and
tocotrienols for beneficial health effects.
Acknowledgments The authors are thankful to Director CSIR-
CFTRI, Mysore for providing infrastructural facilities and The
Coconut Development Board, Kochi, for funding the project.
Table 5 Composition of oils extracted from kernel and testa
Parameters CW CWK CT WCW WCWK WCT
Total phytosterols (mg/100 g) 49.89 ±1.9
a
33.31 ±2.1
b
42.52 ±0.9
c
50.27 ±1.5
a
30.66 ±0.2
b
50.97 ±0.1
a
TPC (mg/100 g) 1.4 ±0.19
a
1.1 ±0.11
b
1.9 ±0.12
c
0.7 ±0.02
d
0.2 ±0.04
e
0.5 ±0.02
d
Phenolic acids (lg/100 g)
Gallic acid 24.7 ±1.2
a
30.3 ±1.1
b
32.1 ±2.1
b
103.9 ±2.2
c
15.9 ±0.7
d
12.6 ±2.8
d
Hydroxybenzoic acid 7.6 ±0.1
a
94.1 ±0.9
b
126.4 ±0.6
c
127.4 ±1.7
c
34.7 ±1.1
d
55.1 ±1.1
e
Vanillic acid 63.8 ±0.3
a
nd nd nd nd nd
Syringic acid 17.9 ±0.4
a
nd nd nd 37.3 ±1.1
b
26.6 ±0.9
c
Coumaric acid 10.0 ±0.7
a
11.2 ±1.1
a
42.1 ±3.1
b
48.9 ±0.0
b
nd 230.6 ±3.5
d
Caffeic acid 3.1 ±0.5
a
4.9 ±0.3
a
12.8 ±1.3
b
nd nd 27.4 ±2.0
c
Ferulic acid 1.7 ±0.5
a
nd 47.5 ±2.04
b
5.4 ±0.4
b
nd 5.0 ±1.0
c
Cinnamic acid 2.4 ±0.9
a
1.3 ±0.6
a
4.1 ±0.8
b
9.8 ±0.3
c
6.9 ±0.9
d
31.7 ±0.2
e
Total 131.2 141.8 313.9 291.4 94.8 389.0
Tocopherols (mg/100 g)
aT 0.6 ±0.02
a
nd nd 3.6 ±0.0
b
2.5 ±0.0
c
0.04 ±0.0
d
b?cT 2.1 ±0.4
a
3.7 ±0.0
b
2.8 ±0.2
c
nd nd 4.0 ±0.1
b
dT ndndndndnd2.9±0.4
a
aT
3
0.2 ±0.0
a
2.1 ±0.2
b
16.6 ±2.4
c
0.1 ±0.0
a
Trace 90.2 ±5.0
d
b?cT
3
Trace 0.9 ±0.1
a
2.2 ±0.1
b
0.4 ±0.0
a
nd 2.9 ±0.6
c
dT
3
nd nd 0.7 ±0.0
a
0.3 ±0.1
a
nd nd
Total (T ?T
3
) mg/100 g 2.9 ±0.4
a
6.7 ±0.5
a
22.3 ±1.6
b
4.4 ±0.8
a
2.5 ±0.0
a
100.1 ±8.5
c
All analyses carried out in triplicates (n=15 for five individual nuts). The values with different superscripts in the rows are significantly
different at p\0.001.
CW copra whole, CWK copra white kernel, CT copra testa, WCW wet coconut whole, WCWK wet coconut white kernel, WCT wet coconut testa.
TPC and total phytosterol content by the colorimetric method and expressed as gallic acid and cholesterol, respectively, nd not detected
J Am Oil Chem Soc (2014) 91:917–924 923
123

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