MARDI Res.Bull., (1987)15,I: (1-7)
PROTEIN AND AMINO ACID PROFILESOF SOME MALAYSIAN FRUITS
J. ZANARIAH* and A. NOOR REHAN*
Keywords:Protein, Amino acids,Malaysianfruits.
RINGKASAN
Kandungan asid amino beberapa buah-buahan tempatan telah dianalisa dengan menggunakan
'Technicon
Sequential Multisampler Amino Acid Analyser'. Jumlah protein buah-buahan tidak banyak
dan kualiti proteinnya tidak tinggi jika dibanding dengan protein daripada sumber haiwan. Ini
disebabkan oleh kekurangan asid amino yang diperlukan dalam profil protein buah-buahan.
Penyelidikan sangat mustahak dilakukan untuk mengetahui jenis-jenis asid amino yang kurang.
Sembilan jenis pisang dan 17 jenis buah-buahan tempatan yang lain telah dianalisa untuk mengetahui
kandungan protein dan asid amino. Didapati bahawa kebanyakan buah-buahan kita mengandungi
protein kurang daripada dua peratus. Profil asid amino bagi buah-buahan yang diimport seperti epal,
oren dan sebagainya dijadualkan di dalam laporan untuk bandingan. Ada beberapa buah-buahan
seperti betik, nangka, jambu batu yang mempunyai potensi sebagai sumber protein yang berkualiti
daripada segi kandungan dan imbangan asid aminonya. Buah-buahan seperti betik dan jambu batu
mempunyai kandungan lisin (iaitu salah satu daripada asid amino perlu) yang tinggi tetapi biasanya
didaoati terhad dalam beras dan makanan harian kita.
INTRODUCTION
Recent studies show that some fruits
contain a relatively high quantity of protein.
This potential protein source has been
indicated by the crude protein content of
their edible portion (Bennv, 1981). Little
work was done to determine the protein
quality, especiallythe amino acid content of
fruits. Most of the studies on amino acids in
fruits concerned their reaction with sugars
producing browning (CzvHntNctw, 1968).
In most studies on fruits, the protein
quality were not investigated. Researchers,
however, had dealt with various nutrient
and flavour components of commercially
grown fruits. The vitamin, carbohydrate and
fat contents, and flavours of many speciesof
citrus and common commercial fruits such
as pineapple, banana, mango and avocado
have been reported (Tnesslen and JosLYN,
1961: CzvHnrNCIw.1968: Nacv. SHew and
VeLoHUts, 1977; Necv and SHew, 1980).
Malaysian fruits have not been reported.
The main objective of this study is, therefore. to determine the protein and amino
acid contents of Malaysian fruits and to
compile the data into a food composition
table.
MATERIALS AND METHODS
Selection of Sample
Nine cultivars of banana and 17 types
of other local fruits were analysed. Nonseasonal fruits like banana, papaya,
pineapple and watermelon were purchased
from the common markets and suPermarkets. Other fruits such as rambutan,
soursop, hog-plum, tamarind, cempedak,
duku langsat, jambu susu, rukam masam
were purchased from night markets, farmers'
markets and the open markets. Some of the
fruits such as duku langsat, cempedak, duian
came from other parts of the country.
Preparation of Fruits
The vitamin, fat, protein and mineral
contents of most Malaysian fruits have been
and RncnB (1970)
reported by Aaoulleu
and compiled by Ten (1985). However, the
The fruits on purchase were carefully
selected to include only fresh fruits of good
quality, matured and just right for con-
protein quality and amino acid profiles of
sumption. The samples were prepared
*Food Technology Division, MARDI,
Serdang, Selangor, Malaysia.
immediately. The inedible skins of some of
the fruits were peeled. The hard core of
pineapple, the seeds and stones of other
fruits were also removed. In the case of
watermelon, only the deseeded mesocarp
was used for sampling. For fruits like guava,
starfruit, hog-plum, and jambu sasa which
have edible skins, only the seeds were
removed. The edible part of each type of
fruit or each variety of banana purchased
from three different locations was chopped
and homogenized. Duplicate samples were
taken from the composite homogenized
mixture for immediate moisture determination.
Laboratory Techniques
Moisture content of each fruit sample
was determined by drying 5 g of the homogenized edible fresh sample at 105'C overnight. The sample was cooled and weighed.
The procedure of drying, cooling and
weighing was repeated until the weight was
constant.The loss in weight was reported as
moisture.
Protein was determined by the
Kjeldahl Technique, and the factor 6.25 was
used to convert total nitrogen to protein.
About 5 g of fresh edible part of the fruit
was digestedin 10 ml H2SO4in the presence
of Kjeldahl catalyst for 16 hours. Ten
millilitres of digested sample was neutralized
with 40% NaOH and further distilled. The
distillate was collected in 2% boric acid and
titrated with 0.02 N of sulphuric acid.
In the determination of amino acid
pattern, the edible part of the fruits was
sliced, ground and dried at 75"C for 24
hours. Each fruit sample was hydrolysed in
duplicates.An amount of 0.4 g of the dried
samplewas put in a test tube and then 1.5 ml
distilled water, 2.5 ml concentratedHCI and
1 ml Norleucine standard (25 micromoles)
were added. Nitrogen gas was flushed in to
remove air and the test tube was sealed over
flame. The sample was hydrolysed at 110'C
for 24 hours. After cooling, the hydrolysate
was washed with water into a 25 ml
volumetric flask containing 10 ml of buffer
neutralizer solution (Sprrz, I973). The
solution was made up to 25 ml with distilled
water and filtered using Whatman No. 42
filter paper. Twenty-five microlitres of the
filtrate was injected into the prepared column
cartridgesof the TSM amino acid analyser.
Citrate buffers and ninhydrin reagent were
used and the amino acids eluted analysed
(ANow. , 1973).
RESULTS AND DISCUSSION
Table I shows the protein and moisture
contents of nine cultivars of banana and 17
other types of Malaysian fruits analysed.
Most of the fruits contained less than 2tlo
total protein and had a high moisture
content. Most of the banana cultivars
contained more than 1% crude protein
(Table I ) and surpassedother fruits with the
exception of durian, tamarind, and
cempedak. The protein and moisture
contents of some imported temperate fruits
(ANoN., 1972) are shown in Table 2.
A lower quantity of protein from a
given food source may yield more nutrient
as human food if its protein is in easily
digestible or assimiliable form, or if it
contains a good balance of the nutritionally
r e q u i r e da m i n o a c i d s( B e n n v , 1 9 8 1 ) .T h e r e fore in considering the relative potential of
fruits as protein sources,the quality as well
as quantity of the protein must be taken into
consideration.Amino acid composition is a
common criterion of the nutritive quality of
protein in food.
Only acid hydrolysed mixtures were
used for quantitation of amino acids of
fruits. Tryptophan was not analysedbecause
acid hydrolysis resulted in nearly complete
decomposition of tryptophan.
Table 3 lists the amino acids considered essentialin human nutrition because
of the inability of human to synthesizethem
(ANoN. ,1974). The limiting essentialamino
acids in a food are determined by relating
their concentrations in that food to their
Table 1. Protein and moisturecontentsof Malaysianfruits (fresh wt. of edible part)
Common name
Banana
Banana
Banana
Banana
Banana
Banana
Banana
Banana
Banana
Durian
Guava
Jackfruit
Papaya
Pineapple
Mangosteen
Rambutan
Sapodilla
Soursop
Starfruit/
carambola
Watermelon
Hog-plum/
Ambarella
Tamarind
Cempedak
Duku langsat
Jambu susu
Rukam masam
Scientificname
Local name
Pisangberangan
Pisangboyan
Pisangrastali
Pisangmas
Pisangabu
Pisangawak
Pisangnangka
Pisangraja
Pisangtanduk
Durian
Jambubatu
Nangka
Betik
Nanas
Manggis
Rambutan
Ciku
Durian belanda
Belimbing
manis
Tembikai
Kedondong
Asam jawa
Cempedak
Duku langsat
Jambususu
Rukam masam
Musa sapientum cv. Berangan
M. sapientum cv. Boyan
Protein
(vo)
Moisture
(E")
1.7
1.0
66.2
78.2
72.2
't1.2
M. sapientum cv. Rastali
1
M. sapientum cv. Mas
1.3
1.1
0.8
1.0
1.3
1.0
2.6
0.8
0.9
0.4
0.5
0.6
0."1
0.4
0.9
0.5
M. paradisiaca cv. Abu
M. sapientum cv. Awak
M. sapientum cv. Nangka
M. sapientum cv. Raja
M. sapientum cv. Tanduk
Durio zibethinus
Psidium guajava
Artocarpus integrafo lia
Carica papaya
Ananas comosus
Garcinia mangostana
Nephelium lappaceum
Achras zapota
Annona muricata
Averrhoa carambola
Citrullus vulgaris
Spondias cytherea
Tamarindus indica
Artocarpus poly p hernia
Lansium domesticum
Eugenia scortechinia
Flaxourtiaceae sp.
A
56.0
65.6
66.2
62.4
71.3
60.6
85.2
78.6
86.9
88.1
87.6
84.7
76.5
8s.5
90.7
0.6
0.7
92.6
87.9
2.6
1.6
0.9
0.4
0.3
62.3
81.0
92.4
88.7
1A
1
Table 2. Protein and moisturecontentsof someimported temperatefruits
(fresh wt. of edible part)
Common name
Local name
Apple
Epal
Anggur
Limau
Grape
Orange
Peach
Pear (Japanese)
Persimmon
Strawberry
Pear
Pisangkaki
Strawberi
Scientific name
Protein
(vo)
Moisture
(%)
Pyrus malus
Vitis vinifera
Citrus sp.
Prunuspersica
Pyrus serotina
Diospyros kaki
Fragaria grandiflora
0.6
0.5
0.8
0.6
0.3
0.6
0.6
84.5
86.0
89.0
89.4
89.1
83.7
90.6
concentrationsin a reference protein. In
1965,FAO/WHO recommendedthe amino
acid pattern of either egg protein or human
milk protein be used for scoring.By 1973,
studiesconductedon human subjectswere
sufficient to propose the 1973FAO/IVHO
provisionalamino acid scoringpatternsbased
on human amino acid requirements.
The total amino acid compositionof
nine varietiesof bananais shownin Table4.
The protein of all varieties of banana,
except pisang tanduk, pisang mas, pisang
boyan and pisang berangan, was high in
lysine. However, only pisang nangka had
more leucinethan in the protein of human
milk or eggand 1973FAOAVHO reference.
Table 3. FAO provisionalamino acid patterns
FAO/WHOr965
Amino acid (g/16g N)
FAO/WHO 1973
H u m a nm i l k
Isoleucine
Leucine
Lysine
Methionine+ cystine
+ tyrosinc
Phenylalanine
Threonine
Tryptophan
Valine
b_4
o.o
8.9
6.3
4.3
1 0I.
8.8
6.4
5.5
10.0
5.1
1.6
7.3
r+.o
t.6
6.6
4.0
't.0
5.5
3.5
6.0
4.0
1.0
5.0
Table 4. Total amino acid compositionof 9 cultivarsof banana
Amino acid
(9/16g N)
Lysine
Histidine
Arginine
Asparticacid
Threonine
Serine
Glutamicacid
Proline
Glycine
Alanine
Cystine
Valine
Methionine
Leucine
Isoleucine
Tyrosine
Phenylalanine
Pisang
Pisang
boyan
rastali
l1.3
7.6
6.1
12.1
4-n
4.8
3.2
1.5
7.5
3.7
4.0
8.3
3.7
4.1
3.8
tracc
trace
Pisang
berangan
4.5
3.9
4.1
10.2
3.ti
3.0
10.6
4.0
-s..5
3.5
1.7
5.3
2.6
0.n
1.9
1.6
6.2
-1.4
1.5
3.9
Pisang
mas
abu
1.7
2.3
0.5
8.5
3.8
4.1
9.3
J.L
4.2
13.6
4.7
5.1
5.9
trace
6.0
2.6
2.3
1.2
l.fl
3.6
1
1
Lysine and the sulphur containing
aminoacidsare amongthe aminoacidsthat
are frequentlydeficientin someMalaysian
commonfoods.Rice, the staplefood of the
Malaysians,is deficientin lysine. Most of
the Malaysiancommon fruits are rich in
lysinecomparedto the provisionalegg and
human milk proteins. Jackfruit, papaya,
starfruit, watermelon are rich in lysine.
Guava,jackfruit,papayaand starfruitwhich
are relativelycheapand availablethroughout the year, have high contentsof leucine
(Tables5 and6). Papaya
and phenylalanine
1 1
6.1
5.3
13.'7
4.4
10.4
4 1
5.7
5.6
trace
From the compositionalpoint of view, the
main amino acids in ripe banana were
glutamic acid and aspartic acid. Pisang
rastaliand pisangraja had moderateamount
of methionine.
Pisang
l.l
t.6
5.4
3.1
1.2
,{.0
5.2
5.-s
trace
7.1
t.4
6.6
3.7
/
a
Pisang
Pisang
awak
nangka
16.0
7.9
7.9
10.9
4.8
5.0
10.8
3.9
6.3
6.7
trace
9.2
1.9
5.5
2.ti
2.0
o.z
18.3
15.3
6.3
16.5
5.6
9.0
18.U
5.6
11.2
il.g
trace
10.2
2.6
10.9
Pisang
raja
13.7
5.7
6.4
ll.fl
4.6
,1.6
11.7
3.3
1,7
5.3
trace
9.5
2.1
6.2
-s.-s
2.7
3.4
2.7
t.L
+.J
Pisang
tanduk
3.3
2.2
3.2
8.2
4.0
4.2
8.6
7.9
4.5
J.Z
0.'7
5.6
0,9
5.6
2.6
0.'7
3.0
was the only fruit found to be rich in
methionine.
The seasonalfruits analysedlike duku
jambu.tuJa,rambutan,rukammasam
langsat,
are high in lysine.Durian is exceptionally
high in sulphur containingamino acids,
cystine and methionine.Jambu susu and
rukam masam are also rich in sulphur
containingamino acid, methionine.Howevermangosteen,
soursopandciku are poor
in most of the essentialamino acids like
valine,lysine,isoleucine
and leucine,Their
contentsfall below the provisionalamino
acid patternof FAO.
The proteinsof importedcommercial
fruits, peach and orange are among the
lowestin both total aminoacid contentand
Table 5. Total amino acid compositions
of commonfruits
Amino acid
(g/16g N)
Lysine
Histidine
Arginine
Aspartic acid
Threonine
Serine
Glutamic acid
Proline
Glycine
Alanine
Cystine
Valine
Methionine
Leucine
Isoleucine
Tyrosine
Phenylalanine
Durian
Guava
4.8
2.0
2.1
9.3
2.6
3.9
1t.9
4.9
2.'7
3.4
19.8
3.0
2.9
10.0
3.8
4.1
6.8
4.0
4.5
0.8
8.4
3.0
4-7
1.7
5.5
3.3
2.2
3.0
3.4
2.0
4.9
2.3
0.9
4.5
Jackfruit
5.4
2.5
1.7
14.6
4.5
5.2
r1.1
5.4
6.2
6.4
trace
6.t
7.4
5.7
3.6
1.5
4.4
Papaya Pineapple
6.3
3.3
2.2
12.0
2.7
4.0
8.3
5.t
5.6
6.6
trace
5.2
2.9
5.9
2.9
t.l
3.7
4.9
1.9
2.2
15.2
2.'7
4.1
7.6
-l_ I
3.9
4.7
1.2
4.4
1.4
4.3
-t. -l
2.8
2.5
Mangosteen
Rambutan
3.9
6.0
1.9
2.9
'7.1
1.6
1.1
4.4
1.5
2.4
4.9
3.8
9.0
J.J
+.+
1.5
7.8
trace
2.1
0
J . l
14.5
trace
3.6
0.9
3.9
2.5
1.0
1.9
2.5
1.2
1.0
1.9
Sapodilla
Soursop
4.3
1.7
1.7
5.2
1.4
2.6
3.2
3.9
2.0
2.9
1.0
1.8
' 1. 1
2.3
3.6
6.8
12.4
3.0
z.z
J.+
trace
trace
1.1
0.6
2.4
0.9
2.3
2.1
1.8
0.8
3.5
1.3
1.4
t.1
Table 6. Total amino acid compositions of common fruits
Amino acid
(g/16g N)
Starfruit
Lysine
7.0
Histidine
3.8
2.6
6.8
2.9
3.3
Arginine
Aspartic acid
Threonine
Serine
Glutamic acid
Proline
Glycine
Alanine
Cystine
Valine
9.1
5.7
3.4
4.2
trace
4.2
Methionine
t.t
Leucine
6.5
3.3
Isoleucine
Tyrosine
1.4
Phenylalanine
3.2
waterDuku
Yot Tamarind cempedak
melon Dlum
langsat
10.24
1.0
10.'7
4.0
2.7
1.2
9.6
6.4
4.5
2.6
10.4
5.2
14.5
1.4
7.2
2.6
3.7
4.0
2.4
3.1
15.8
2.2
1.6
2.7
z. t
o. t
0.3
trace
2.6
0.9
2.6
3.2
1.9
2.2
5.4
0.9
2.2
1.6
1.6
3.5
5.2
l 5.9
2.8
2.9
trace
1.6
0.3
2.7
1.6
2.1
1.8
balanceof required amino acids(Table 7).
Among the importedfruits, apples,grapes,
pears, orangesare availabledaily in our
Malaysianmarket. However, persimmons
are seasonaland strawberryis rarely available. On the basisof milligramsof required
amino acidsper 100grammesof fresh fruit,
5.3
1.7
4.O
9.5
4.2
4.3
8.4
9.0
4.8
5.0
1.0
5.8
0.9
6.4
3.7
0.9
3.6
5.9
3.8
J.J
18.9
2.8
4.5
7.0
3.3
3.7
5.8
trace
3.5
1'1
4.3
2.7
1.0
2.8
Bolled cempedak
seed
Jambu
susu
Rukam
masam
7.9
3.3
4.3
7.6
14.7
4.5
7.6
10.1
4.4
1.4
0.8
5.6
l0. t
5.1
5.4
12.3
5.6
3.1
4.5
2.5
A )
< 7
4.1
4.5
5.4
0.8
5.1
4.0
5.0
trace
6.4
2.7
6,2
3.5
1.1
4.1
5.3
3.7
1.9
5.9
A
A
J . l
J . I
1.8
0.8
2.9
0.1
2.9
2.1
1.1
2.7
several of our fruits have a higher quality of
protein as well as higher amounts of protein
than some of the more common commercial
fruits. This is indicated in Table 8 where the
essential amino acid contents of mango,
durian, cempedak and papaya are compared
with common dried date, peach and orange.
Table 7. Total amino acid compositionsof imported fruits
Amino acid
(g/16g N)
Apple
Lysine
Histidine
Arginine
Asparticacid
Threonine
5.9
1.9
2.7
20.8
Serine
Glutamicacid
Proline
Glycine
Alanine
Cystine
Valine
Methionine
4.3
11.2
3.5
Leucine
Isoleucine
Tyrosine
Phenylalanine
J. t
-). L
Grapes
Orange
2.2
3.9
1 1
20.8
3.4
3.0
t -q
2.6
A
1
t.6
2.7
1.4
6.4
14.1
1.5
2.9
2.1
2.1
l t.4
3.4
4.2
l.l
1.2
44.8
2.6
12.2
5.6
t0.2
0.6
1.2
17.6
3.4
1.9
4.9
l.l
4.9
8.6
2.2
2.1
0.8
1.8
2.1
5.0
.
2.9
2.1
1.6
2.7
3.7
2.2
) 4
3.8
3.5
Strawberrv
5.1
2.1
5.8
.1.0
1.9
8.3
6.1
22.4
3.0
3.8
14.7
3.2
4.0
5.1
0.9
2.9
0.2
5.1
2.2
3.4
2.9
+.J
3.5
17.6
3.0
3.4
3.5
2.2
4.6
0.9
A
1.9
0.9
4.0
0.9
0.4
2.9
3.8
3.8
1.5
2.7
-1.4
Persimmons
2.7
5.3
12.2
2. r4.8
4.5
1.3
1.0
0.8
6.2
3.5
Pear
6.4
4.5
a 1
1.6
Table 8. Content of essentialamino acids (mg/100 g fresh fruit)
Amino acid
Isoleucine
Leucine
L,ysine
Methionine
Histidine
Cystine
Phenylalanine
Dried date*
66
l14
8l
22
33
52
74
Threonine
2l
76
Valine
93
Tyrosine
Peach
IJ
29
30
31
17
9
l8
21
27
40
*
O r a n g e*
Mango*
Durian
Cempedak
L-)
20
85.8
113
124.t3
_s9.2
102.1
84.4
1 1 1
14.,1
1i.6
52
78
78
27.2
13.2
22
32
28
7
13
4
19
+-l
12
t2
10
30
17
12
ll
20
-ll
29
57.2
61.6
t22.2
i6
Papaya
11.6
23.6
zJ.z
5 1. 6
74.4
Trace
14.8
4.4
67.2
92.8
10.8
20.8
*Source:ANoH.(1970).
CONCLUSION
Researchhas been reported on various
nutrient components of our fruits but these
studies have not included the evaluation of
quantity and quality of protein. Some of our
Malaysian fruits have good balance of the
essentialamino acids and they can provide
significant sources of protein in our diet.
Our staple food, rice, is known to be
deficient in the essentialamino acid lysine
and fruits rich in lysine like papaya, guava
can supplement the intake. Most of our
fruits contain less than 2Vo protein but they
are also rich sourcesof other nutrients such
a s V i t a m i n C , a n d m i n e r a l e l e m e n t s ,a n d
hish in fibre.
ABSTRACT
The total amino acid content of some Malaysianfruits were determinedusing the Technicon
SequentialMultisamplerAmino Acid Analyser.In general,fruits are not consideredasgoodsourcesof
protein in terms of quality comparedto animal sources.It is thereforeimportant to investigatethe
proteinqualityespeciallythe aminoacidprofilesof localfruits. Nine varietiesof bananasand 17typesof
localfruitswereanalysedfor their proteinand aminoacids.Many of the fruits werefound to containless
than 2Voprotein. The amino acid profiles of imported fruits suchas apples,oranges,and others are
tabled in this article for comparison.There are some local fruits suchas papaya,jackfruit and guava
whichhavepotentialas protein sourcesand containa good balanceof the nutritionallyrequiredamino
acids.Papayaand guavaare rich in lysine,one ofthe essentialamino acidswhich is often found limiting
in rice and other commonfoods.
.
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