MARDI Res.Bull., (1987)15, I: (1-7)

PROTEIN AND AMINO ACID PROFILESOF SOME MALAYSIAN FRUITS

J. ZANARIAH* andA. NOOR REHAN*

Keywords:, Amino acids,Malaysian fruits.

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 Malaysian fruits have not been reported. The main objective of this study is, there- Recent studies show that some fruits fore. to determine the protein and amino contain a relatively high quantity of protein. acid contents of Malaysian fruits and to This potential protein source has been compile the data into a food composition indicated by the crude protein content of table. their edible portion (Bennv, 1981). Little work was done to determine the protein MATERIALS AND METHODS quality, especiallythe amino acid content of fruits. Most of the studies on amino acids in Selection of Sample fruits concerned their reaction with sugars producing browning (CzvHntNctw, 1968). Nine of and 17 types of other local fruits were analysed. Non- In most studies on fruits, the protein seasonal fruits like banana, , quality were not investigated. Researchers, pineapple and watermelon were purchased however, had dealt with various nutrient from the common markets and suPer- and flavour components of commercially markets. Other fruits such as rambutan, grown fruits. The , and , hog-plum, , cempedak, contents, and flavours of many speciesof duku langsat, jambu susu, rukam masam citrus and common commercial fruits such were purchasedfrom night markets, farmers' as pineapple, banana, mango and avocado markets and the open markets. Some of the have been reported (Tnesslen and JosLYN, fruits such as duku langsat, cempedak, duian 1961:CzvHnrNCIw. 1968: Nacv. SHew and came from other parts of the country. VeLoHUts, 1977; Necv and SHew, 1980). Preparation of Fruits The vitamin, fat, protein and contents of most Malaysian fruits have been The fruits on purchase were carefully reported by Aaoulleu and RncnB (1970) selected to include only fresh fruits of good and compiled by Ten (1985). However, the 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, . immediately. The inedible skins of some of volumetric flask containing 10 ml of buffer the fruits were peeled. The hard core of neutralizer solution (Sprrz, I973). The pineapple, the and stones of other solution was made up to 25 ml with distilled fruits were also removed. In the case of water and filtered using Whatman No. 42 watermelon, only the deseeded mesocarp filter paper. Twenty-five microlitres of the was used for sampling. For fruits like guava, filtrate was injected into the prepared column starfruit, hog-plum, and jambu sasa which cartridgesof the TSM amino acid analyser. have edible skins, only the seeds were Citrate buffers and ninhydrin reagent were removed. The edible part of each type of used and the amino acids eluted analysed fruit or each variety of banana purchased (ANow. , 1973). from three different locations was chopped and homogenized. Duplicate sampleswere RESULTS AND DISCUSSION taken from the composite homogenized mixture for immediate moisture determina- Table I shows the protein and moisture tion. contents of nine cultivars of banana and 17 other types of Malaysian fruits analysed. Laboratory Techniques Most of the fruits contained less than 2tlo total protein and had a high moisture Moisture content of each fruit sample content. Most of the banana cultivars was determined by drying 5 g of the homo- contained more than 1% crude protein genized edible fresh sample at 105'C over- (Table I ) and surpassedother fruits with the night. The sample was cooled and weighed. exception of durian, tamarind, and The procedure of drying, cooling and cempedak. The protein and moisture weighing was repeated until the weight was contents of some imported temperate fruits constant.The lossin weight was reported as (ANoN., 1972) are shown in Table 2. moisture. A lower quantity of protein from a Protein was determined by the given food source may yield more nutrient Kjeldahl Technique, and the factor 6.25 was as human food if its protein is in easily used to convert total nitrogen to protein. digestible or assimiliable form, or if it About 5 g of fresh edible part of the fruit contains a good balanceof the nutritionally was digestedin 10 ml H2SO4in the presence requiredamino acids(Bennv, 1981).There- of Kjeldahl catalyst for 16 hours. Ten fore in consideringthe relative potential of millilitres of digested sample was neutralized fruits as protein sources,the quality as well with 40% NaOH and further distilled. The as quantity of the protein must be taken into distillate was collectedin 2% boric acid and consideration.Amino acid composition is a titrated with 0.02 N of sulphuric acid. common criterion of the nutritive quality of protein in food. In the determination of amino acid pattern, the edible part of the fruits was Only acid hydrolysed mixtures were sliced, ground and dried at 75"C for 24 used for quantitation of amino acids of hours. Each fruit sample was hydrolysed in fruits. Tryptophan was not analysedbecause duplicates.An amount of 0.4 g of the dried acid hydrolysis resulted in nearly complete samplewas put in a test tube and then 1.5 ml decompositionof tryptophan. distilledwater, 2.5 ml concentratedHCI and 1 ml Norleucine standard (25 micromoles) Table 3 lists the amino acids con- were added. Nitrogen gas was flushed in to sideredessential in human nutrition because remove air and the test tube was sealed over of the inability of human to synthesizethem flame. The sample was hydrolysed at 110'C (ANoN. ,1974). The limiting essentialamino for 24 hours. After cooling, the hydrolysate acids in a food are determined by relating was washed with water into a 25 ml their concentrations in that food to their Table 1. Protein and moisturecontents of Malaysianfruits (fresh wt. of edible part)

Common name Local name Scientificname Protein Moisture (vo) (E")

Banana Pisangberangan Musa sapientum cv. Berangan 1.7 66.2 Banana Pisangboyan M. sapientum cv. Boyan 1.0 78.2 Banana Pisangrastali M. sapientum cv. Rastali 1A 72.2 't1.2 Banana Pisangmas M. sapientum cv. Mas 1.3 Banana Pisangabu M. paradisiaca cv. Abu 1.1 56.0 Banana Pisangawak M. sapientum cv. Awak 0.8 65.6 Banana Pisangnangka M. sapientum cv. Nangka 1.0 66.2 Banana Pisangraja M. sapientum cv. Raja 1.3 62.4 Banana Pisangtanduk M. sapientum cv. Tanduk 1.0 71.3 Durian Durian 2.6 60.6 Guava Jambubatu Psidium guajava 0.8 85.2 Nangka integrafo lia 0.9 78.6 Papaya Betik Carica papaya 0.4 86.9 Pineapple Nanas Ananas comosus 0.5 88.1 Manggis Garcinia mangostana 0.6 87.6 Rambutan Rambutan Nephelium lappaceum 0."1 84.7 Sapodilla Ciku Achras zapota 0.4 76.5 Soursop Durian belanda Annona muricata 0.9 8s.5 Starfruit/ Belimbing Averrhoa carambola 0.5 90.7 carambola manis Watermelon Tembikai Citrullus vulgaris 0.6 92.6 Hog-plum/ Kedondong Spondias cytherea 0.7 87.9 Ambarella Tamarind Asamjawa Tamarindus indica 2.6 1A 1 Cempedak Cempedak Artocarpus poly p hernia 1.6 62.3 Duku langsat Duku langsat Lansium domesticum 0.9 81.0 Jambu susu Jambususu Eugenia scortechinia 0.4 92.4 Rukam masam Rukam masam Flaxourtiaceae sp. 0.3 88.7

Table 2. Protein and moisturecontents of someimported temperatefruits (fresh wt. of edible part)

Protein Moisture Common name Local name Scientific name (vo) (%) Apple Epal Pyrus malus 0.6 84.5 Grape Anggur Vitis vinifera 0.5 86.0 Orange Limau Citrus sp. 0.8 89.0 Peach Prunuspersica 0.6 89.4 Pear (Japanese) Pear Pyrus serotina 0.3 89.1 Persimmon Pisangkaki Diospyros kaki 0.6 83.7 Strawberi Fragaria grandiflora 0.6 90.6 concentrationsin a reference protein. In The total amino acid compositionof 1965,FAO/WHO recommendedthe amino nine varietiesof bananais shownin Table4. acid pattern of either eggprotein or human The protein of all varieties of banana, milk protein be used for scoring.By 1973, except pisang tanduk, pisang mas, pisang studiesconducted on human subjectswere boyan and pisang berangan, was high in sufficientto proposethe 1973FAO/IVHO lysine. However, only pisang nangka had provisionalamino acid scoringpatterns based more leucinethan in the protein of human on human amino acid requirements. milk or eggand 1973FAOAVHO reference. Table3. FAO provisionalamino acid patterns FAO/WHOr965 Amino acid (g/16 g N) FAO/WHO 1973 Humanmilk

Isoleucine b_4 o.o 4.0 't.0 Leucine 8.9 8.8 Lysine 6.3 6.4 5.5 Methionine+ cystine 4.3 5.5 3.5 Phenylalanine+ tyrosinc 10.I 10.0 6.0 Threonine r+.o 5.1 4.0 Tryptophan t.6 1.6 1.0 Valine 6.6 7.3 5.0

Table4. Total aminoacid composition of 9 cultivarsof banana

Amino acid Pisang Pisang Pisang Pisang Pisang Pisang Pisang Pisang Pisang (9/16 g N) berangan boyan rastali mas abu awak nangka raja tanduk

Lysine 4.5 4.8 l1.3 1.7 11 16.0 18.3 13.7 3.3 Histidine 3.9 3.2 7.6 2.3 6.1 7.9 15.3 5.7 2.2 Arginine 4.1 1.5 6.1 0.5 5.3 7.9 6.3 6.4 3.2 Asparticacid 10.2 7.5 12.1 8.5 13.'7 10.9 16.5 ll.fl 8.2

Threonine 3.ti 3.7 J.L 3.8 4.8 5.6 4.6 4.0 Serine 3.0 4.0 4.2 4.1 4.4 5.0 9.0 ,1.6 4.2 Glutamicacid 10.6 8.3 13.6 9.3 10.4 10.8 18.U 11.7 8.6 Proline 4.0 3.7 4.7 11 41 3.9 5.6 3.3 7.9 Glycine -s..5 4.1 5.1 5.7 5.2 6.3 11.2 1,7 4.5 Alanine 4-n 3.8 5.9 5.6 5.-s 6.7 il.g 5.3 J.Z Cystine tracc trace trace trace trace trace trace trace 0.'7 Valine 3.5 1.9 6.0 l.l 7.1 9.2 10.2 9.5 5.6 Methionine 1.7 1.6 2.6 t.6 t.4 1.9 2.6 2.1 0,9 Leucine 5.3 6.2 2.3 5.4 6.6 5.5 10.9 6.2 5.6 Isoleucine 2.6 -1.4 1.2 3.1 3.7 2.ti -s.-s 3.4 2.6 Tyrosine 0.n 1.5 l.fl 1.2 2.0 2.7 2.7 0.'7 Phenylalanine 3.9 3.6 ,{.0 /a o.z t.L +.J 3.0

From the compositionalpoint of view, the was the only fruit found to be rich in main amino acids in ripe banana were methionine. glutamic acid and aspartic acid. Pisang rastaliand pisangraja had moderateamount The seasonalfruits analysed like duku of methionine. langsat,jambu.tuJa, rambutan, rukam masam are high in lysine.Durian is exceptionally Lysine and the sulphur containing high in sulphur containingamino acids, aminoacids are among the aminoacids that cystineand methionine.Jambu susu and are frequentlydeficient in someMalaysian rukam masam are also rich in sulphur commonfoods. Rice, the staplefood of the containingamino acid, methionine.How- Malaysians,is deficientin lysine.Most of evermangosteen, soursop and ciku arepoor the Malaysiancommon fruits are rich in in most of the essentialamino acids like lysinecompared to the provisionalegg and valine,lysine, isoleucine and leucine, Their human milk . Jackfruit, papaya, contentsfall below the provisionalamino starfruit, watermelonare rich in lysine. acidpattern of FAO. Guava,jackfruit, papaya and starfruit which are relativelycheap and availablethrough- The proteinsof importedcommercial out the year, havehigh contentsof leucine fruits, peach and orange are among the andphenylalanine (Tables 5 and6). Papaya lowestin both total aminoacid content and Table5. Total aminoacid compositions of commonfruits

Amino acid Durian Guava Jackfruit Papaya Pineapple Mangosteen Rambutan Sapodilla Soursop (g/16g N)

Lysine 4.8 4.9 5.4 6.3 4.9 3.9 6.0 4.3 2.9 Histidine 2.0 2.'7 2.5 3.3 1.9 1.6 1.9 1.7 1.0 Arginine 2.1 3.4 1.7 2.2 2.2 1.1 2.9 1.7 1.8 '7.1 '1 Aspartic acid 9.3 19.8 14.6 12.0 15.2 4.4 5.2 .1 Threonine 2.6 3.0 4.5 2.7 2.'7 1.5 1.4 2.3 Serine 3.9 2.9 5.2 4.0 4.1 2.4 4.9 2.6 3.6 Glutamic acid 1t.9 10.0 r1.1 8.3 7.6 3.8 9.0 3.2 6.8

Proline 3.8 6.8 5.4 5.t -l_ I J.J +.+ 3.9 12.4

Glycine 4.1 4.0 6.2 5.6 3.9 1.5 J.l 2.0 3.0 Alanine 8.4 4.5 6.4 6.6 4.7 7.8 14.5 z.z J.+ Cystine 3.0 0.8 trace trace 1.2 trace trace trace trace Valine 4-7 3.4 6.t 5.2 4.4 2.1 3.6 1.1 1.8 Methionine 1.7 2.0 7.4 2.9 1.4 0 0.9 0.6 0.8 Leucine 5.5 4.9 5.7 5.9 4.3 2.5 3.9 2.4 3.5 Isoleucine 3.3 2.3 3.6 2.9 -t. -l 1.2 2.5 0.9 1.3 Tyrosine 2.2 0.9 1.5 t.l 2.8 1.0 1.0 2.3 1.4 Phenylalanine 3.0 4.5 4.4 3.7 2.5 1.9 1.9 2.1 t.1

Table 6. Total amino acid compositions of common fruits

Amino acid water- Duku Jambu Rukam Bolled cempedak Starfruit Yot Tamarind cempedak (g/16g N) melon Dlum langsat susu masam

Lysine 7.0 10.24 10.'7 2.7 5.3 5.9 7.9 14.7 AA Histidine 3.8 1.0 4.0 1.2 1.7 3.8 3.3 4.5 1.4

Arginine 2.6 9.6 5.2 1.4 4.O J.J 4.3 7.6 0.8 Aspartic acid 6.8 6.4 14.5 7.2 9.5 18.9 7.6 10.1 5.6

Threonine 2.9 4.5 2.4 2.6 4.2 2.8 4.1 4.4 J.l Serine 3.3 2.6 3.1 3.7 4.3 4.5 4.5 5.4 3.1 Glutamic acid 9.1 10.4 15.8 5.2 8.4 7.0 l0.t 12.3 4.5 Proline 5.7 4.0 2.2 l 5.9 9.0 3.3 5.1 5.6 2.5 A) <7 Glycine 3.4 1.6 2.7 2.8 4.8 3.7 J.I Alanine 4.2 z. t o. t 2.9 5.0 5.8 5.4 5.0 1.8 Cystine trace 0.3 trace trace 1.0 trace 0.8 trace 0.8 Valine 4.2 2.6 5.4 1.6 5.8 3.5 5.1 6.4 2.9 Methionine t.t 0.9 0.9 0.3 0.9 1'1 4.0 2.7 0.1 Leucine 6.5 2.6 2.2 2.7 6.4 4.3 6,2 5.3 2.9 Isoleucine 3.3 3.2 1.6 1.6 3.7 2.7 3.5 3.7 2.1 Tyrosine 1.4 1.9 1.6 2.1 0.9 1.0 1.1 1.9 1.1 Phenylalanine 3.2 2.2 3.5 1.8 3.6 2.8 4.1 5.9 2.7 balanceof required amino acids(Table 7). several of our fruits have a higher quality of Among the importedfruits, apples,grapes, protein as well as higher amounts of protein pears, orangesare availabledaily in our than some of the more common commercial Malaysianmarket. However, persimmons fruits. This is indicated in Table 8 where the are seasonaland strawberryis rarely avail- essential amino acid contents of mango, able. On the basisof milligramsof required durian, cempedak and papaya are compared amino acidsper 100grammes of fresh fruit, with common dried date, peach and orange. Table 7. Total amino acid compositionsof imported fruits

Amino acid Apple Grapes Orange Pear Persimmons Strawberrv (g/16g N)

Lysine 5.9 2.2 5.3 2.7 5.1 .1.0 Histidine 1.9 3.9 1.4 2.1 l.l 2.1 1.9 Arginine 2.7 11 6.4 2.1 1.2 5.8 +.J Asparticacid 20.8 12.2 14.1 l t.4 44.8 8.3 22.4 Threonine J. t 2. r- 1.5 3.4 2.6 6.1 3.0 Serine 4.3 4.8 2.9 4.2 5.0 3.5 3.8 Glutamicacid 11.2 20.8 12.2 17.6 8.6 17.6 14.7 Proline 3.5 3.4 5.6 3.4 2.2 3.0 3.2 .A Glycine -). L 3.0 t0.2 1.9 3.4 4.0 Alanine 4.5 A1 0.6 4.9 1.9 3.5 5.1 Cystine 1.3 t.6 1.2 l.l 0.9 2.2 0.9 Valine 1.0 2.7 3.8 4.9 4.0 4.6 2.9 Methionine 0.8 -1.4 1.5 3.8 0.9 0.9 0.2 Leucine 6.2 2.1 2.7 3.5 0.4 6.4 5.1 Isoleucine 3.5 0.8 2.9 1.6 2.9 4.5 2.2 a1 Tyrosine t -q 1.8 2.1 2.7 3.8 3.4 Phenylalanine 2.6 2.1 3.7 2.2 )4 1.6 2.9

Table 8. Content of essentialamino acids (mg/100 g fresh fruit) * * Amino acid Dried date* Peach Orange Mango* Durian Cempedak Papaya

Isoleucine 66 IJ L-) 20 85.8 _s9.2 11.6 Leucine l14 29 22 32 113 102.1 23.6 L,ysine 8l 30 +-l 28 124.t3 84.4 zJ.z Methionine 22 31 12 7 111 14.,1 1i.6 Histidine 33 17 t2 13 52 27.2 13.2 Cystine 52 9 10 4 78 i6 Trace Phenylalanine 74 l8 30 19 78 51.6 14.8 Tyrosine 2l 21 17 ll 57.2 74.4 4.4 Threonine 76 27 12 20 61.6 67.2 10.8

Valine 93 40 -ll 29 t22.2 92.8 20.8 *Source:ANoH. (1970).

CONCLUSION Our staple food, rice, is known to be deficient in the essentialamino acid lysine Researchhas been reported on various papaya, guava nutrient componentsof our fruits but these and fruits rich in lysine like studieshave not included the evaluation of can supplement the intake. Most of our quantity and quality of protein. Some of our fruits contain lessthan 2Vo protein but they Malaysian fruits have good balance of the are also rich sourcesof other nutrients such essentialamino acids and they can provide as , and mineral elements,and significant sources of protein in our diet. hish in fibre.

ABSTRACT

The total amino acid contentof someMalaysian fruits were determinedusing the Technicon SequentialMultisampler Amino Acid Analyser.In general,fruits are not consideredas good sources of protein in terms of quality comparedto animal sources.It is thereforeimportant to investigatethe proteinquality especially the aminoacid profiles of localfruits. Nine varietiesof bananasand 17types of localfruits were analysed for their proteinand amino acids. Many of the fruitswere found to containless than 2Voprotein. The amino acid profilesof importedfruits suchas apples,oranges, and othersare tabled in this articlefor comparison.There are somelocal fruits suchas papaya,jackfruit and guava whichhave potential as protein sourcesand containa goodbalance of the nutritionallyrequired amino acids.Papaya and guavaare rich in lysine,one ofthe essentialamino acids which is often found limiting in rice and other commonfoods.

. REFERENCES

ABDULLAH,F. and Recng, M.H.H, (1970).Vitamin C CzvunrNcrw,N. (1968). 'Tropical Fruit Technology'. content, pH-value and titratable acidity of 26 Dept. of Chem. & Technol., Central Univ., typesof Malayanfresh fruits grownin Selangor. Marscay,Venezuela. ' agric' J' 47' 416' FAo/wHo (1965). wortd Heatth org. Tech. Rep.ser. Food and Agric' org' Rep' ser' (1970) ANoN. . Amino acid content of foods and l9l *3i11*' biologicaldata on protein. Rome: FAO. Nrcv, S. and SHnw, P.E. (1980). Tropical and - (1972). Food compositiontable for use in East Subtropical Frulls, Westport: Avi Pub. Co. .4sra.Food Policyand Nutrition,U.N., Rome: F.AO. NAGv,S., SHrw, P.E. and Vslosurs, M.K. (1977). Citrus Scienceand Technology, Vol. I and 2, westport: Avi Pub Co' (1973). Technicon TSM systemoperation Manual.TechnicalPub.No.TAI-O233-10,New Sprrz, H.p. (1973). A new approachfor sample York: TechniconInstrument Corp. preparationof protein hydrolysatesfor amino acidanalysis. Anal. Biochem.J. 56,66-73. ANoN. (1974).Recommended Dietary Allowances 8th TEE' E.S. (1985). ed., Washington,D.C.: Nat. Academyof Sci. Nutrient Compositionof Malaysian Foods- A preliminaryTable (First Update).

BEnnv,R.E. (1981).Tropical fruits and vegetablesas Tnesslsn,D.K. and JosLyN,M.A. (1961).Fruit and potential protein sources. J. Food Technol. VegetableJuice processingTech. Westport: Avi Nov.,45-9. Pub.Co.

Acceptedfor publication on I April 1987.