sdarticle_2201

Industrial Crops and Products 13 (2001) 93100

Promising oil producing seed species of Western Ghats(Tamil Nadu, India)

G.D.P.S. Augustus a,*, G.J. Seiler b

a Research Center in Botany, V.H.N.S.N. College, Virudhunagar 626 001, Indiab USDA, ARS, Northern Crop Science Lab., P.O. Box 5677, Fargo, ND 58105, USA

Received 21 January 2000; received in revised form 4 May 2000; accepted 12 May 2000

Abstract

Fifteen species of plants from the Western Ghats were screened as alternative sources of energy, oil, polyphenol,hydrocarbon, and phytochemicals. The highest oil content was observed in Achras sapota with 13.8%. The highestpolyphenol and hydrocarbon content was observed in seeds of Dalbergia sissoo with 7.1% and 1.9%, respectively. Theseeds of Prosopis spicigera yielded the highest protein content with 20.9%. P. spicigera exhibits highest quantity ofcarbohydrate with 7.9%. The gross heat value of 5506.0 cal:g for the seeds of Terminalia tomentosa was the highestamong the species analysed. The gross heat value of oil and hydrocarbon fractions of A. sapota were very high with8717.0 and 9930.0 cal:g, respectively. The fatty acid composition of Calophyllum elatum seed oil contained oleic acid(38.02%), palmitic acid (20.98%), and linoleic acid (14.48%). The hydrocarbon fractions were also analysed todetermine the type of isoprene present. 2001 Elsevier Science B.V. All rights reserved.

Keywords: Seeds; Oil; Hydrocarbon; Polyphenol; Gross heat value; Fatty acid; Protein

www.elsevier.com:locate:indcrop

1. Introduction

Oils and waxes are commonly found in manyplant species. Oils are abundant in seeds, whilewaxes are normally abundant on the surface ofleaves or stems. Most of the vegetable oils usedtoday are produced in agricultural systems andare necessary in one way or another for a varietyof industrial uses. Vegetable oils also have great

potential to be used as liquid fuel or as a sourceof hydrocarbons. Vegetable oils are combustibleand some will combust in diesel engines. Earliersystematic screening programs for oil-producingcrops from diverse plant species have been under-taken and some promising candidates with seedoils with various fatty acids have been reported(Princen, 1977). Polyphenol is a generic term re-ferring to a variety of phytochemicals with ahydroxy substituted aromatic ring. According toBuchanan et al. (1980) composition of polyphe-nols is species specific, depends on the nature ofpartitioning solvents, the heating sometimes usedto solubilize the acetone extract (Abbott et al.,

* Corresponding author. Present address: Grace Cottage, 1Mangalapuram 1st Lane, Dindigul 624 003, Inida.

E-mail address: [email protected] (G.D.P.S. Au-gustus).

0926-6690:01:$ - see front matter 2001 Elsevier Science B.V. All rights reserved.

PII: S0926-6690(00)00056-X

G.D.P.S. Augustus, G.J. Seiler : Industrial Crops and Products 13 (2001) 9310094

1990) and consists of a complex mixture of con-stituents such as tannins, phlobaphenes, lipids,sugars and substituted ring compounds. The ob-jective of this study was to determine the ex-tractable yields, heat content, and chemicalcomposition of several seed species and to give anoverview of the chemical utilization of plant mate-rial for liquid fuels and as industrial rawmaterials.

2. Materials and methods

2.1. Seed samples

Fifteen species belonging to various familieswere collected from courtallum to srivilliputhur

R.F. of Western Ghats, Tamil Nadu, India (Table1). Healthy seed samples were collected for a totalfresh weight of 20002500 grams from the respec-tive species belonging to the same agro-climaticzone. They were randomly collected from a mini-mum of 1525 populations which were com-posited into one sample for chemical analysis.Each sample was subsampled twice. Seed sampleswere allowed to dry in a sheltered area at ambienttemperature ranging from 10 to 30C and wereground in a Wiley mill equipped with a 1 mmsieve.

2.2. Extraction of oil, polyphenol andhydrocarbon fractions

Extractables were removed from each samplewith acetone and then with hexane in a soxhlet

Table 1Composition of chemical constituents of species from Western Ghats

Name of the species Yield of extractablesa

HydrocarbonPolyphenolOilProtein(%) (%)(%) (%)

GuttiferaeCalophyllum elatum Bedd. 12.290.15a0.890.11a 4.790.11a 1.190.26a

2.890.20 3.690.17C. inophyllum L. 1.190.181.590.16Malvaceae

0.890.165.390.238.990.15Bombax malabaricum Dc. 10.890.11Meliaceae

5.090.20 4.490.30Azadirachta indica A. Juss. 1.190.407.690.12Leguminosae

4.090.36Dalbergia sissoo Roxb. 4.890.38 7.190.35 1.990.25Leucaena glauca Benth. 1.090.146.290.3212.790.30 1.490.21

3.790.28Pongamia glabra Vent. 10.490.14 2.690.42 1.390.36Prosopis spicigera L. 20.990.39 2.390.37 0.890.32 0.690.14

2.790.16 0.990.20Pterocarpus marsupium Roxb. 0.990.281.890.25Combretaceae

12.390.26Anogeissus latifolia Wall. 1.690.34 2.190.29 1.590.276.890.21 2.190.30 1.790.54Terminalia tomentosa W.& A. 1.390.11

Myrtaceae10.190.13 1.090.10Syzygium jambolanum Dc. 1.690.14 0.390.32

Sapotaceae0.790.102.090.3913.890.1312.690.42Achras sapota L.

Apocynaceae3.690.38Rauwolfia serpentina 9.390.15 1.590.21 1.390.13

Benth. Ex KurzEuphorbiaceae

6.290.27 4.590.13 2.790.11 1.490.44Jatropha gossypifolia L.

a Values are mean of three replicates, and 9S.D.

G.D.P.S. Augustus, G.J. Seiler : Industrial Crops and Products 13 (2001) 93100 95

apparatus for 24 h in each solvent. Care wastaken for complete removal of acetone from theresidue before hexane extraction. Acetone extractswere allowed to air dry, then partitioned betweenhexane and aqueous ethanol (water:ethanol) togive oil and polyphenol, respectively. After sol-vent removal, these fractions were dried andweighed gravimetrically for yield. After hexaneremoval, the hydrocarbon fractions from the sec-ond 24 h extraction were dried and weighed foryield (Buchanan et al., 1978a,b).

2.3. Estimation of protein and ash content

Ash content was estimated gravimetrically byigniting the dry sulphuric acid digested residue inan electric Bunsen burner following the method ofGoering and Van Soest (1970). Protein contentwas determined by Kjeldahl method (AOAC,1980).

2.4. Estimation of carbohydrate

Carbohydrates of seed samples were estimatedusing a spectrophotometer following the phenolsulfuric acid method of Dubois et al. (1951, 1956).

2.5. NMR studies

NMR spectra for hydrocarbon samples wereobtained using a Bruker AC 300F NMR spec-trophotometer (300 MHZ) with CDCl3 as thesolvent and tetramethylsilane (TMS) as the inter-nal standard.

2.6. Fatty acid composition

Methyl esters of seed oil samples were preparedfollowing Metcalfe and Wang (1981), and ana-lyzed for their fatty acid composition using aGLC equipped with a SE 30 column and nitrogenas the carrier gas.

2.7. Gross heat 6alue

Gross heat value of seed samples, oil, andhydrocarbon fractions were determined using aBomb calorimeter (Toshniwal Bomb Calorimeter,

model cc.0.1). The gross heat values were ex-pressed in cal:g (Anonymous, 1966).

2.8. Statistical analysis

Three replications of each sample were evalu-ated for extraction of chemical constituents andgross heat value. Values in tables are the means ofthree replications and the standard deviation (9S.D.).

3. Results and discussion

3.1. Yield of protein, oil, polyphenol andhydrocarbon

Protein, oil, polyphenol, and hydrocarbonyields of the 15 seed species are shown in Table 1.The pods of Prosopis spicigera had the highestprotein content with 20.9% followed by Leucaenaglauca and Achras sapota with 12.7 and 12.6%,respectively. Seeds of Calophyllum elatum had thelowest protein content with only 0.8%, while ninespecies had more than 5% protein content. If thespecies with high protein content are properlyhandled and processed, they have the potential toprovide a protein rich food for cattle as suggestedby Pirie (1975). However, it should be noted thatantinutritional factors may complicate its use asanimal feed (Shirley, 1986; Kellems and Church,1998). Presence of alkaloids in the samples pose agreat threat to the palatability of plant materialby cattle. Glucosides viz. saponin are highly poi-sonous to both man and animals. Phytates createnutritional digestive problems when seeds areused for human food or fed to livestock, becauseof the unavailability of the minerals in animalnutrition. This however can be easily over comeby modern food processing techniques (Copeland,1988). Extractive free residues would be the mainproduct by weight of a botanochemical extractionprocess and would be available as flakes forsubsequent chemical or microbiological conver-sion to a wide variety of secondary botanochemi-cals as described by Buchanan et al. (1980). Awide variety of enzymatic and fermentative con-versions of extractive free residues are possible.


Table 2Ash and carbohydrate content of species of Western Ghats

Species Ash Carbohydrate Totalb

(%)a(%)a

Guttiferae0.290.04aCalophyllum 0.690.17a 19.6b

elatum1.690.16 11.6C. inophyllum 1.090.13

Malvaceae0.990.06 2.190.28Bombax 28.8

malabaricumMeliaceaeAzadirachta 0.690.2 2.490.09 21.1

indicaLeguminosae

1.390.191.690.03 20.7Dalbergia sissoo0.790.07Leucaena glauca 1.790.24 23.70.490.05Pongamia glabra 0.0290.27 18.420.190.04 7.990.26 32.6Prosopis

spicigera0.390.07 1.990.16Pterocarpus 8.5

marsupiumCombretaceaeAnogeissus 0.390.19 2.090.12 19.8

latifolia0.390.11Terminalia 3.190.19 15.3

tomentosaMyrtaceaeSyzygium 2.790.14 5.390.21 21.0

jambolanumSapotaceae

1.590.19Achras sapota 30.70.190.04ApocynaceaeRauwolfia 0.790.09 0.690.23 17.0

serpentinaEuphorbiaceaeJatropha 0.490.03 1.590.19 16.7

gossypifolia

a Values are mean of three replicates and 9S.D.b TotalProtein oil polyphenol hydrocarbon ash

carbohydrate.

ucts such as shortenings, salad and cooking oils(cotton seed oil) and margarines, while largequantities serve as feed and in industrial appli-cations. Industrial applications include chemicalssuch as plasticizers, which add pliability to othersubstances; stabilizers, which help other sub-stances resist chemical change; emulsifiers, whichenable the mixing of normally unmixable liq-uids; surfactants, which reduce the surface ten-sion of liquids and are commonly used indetergents; and esters, nylons and resins, whichare basic ingredients in many products. Besidesdetergents and plastics, products that containchemicals derived from vegetable oils include lu-bricants coatings, corrosion inhibitors, adhesives,cleaners, cosmetics, water repellents and fuels(Bagby, 1996). Vegetable oils have great poten-tial as reliable and renewable sources of fuel forcompression ignition engines. If these oil sam-ples are properly treated to reduce their viscos-ity (Bagby, 1996), they have potential as analternate to conventional oils.

Dalbergia sissoo and Bombax malabaricumwere the only two species that yielded morethan 5% polyphenols.

D. sissoo had the highest hydrocarbon contentwith 1.9% followed by Anogeissus latifolia with1.5%. Hydrocarbon contents of more than 1.0%were observed in ten species. According toMcLaughlin and Hoffman (1982), in most ofthe non-resin and non-latex plants, thehydrocarbon content varied from 0 to 4% oftotal dry weight of the plant. Results fromCalvins Lab showed that most of the laticifer-ous plants contain 114% hydrocarbons(Nielsen et al., 1977).

Seed samples contained 0.027.9% carbohy-drates (Table 2). P. spicigera had the highestquantity of carbohydrate (7.9%), while P. glabrahad the lowest with 0.02%. The difference be-tween the reported compounds and the totalmass balance could be accounted for bystarch, cellulose, hemicellulose, minerals, andunknown compounds. All seeds had an ash con-tent below 1.0%, except for three species C.inophyllum, D. sissoo, and Syzygium jambolanum(Table 2). High ash content has a negative effecton the calorific value (Van Emon and Seiber,1985).

These residues might also serve as suitable sub-strate in the production of pullulan, astaxanthin,and xylitol (Leathers et al., 1992).

The seeds of A. sapota yielded 13.8% oil fol-lowed by C. elatum with 12.2% and Pongamiaglabra with 10.4%. Oil of seven species wereslightly gummy and viscous in nature at roomtemperature. Plant oils are used for food prod-


3.2. Gross heat 6alue

Gross heat value of seeds, oil, and hydrocar-bons are presented in Table 3. Comparative fuelvalues of representative biomass and fossil fuels

are also included in Table 3 for comparison. Thegross heat value of the seeds, oil fraction, andhydrocarbon fractions are an indicator of theirpotential use as an intermediate energy source.Gross heat value of seeds ranges from 3141.0 to

Table 3Gross heat values of oil, hydrocarbons and seeds of species of Western Ghats

Gross heat valueaSpecies

Hydrocarbon (cal:g) Seeds (cal:g)Oil (cal:g)

GuttiferaeCalophyllum elatum 3141.0930.5a7990.0935.3a7542.0919.1a

C. inophyllum 7554.1915.4 7965.0928.2 3996.0935.8

MalvaceaeBombax malabaricum 3676.4949.28389.0925.37651.4930.4MeliaceaeAzadirachta indica 7646.2918.97013.4928.0 4345.6928.0

LeguminosaeDalbergia sissoo 4075.0918.07228.0931.2 8195.0923.8

7606.2918.2Leucaena glauca 8040.0927.5 4496.2927.0Pongamia glabra 4051.4922.07757.3929.57400.3921.5

3529.1916.78441.0929.7 8547.3928.1Prosopis spicigera8015.0915.5Pterocarpus marsupium 3730.0923.07666.0924.4

Combretaceae7664.3926.3Anogeissus latifolia 3400.0920.27252.0928.0

Terminalia tomentosa 7802.0924.77778.0917.6 5506.0932.8

Myrtaceae8150.4927.8Syzygium jambolanum 3671.0929.87752.4935.2

SapotaceaeAchras sapota 4604.0927.39930.0927.68717.0918.9

Apocynaceae7017.3937.2 3558.0914.2Rauwolfia serpentina 7840.0921.5

Euphorbiaceae8172.0924.4 3550.0919.0Jatropha gossypifolia 7707.4920.1

Biomass and fossil fuelsRice Straw hulls 3333b

3888bLignite coalCattle manure 4111b

5167bCorn cobsMunicipal refuse 5278b

5353bMethanolAnthracite coal 7111b

Fuel oil (Mexico) 10 308b

Crude oil 10 531b

Gasoline 11 256b

a Values are mean of three replicates and 9S.D.b Van Emon and Seiber (1985).


Table 4Nature of hydrocarbon

Nature of hydrocarbonSpecies

GuttiferaeCalophyllum The hydrocarbon may have methyl

1,23,4 moietieselatumC. inophyllum The hydrocarbon may have cismethyl

with 1,2 moietyMalvaceaeBombax The hydrocarbon may have cis-methyl

malabaricum with 1,23,4 moietiesmethylenenearly transvinylene protons

MeliaceaeThe hydrocarbon may have cis-methylAzadirachtawith 1,23,4 moietiesmethyleneindicanearly transvinylene protons

LeguminosaeThe hydrocarbon may have cis-methylDalbergia sissoowith 1,2 moietyvinylene protonsThe hydrocarbon may haveLeucaena glaucacis,trans-methyl with 1,23,4moietiesmethylene nearlycisvinylene protonsThe hydrocarbon may havePongamia glabracis,trans-methyl with 1,23,4moietiesmethylene nearlytransvinylene protons

Prosopis The hydrocarbon may have methyl with1,23,4 moietiesmethylene nearly cisspicigeraThe hydrocarbon may have methyl 1,2Pterocarpusmoietymarsupium

CombretaceaeAnogeissus The hydrocarbon may have methyl 3,4

moietylatifoliaTerminalia The hydrocarbon may have

trans-methyl with 1,23,4 moietiestomentosaMyrtaceae

The hydrocarbon may haveSyzygiumcis,trans-methyl with 1,23,4 moietiesjambolanum

SapotaceaeThe hydrocarbon may have cis-methylAchras sapota1,23,4 moietiesmethylene nearlytransvinylene protons

ApocynaceaeThe hydrocarbon may haveRauwolfiacis,trans-methyl 1,23,4serpentinamoietiesmethylene nearlytransvinylene protons

EuphorbiaceaeJatropha The hydrocarbon may have

gossypifilia cis,trans-methyl with 1,23,4 moieties

gross heat value than rice straw hulls (3333 cal:g).Seven species had gross heat values above 3900cal:g which is higher than that of rice straw hullsand lignite coal (3888 cal:g). Four species hadhigher gross heat values than cattle manure (4111cal:g). The gross heat value for Terminalia tomen-tosa was 5506.0 cal:g which is higher than munic-ipal refuse, or methanol with 5278.0 and 5353.0cal:g, respectively and also higher than the aver-age heat content of hardwood (4781.0 cal:g) andsoftwood (5010.0 cal:g). This would clearly indi-cate that seeds could be a supplement to wood forfuel (Van Emon and Seiber, 1985).

The gross heat values of the oil fraction variedfrom 7013.4 to 8717.0 cal:g. The oil fraction ofAzadirachta indica (7013.4 cal:g) and Rauwolfiaserpentina (7017.3 cal:g) had lower gross heatvalues than anthracite coal, however, the grossheat value of all others species were higher thanthat of anthracite coal (7111.0 cal:g). The oilfraction of A. sapota had a calorific value above8500.0 cal:g with the potential to yield extremelyhigh quantities of oil (Table 1). This species couldserve as an alternate to conventional oil in thefuture. The gross heat value of the hydrocarbonfraction ranged from 7646.2 to 9930.0 cal:g. Thecalorific values of the hydrocarbon fraction for allspecies were higher than that of anthracite coal.The hydrocarbon fraction of A. sapota had acalorific value of 9930.0 cal:g. Eight species hadcalorific values above 8000.0 cal:g for the hydro-carbon fraction. The calorific value depends onthe composition of the hydrocarbon fraction andits content of rubber, gutta, wax, and their molec-ular weights.

3.3. NMR spectroscopy

The results of the NMR spectra are presentedin Table 4. Cis-methyl was observed at 1.63 ppmand trans-methyl at 1.53 ppm. The methyleneresonance appears near 2.1 and 2.03 ppm for cisand trans, respectively. The position of vinyleneproton resonance is insensitive to the geometricalisomerism about the double bond and appears at5.2 ppm for both cis and trans structures. The twoother geometrical modifications of poly-isopreneunits are 3,4 vinylene protons at 4.75 ppm, while

5506.0 cal:g. Six species had calorific values above4000 cal:g. One species, C. elatum, had a lower


1,2 vinylene protons appears at 4.95 ppm. Themost useful resonances for analytical purposes arethe methyl peaks at 1.59 ppm for 3.4 units and1.05 ppm for 1.2 units (Chen, 1962; Bovey, 1972).Poly-isoprene is the main constituent of latex,which varies in quantity and weights from speciesto species. Rubber is synthesized in over 2000plant species representing about 300 genera of 700families.

3.4. Fatty acid composition

C. elatum has an oil content of 12.2% whichwas analysed for its fatty acid composition. Thefatty acids were comprised of saturated and un-saturated fatty acids such as 1.25% of myristicacid (14:0), 20.98% of palmitic acid (16:0), 1.0%of heptadecanoic acid (17:0), 12.48% of stearicacid (18:0), 38.02% of oleic acid (18:1), 14.48% oflinoleic acid (18:2), 3.12% of 21:0 and three unde-termined compounds (8.68%). Palmitic acid findsits use in the preparation of palmitates of vitaminA and chloramphenicol (Balaji, 1995). Stearic acidis useful in soap, stearin, and in the candleindustries.

4. Conclusion

This study showed that several species of plantsfrom the Western Ghats Region, especially A.sapota and C. elatum are capable of producinghigh quantities of polyphenols, hydrocarbons, andoil. The high calorific value of oil and hydrocar-bon fractions of A. sapota above 8500.0 cal:g withthe potential to yield high quantities of oil couldserve as an alternate to conventional oil in thefuture. Bio-inductional studies are also recom-mended on these species to increase the quantityof extractables as achieved by Jayabalan et al.(1994).

The dependence of man on plant products is asold as the history of civilization. Historical trendspredicted changes in mans needs and the knowl-edge of plant potential has changed his perspec-tives about plants. The traditional division ofplants into primary, secondary and tertiary poolsreflects the utilization and economic importance

of plants. The primary pool is composed of stapleplants, with food plants and cultivated ones. Themajor needs of man are met by this pool, al-though the secondary pool also delivers some ofthe important fruits, beverages, and vegetables.The secondary pool is complimentary to the pri-mary pool and reflects the regional or nationalusages. The tertiary pool is composed of wild,protected, and occasionally some cultivatedplants. This pool provides a wealth of resources atthe subsistence level and constitute a maximumnumber of plants. This pool is the most underutilized or under exploited one compared to thebetter utilized primary and secondary pools. Thetertiary pool requires no special agronomic tech-nique. Careful breeding and genetic improvementof these plants can help in producing novel com-pounds on a large scale to meet mans growingdemand especially in the energy sector. All possi-ble needs cannot be met using a single plant.Hence, a careful selection of species with maxi-mum potential for desirable oil producing quali-ties need to be selected which can be geneticallyimproved for desired compounds using moderntechniques.

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