Catolé palm ( Syagrus oleracea Mart ) fruits : fatty and amino acids composition By

Los frutos de la Palmera catolé (Syagrus oleracea Mart) fueron analizados para determinar su composición química. Las fracciones de la pulpa y almendra contenían 0,7 y 40.0% de lípidos. El aceite de almendra fresca mostró una pequeña concentración de peróxidos pero no presentó ácidos grasos libres. El índice de iodo y de saponificación fueron 27,4 y 226, respectivamente. Fue observada una gran diferencia cualitativa como también cuantitativa en la composición de ácidos grasos entre el aceite de la pulpa y de la almendra. 15 y 19 ácidos grasos fueron identificados en el aceite de la pulpa y de la almendra, respectivamente. Esos aceites contenían 48,9 y 73,2% de ácidos grasos saturados. El principal ácido graso saturado del aceite de la pulpa fue el ácido palmítico (C16), mientras que en el aceite de almendra fue encontrado ácido laúrico (C12). El ácido oleico fue el principal ácido graso monoinsaturado en ambos aceites. En el aceite de la pulpa, ácido linoleico (C18:2) y linolénico (C18:3) estaban presentes en concentraciones de 23.5 y 11.3% respectivamente, mientras que solo el aceite de la almendra contenía 3,59% de ácido linoleico. En relación a la composición de aminoácidos, las proteínas de la pulpa presentaron mejor perfil de aminoácidos que de la almendra. En las proteínas de la pulpa, los aminoácidos esenciales estab an presentes en co ncen trac iones mayores q ue las recomendadas por la FAO, excepto metionina y lisina, mientras que la proteína de la almendra estaban deficiente en todos los aminoácidos esenciales, excepto fenilalanina, isoleucina y treonina.


INTRODUCTION
The palm tree belong to Palmae or Palmaceae, family which include about 3.000 to 3.700 species distributed among 240 to 387 genres, out of which about 200 native and 200 exotic species of palms grow in Brazil (Lorenzi, 1992).The catolé (Syagrus oleracea Mart) is one of the native species, which has its origin and habitat in the northeast and southeast regions of Brazil.The specie is also known as guariroba, goriroba, gueroba, coquero amargoso, coquero guariroba, pati amargosa etc (Lorenzi, 1992).Catolé palm tree possesses a straight trunk reaching to a height of about 20 meters.The leaves are about 3 meters in length.Each bunch contains 10 to 40 fruits (Correia, 1975).Although palmetto (palm heart) is its principal product, almost everything of this palm is utilised by human and animals.The nuts are an important complement for animal nutrition, and kernels are used in the manufacture of sweets.Besides, kernel oil is used for edible purpose and in soap manufacture.Due to its multiple utilities, and to the fact that this palm is easy to cultivate, its plantation becomes lucrative.
Scientific literature on this palm specie is scanty.Glassman (1972Glassman ( , 1974) ) quantified its gene and anatomy.With regard to its utilisation, Correia (1975) and Ramalho et al. (1991) recommended production of palmetto and honey, respectively.In spite of the fact that kernel of this palm contains about 60% lipids (Correia, 1975), no report is so far published on the characterisation and composition of this oil except for one on fatty acid composition of mesocarp oil (Lubrano,1994).However, detailed information on the properties and fatty acid composition of oils of mesocarp and kernel portions of the fruit as well as amino acid composition of their proteins is so far lacking.Therefore the present work was undertaken to furnish data on these aspects of the catolé (Syagrus oleracea Mart) palm fruits.

Palm fruits
Catolé palm (Syagrus oleracea Mart) fruits were obtained from a farm situated in the city of João Pessoa, northeast region of Brazil.The fruits were divided into 5 lots and the pulp and seeds were separated manually using a stainless steel knife.The seeds were broken and kernels were separated.The pulp and kernels were dried at 40 o C overnight, triturated in a mill and screened through 40 mesh sizes.The powdered pulp and kernels from each lot were packed separately in polyethylene bags and stored at 4 o C in a refrigerator.

Proximate analysis of catolé pulp and kernels
Moisture, protein, lipid, ash and crude fibre contents were determined following the standard methods of the Association of Official Analytical Chemists (AOAC, 1990).Total carbohydrate content was calculated from difference.Samples from 5 lots were analysed in duplicate.

Extraction of oil
The oil was extracted from the dried and triturated pulp and kernels with hexane in a Soxhlet extraction apparatus.After completion of extraction, solvent was recovered.Residual solvent from the oil was removed in a boiling water bath.For physical, physicochemical and fatty acids analysis, pulp and kernel oils from three of the original five lots were analysed in duplicate.
Defatted pulp and kernel meals were stored in a refrigerator at 4 o C for amino acids analysis.

Physical and physicochemical properties of kernel oil
Determination of physical and physicochemical properties was carried out only with kernel oil.Refractive index and specific gravity of kernel oil were determined at 40 o C as the oil was partially solid at room temperature.For determination of acid, peroxide, iodine and saponification values, standard AOAC (1990) methods were used.

Fatty acid composition of pulp and kernel oils
Fatty acids were transformed to their methyl esters (FAME) following the method of Hartman and Lago (1973) and were determined by using a gas chromatograph HP 5890 Series II (Hewlett Packard) equipped with a flame ionisation detector.1.5%l of the FAME sample were injected and GC separation was carried out on HP-INNOwax capillary column (Hewlett Packard; 30m length, 0.25 mm id. and 0.25m film thickness).The carrier gas (helium) head pressure and column flow rate were maintained at 11.5 psi and 1ml/min, respectively.The oven temperature was initially held at 120 o C for 1 min, increased to 210 o C at a rate of 8 o C/min and maintained at 210 o C for 45 min.The temperatures of injection port and detector were 250 o C and 280 o C, respectively.FAME were positively identified by matching their retention time data and mass spectra with those of the authentic standards obtained from various firms (Sigma; Nu-Chek-Prep, USA) which were also run under identical analytical conditions using high resolution GC-MS system (GCQ of Finnigan Mat).

Amino acid composition
The solvent extracted meals were used for determination of amino acids in an amino acid analyser (Biochrome 20, Pharmacia).Twenty milligrams of finely powdered sample were taken in an ampoule and hydrolysis was carried out using 1 ml of 6N HCl containing 0.1% phenol at 110 o C for 20 hours.The hydrolysate was dried in a vacuum desiccator, redissolved in 1 ml of sodium citrate buffer 0.2 M (pH 2.2) and filtered using Millipore micro-filters of 0.45 µM porosity.Fifteen micro-litres of the solution were injected directly in amino acid analyser containing high performance ion exchange column (Bio 20 Peek) using sodium citrate buffer of increasing pH (3.20, 4.25 and 6.45) programmed to inject automatically in the column.On column exit, amino acids mix with ninhydrin reagent resulting in a violet-blue colour.The colour intensity is read at 570 nm except for proline and hydroxyproline (yelloworange) at 440 nm.The peak area of each amino acid present in the sample protein was quantified taking in to consideration the peak area of amino acid in standard amino acids mixture.
Three samples each of defatted pulp and kernel meal obtained after oil extraction were analysed for their amino acids composition.

The proximate composition
The proximate analysis of dried catolé (Syagrus oleracea Mart) pulp and kernels is shown in Table I.

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Grasas y Aceites The lipid was the principal constituent of the dried kernels present at a concentration of 40.0% but a very low concentration (0.7%) was observed in pulp.Both fractions contained almost similar concentrations of proteins.Besides these constituents, compared to the pulp (6.2%) crude fibre was also present in high concentrations (23.9%) in dried kernels.However, total carbohydrate content of the pulp was much higher (60 %) than that of kernel.Low concentrations of proteins has also been reported for other dried palm fruit pulp and kernels such as Astrocaryum vulgare Mart (6.7 and 8.4%, Picanço, 1996 and8.4 and12.0% Bora et al, 2001) and Elaeis guineensis (3.4 and 4.9%, respectively; Moreira 2000).Contrary to catolé palm fruits in our study, these authors reported high lipid content in the pulp of Astrocaryum vulgare Mart and Elaeis guineensis palm fruits.

Physical and physicochemical properties of kernel oil
Table II shows data on some physical and physicochemical properties of kernel oil.Freshly extracted oil from kernels showed low peroxide value and no free fatty acids.Low iodine value (27.4) and reasonably high saponification value 226) reflect the possibility that the oil contained small chain saturated fatty acids.For another palm specie Astrocaryum vulgare Mart kernel oil, low iodine value (12.5) and a saponification value of 231 has been reported by Bora et al (2001).Moreira (2000) also reported iodine and saponification values of 18.9 and 221 for Elaeis guineensis kernel oil, respectively.Similarly for the kernel oil of Acrocomia intumescens palm fruits, Correia (1975) reported iodine and saponification values in the range of 16.2-30 and 214-254, respectively.

Fatty acid composition of pulp and kerne oils
The fatty acid composition of Syagrus oleracea Mart fruit pulp and kernel oils is shown in Table III.A wide difference between fatty acid composition of the pulp and kernel oils was observed.Fifteen fatty acids were detected in pulp oil and 19 fatty acids including The catolé pulp and kernel sam ples were dried in an oven overnight at 40 o C before analysis.
The results represent the m ean of the analysis of five lots of pulp and kernel fractions of catolé fruit.Tr -Traces (co ncen tra tion less than 0.06 % of the total fatty acids) Nd -Not detecte d The resu lts re pre sent the m ean of the a na lysis of the oils o f thre e lots of pulp an d ke rne l fractions of cato lé fru its 148 Grasas y Aceites Among saturated fatty acids in pulp oil, C 16 was the principal acid with 36.36% of the total fatty acids concentration followed by C 12 , C 18 and C 14 with 3.91, 3.36 and 2.14% concentrations respectively.The kernel oil, similar to other palm oils presented C 12 (lauric acid) as its principal acid (41.58%), while C 14 (9.68%),C 16 (7.19%),C 8 (5.32%), C 10 (4.54%) and C 18 (3.54%)were also present in appreciable concentrations.
Oleic acid (C 18:1 ) was the dominant monounsaturated fatty acid in both oils constituting about 99.6 and 84,9% of mono-unsaturated fatty acids with concentration of 23.9 and 16.9% of total fatty acids in pulp and kernel oils, respectively.In comparison to kernel oil, the pulp oil contained high concentrations (34.57%) of polyunsaturated fatty acids.The oil was rich in linoleic (C 18:2 ) and linolenic (C 18:3 ) acids which were present at 23.5 and 11.0% concentrations.These acids represent the family of ω-6 and ω-3 fatty acids, respectively and are precursor of arachidonic acid, which is transformed into long chain polyunsaturated fatty acids such as eicosapentaenoic (C 20:5 ), and decosahexanoic (C 22:6 ) acid.These fatty acids, besides other functions are important in the formation of eicosanoides.The eicosanoides include prostaglandins (PG), tromboxans (TX), prostacyclines (PGI) and leucotriens (LT).These compounds play an important role in the mediation of imunological allergic and inflammatory reactions and in the control of hermostacy (Calder, 1993;Voss, 1994).

Amino acid composition of pulp and kernel proteins
The data on amino acid composition of the catolé fruit pulp and kernel proteins are presented in Table IV.Similar to oil seed proteins, catolé pulp and kernel proteins are rich in aspartic (7.64 and 15.04 g/100g of protein, respectively) and glutamic (13.97 and 22.68 g/100g of protein, respectively) acids.Besides these amino acids, arginine was also present in fairly Other non-essential amino acids such as alanine, glycine, proline and serine were also present in good concentrations.
In relation to the essential amino acids, the pulp proteins possessed a better profile.Except for methionine and lysine, which were the first and second limiting amino acids (40.9 and 92.7% of reference protein), other essential amino acids in pulp proteins were present in concentrations higher than recommended by FAO (1981).Similar observation for other palm fruits: Astocaryum tucuma Mart (Hall et al, 1981) and Astocaryum vulgare Mart (Bora et al, 2001) that the fruit pulp contained large quantities of all essential amino acids, except sulphur amino acids also appeared in the scientific literature.The kernel proteins with exception to phenylalanine, isoleucine and threonine contained other essential amino acids in concentrations ranging from 41.8 to 89.4% to that of FAO reference protein.Thus catolé fruit pulp proteins can be considered for use in the formulation of high quality protein foods with other protein sources which are rich in methionine and lysine but deficient in other essential amino acids.

Table II Physical and physico-chemical properties (Mean ± SD) of catolé seed kernel oil
T he results represent th e m e an of the an alysis of the oils of three lots of pulp and ke rnel fractions of c ato lé fruit.S D -S tan dard D eviation 7 in trace concentrations, in kernel oil.The distribution of fatty acids was as follows: saturated 48.9%, mono-unsaturated 16.9% and polyunsaturated 34.6% in pulp oil, while kernel oil contained 72.3% saturated, 23.9% monounsaturated and 3.6% polyunsaturated fatty acids.Normally, odd carbon numbered fatty acids are not reported in oils, but kernel oil showed the presence of C 7 , C 9 , C 11 , C 13 and C 15 fatty acids, though at trace concentrations.However C 15: 0, C 17:0 and C 17:1 fatty acids were found in pulp oil at concentrations of 0.35, 0.92 and 0.44% of total fatty acids.