Study of the composition of pyracantha crenulata roem seed , oil and meal

Semillas de Pyracantha crenulata Roem, provenientes de frutos cosechados en Olavarría (provincia de Buenos Aires, Argentina) se trataron con hexano (soxhlet) obteniéndose el aceite crudo (rendimiento: 5,5 %) y la harina residual de extracción. Las características fisicoquímicas del aceite crudo fueron: índice de refracción: 1,4770 (a 25C); índice de iodo: 121; índice de saponificación: 203; insaponificable: 7,4%, índice de peróxidos (mEq/kg) 8,7. Se determinó la composición acídica del aceite por cromatografía gas-líquido. Los ácidos grasos mayoritarios fueron: ácido linoleico (61,1%), ácido oleico (17,3%) y ácido palmítico (17,4%). La harina residual de extracción contenía baja proporción de proteína cruda (13% b.s), considerable contenido de fibra cruda; y un valor de fibra detergente neutra relativamente alto, lo que concuerda con la muy baja digestibilidad observada. Se informan valores de cenizas, minerales e hidratos de carbono.


INTRODUCTION
Pyracantha crenulata Roem is a 1 to 3 metre highly ramified and prickly bush.Some of its characteristics are: 5 cm length alternate oblong leaves, shrewdly jogged and brilliant on their superior side, white flowers and orange colour fruit.It belongs to the family Rosaceae, from which many fruits (naturally or processed) are used for food, such as plums, apricots or hit-rose.This kind of plant comes from China and it is widely used as an ornamental plant (Cabrera, 1963;Dinitri, 1987).
Studies about fruit composition of the Pyracantha genus have been carried out (Maskey and Shah, 1982;Deng et al, 1990;Wong et al., 1992;Quiroga et al.,1994) and information referred to crude oil extraction characteristics has been obtained (Suzuki et al., 1973;Mitsushashi et al., 1977;Endo et al, 1983), but data available on extracted meal composition is scanty (Wiese et al, 1995).An exhaustive survey of the literature reveals that no information is available on the characteristics and chemical composition of seed of P. crenulata Roem.
Due to the wide distribution in Argentina, it was considered of interest to perform a study on the general chemical composition of this seed species so as to contribute with data that determine its possible utilisation.The present investigation was carried out to determinate the physical and chemical characteristics of seeds, oil and meal of P. crenulata Roem.

EXPERIMENTAL
Seeds of ripe fruits harvested in Olavarría (Buenos Aires province, Argentine, crop 2000) were manually separated and their size, mean weight and moisture content were determined.The seeds were ground, and the lipid fraction was extracted with n-hexane (Soxhlet).The remaining solvent was removed from the residual meal (40-50 o C, vacuum).

Lipid fraction examination
The physical and chemical characteristics of the lipid fractions were determined according to the following methods: refractive index (Abbe refractometer, 25 o C);
Fatty acid composition was assessed by gas chromatography-mass spectrometry (GC/MS) of the methyl esters of the total acids, free of the unsaponifiable fraction, obtained by esterification with methanol containing 1.5 % H2SO4 (Hilditch and Williams, 1964).A GC-MS Hewlett Packard (gas chromatograph 5890-mass spectrometer 5972) was employed.The GC was equipped with a SPB-5 capillary column (30 m x 0.25 mm, 2.5 µm film thickness).The oven temperature was programmed from 70 o C to 290 o C with a 10 o C/min increase.The injector temperature was 280 o C. The carrier gas was helium at a flow rate of 30 mL/min.Methyl esters of fatty acid were identified by comparison with the retention times and mass spectrums of standards.
The presence of conjugated polyunsaturated acids was investigated spectrophotometrically according to method Cd-758 (AOCS, 1998).
The methyl esters were examined by infrared (IR) absorption as a liquid film on a FTIR Nicolet Magna System 550 spectrometer.
The following data are triplicate averages expressed on dry basis (d.b.).

RESULTS AND DISCUSSION
Physical and chemical characteristics and composition of P. crenulata Roem are shown in Table I and II.Table I shows a high value in the number of seeds per gram, thus implying that the seed size is very small, as corroborated by data about these seed dimensions.
Seed moisture content was relatively high (10.4%)yielding 5.5 % (d.b.) of a limpid yellow oil at room temperature, by extraction with hexane.Oil yield is quite low but similar to those reported for P. angustifolia (Endo et al., 1983) and P. atalantoides (Wiese et al., 1995).
The high level of unsaponifiable fraction and the high saponification value suggest a low concentration of acids with a high molecular weight (Table II).However, the unsaponifiable matter (%) was smaller than the value reported by Endo et al. (1983) for P. angustifolia and by Wiese et al, (1995) for P. atalantoides (20.5% and 12 %, respectively).Some parameters indicating either the oil quality or its deterioration such as the peroxide value and 1 .4 7 7 0 V i s c o s i t y ( c p ; 2 5 C ) 5 7 .9 4 S p e c i f i c g r a v i t y ( 1 5 C ) 0 .9 2 0 5 C o m b u s t i o n h e a t ( c a l / g ) 9 .4 0 2

Table II Physical and chemical Characteristics of Pyracantha crenulata Roem.
Seed lipid fraction acid value resulted relatively low, the latter indicating low lipase activity.
The results of the fatty acid composition expressed in methyl ester percentages are shown in Table III.
The iodine value was calculated in base to this composition (Table II).It indicated that the oil was of the semidrying type.Major components were linoleic, palmitic and oleic acids, in that order.The high linoleic acid value (61.1 %) was similar to those found in safflower and sunflower oils (Gustone et al, 1994).This percentage was considerably greater than the values reported by Endo et al. (1983) and Suzuki et al. (1973) for P. angustifolia (45.2% and 22.5%, respectively).The content of linoleic acid is highly interesting due to its nutritional importance (essential fatty acid).The percentage of saturated acids was 21.1%, mostly consisting of palmitic acid.But the content of palmitic acid was less than the 23.7% and 37.4% reported by Endo et al. (1983) and Suzuki et al. (1973, respectively, for P. angustifolia.The arachidic acid (only acid with more than 18 carbon atoms detected) was present in small amounts (0.8%).
IR spectra showed a bond at 3435 cm -1 , indicative of the presence of the hydroxyl group.Bonds at 914-847 cm -1 relative to the probable presence of the epoxy groups were detected as well.
In spite of having a fatty acid composition with characteristics similar to sunflower oil, the P. crenulata Roem oil yield is quite lower, showing the seed as a poor lipid source for industrial application.
Table IV lists the results achieved from the analysis of the meal.P. crenulata meal had higher contents of fiber (34.4%),particularly cellulose, and lowers content of protein (13 % d.b.) and ash (5.2 %d.b.).The carbohydrate concentration was very low for both reducing and non-reducing sugar with an important concentration in hydrolyzable carbohydrates.Our values for P. crenulata are similar to data on carbohydrate concentration for P. atalantoides meal reported by Wiese et al. (1995).
The analysis of the ash showed a significant (>1000 ppm) concentration of sodium, calcium and magnesium.Copper, zinc and phosphorus ranged from 24 to 300 ppm (Table IV) The low concentration of phosphorus determined that the Ca/P ratio was greater than that one required for an adequate absorption in infants and adults (1,5:1 and 1:1, respectively; Llyod et al., 1982).
As regards to animal feeding, although the protein content of the meal showed a value considered adequate for a good ruminant functioning, the crude fiber content and the cellular wall membrane content (NDF) was considerably high, concordant with the low digestibility observed.These results indicated that meal would be useful only for animal maintenance or for increasing their weight slightly (Aello and Di Marco, 1997).
We believe that these preliminary findings will prove useful for further studies on P. crenulata Roem seed, particularly regarding the aminoacid composition of seed proteins and its potentially toxic components.P. crenulata Roem belongs to a genus where most members produce hydrogen cyanide.This toxin is found mainly in the leaves and seed, usually in small quantity.In small doses, hydrogen cyanide has been shown to stimulate respiration and improve digestion.However, in excess it can cause respiratory failure and even death (Plants For A Future andKen Fern , 1992-2002).

F
w n i e b l a c k N u m b e r o f s e e d s / g 3 1 5 L e n g t h ( m m ) 2 .6 8 ± 0 .3 1 9 T h i c k n e s s ( m m ) 1 u c i n g s u g a r s % ( a s g l u c o s e ) 0 .7 N o n r e d u c i n g s u g a r s % ( a s s u c r o s e ) 1 . 1 H y d r o l y z a b l e c a r b o h y d r a t e s % ( a s s t a r c h ) 1 2 .0 U r e a s e a c t i v i t y U n d e t e c t e d O r g a n i c m a t t e r ( % ) 9 3 .1 N e u t r a l d e t e r g e n t f i b e r ( N D F ) 6 1 .0 A c i d d e t e r g e n t f i b e r ( A D F ) 4 1 .7 L i g n i n8 .5 C e l l u l o s e 3 2 .6 S i l i c a t r a c e s D r y m a t t e r d i g e s t i b i l i t y 2 3 .4 O r g a n i c m a t t e r d i g e s t i b i l i t y 1 9 .5 D i g e s t i b l e e n e r g y 0 .7 T o t a l p h o s p h o r u s ( and digestible energy, all the results are expressed on a dry basis.