Assiut J. of Agric. Sci., 42 No.2 (222-237) Chemical Properties and Lipid Profile of Egyptian Nahid M. El-Shimy, Laila A. Shekib, Nesrin A. El-Shehy Food Science and Technology Department, Faculty of Agriculture, Alexandria University, Egypt. Abstract: linoleic and α-linolenic acids. Pecan is a promising crop The ratio between unsaturated that can replace walnuts and it fatty acids to saturated fatty acids can be consumed for its potential was 11.20:1 and 09.96:1 for De- health benefit. In this study two sirable and Moneymaker culti- cultivars of pecan (Carya illino- vars, respectively. Pecan kernels inensis) grown in Egypt; Desir- contained omega-3 fatty acids able and Moneymaker cultivars, (ώ3) family: α-linolenic acid, were investigated for their kernel eicosapentaenoic acid (EPA) and colours' chemical composition docosahexaenoic acid (DHA) in (moisture, sugars, starch, crude both cultivars. lipids , crude proteins, crude fi- Peroxide, p-anisidine, total bers and ash. Lipid oxidation of oxidation values (totox value), pecan was evaluated by measur- acidity, free fatty acids, and thio- ing: peroxide, p-anisidine, total barbituric acid value (TBA) of oxidation values and thiobarbi- Desirable cultivar were statisti- turic acid value was also deter- cally significant lower than those mined. Moreover, determination of Moneymaker cultivar. of profile and minerals Keywords: Pecan (Carya illino- content were carried out. inensis), acidity value, free fatty The major chemical compo- acids value, peroxide value, p- sition in pecan cultivars was anisidine value, omega-3 fatty crude lipids (74.84% - 75.94%). acids, thiobarbituric acid value. Moneymaker had higher total Introduction : carbohydrates and sugars and Pecan (Carya illinoinensis), lower protein than those of De- which belongs to the family Jug- sirable cultivar, while no signifi- landaceae, is one of the oldest cant differences were observed in tree nuts in the world. In Egypt, crude fiber and total ash among pecan was grown in the last years the two pecan cultivars. Potas- of 20th century in scattered areas. sium, phosphorus, magnesium, Pecan is a promising crop that iron, copper, zinc and calcium can replace walnut. According to are the major minerals in both of Kays, (1979) and Senter and pecan cultivars. Fatty acids pro- Forbus, (1979) the colour of pe- file of both pecan cultivars is can kernels is affected by mois- characterized by its high content ture content, storage temperature, of unsaturated fatty acids; oleic, atmospheric gas composition and Received on: 26/2/2011 Accepted for publication on: 22/3/2011 Referees: Prof.Dr. Mohamed N. El-Reefi Prof.Dr Mohamed R. Abdel-aal El-Shimy et al. 2011 exposure to light. Also, deteriora- matter. The same authors re- tion of pecan kernel is often ac- ported that starch content was companied by darkening of their 0.46, 0.74, and 0.06 g/100g dry colour, which influences proces- matter in pecan, and sors and consumers to associate walnut, respectively (Fourie and light coloured kernels with pecan Basson, 1990 and USDA, 2008). quality. Silva et al. (1990) and Senter (1976) detected sixteen Silva et al. (1995) reported that minerals in 10 pecan cultivars, the moisture content of pecan using atomic absorption and decreased as the harvest date was emission spectroscopy, and he delayed, and moisture content showed that there were signifi- may be a possible index of ma- cant differences among cultivars turity. Singanusong et al., (2003) in the quantities of copper, iron, stated that there were high sig- chromium, manganese, boron, nificant variations between the zinc, barium, phosphorus, potas- different pecan cultivars, with sium and calcium. respect to their moisture content, Venkatachalam and Sathe which ranged between 3.0 to (2006) and Villarreal-Lozoya et 4.7%. Total lipids of different al. (2007) indicated that oleic varieties of nuts ranged from acid (C18:1) was the main con- 50.60 to 76.20%, and also, it was stituent of monounsaturated lip- found that maturity and harvest ids, and (C18:2) was date affected the total lipid con- the major polyunsaturated fatty tent (Singanusong et al., 2003 acid in pecan oil. Furthermore, it and USDA, 2005). Crude protein was reported that the total in pecan, almond, and walnut amount of unsaturated fatty acids ranged from 9.17 to 16.66%. The content in pecan was higher than variations in crude protein may that of saturated one (Sabate be due to differences in cultivars, ,2003 and Haddad et al., 2006). cultural practices, season and Moreover, Sioen et al. (2006) geographic locations (Sin- reported that nuts content of li- ganusong et al., 2003 and USDA, noleic acid, α-linolenic acid, ei- 2008). USDA (2008) reported cosapentaenoic acid (EPA), total that total dietary fiber of pecan, omega-6 and total omega-3 were almond and walnut was 9.60, 6.60, 3.50, 0.60, 6.60 and 3.10%, 12.20 and 6.70 g/100g dry mat- respectively. Also, it was found ter, while, total carbohydrates that refractive index (25°C), io- contents were 13.86, 21.67 and dine value and saponification 13.17 g/100g dry matter, respec- value in some pecan cultivars tively. Furthermore, Singanusong ranged from 1.47 to 1.47, 100.35 et al. (2003) stated that sucrose to 108.20 and 189.29 to 191.49, was the only sugar found in pe- respectively. Kaijser et al. (2000) can kernels at maturity in detect- reported that peroxide value of able quantities, which ranged nuts ranged from 0.56 to 3.61 from 3.10 to 4.68 g/100g dry meq O2 /kg oil. Oxidation is

223 Assiut J. of Agric. Sci., 42 No.2 (212-227) catalyzed by a number of factors determined according to the such as; oxygen, light, heat, AOAC (2003). heavy metals, pigments, alkaline 2.4.Oil extraction conditions, and unsaturation de- Oil was extracted by chloroform: gree of (Dziezak, 1986). Pyr- methanol mixture (2:1, v / v) ac- iadi and Mason (1968) found that cording to the method described there were differences between by folch et al., (1957). pecan cultivars in peroxide value The minerals were deter- and thiobarbituric acid value mined according to the method (TBA). described in AOAC (2003). Cal- This work was conducted to cium, iron, magnesium, zinc, bo- study the difference between De- ron, barium and copper were de- sirable and Moneymaker Egyp- termined using Buck scientific tian pecan cultivars regarding 210-VGP Atomic Absorption kernels colour, chemical compo- Spectrophotometer. Phosphorus sition (moisture content, dry mat- was determined calorimetrically, ter, sugars, sucrose, starch, crude using SLM. Mingo 3000 Arrg. lipids, crude proteins, crude fi- spectrophotometer. Potassium bers, ash and minerals), fatty ac- and sodium were estimated by ids profile and physicochemical flame photometer. properties of pecan oil. Fatty acid methyl esters Material and methods (FAME) of were performed 2.1. Materials according to the procedure of Two cultivars of pecan fruits Radwan (1978). A sample of oil namely: Desirable and Money- (50 mg) was transferred into maker were brought from Agri- screw cap vial Benzene (2ml) culture Ministry of Egypt. The and 1% H2So4 (10 ml) in absolute fruits were shelled and the ker- methanol were added. The vial nels were packed in polyethylene was covered under stream of ni- bags and stored at (-16 – -18°C) trogen gas before heating in an until analyzed. oven at 90°C for 90 min. Dis- 2.2. Colour of pecan kernels tilled water (10 ml) was then Colour of pecan kernels was added to the cooled vial. The measured by Lovibond system methyl esters in each vial were using Schofield Tintometer Type extracted with 5 ml of petroleum IA made by Tintometer LTD for three times. Analysis of fatty Salibury Inst No. 2242 – England acid methyl esters were carried (Mackinnery and Little, 1962). out using a gas chromatography 2.3. Chemical analysis (HP 6890 Hewlett Packared Co., Moisture content, dry mat- Wilmington, DE, USA) AHP-5 ter, total sugars, reducing and (5% diphenyl 95% dimethyl poly non reducing sugars, sucrose, siloxane) capillary column starch, crude lipids, crude pro- (30m×0.32mm×0.25µm) and teins, crude fibers and ash were flame ionization detector were used. Injector and detector tem-

224 El-Shimy et al. 2011 perature were 220°C and 250°C, ambient temperature. The ab- respectively. N2 was employed as sorbance of the reaction solution the carrier gas at a flow rate of was measured in a 1 cm cuvette 0.8 ml/min., the fatty acid com- at 530 nm against distilled water. position was determined by area 2.6. Statistical analysis percentage and confirmation of Statistical analysis was fatty acid was performed by done by FACTOR and L.S.D. comparison of methyl ester with procedures available within the retention time. MSTAT-C software package 2.5. Physicochemical properties (Ver. 1.2, 1991). Analysis of of pecan oil variance of different experiments Refractive index, iodine was performed according to Steel value, saponification value and p- and Torrie (1980). anisidine value (AV) were de- Results and discussion termined as described in AOCS 3.1. Colour of pecan kernels (1990). The peroxide value (PV) The data of Table (1) show of pecan oil was determined ac- the colour of pecan kernels as cording of the AACC (1995). measured by Lovibond tintome- Total oxidation value (totox ter. It was observed that Desir- value) was calculated from the able tends to be slightly more following equation: yellow in colour than that of Totox value = 2 × Peroxide Moneymaker, while the oppo- value (PV) + P-Anisidine value site was observed for the red (AV) according to IUPAC colour. Colour is optimum when (1979). Acidity and free fatty the moisture content of pecan is acids values of pecan oil were 3.5–4.0% (Senter and Forbus, determined according to the 1979 and Hao et al., 1989). AACC (1995). Thiobarbituric 3.2. Chemical composition of acid value (TBA) of pecan oil raw pecan was determined according to The results of Table (2) Pokorny and Dieffenbacher show that Desirable cultivar had (1989). Accurately 100 mg of the significantly lower content of oil sample was weighted into a moisture (4.17%) than that of 25 ml volumetric flask, dissolved Moneymaker cultivar (4.80%). in a small volume of 1-butanol Heaton et al. (1975), Silva et al. and made up to volume with 1- (1990), Silva et al. (1995) and butanol. Five ml of sample solu- Singanusong et al. (2003) re- tion were transferred to a dry test ported that moisture content of tube and 5 ml of TBA reagent several pecan cultivars ranged solution (2 mg/1ml 1-butanol) from 3.00 to 4.70%. Dry matter were added. The tube was closed, content in pecan cultivars Desir- mixed well and placed into a able and Moneymaker were thermostated bath at 95°C. After 95.83 and 95.20% respectively. 120 minutes, the sample tube was Desirable cultivar was signifi- cooled under running tap water to cantly higher than Moneymaker

225 Assiut J. of Agric. Sci., 42 No.2 (212-227)

Table 1. Pecan kernels colour (measured by Lovibond tintometer) Colour Cultivars M±SD* Blue Yellow Red Desirable 2.90a**±0.21 3.80a±0.20 3.00a±0.23 Moneymaker 2.90a±0.20 3.60a±0.22 3.60a±0.22 L.S.D 0.364 1.260 1.050 *M±SD = Mean ± Standard Deviation. **Means in the same column sharing the same letters are not signifi- cantly different, using the revised L.S.D test at 0.05 level.

Table 2. Chemical composition of pecan kernel cultivars (on dry weight basis)

Cultivars Component (%) Moneymaker Desirable M±SD* M±SD L.S.D Moisture content 4.17b**±0.67 4.80a±0.64 0.24 Dry matter 95.83a±0.67 95.20b±0.64 0.24 Crude lipids 75.94a±5.03 74.84b±5.13 0.34 Crude protein 9.15a±4.43 8.08b±4.54 0.27 Crude fiber 3.93a±0.17 3.71a±0.24 0.34 Ash 1.61a±0.37 1.50a±0.24 0.26 Total carbohy- 9.13b±1.10 10.78a±1.28 0.16 drates1 Total sugars 4.12a±1.03 4.65a±1.45 0.63 Reducing sugars N.D*** N.D - Non-reducing sug- 4.12a±1.03 4.65a±1.45 0.63 ars Sucrose 3.91a±0.98 4.42a±1.37 0.60 Starch 0.463a±0.13 0.580a±0.13 0.56 *M±SD = Mean ± Standard Deviation. **Means between columns sharing the same letters are not signifi- cantly different, using the revised L.S.D test at 0.05 level. ***N.D = Not Detected 1- Calculated by difference.

226 El-Shimy et al. 2011 cultivar in dry matter content. protein which ranged from 8.07 The results in Table (2) to 17.34%. They attributed these clearly show that the major variations to the differences in chemical component in pecan is cultivars, cultural practices, sea- crude lipid, Desirable pecan cul- son and geographic locations. tivar had significantly higher Crude fibers content were crude lipid content (75.94%) than 3.93 and 3.71% in Desirable and that of Moneymaker cultivar Moneymaker, cultivars respec- (74.84%), these findings are rela- tively, with no significant differ- tively in accordance with that of ences between them (Table; 2). Kays (1987) and Singanusong et USDA (2008) reported that the al. (2003) who reported also that dietary fibers content of pecan oil is the major constituent of kernels ranged from 1.60 to 9.60 pecan, with oil level ranged from % while, the total dietary fiber of 58.06 to 79.96%. Moreover, the almond and walnut was 12.20 same authors stated that the and 6.70 %, respectively. chemical composition of pecan No significant difference was plays an important role in main- observed also, in ash content be- taining quality, which means tween both of Desirable and that, pecan with the highest crude Moneymaker pecan cultivars ash lipid ratio is the best in flavour contents were 1.61 and 1.50% for and quality. Desirable and Moneymaker pe- It can be noted that, there can cultivars, respectively. was an inversely proportional USDA (2008) reported that ash relationship between moisture content in pecan, almond and content and crude lipids content walnut were 1.49, 2.99 and in both cultivars of pecan. These 1.78%, respectively. results are in good agreement Total carbohydrates of pecan with previous findings of cultivars are given in Table (2), Beuchat (1978) who noticed that Moneymaker had significantly there was an inversely propor- higher total carbohydrates con- tional relationship between val- tent (10.78%) than that of Desir- ues obtained for percentages of able cultivar (9.13%). These moisture and lipid in nuts. findings are relatively in agree- Protein is considered to be ment with USDA (2008) who the third constituent in pecan. reported that total carbohydrates The results given in Table (2) contents were 13.86 and 13.17% show that Desirable pecan culti- in pecan and walnut, respec- var had significantly higher crude tively. Total sugars content was protein content (9.15%) than that 4.12 and 4.65% (Table; 2) in De- of Moneymaker cultivar (8.08%), sirable and Moneymaker, pecan these results are compatible with cultivars respectively. Reducing the data reported by Singanusong sugars were not detected in pecan et al. (2003) who found that pe- cultivars; meanwhile, Money- can kernels are a good source of maker cultivar was significantly

227 Assiut J. of Agric. Sci., 42 No.2 (212-227) higher in non reducing sugars Minerals contents of Desir- than Desirable. These data are in able and Moneymaker pecan cul- accordance with Fourie and Bas- tivars are presented in Table (3). son (1990) and Borges et al. Potassium, phosphorus, magne- (2008). sium and calcium were the major The results of Table (2) illus- minerals in both cultivars, while trate that sucrose contents were Sodium was found in a small 3.91 and 4.42% in Desirable and amount. It could be concluded Moneymaker pecan cultivars, that pecan is considered to be an respectively. Singanusong et al. excellent source of bioelements (2003) reported that sucrose con- as a result of its high content of tent in pecan ranged from 3.10 to the essential elements; iron, cop- 4.68 g/100g dry matter, they also per and zinc. On the other hand, stated that sucrose content was magnesium, potassium and cal- the only sugar found in pecan cium were significantly higher in kernels at maturity, and increased Desirable than those found in as kernels developed. And they Moneymaker cultivar. The min- suggested that the increase in eral contents of nuts, particularly total lipids may be due to conver- magnesium and copper may play sion of carbohydrates other than an important role in the mecha- sucrose to total lipids. nism of the protection against However, conversion of su- coronary heart disease (Morgan crose to lipid is a function of the and Clayshulte, 2000). Wakeling available sucrose and to a degree, et al. (2001) reported that miner- it is used for respiration and fatty als content of pecan kernels de- acid metabolism. Therefore, pends on cultivars, location, cli- these factors can interact to affect mate and agricultural practices. the sucrose content at any given 3.3. Fatty acids composition time. USDA (2008) reported that The fatty acid contents of lactose and maltose were not de- both pecan kernel cultivars are tected in pecan and walnut, but given in Table (4). Pecan oil gen- glucose and fructose were 0.04 erally contained higher percent- and 0.04 % in pecan , 0.08 and age of unsaturated fatty acids 0.09 % in walnut. Starch contents than saturated ones. There were were 0.463 and 0.580% in Desir- no significant differences be- able and Moneymaker pecan cul- tween Desirable and Money- tivars, respectively, with no sig- maker pecan cultivars in respect nificant differences between both of their content of fatty acids. pecan cultivars. The result agreed Clearly, the fatty acids profile of with the previous finding of pecan oil is characterized by its USDA (2008) who reported that high content of (89.071 starch contents were 0.46 g/100g and 87.625%), linoleic acid (1.07 in pecan, on the contrary, starch and 1.220%), and α-linolenic contents of walnut were 0.06 acid (1.01 and 0.98%) for Desir- g/100g. able and Moneymaker pecan cul

228 El-Shimy et al. 2011

Table 3. Minerals content of pecan kernel cultivars (mg/100g dry weight basis) Cultivars Minerals Desirable Moneymaker L.S.D M±SD* M±SD K 660.00a**±0.75 540.00b±0.74 1.98 Mg 170.00a±0.20 160.00b±0.32 1.20 P 610.00a±0.65 500.00b±0.65 0.03 Ca 21.00a±0.50 10.50b±0.40 1.50 Zn 10.50a±0.33 8.16b±0.22 0.99 Na 0.45b±0.20 0.63a±0.20 0.02 Fe 1.93a±0.44 2.11a±0.45 0.54 Cu 0.82a±0.88 0.87a±0.87 0.07 B 0.81a±0.21 0.74a±0.23 0.67 Ba 0.55a±0.42 0.63a±0.41 0.09 *M±SD = Mean ± Standard Deviation. **Means between columns sharing the same letters are not signifi- cantly different, using the revised L.S.D test at 0.05 level.

229 Assiut J. of Agric. Sci., 42 No.2 (212-227) Table 4. Fatty acids composition of raw pecan cultivars oil

Cultivars Fatty acids composition (%) Desirable Moneymaker L.S.D

Saturated Fatty Acids

Caproic C6:0 00.05a* 00.08a 0.102 Caprylic C8:0 00.02a 00.04a 0.101 Myristic C14:0 00.04a 00.05a 0.101 Palmitic C16:0 05.00a 05.94a 2.442 Stearic C18:0 02.94a 02.78a 0.415 Arachidic C20:0 00.11a 00.15a 0.100

Monounsaturated Fatty Acids

Palmitoleic C16:1 ώ7 00.10a 00.09a 0.100 Oleic C18:1 ώ9 89.07a 87.62a 4.079 Erucic C22:1 ώ9 00.04a 00.04a 0.110

Polyunsaturated Fatty Acids

Linoleic C18:2 ώ6 01.07a 01.22a 0.266 α-Linolenic C18:3 ώ3 01.01a 00.98a 0.101 Arachidonic C20:4 ώ6 00.24a 00.22a 0.101 EPA1 C20:5 ώ3 00.06a 00.05a 0.100 DHA2 C22:6 ώ3 00.10a 00.11a 0.101 SFA3 08.19a 09.06a 1.654 UFA4 91.72a 90.36a 2.063 MUFA5 89.21a 87.76a 2.665 PUFA6 02.50a 02.59a 0.257 U:S ratio7 11.20:1a 09.96:1a 2.241 ώ6:ώ3 ratio 01.12:1a 01.25:1a 0.236 *Means between columns sharing the same letters are not signifi- cantly different, using the revised L.S.D test at 0.05 level. 1- EPA= Eicosapentaenoic acid 2- DHA= Docosahexaenoic acid 3- SFA= Saturated fatty acids 4- UFA = MUFA + PUFA 5- MUFA= Monounsaturated fatty acids 6- PUFA= Polyunsaturated fatty acids 7- U: S ratio = Unsaturated/Saturated ratio

230 El-Shimy et al. 2011 tivars, respectively. These results acids are essential for normal are in accordance with those of cellular function, and act as pre- Villarreal-Lozoya et al. (2007) cursors for the synthesis of who confirmed that oleic acid, longer chained poly-unsaturated linoleic acid and α-linolenic acid fatty acids (PUFAs) such as; ara- were the major components chidonic (AA), eicosapentaenoic among unsaturated fatty acids, (EPA) and docosahexaenoic ac- while palimitic and stearic acids ids (DHA), which have been were the major constituents shown to partake in numerous among saturated fatty acids in the cellular functions affecting mem- different pecan cultivars. brane fluidity, membrane enzyme Total saturated fatty acids activities and eicosanoid synthe- (SFA) were (08.19 and 09.06%), sis (Youdim et al., 2000). Also, while total unsaturated fatty acids Morgan and Clayshulte (2000) (UFA) were (91.72 and 90.36%), compared dietary intakes of two the ratio between them was group's people who consumed (11.20:1 and 9.96:1) unsaturated: and did not consumed pecan. saturated fatty acids, and the ratio They found that dietary , between omega-6 (ώ6) to omega- monounsaturated fat, polyunsatu- 3 (ώ3) was 1.12:1 and 1.25:1, for rated fat, insoluble fiber, magne- Desirable and Moneymaker, pe- sium, and energy were signifi- can cultivars respectively. Toro- cantly higher in the pecan diet Vazquez et al. (1999) stated that group than in free pecan diet pecan kernel oils had a high (control group). Body weight of amount of monounsaturated fatty people was unchanged in both acids, depending on growing groups. conditions, maturity and variety. 3.4. Physicochemical proper- Furthermore, pecan kernels con- ties of raw pecan oil tained omega-3 (ώ3) family: α- The physicochemical prop- Linolenic acid, eicosapentaenoic erties of the oil extracted from acid (EPA) and docosahexaenoic two pecan kernel cultivars are acid (DHA) in both cultivars be- presented in Table (5). Values of ing 1.01, 0.06 and 0.10%, respec- refractive index of pecan oil are tively, in Desirable pecan culti- within the range for most com- var; 0.98, 0.05 and 0.11%, re- mon vegetable oils, they were spectively, in Moneymaker pecan 1.47 and 1.47 for Desirable and cultivar. Sioen et al. (2006) and Moneymaker pecan cultivars, Astorg et al. (2004) reported that respectively, with no significant linoleic acid, α-linolenic acid, differences between them. Iodine eicosapentaenoic acid (EPA) and value is an indicator for the de- docosahexaenoic acid (DHA) gree of saturation for the fatty contents in walnut were 0.05, acids, which means that iodine 0.11, 0.05 and 0.05%, respec- value decreases as the saturation tively. Linoleic and α-linolenic rate increases. In our results it

231 Assiut J. of Agric. Sci., 42 No.2 (212-227) was found that of (0.87) than that of Moneymaker Desirable pecan cultivar had sig- cultivar (1.01). These results are nificantly lower value (104.10) with the recommended values for than that of Moneymaker oil acceptability as mentioned by (110.61). William et al., (1977) Miraliakbari and Shahidi (2008). reported that iodine value of The total oxidation value (to- American pecan oils ranged from tox value) is used as a measure of 95 to 122. the precursor of non-volatile car- High saponification value in- bonyls present in processed oil, dicates the presence of short plus any further oxidation com- chain fatty acids, which consti- pounds developed during storage. tute the glyceridic part of the oil. The data in Table (5) show that Accordingly, the resulting oil has Desirable had a slightly lower a low molecular weight. Data of totox value (7.59) than that of Table (5) show that saponifica- Moneymaker cultivar (8.69). tion values of pecan oil were The data in Table (5) of acidity 190.17 and 191.82 in Desirable value is used to quantify the and Moneymaker pecan culti- amount of acidity present in the vars, respectively. There were no oils. Acidity values were low in significant differences between the two pecan cultivars. It was them. The peroxide value is an (0.19 mg NaoH /g sample) for important indicator for oil oxida- Desirable cultivar being slightly tion. It can be used as a meas- lower than that of Moneymaker urement of the extent to which cultivar (0.21 mg NaoH /g sam- rancidity reactions have occurred ple). Free fatty acids value was during storage. Data in Table (5) slightly lower in Desirable culti- show that Desirable pecan culti- var (1.33%) than that of Money- var had obvious lower peroxide maker cultivar (1.49%). Forbus value content (3.36 meq O2 /kg et al. (1980) found that free fatty oil) than that of Moneymaker acids of pecan kernel oil ranged pecan cultivar (3.84 meq O2 /kg from 0.05 to 0.38%. Thiobarbi- oil). Furthermore, overall perox- turic acid value (TBA value) is ide value formation is generally another oil oxidation indicator. low in whole pecan nuts as the The data in Table (5) show that kernel is protected by a thick Desirable pecan cultivar was pericarp. The same conclusion slightly lower (0.81) in TBA was found by Kaijser et al. value than that of Moneymaker (2000). pecan cultivar (0.83). Mexis et P-Anisidine value test is used al. (2009) found that fresh walnut to assess the secondary oxidation had a very low content of TBA of oil or fat, which is mainly im- value, changes in TBA value are putable to aldehydes and ketones. affected by storage time, packag- The data in Table (5) show that ing material and light. Desirable cultivar had signifi- cantly lower p-anisidine value

232 El-Shimy et al. 2011

Table 5. Physicochemical properties of pecan kernel cultivars oil

Cultivars Properties Desirable Moneymaker M±SD* M±SD L.S.D Refractive Index1 1.47a**±0.0004 1.47a±0.0001 0.003 Iodine value 104.10b±0.75 110.61a±0.55 1.22 Saponification value 190.17a±1.27 191.82a±1.36 1.78 Peroxide value2 (PV) 3.36b±0.03 3.84a±0.08 0.47 P-Anisidine value3 (AV) 0.87b±0.18 1.01a±0.12 0.12 Totox value4 7.59b±0.15 8.69a±0.13 0.88 Acidity value5 0.19a±0.02 0.21a±0.04 0.22 Free Fatty acids6 1.33a±0.03 1.49a±0.05 0.26 TBA value7 0.81a±0.46 0.83a±0.32 0.36 *M±SD = Mean ± Standard Deviation. **Means between columns sharing the same letters are not signifi- cantly different, using the revised L.S.D test at 0.05 level. 1- 25ºC 2- meq O2 /kg oil 3- P-Anisidine value = 4- Total oxidation value (Totox value) = 2PV+ AV 5- mg NaoH /g sample 6- as % oleic acid 7-TBA value =

233 Assiut J. of Agric. Sci., 42 No.2 (212-227)

Conclusions ture content in tree nuts. J. The study declared that pe- Food Sci. 43. 754-758. can and its oil are a very rich Borges, O.; Goncalves, B.; Car- source of polyunsaturated fatty valho, J.; Correia, P. and acids and omega-3 fatty acid and Silva, A. (2008). Nutritional highly resistant to oxidation. In quality of chestnut (Castanea addition, it could be observed sativa) cultivars from Portu- that there was a significant dif- gal. Food Chem. 106: 976- ference between the two Egyp- 984. tian cultivars, where Desirable Dziezak, J. D. (1986). Preserva- cultivar seems to have a higher tives: Antioxidants. The ulti- quality attributes than Money- mate answer to oxidation. maker one. Also, pecan is con- Food Technol. 40(9): 94-102. sidered to be an excellent source Folch, J., Lee, M. and Sloane- of bioelements. Stanley, G. H., (1957): A References simple method for the isola- American Oil Chemists' Society tion and purification of total (AOCS). (1990). Official and lipids from animal tissues. Tentative methods of the J. Biological Chem. 226, 497- American Oil Chemists' Soci- 510. ety, 3rd ed., AOCS, Illinois, Forbus, W. R.; Senter, S. D.; USA. Lyon, B. G. and Dupuy, H. P. American Association of Cereal (1980). Correlation of objec- Chemists (AACC). (1995). tive and subjective measure- Cereal Laboratory Method. ments of pecan kernel quality. American association of Ce- J. Food Sci. 45: 1376 -1379. real Chemists, Inc., St. Paul, Fourie, P. C. and Basson, D. S. Minnesota, USA. (1990). Sugar content of al- Association of Official Analyti- mond, pecan and macadamia cal Chemists (AOAC). nuts. J. Agri. Food Chem. (2003). Official methods of 38(1): 101-104. analytical. Helrich, K. ed. 17th Haddad, E.; Jambazian, P.; Ka- ed. Virginia, USA. runia, M.; Tanzman, J. and Astorg, P.; Arnault, N.; Czer- Sabate, J. (2006). A pecan en- nichow, S; Noisette, N.; riched diet increases γ- Galan, P and Herberg, S. tocopherol/cholesterol and (2004). Dietary intake and decreases thiobarbituric acid food sources of n-6 and n-3 reactive substances in plasma PUFA in French Adult Men of adults. Nutr. Res. 26: 397- and women. Lipids. 39(6): 402. 527-535. Hao, D. Y.; Heaton, E. K. and Beuchat, L. R. (1978). Relation- Beuchat, L. R. (1989). Micro- ship of water activity to mois- bial, composition and other quality characteristics of pe-

234 El-Shimy et al. 2011 can kernels stored at – 20°C of minor components of tree for twenty-five years. J. Food nut oils. Food Chem. 111(2): Sci. 54(2): 472-474. 421-427. Heaton, E. K.; Worthington, R. Morgan, W. A. and Clayshulte, E. and Shewfelt, A. L. (1975). B. J. (2000). lower Pecan nut quality. Effect of low-density lipoprotein cho- time of harvest on composi- lesterol in people with normal tion, sensory and quality lipid levels. J. Am. Diet characteristics. J. Food. Sci. Assoc. 100: 312-318. 40:1260-1263. Pokorny, J. and Dieffenbacher, International Union of Pure and A. (1989). Determination of Applied Chemistry (IUPAC). 2-thiobarbituric acid value: (1979). Standard Methods for direct method. Pure and Appl. the analysis of oils, fats and Chem. 61(6): 1165-1170. derivatives. Method 2-102. Pyriadi, T. M. and Mason, M. E. oxford. England. (1968). Composition and sta- Kaijser, A.; Dutta, P. and Savage, bility of pecan oils. J. Am. Oil G. (2000). Oxidative stability Chem. Soc. 45: 437-440. and lipid composition of Radwan, S. S. (1978). Coupling macadamia nuts grown in of two dimensional thin layer New Zealand. Food Chem. chromatography with gas 71: 67-70. chromatography for the quan- Kays, S. J. (1979). Pecan kernel titative analysis of lipid colour changes during matu- classes and their constituent ration, harvest, storage and fatty acids. J. Chromatogr. distribution. Pecan Q. 13(3): Sci. 16: 538-542. 4-6. Sabate, J. (2003). Nut consump- Kays, S. J. (1987). Pecan quality tion and body weight. Am. J. as affected by pre-, post har- Clin. Nutr. 78: 647S- 650S. vest handling, storage and Senter, S. D. (1976). Mineral marketing conditions. Pecan composition of pecan nut- South. 21: 22-26. meats. J. Food Sci. 41: 963- Mackinnery, G. and Little, A. 964. (1962). Colour of food. AVI Senter, S. D. and Forbus, W. R. Publishing Co., West port. (1979). Effect at acetylated USA. monoglyceride coatings on Mexis, S. F.; Badeka, A. V.; Ri- pecan kernel shelf-life. J. ganakos, K. A.; Karakostas, Food Sci. 44: 1752 -1755. K. X. and Kontominas, M. G. Silva, J. L.; Herrera, E. and (2009). Effect of packaging Matta, F. B. (1990). Changes and storage conditions on in kernel quality of pecan cul- quality of shelled walnuts. tivars harvested at different Food Control. 20(8):743-751. maturity stages during two Miraliakbari, H. and Shahidi, F. years. J. Miss. Acad. Sci. 35: (2008). Antioxidant activity 41-44.

235 Assiut J. of Agric. Sci., 42 No.2 (212-227) Silva, J. L.; Matta, F. B. and United States Department of Ag- Herrera, E. (1995). Quality riculture (USDA). (2008). Na- indices and sensory scores tional Nutrient database for support early harvest of pe- Standard References. Ver. 21. cans. Hort. Technol. 5: 208- International Nut and Dried 211. Fruit Foundation. http://www. Singanusong, R.; Mason, R. L. nal. usda. gov/ foodcomp.htm. and Darcy, B. R. (2003). Venkatachalam, M. and Sathe, S. Compositional changes of K. (2006). Chemical composi- Australia grown Western tion of selected edible nut Schely pecans [Carya illino- seeds. J. Agric. Food Chem. inensis (Wangenh.) K. Koch] 54(13): 4705-4714. during maturation. J. Agric. Villarreal-Lozoya, J. E.; Lo- Food Chem. 51(2): 406-412. bardini, L. and Cisneros- Sioen, I. A.; Pynaert, I.; Matthys, Zevallos. L. (2007). Phyto- C.; Backer, G. D.; Camp, J. chemical constituents and an- V. and Henauw, S. D. (2006). tioxidant capacity of different Dietary intakes and food pecan (Carya illinoinensis sources of fatty acids for Bel- (Wangenh.) K. Koch) culti- gian woman, focused on n-6 vars. Food Chem. 102: 1241- and n-3 polyunsaturated fatty 1249. acid. Lipids. 41(5): 415-422. Wakeling, L. T.; Mason, R. L.; Steel, R. G. and Torrie, J. H. Arcy, B. R. and Caffin, N. A. (1980). Principles and proce- (2001). Composition of pecan dures of statistics. 2nd ed., cultivars Wichita and Western McGrawe-Fill, New York, Schely [Carya illinoinensis USA. (Wangenh.) K. Koch] grown Toro-Vazquez, J. F.; Charo- in Australia. J. Agric. Food Alonso, M. A. and Perez- Chem. 49(3): 1277-1281. Briceno, F. (1999). Fatty ac- William, P. F.; Curtis, R. J.; Bur- ids composition and its rela- gess, L. S. and Bunker, N. J. tionship with physicochemical 1977. Pecans handling, stor- properties of pecan (Carya il- age, processing and utiliza- linoinensis) oil. J. Am. Oil tion. Georgia Agric. Exp. Sta- Chem. Soc. 76(8): 957-965. tion. 35: 71-76. United States Department of Ag- Youdim, K. A.; Martin, A. and riculture (USDA). (2005). Joseph, J. A. (2000). Essential Nutrient database Ver.17 fatty acids and the brain: pos- .http://www. nal.usda. sible health implications. Int. gov/foodcomp. Accessed J. Devl. Neuroscience. 18: 28.05.05. 383-399.

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ﺍﻟﺨﻭﺍﺹ ﺍﻟﻜﻴﻤﺎﻭﻴﺔ ﻭﺨﻭﺍﺹ ﺍﻟﺩﻫﻭﻥ ﻟﻠﺒﻴﻜﺎﻥ ﺍﻟﻤﺼﺭﻱ ﻨﺎﻫﺩ ﻤﺤﻤﺩ ﺍﻟﺸﻴﻤﻲ، ﻟﻴﻠﻰ ﻋﺒﺩ ﺍﻟﻬﺎﺩﻱ ﺸﻜﻴﺏ، ﻨﺴﺭﻴﻥ ﻋﺒﺩ ﺍﻟﻬﺎﺩﻱ ﺍﻟﺸﻴﺤﻲ ﻗﺴﻡ ﻋﻠﻭﻡ ﻭﺘﻜﻨﻭﻟﻭﺠﻴﺎ ﺍﻷﻏﺫﻴﺔ ﻜﻠﻴﺔ ﺍﻟﺯﺭﺍﻋﺔ – ﺠﺎﻤﻌﺔ ﺍﻹﺴﻜﻨﺩﺭﻴﺔ – ﺠﻤﻬﻭﺭﻴﺔ ﻤﺼﺭ ﺍﻟﻌﺭﺒﻴﺔ ﺍﻟﺒﻴﻜﺎﻥ ﻤﻥ ﺍﻟﻤﺤﺎﺼﻴل ﺍﻟﻬﺎﻤﺔ ﻭﺍﻟﺫﻱ ﻴﻤﻜﻥ ﺃﻥ ﻴﺤل ﻤﺤل ﻋﻴﻥ ﺍﻟﺠﻤل، ﻭﻟﻪ ﻓﻭﺍﺌﺩ ﺼﺤﻴﺔ ﻫﺎﻤﺔ. ﺃﺠﺭﻴﺕ ﻫﺫﻩ ﺍﻟﺩﺭﺍﺴﺔ ﻋﻠﻰ ﺼﻨﻔﻴﻥ ﻤﻥ ﺍﻟﺒﻴﻜﺎﻥ ﺍﻟﻤﺼﺭﻱ Carya) (illinoinensis ﻭﻫﻤﺎ Desirable , Moneymaker . ﻭﻗﺩ ﺘﻡ ﺩﺭﺍﺴﺔ ﺨﻭﺍﺼﻬﺎ ﺍﻟﻤﺨﺘﻠﻔﺔ ﻭﻟﻭﻥ ﺍﻟﺤﺒﺔ ﻭﺍﻟﺘﺭﻜﻴﺏ ﺍﻟﻜﻴﻤﺎﻭﻱ (ﺍﻟﺭﻁﻭﺒﺔ – ﺍﻟﺴﻜﺭﻴﺎﺕ ﺍﻟﻜﻠﻴﺔ – ﺍﻟﻨﺸﺎ – ﺍﻟﺩﻫﻭﻥ – ﺍﻟﺒﺭﻭﺘﻴﻥ ﺍﻟﺨﺎﻡ – ﺍﻷﻟﻴﺎﻑ ﺍﻟﺨﺎﻡ- ﺍﻟﺭﻤﺎﺩ). ﻭﺃﻴﻀﺎ ﺘﻡ ﺘﻘﻴﻴﻡ ﻤﺩﻯ ﻗﺎﺒﻠﻴﺔ ﺍﻟﺩﻫﻭﻥ ﻟﻸﻜﺴﺩﺓ، ﻭﺫﻟﻙ ﺒﻘﻴﺎﺱ ﺭﻗﻡ ﺍﻟﺒﻴﺭﻭﻜﺴﻴﺩ- ﺍﻟﺒﺎﺭﺍﺃﻨﺴﻴﺩﻴﻥ – ﻗﻴﻡ ﺍﻟﺘﺄﻜﺴﺩ ﺍﻟﻜﻠﻴﺔ – ﻗﻴﻤﺔ thiobarbituric acid . ﻜﻤﺎ ﺘﻡ ﺃﻴﻀﺎ ﺘﻘﺩﻴﺭ ﺍﻟﻤﺤﺘﻭﻯ ﻤﻥ ﻜل ﻤﻥ ﺍﻷﺤﻤﺎﺽ ﺍﻟﺩﻫﻨﻴﺔ ﻭﺍﻟﻤﻌﺎﺩﻥ. ﻭﺠﺩ ﻤﻥ ﺍﻟﺩﺭﺍﺴﺔ ﺃﻥ ﺍﻟﺩﻫﻭﻥ ﺘﻤﺜل (٧٤,٨٤% - ٧٥,٩٤%)، ﻴﺤﺘﻭﻱ ﺼﻨﻑ Moneymaker ﻋﻠﻰ ﻨﺴﺏ ﺃﻋﻠﻰ ﻤﻥ ﻜل ﻤﻥ ﺍﻟﻜﺭﺒﻭﻫﻴﺩﺭﺍﺕ ﻭﺍﻟﺴﻜﺭﻴﺎﺕ ﺍﻟﻜﻠﻴﺔ ﻭﻨﺴﺏ ﺃﻗل ﻤﻥ ﺍﻟﺒﺭﻭﺘﻴﻥ ﻤﻘﺎﺭﻨﺔ ﺒﺼﻨﻑ Desirable ، ﺒﻴﻨﻤﺎ ﻟﻡ ﻴﻼﺤﻅ ﺃﻱ ﻓﺭﻭﻕ ﻤﻌﻨﻭﻴﺔ ﺒﻴﻥ ﺼﻨﻔﻲ ﺍﻟﺒﻴﻜﺎﻥ ﻤﻭﻀﻊ ﺍﻟﺩﺭﺍﺴﺔ ﻓﻲ ﺍﻟﻤﺤﺘﻭﻯ ﻤﻥ ﺍﻷﻟﻴﺎﻑ ﺍﻟﺨﺎﻡ ﻭﺍﻟﺭﻤﺎﺩ. ﻭﻗﺩ ﻭﺠﺩ ﺃﻴﻀﺎ ﺃﻥ ﺃﻜﺜﺭ ﺍﻟﻤﻌﺎﺩﻥ ﺘﻭﺍﺠﺩﺍ ﻓﻲ ﻜل ﻤﻥ ﺼﻨﻔﻲ ﺍﻟﺒﻴﻜﺎﻥ (Moneymaker ، Desirable) ﺍﻟﺒﻭﺘﺎﺴﻴﻭﻡ – ﺍﻟﻔﻭﺴﻔﻭﺭ - ﺍﻟﻤﺎﻏﻨﻴﺴﻴﻭﻡ – ﺍﻟﺤﺩﻴﺩ – ﺍﻟﻨﺤﺎﺱ – ﺍﻟﺯﻨﻙ – ﺍﻟﻜﺎﻟﺴﻴﻭﻡ. ﺘﻤﻴﺯ ﻜﻼ ﻤﻥ ﺼﻨﻔﻲ ﺍﻟﺒﻴﻜﺎﻥ ﻤﻭﻀﻭﻉ ﺍﻟﺩﺭﺍﺴﺔ ﺒﺤﺘﻭﺍﺌﻬﻤﺎ ﻋﻠﻰ ﻨﺴﺏ ﻋﺎﻟﻴﺔ ﻤﻥ ﺍﻷﺤﻤﺎﺽ ﺍﻟﺩﻫﻨﻴﺔ ﻏﻴﺭ ﺍﻟﻤﺸﺒﻌﺔ ﻜﺤﻤﺽ ﺍﻷﻭﻟﻴﻙ ﻭ ﺤﻤﺽ ﺍﻟﻠﻴﻨﻭﻟﻴﻙ ﻭﺤﻤﺽ ﺍﻷﻟﻔﺎ ﻟﻴﻨﻭﻟﻴﻨﻙ. ﻭﻗﺩ ﻜﺎﻨﺕ ﺍﻟﻨﺴﺒﺔ ﺒﻴﻥ ﺍﻷﺤﻤﺎﺽ ﺍﻟﺩﻫﻨﻴﺔ ﻏﻴﺭ ﺍﻟﻤﺸﺒﻌﻪ ﺍﻟﻰ ﺍﻷﺤﻤﺎﺽ ﺍﻟﺩﻫﻨﻴﺔ ﺍﻟﻤﺸﺒﻌﺔ ﻫﻲ ١:١١,٢٠، ١:٩,٩٦ ﻓﻲ ﻜل ﻤﻥ ﺼﻨﻔﻲ ﺍﻟﺒﻴﻜﺎﻥ (Moneymaker , Desirable) ﻋﻠﻰ ﺍﻟﺘﺭﺘﻴﺏ. ﻭﻭﺠﺩ ﺃﻴﻀﺎ ﺃﻥ ﺍﻟﺒﻴﻜﺎﻥ ﻴﺤﺘﻭﻱ ﻋﻠﻰ ﻋﺎﺌﻠﺔ ﺍﻷﺤﻤﺎﺽ ﺍﻟﺩﻫﻨﻴﺔ ﺃﻤﻴﺠﺎ ٣ ﻭﻫﻡ: ﺤﻤﺽ ﺍﻷﻟﻔﺎ ﻟﻴﻨﻭﻟﻴﻨﻙ ﻭ (eicosapentaenoic acid (EPA ﻭ docosahexaenoic acid (DHA) ﻓﻲ ﻜل ﻤﻥ ﺍﻟﺼﻨﻔﻴﻥ. ﻭﻗﺩ ﻭﺠﺩ ﻤﻥ ﺍﻟﺩﺭﺍﺴﺔ ﺍﻥ ﺭﻗﻡ ﺍﻟﺒﻴﺭﻭﻜﺴﻴﺩ- ﺍﻟﺒﺎﺭ ﺃﻨﺴﻴﺩﻴﻥ- ﻗﻴﻡ ﺍﻟﺘﺄﻜﺴﺩ ﺍﻟﻜﻠﻴﺔ – ﺭﻗﻡ ﺍﻟﺤﻤﻭﻀﺔ- ﻭﻗﻴﻤﺔ ﺍﻟـ Thiobarbituric acid ﻓﻲ ﺼﻨﻑ ﺍﻟـ Desirable ﻜﺎﻨﺕ ﻤﻨﺨﻔﻀﺔ ﻤﻌﻨﻭﻴﺎﹰ ﺒﺎﻟﻤﻘﺎﺭﻨﻪ ﺒﺼﻨﻑ Moneymaker

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