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Study of the effects of extraction methods on Argan oil quality through its metal content
Industrial Crops & Products 109 (2017) 182–184
Contents lists available at ScienceDirect
Industrial Crops & Products journal homepage: www.elsevier.com/locate/indcrop
Study of the effects of extraction methods on Argan oil quality through its metal content ⁎⁎
MARK
⁎
Fatima Ezzahra Ennoukha, Rahma Bchitoua, , Faez Mohammeda,b, , Dominique Guillaumec, Hicham Harhard, Ahmed Bouhaoussa a
Laboratoire de Nanostructure, Génie des Procédés et Environnement, Département de Chimie, Faculté des Sciences, Université Mohammed V, Rabat, Morocco University Sana'a, Faculty of Education, Arhab, Sana'a, Yemen c Institut de ChimieMoléculaire de Reims, School of Medicine-Pharmacy, CNRS-UMR 7312, 51 Rue Cognacq Jay, 51100 Reims, France d Laboratoire de Chimie des Plantes et de Synthe‘se Organique et Bioorganique, Faculté des Sciences, Université Mohammed V, BP 1014 Rabat, Morocco b
A R T I C L E I N F O
A B S T R A C T
Keywords: Argan oil Extraction methods Metal content
Argan oil is an edible oil highly valued as a traditional healthy food ingredient, and increasingly used in the cosmetic industry. This work was aimed at studying the effects of extraction methods on metals content of oil, in order to determine the optimal extraction method. For this purpose, we analysed of argan oil, extracted from argan kernels collected in four regions of Morocco, following three different process (traditional, mechanical, by solvent). Oil quality was assessed by determining levels of dietary and heavy metals. Abundance and mineralogical residence of 11 elements have been also determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Results showed that no significant variations exist among the studied samples in terms of the levels of dietary elements and heavy metals and hence of oil quality. Our study shows that there is not a preferred method for argan oil extraction in view to preparing high quality Argan oil.
1. Introduction Currently argan oil has gained worldwide popularity because of its quality, the potential health benefits derived from its use and its strict purity control. Argan oil, obtained from the pit of Argania spinosa, it exists as beauty and edible oil. Beauty oil is prepared from unroasted kernels and is endowed with numerous dermocosmetologic properties (Guillaume and Charrouf, 2011). It is the basic ingredient of the Amazigh diet (Charrouf and Guillaume, 2010) and its regular consumption is beneficial for human health (El Monfalouti et al., 2010). Be made according to traditional method, press- or solvent-extraction, argan oil is extracted following a multistep procedure (Charrouf and Guillaume, 1999). Traditionally, argan oil has been prepared exclusively by Berber women (Charrouf et al., 2002), by used of a stone mill. This process is long; for a single person 58 h of work are necessary to get 2–2.5 L of oil, and its. leads to oil batches having variable organoleptic properties due to non-reproducible roasting (Charrouf et al., 2006) and chemical composition of oil batches (Hilali et al., 2005). Mechanical press extraction is a more recent approach to prepare argan oil. A single person
can obtain 4–6 L of oil after 13 h of work. (El Monfalouti et al., 2010). Finally the most frequenly used method for industrial or laboratory purposes is extraction by solvent (Charrouf and Guillaume 2008). Quality and chemical composition of the extracted oil may vary from one extraction method to another. Oil quality and its stability are very important for the consumer’s desirable use. The quality of any oil is indicated by some physicochemical properties which provide an indication on both the nutritive and physical quality of the oil. These properties include peroxide value, iodine value, free fatty acid, saponification value, color appearance etc. To retain oil quality, care must be taken when processing vegetable oils to prevent their deformation as they easily undergo oxidative deterioration, hence shortening their shelf-life. One of the most important quality criteria of vegetable oils is its metal content. The presence of metals in vegetable oils is due to both endogenous factors, connected with the plant metabolism as well as exogenous factors due to contamination during the agronomic techniques of production and the collection of seeds during the oil extraction and treatment processes, as well as systems and materials of packaging and storage. (Coco et al., 2003; Dantas et al., 2003).
⁎ Corresponding author at: Laboratoire de Nanostructure, Génie des Procédés et Environnement, Département de Chimie, Faculté des Sciences, Université Mohammed V, Rabat, Morocco. ⁎⁎ Corresponding author. E-mail addresses: [email protected] (R. Bchitou), [email protected] (F. Mohammed).
http://dx.doi.org/10.1016/j.indcrop.2017.08.039 Received 5 June 2017; Received in revised form 19 August 2017; Accepted 21 August 2017 0926-6690/ © 2017 Elsevier B.V. All rights reserved.
Industrial Crops & Products 109 (2017) 182–184
F.E. Ennoukh et al.
and produced argan oil without mixing the dough with water. Extraction of argan oil by solvent was performed following the ISO 659 recommendation (ISO 659, 1998). Twenty grams of ground kernels were placed in a Soxhlet apparatus and extracted with 150 mL of hexane for 8 h. The organic phase was then concentrated under vacuum and dried for 5 min in an oven at 105 °C. 2.2. Apparatus ICP-AES spectrometer (JobinYvon, Ultima 2) with axial viewed plasma was used for the mineral contents determination in each argan oil sample. The operating conditions were set as follows: power 1.15–1.2 kW, plasma flow gas 12–14 L/min, auxiliary gas flow 1.5 L/ min and nebulizer gas flow 0.2 L/min. The wavelengths used for the quantification were: Cadmium 214.440 nm, Chromium 205.560 nm, Zinc 213.857 nm, Copper 324.752 nm, Iron 238.204 nm, Potassium 766.490 nm, Magnesium 279.077 nm, Manganese 257.610 nm, Sodium 588.995 nm, Tin 235.848 nm and Phosphorus 178.287 nm.
Fig. 1. Areas of Morocco from which argan fruit were harvested (taken from Mohammed et al., 2013a).
2.3. Minerals
The presence of heavy metals in vegetable oils may have a negative influence on the quality of oils, causing changes to their taste and smell. Such changes in oil quality, called “taste reversion,” are caused by the occurrence of the following metals: Fe, Cu, Cr, Zn, and Mn, which, through their ability to form radicals, facilitate the process of oxidation of fats (Zioła-frankowsk et al., 2011). We have previously studied several factors influencing metal content both through the study of the effect of geographical location or roasting process (Mohammed et al., 2013a,b). The aim of this present work is to investigate the influence of the extraction process on argan oil metal content.
For mineral analysis, 0.25 g of argan oil was accurately weighed in vessel tubes, 10 mL of concentrated HNO3 (69.5%) and 8 mL of H2O2 (35%) were added and the tubes were heated on at 140 °C for 4 h. During all of the tests, the pressure was kept at 45 bar, and the ventilation was 3 min. After cooling, 1 mL of HNO3 (1%) was added and the final volume was adjusted to 25 mL with deionized water and measured by inductively coupled plasma atomic emission spectroscopy (ICPAES). 3. Results and discussion
2. Materials and methods
Edible oil is usually examined for metal content for a variety of reasons: some elements have a metabolic role, others have toxic characteristics, and others can affect the quality of oil (Gonzálvez et al., 2010). In this sense, trace analysis is employed to determine whether toxic elements are present at levels that might be hazardous to human health. Trace metal profiling can be used to characterize a food (Zeiner et al., 2005). Prior to metal content analysis, we determined the initial quality of all our samples prepared using the differences techniques of extraction. Argan fruit was collected from four regions; the fruit of each region was harvested from the same tree, the same color of maturity, and at the same time. Tables 1 and 2 summarize the content and mean value (mg/l) of the dietary elements composition found in the oil samples extracted with different methods. In general, the data showed sufficiently little variability to assess that all argan oil samples present, in terms of dietary elements, a similar composition, independently from the extraction process. For most of the elements analysed in edible argan oil, and with respect of the extractive methods, Calcium was the only element to be frequently in higher amount in traditional oil than oil press. High
2.1. Sample collection and preparation Argan fruit was harvested from four regions of Morocco (Essaouira, Ait Baha, Agadir, Taroudant) as shown in Fig. 1. For every harvest, 30 kg of fruit were collected. Fruit was processed (drying and peeling) using the argan-cooperative traditional technique (Charrouf and Guillaume, 2008). Oil samples were prepared using three extraction processes (traditional, mechanical, by solvent) from argan kernels manually collected from each locations. To prepare edible oil; the almonds were roasted at 110C for 30 min (roaster: SMIR, Technotour Agadir, Morocco). Traditional Extraction: Argan oil was obtained using manual methods by women. Argan kernels were crushed in a rotary arm grinding stone. The resulting paste was mixed by hand and small quantities of warm water were sequentially added. Oil separated from the paste was recovered and then filtered. Press extraction: This method used mechanical presses (Komet DD85G-IBG Montforts Oekotec GmbH). Almonds were directly pressed Table 1 Dietary element amounts (mg l−1) in edible argan oil. Region
Method
Ca
Cd
Cr
Cu
Fe
K
Mg
Mn
P
Sn
Zn
Agadir Agadir Ait Baha Ait Baha Essaouira Essaouira Tarroudant Tarroudant
Tradi Pres Tradi Pres Tradi Pres Tradi Pres
6.7 a 7.37b 7.17b 8.17c 6.27d 8.45c 6.12d 8.65c
0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a
BDL BDL BDL BDL BDL BDL BDL BDL
0.01a 0.02a 0.03a 0.02a 0.02a 0.02a 0.02a 0.02a
0.43a 0.47a 0.51a 0.46a 0.35a 0.47a 0.64a 0.45a
1.12a 1.11a 1.23a 1.17a 1.78a 1.02a 0.91a 1.02a
1.92a 2.28a 2.20a 2.45a 1.86a 2.64a 2.07a 2.63a
0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a
2.39a 2.50a 2.68a 2.43a 2.14a 2.32a 2.07a 2.25a
0.19a 0.62b 0.18a 0.66b 0.11a 0.64b 0.27a 0.62b
0.03a 0.03a 0.03a 0.03a 0.04a 0.02a 0.03a 0.04a
a,d
: For a similar analysis, given values indexed with the same letter are not significantly different. BDL; below detection limits.
183
Industrial Crops & Products 109 (2017) 182–184
F.E. Ennoukh et al.
Table 2 Dietary element amounts (mg l−1) in beauty argan oil.
a,c
Region
Method
Ca
Cd
Cr
Cu
Fe
K
Mg
Mn
P
Sn
Zn
Agadir Agadir Agadir Ait Baha Ait Baha Ait Baha Essaouira Essaouira Essaouira Tarroudant Tarroudant Tarroudant
Tradi Pres Solv Tradi Pres Solv Tradi Pres Solv Tradi Pres Solv
8.39a 8.56a 6.82b 6.93b 7.69b 9.07a 10.31c 8.42a 6.77b 9.17a 9.96a 10.58c
0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a
BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL
0.02a 0.02a 0.03a 0.02a 0.02a 0.02a 0.02a 0.02a 0.03a 0.02a 0.03a 0.03a
0.21a 0.31a 0.19b 0.93b 0.37a 0.28c 0.03a 0.29c 0.81b 0.01a 0.17c 0.03a
0.98a 1.18a 1.31a 1.13a 0.66a 2.10b 1.57a 1.07a 0.62a 1.84a 0.94a 3.56b
2.44a 2.46a 1.81a 2.11a 1.99a 2.43a 2.79a 2.44a 1.74a 2.59a 2.64a 3.17b
0.01a 0.01a 0.02a 0.02a 0.01a 0.01a 0.02a 0.01a 0.01a 0.02a 0.01a 0.02a
2.42a 2.46a 2.28a 2.61a 2.18a 2.92a 2.60a 2.06a 2.15a 2.51a 1.89a 1.87a
0.71a 0.23b 1.30a 0.40b 0.12b 0.77a 1.13a 0.20b 0.33b 0.75a 0.09b 0.84a
0.04a 0.03a 0.06a 0.03a 0.03a 0.03a 0.02a 0.04a 0.03a 0.03a 0.03a 0.01a
: For a similar analysis, given values indexed with the same letter are not significantly different. BDL; below detection.
References
calcium content in argan oil extracted by traditional method can result from the water used during oil extraction. While, similar amounts were found for another elements in edible oil extracted by mechanical pressing and hand- pressing. Those results demonstrate that the extracting step by press and traditional method has no influence on the element content in argan oil. More precisely, it can be said that extraction method does not modify the dietary element content of the argan oil therefore dietary element content is a non-variable parameter that can be used to ascertain the quality of edible argan oil. Similar same results were observed for beauty oil. The content of dietary element was significantly stable in oil samples extracted by the three different methods. For the four locations studied, no major significant variations exist among calcium content in oil of solvent extracted for location of Agadir and Essaouira. Whereas, the calcium content was similar in the oil extracted by three methods for Ait Baha and Tarroudant. Our study revealed that extraction process has no influence on the amount of dietary elements. Those results demonstrate that, in terms of dietary elements, Argan oil quality is not affected by the methods of extraction.
Charrouf, Z., Guillaume, D., 1999. Ethnoeconomical: ethnomedical and phy-tochemical study of Argania spinosa (L) Skeels. J. Ethnopharmacol. 67 7–1. Charrouf, Z., Guillaume, D., 2008. Argan oil, functional food, and the sustainable development of the argan forest. Nat. Prod. Commun. 3, 283–288. Charrouf, Z., Guillaume, D., 2010. Should the Amazigh diet (regular and moderate arganoil consumption) have a beneficial impact on human health? Crit. Rev. Food Sci. Nut. 50, 473–477. Charrouf, Z., Guillaume, D., Driouich, A., 2002. The argan tree, an asset for Morocco. Biofutur 220, 54–57. Charrouf, Z., El Hamchi, H., Mallia, S., Licitra, G., Guillaume, D., 2006. Influence of roasting and seed collection on argan oil odorant composition. Nat. Prod. Commun. 1, 399–404. Coco, F., Ceccon, L., Ciraolo, L., Novelli, V., 2003. Determination of cadmium (II) and zinc (II) in olive oils by derivative potentiometric stripping analysis. Food Control. 14, 55–59. Dantas, T.N.C., Neto, A.A.D., Moura, M.C.P.A., Neto, E.L.B., Forte, K.R., Leite, R.H.L., 2003. Heavy metals extraction by microemulsions. Water Res. 37, 2709–2717. El Monfalouti, H., Guillaume, D., Denhez, C., Charrouf, Z., 2010. Therapeutic potential of argan oil – a review. J. Pharm. Pharmacol. 62, 1669–1675. Gonzálvez, A., Armenta, S., de la Guardia, M., 2010. Adulteration detection of argan oil by inductively coupled plasma optical emission spectrometry. Food Chem. 121, 878–886. Guillaume, D., Charrouf, Z., 2011. Argan oil and other argan products; use in dermocosmetology. Eur. J. Lipid Sci. Technol. 113, 403–408. Hilali, M., Charrouf, Z., Aziz, El, Soulhi, A., Hachimi, L., Guillaume, D., 2005. Influence of origin and extraction method on argan oil physico-chemical characteristics and composition. J. Agric. Food Chem. 53, 2081–2087. ISO 659 1998 Oilseeds-Determination of Oil Content (Reference Method)–EN. ISO 659 1998. Mohammed, F.A.E., Bchitou, R., Bouhaouss, A., Gharby, S., Harhar, H., Guillaume, D., Charrouf, Z., 2013a. Can the dietaryelement content of virgin argan oilsreallybeused for adulterationdetection? Food Chem. 136, 105–108. Mohammed, F.A.E., Bchitou, R., Boulmane, B., Bouhaouss, A., Guillaume, D., 2013b. Modeling of the distribution of heavy metals and trace elements in argan forest soil and parts of argan tree. Food Chem. 136, 105–108. Zeiner, M., Steffan, I., Cindric, J.I., 2005. Determination of trace elements in olive oil by ICP-AES and ETA-AAS: A pilot study on the geographical characterization. Microchem. J. 81, 171–176. Zioła-frankowsk, A., Frankowski, M., Szyczewski, P., 2011. Determination of heavy metals in vegetable oils. Lab 5–6, 58.
4. Conclusion The ICP-AES technique is widely regarded as the most important analytical technique used for evaluation of oil. It could be used to detect some adulterations in edible oil as well as in beauty argan oil in addition to campesterol content analysis. Our results show that the level of dietary elements in argan oil remains unchanged, regardless of the extraction techniques. Conflict of interest The authors declare that there are no conflicts of interest.
184
Contents lists available at ScienceDirect
Industrial Crops & Products journal homepage: www.elsevier.com/locate/indcrop
Study of the effects of extraction methods on Argan oil quality through its metal content ⁎⁎
MARK
⁎
Fatima Ezzahra Ennoukha, Rahma Bchitoua, , Faez Mohammeda,b, , Dominique Guillaumec, Hicham Harhard, Ahmed Bouhaoussa a
Laboratoire de Nanostructure, Génie des Procédés et Environnement, Département de Chimie, Faculté des Sciences, Université Mohammed V, Rabat, Morocco University Sana'a, Faculty of Education, Arhab, Sana'a, Yemen c Institut de ChimieMoléculaire de Reims, School of Medicine-Pharmacy, CNRS-UMR 7312, 51 Rue Cognacq Jay, 51100 Reims, France d Laboratoire de Chimie des Plantes et de Synthe‘se Organique et Bioorganique, Faculté des Sciences, Université Mohammed V, BP 1014 Rabat, Morocco b
A R T I C L E I N F O
A B S T R A C T
Keywords: Argan oil Extraction methods Metal content
Argan oil is an edible oil highly valued as a traditional healthy food ingredient, and increasingly used in the cosmetic industry. This work was aimed at studying the effects of extraction methods on metals content of oil, in order to determine the optimal extraction method. For this purpose, we analysed of argan oil, extracted from argan kernels collected in four regions of Morocco, following three different process (traditional, mechanical, by solvent). Oil quality was assessed by determining levels of dietary and heavy metals. Abundance and mineralogical residence of 11 elements have been also determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Results showed that no significant variations exist among the studied samples in terms of the levels of dietary elements and heavy metals and hence of oil quality. Our study shows that there is not a preferred method for argan oil extraction in view to preparing high quality Argan oil.
1. Introduction Currently argan oil has gained worldwide popularity because of its quality, the potential health benefits derived from its use and its strict purity control. Argan oil, obtained from the pit of Argania spinosa, it exists as beauty and edible oil. Beauty oil is prepared from unroasted kernels and is endowed with numerous dermocosmetologic properties (Guillaume and Charrouf, 2011). It is the basic ingredient of the Amazigh diet (Charrouf and Guillaume, 2010) and its regular consumption is beneficial for human health (El Monfalouti et al., 2010). Be made according to traditional method, press- or solvent-extraction, argan oil is extracted following a multistep procedure (Charrouf and Guillaume, 1999). Traditionally, argan oil has been prepared exclusively by Berber women (Charrouf et al., 2002), by used of a stone mill. This process is long; for a single person 58 h of work are necessary to get 2–2.5 L of oil, and its. leads to oil batches having variable organoleptic properties due to non-reproducible roasting (Charrouf et al., 2006) and chemical composition of oil batches (Hilali et al., 2005). Mechanical press extraction is a more recent approach to prepare argan oil. A single person
can obtain 4–6 L of oil after 13 h of work. (El Monfalouti et al., 2010). Finally the most frequenly used method for industrial or laboratory purposes is extraction by solvent (Charrouf and Guillaume 2008). Quality and chemical composition of the extracted oil may vary from one extraction method to another. Oil quality and its stability are very important for the consumer’s desirable use. The quality of any oil is indicated by some physicochemical properties which provide an indication on both the nutritive and physical quality of the oil. These properties include peroxide value, iodine value, free fatty acid, saponification value, color appearance etc. To retain oil quality, care must be taken when processing vegetable oils to prevent their deformation as they easily undergo oxidative deterioration, hence shortening their shelf-life. One of the most important quality criteria of vegetable oils is its metal content. The presence of metals in vegetable oils is due to both endogenous factors, connected with the plant metabolism as well as exogenous factors due to contamination during the agronomic techniques of production and the collection of seeds during the oil extraction and treatment processes, as well as systems and materials of packaging and storage. (Coco et al., 2003; Dantas et al., 2003).
⁎ Corresponding author at: Laboratoire de Nanostructure, Génie des Procédés et Environnement, Département de Chimie, Faculté des Sciences, Université Mohammed V, Rabat, Morocco. ⁎⁎ Corresponding author. E-mail addresses: [email protected] (R. Bchitou), [email protected] (F. Mohammed).
http://dx.doi.org/10.1016/j.indcrop.2017.08.039 Received 5 June 2017; Received in revised form 19 August 2017; Accepted 21 August 2017 0926-6690/ © 2017 Elsevier B.V. All rights reserved.
Industrial Crops & Products 109 (2017) 182–184
F.E. Ennoukh et al.
and produced argan oil without mixing the dough with water. Extraction of argan oil by solvent was performed following the ISO 659 recommendation (ISO 659, 1998). Twenty grams of ground kernels were placed in a Soxhlet apparatus and extracted with 150 mL of hexane for 8 h. The organic phase was then concentrated under vacuum and dried for 5 min in an oven at 105 °C. 2.2. Apparatus ICP-AES spectrometer (JobinYvon, Ultima 2) with axial viewed plasma was used for the mineral contents determination in each argan oil sample. The operating conditions were set as follows: power 1.15–1.2 kW, plasma flow gas 12–14 L/min, auxiliary gas flow 1.5 L/ min and nebulizer gas flow 0.2 L/min. The wavelengths used for the quantification were: Cadmium 214.440 nm, Chromium 205.560 nm, Zinc 213.857 nm, Copper 324.752 nm, Iron 238.204 nm, Potassium 766.490 nm, Magnesium 279.077 nm, Manganese 257.610 nm, Sodium 588.995 nm, Tin 235.848 nm and Phosphorus 178.287 nm.
Fig. 1. Areas of Morocco from which argan fruit were harvested (taken from Mohammed et al., 2013a).
2.3. Minerals
The presence of heavy metals in vegetable oils may have a negative influence on the quality of oils, causing changes to their taste and smell. Such changes in oil quality, called “taste reversion,” are caused by the occurrence of the following metals: Fe, Cu, Cr, Zn, and Mn, which, through their ability to form radicals, facilitate the process of oxidation of fats (Zioła-frankowsk et al., 2011). We have previously studied several factors influencing metal content both through the study of the effect of geographical location or roasting process (Mohammed et al., 2013a,b). The aim of this present work is to investigate the influence of the extraction process on argan oil metal content.
For mineral analysis, 0.25 g of argan oil was accurately weighed in vessel tubes, 10 mL of concentrated HNO3 (69.5%) and 8 mL of H2O2 (35%) were added and the tubes were heated on at 140 °C for 4 h. During all of the tests, the pressure was kept at 45 bar, and the ventilation was 3 min. After cooling, 1 mL of HNO3 (1%) was added and the final volume was adjusted to 25 mL with deionized water and measured by inductively coupled plasma atomic emission spectroscopy (ICPAES). 3. Results and discussion
2. Materials and methods
Edible oil is usually examined for metal content for a variety of reasons: some elements have a metabolic role, others have toxic characteristics, and others can affect the quality of oil (Gonzálvez et al., 2010). In this sense, trace analysis is employed to determine whether toxic elements are present at levels that might be hazardous to human health. Trace metal profiling can be used to characterize a food (Zeiner et al., 2005). Prior to metal content analysis, we determined the initial quality of all our samples prepared using the differences techniques of extraction. Argan fruit was collected from four regions; the fruit of each region was harvested from the same tree, the same color of maturity, and at the same time. Tables 1 and 2 summarize the content and mean value (mg/l) of the dietary elements composition found in the oil samples extracted with different methods. In general, the data showed sufficiently little variability to assess that all argan oil samples present, in terms of dietary elements, a similar composition, independently from the extraction process. For most of the elements analysed in edible argan oil, and with respect of the extractive methods, Calcium was the only element to be frequently in higher amount in traditional oil than oil press. High
2.1. Sample collection and preparation Argan fruit was harvested from four regions of Morocco (Essaouira, Ait Baha, Agadir, Taroudant) as shown in Fig. 1. For every harvest, 30 kg of fruit were collected. Fruit was processed (drying and peeling) using the argan-cooperative traditional technique (Charrouf and Guillaume, 2008). Oil samples were prepared using three extraction processes (traditional, mechanical, by solvent) from argan kernels manually collected from each locations. To prepare edible oil; the almonds were roasted at 110C for 30 min (roaster: SMIR, Technotour Agadir, Morocco). Traditional Extraction: Argan oil was obtained using manual methods by women. Argan kernels were crushed in a rotary arm grinding stone. The resulting paste was mixed by hand and small quantities of warm water were sequentially added. Oil separated from the paste was recovered and then filtered. Press extraction: This method used mechanical presses (Komet DD85G-IBG Montforts Oekotec GmbH). Almonds were directly pressed Table 1 Dietary element amounts (mg l−1) in edible argan oil. Region
Method
Ca
Cd
Cr
Cu
Fe
K
Mg
Mn
P
Sn
Zn
Agadir Agadir Ait Baha Ait Baha Essaouira Essaouira Tarroudant Tarroudant
Tradi Pres Tradi Pres Tradi Pres Tradi Pres
6.7 a 7.37b 7.17b 8.17c 6.27d 8.45c 6.12d 8.65c
0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a
BDL BDL BDL BDL BDL BDL BDL BDL
0.01a 0.02a 0.03a 0.02a 0.02a 0.02a 0.02a 0.02a
0.43a 0.47a 0.51a 0.46a 0.35a 0.47a 0.64a 0.45a
1.12a 1.11a 1.23a 1.17a 1.78a 1.02a 0.91a 1.02a
1.92a 2.28a 2.20a 2.45a 1.86a 2.64a 2.07a 2.63a
0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a
2.39a 2.50a 2.68a 2.43a 2.14a 2.32a 2.07a 2.25a
0.19a 0.62b 0.18a 0.66b 0.11a 0.64b 0.27a 0.62b
0.03a 0.03a 0.03a 0.03a 0.04a 0.02a 0.03a 0.04a
a,d
: For a similar analysis, given values indexed with the same letter are not significantly different. BDL; below detection limits.
183
Industrial Crops & Products 109 (2017) 182–184
F.E. Ennoukh et al.
Table 2 Dietary element amounts (mg l−1) in beauty argan oil.
a,c
Region
Method
Ca
Cd
Cr
Cu
Fe
K
Mg
Mn
P
Sn
Zn
Agadir Agadir Agadir Ait Baha Ait Baha Ait Baha Essaouira Essaouira Essaouira Tarroudant Tarroudant Tarroudant
Tradi Pres Solv Tradi Pres Solv Tradi Pres Solv Tradi Pres Solv
8.39a 8.56a 6.82b 6.93b 7.69b 9.07a 10.31c 8.42a 6.77b 9.17a 9.96a 10.58c
0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a 0.01a
BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL BDL
0.02a 0.02a 0.03a 0.02a 0.02a 0.02a 0.02a 0.02a 0.03a 0.02a 0.03a 0.03a
0.21a 0.31a 0.19b 0.93b 0.37a 0.28c 0.03a 0.29c 0.81b 0.01a 0.17c 0.03a
0.98a 1.18a 1.31a 1.13a 0.66a 2.10b 1.57a 1.07a 0.62a 1.84a 0.94a 3.56b
2.44a 2.46a 1.81a 2.11a 1.99a 2.43a 2.79a 2.44a 1.74a 2.59a 2.64a 3.17b
0.01a 0.01a 0.02a 0.02a 0.01a 0.01a 0.02a 0.01a 0.01a 0.02a 0.01a 0.02a
2.42a 2.46a 2.28a 2.61a 2.18a 2.92a 2.60a 2.06a 2.15a 2.51a 1.89a 1.87a
0.71a 0.23b 1.30a 0.40b 0.12b 0.77a 1.13a 0.20b 0.33b 0.75a 0.09b 0.84a
0.04a 0.03a 0.06a 0.03a 0.03a 0.03a 0.02a 0.04a 0.03a 0.03a 0.03a 0.01a
: For a similar analysis, given values indexed with the same letter are not significantly different. BDL; below detection.
References
calcium content in argan oil extracted by traditional method can result from the water used during oil extraction. While, similar amounts were found for another elements in edible oil extracted by mechanical pressing and hand- pressing. Those results demonstrate that the extracting step by press and traditional method has no influence on the element content in argan oil. More precisely, it can be said that extraction method does not modify the dietary element content of the argan oil therefore dietary element content is a non-variable parameter that can be used to ascertain the quality of edible argan oil. Similar same results were observed for beauty oil. The content of dietary element was significantly stable in oil samples extracted by the three different methods. For the four locations studied, no major significant variations exist among calcium content in oil of solvent extracted for location of Agadir and Essaouira. Whereas, the calcium content was similar in the oil extracted by three methods for Ait Baha and Tarroudant. Our study revealed that extraction process has no influence on the amount of dietary elements. Those results demonstrate that, in terms of dietary elements, Argan oil quality is not affected by the methods of extraction.
Charrouf, Z., Guillaume, D., 1999. Ethnoeconomical: ethnomedical and phy-tochemical study of Argania spinosa (L) Skeels. J. Ethnopharmacol. 67 7–1. Charrouf, Z., Guillaume, D., 2008. Argan oil, functional food, and the sustainable development of the argan forest. Nat. Prod. Commun. 3, 283–288. Charrouf, Z., Guillaume, D., 2010. Should the Amazigh diet (regular and moderate arganoil consumption) have a beneficial impact on human health? Crit. Rev. Food Sci. Nut. 50, 473–477. Charrouf, Z., Guillaume, D., Driouich, A., 2002. The argan tree, an asset for Morocco. Biofutur 220, 54–57. Charrouf, Z., El Hamchi, H., Mallia, S., Licitra, G., Guillaume, D., 2006. Influence of roasting and seed collection on argan oil odorant composition. Nat. Prod. Commun. 1, 399–404. Coco, F., Ceccon, L., Ciraolo, L., Novelli, V., 2003. Determination of cadmium (II) and zinc (II) in olive oils by derivative potentiometric stripping analysis. Food Control. 14, 55–59. Dantas, T.N.C., Neto, A.A.D., Moura, M.C.P.A., Neto, E.L.B., Forte, K.R., Leite, R.H.L., 2003. Heavy metals extraction by microemulsions. Water Res. 37, 2709–2717. El Monfalouti, H., Guillaume, D., Denhez, C., Charrouf, Z., 2010. Therapeutic potential of argan oil – a review. J. Pharm. Pharmacol. 62, 1669–1675. Gonzálvez, A., Armenta, S., de la Guardia, M., 2010. Adulteration detection of argan oil by inductively coupled plasma optical emission spectrometry. Food Chem. 121, 878–886. Guillaume, D., Charrouf, Z., 2011. Argan oil and other argan products; use in dermocosmetology. Eur. J. Lipid Sci. Technol. 113, 403–408. Hilali, M., Charrouf, Z., Aziz, El, Soulhi, A., Hachimi, L., Guillaume, D., 2005. Influence of origin and extraction method on argan oil physico-chemical characteristics and composition. J. Agric. Food Chem. 53, 2081–2087. ISO 659 1998 Oilseeds-Determination of Oil Content (Reference Method)–EN. ISO 659 1998. Mohammed, F.A.E., Bchitou, R., Bouhaouss, A., Gharby, S., Harhar, H., Guillaume, D., Charrouf, Z., 2013a. Can the dietaryelement content of virgin argan oilsreallybeused for adulterationdetection? Food Chem. 136, 105–108. Mohammed, F.A.E., Bchitou, R., Boulmane, B., Bouhaouss, A., Guillaume, D., 2013b. Modeling of the distribution of heavy metals and trace elements in argan forest soil and parts of argan tree. Food Chem. 136, 105–108. Zeiner, M., Steffan, I., Cindric, J.I., 2005. Determination of trace elements in olive oil by ICP-AES and ETA-AAS: A pilot study on the geographical characterization. Microchem. J. 81, 171–176. Zioła-frankowsk, A., Frankowski, M., Szyczewski, P., 2011. Determination of heavy metals in vegetable oils. Lab 5–6, 58.
4. Conclusion The ICP-AES technique is widely regarded as the most important analytical technique used for evaluation of oil. It could be used to detect some adulterations in edible oil as well as in beauty argan oil in addition to campesterol content analysis. Our results show that the level of dietary elements in argan oil remains unchanged, regardless of the extraction techniques. Conflict of interest The authors declare that there are no conflicts of interest.
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