Pérez-Pérez, Alamilla-Beltrán, Jiménez-Martínez, Pereyra-Castro, Ortiz-Moreno, Plazola-Jacinto, Camacho-Díaz, and Hernández Ortega: Evaluation of acute toxicity and chemical composition of refined oil Moringa oleifera cultivated in Mexico



Introduction

The oil obtained from Moringa oleifera (M. oleifera) seeds is highly monounsaturated on account of its oleic acid content, which is higher than 60% (Chiou & Kalogeropoulos, 2017). The consumption of oleic acid reduces the plasmatic concentration of cholesterol, plays an important role in decreasing the incidence of brain disorders, such as dementia and Alzheimer´s, and inhibits the occurrence of colorectal cancer (Srivastava & Bhargava, 2012) In addition to oleic acid, M. oleifera seed oil contains linoleic acid (0.3-1.3%) and α-linolenic acid (0.3-0.5%) (Anwar, Zafar & Rashid, 2006; Sánchez-Machado et al., 2015). These fatty acids are essential and from them, other long-chain polyunsaturated fatty acids are synthetized in the organism. The latter give origin to eicosanoids (leukotrienes, prostaglandins, and thromboxanes), which act as hormonal cell messengers (Saini & Keum, 2018).

Eicosanoids synthetized from linoleic and α-linolenic acids have antagonistic effects in the human organism. Linoleic acid (ω6) derivatives generate inflammatory, thrombotic, and arrhythmic metabolites, which play an important role in the immune system. In contrast, linolenic acid (ω3) derivatives have an anti-inflammatory, anti-thrombotic, and anti-arrhythmic effect (Saini & Keum, 2018). For this reason, a specific ratio of these fatty acids (ω6:ω3) must be consumed. The recommended consumption ratio, in order to avoid a pro-inflammatory or immunodeficient state, is in the range of 1:1-2:1 (Orsavova, Misurcova, Vavra, Vicha & Mlcek, 2015).

Due to the health benefits that the consumption of oleic, linoleic, and α-linolenic acids provides, it is preferred to use vegetable oils containing these fatty acids, such as M. oleifera seed oil (Orsavova et al., 2015).

M. oleifera seeds and M. oleifera seed oil toxicity has been previously reported in some studies. Al-Said et al. (2012), and Ilesanmi, Gungula & Nadro (2017) reported that the M. oleifera seed oil, not presented acute toxicity in rats. While, Chivapat et al. (2012) reported the presence of acute toxicity signs and lethality, when administering an ethanolic extract of seeds to ICR mice, and Al-Anizi, Hellyer & Zhang (2014) reported that the cytotoxicity and genotoxicity of the hydrophobic extract of seeds, attributing such toxicity to alkaloids, enzymes, and glycosinolates associated to oil.

The concentration of the toxic compounds (like alkaloids) in M. oleifera seeds, depends on the geographical region and the climatic conditions in which the plant develops (Ukwueze, Okogwu, Ebem, Nwonumara & Nwodo, 2019). There has been no study performed on the toxicity of the oil obtained from M. oleifera seeds cultivated in Mexico.

The alkaloids, enzymes and glycosinolates associated with the M. oleifera oil toxicity, can be removed through a refining process (Siano et al., 2016), therefore this process could be an alternative to reduce the oil toxicity. However, in addition to the removal of toxic compounds of the oil, natural antioxidants are also lost during the refining process. Consequently, the oxidative stability of some oils is reduced after the refining process (Siano et al., 2016). Besides the loss of bioactive compounds during this process, harmful substances like chloropropanols (Zulkurnain et al., 2012) and trans fatty acids (Vaisali, Charanyaa, Belur & Regupathi, 2015) can be formed. Thus, there is a new tendency towards the consumption of vegetable oils without refining (crude oils) (Durmaz & Gökmen, 2019).

Therefore this work aimed to evaluate the effect of the refining process on the acute toxicity of M. oleifera seed oil obtained from a Mexican variety, the fatty acid profile, and the physicochemical properties of crude and refined oil.

Materials and methods

Moringa oleifera seeds

M. oleifera seeds were grown and purchased in Morelia, Michoacán, Mexico. The seeds were manually cleaned and peeled; and subsequently stored in plastic bags until the oil extraction.

Chemical reagents

All chemicals used in this work were reagent grade. Hexane, hydrochloric acid, ethanol, sodium hydroxide and potassium hydroxide were purchased from J.T Baker; acetone, and potassium iodide were purchased from Fermont; acetic acid and dichloromethane were purchase from Meyer; sodium thiosulfate was purchase from Hycel, iodine monobromide and DPPH (2,2-diphenyl-1-picrylhydrazyl) were purchased from Sigma Aldrich

Oil extraction

The oil was obtained by pressing with a hydraulic press (500, Taiwan) at a pressure of 500 kgf/cm2. During the extraction, temperature was set to 85 °C in order to inactivate enzymes from the oil, which could act as toxic components. The oil extraction yield was calculated with Equation 1.

(1)
Oil extraction yield (%) = (ApAs) x 100     

Where: Ap is the mass (g) of the oil of 100 g of seeds extracted by mechanical pressing; and As is the mass (g) of the total oil of 100 g of seeds.

Oil refining process

The chemical refining process was carried out following the methodology described by Crexi, Monte, Soares & Pinto (2010), with some modifications. This process consisted of four stages: degumming, neutralization, washing, and bleaching. The degumming stage was performed by adding water to the oil in proportion 1:4, followed by the addition of 1% of concentrated hydrochloric acid, in relation to the oil mass. The mixture was heated at 80 °C for 30 min, continuously stirring. Then, the oil was centrifuged (Hermle Z326K, Wehingen, Germany) at 10,000 rpm for 15 min. The neutralization stage was carried out by heating the oil at 75 °C and adding 15% of sodium hydroxide 1 mol/L, in relation to the oil mass, and stirring the mixture for 15 min. Then, the oil was centrifuged at 10,000 rpm for 15 min. Subsequently, for the third stage of the refining process, the oil was washed three times with water at 90 °C. The bleaching stage was performed by adding activated carbon to the oil and finally centrifuging it at 10,000 rpm during 25 min. The refined oil recovery yield was calculated for each stage of the refining process using Equation 2.

(2)
Refined oil recovery yield (%) = (P0Pi) x 100

Where: Po is the mass (g) of oil obtained at the end of each stage of the refining process and Pi is the initial mass (g) of oil.

Determination of acute toxicity

The acute toxicity of the crude and refined M. oleifera oils was evaluated following the guidelines of the Organization for Economic Cooperation and Development guidelines OECD No. 423 (2001) in male ICR mice, weighing between 0.031-0.038 kg. Before starting the trial, the mice were kept in laboratory conditions during seven days for an adaptation period. The mice were divided in three groups of three mice each. The oil was orally administered to the mice with a cannula. Two doses (300 and 2,000 mg/kg of body weight) of the crude oil were administered and a single dose of the refined oil (2,000 mg/kg). The overall behavior of the mice was continuously monitored during the first two hours after the oil administration; then, every 2 h during 24 h, and finally, daily during 14 days, recording toxicity signals (piloerection, tremors, convulsions, diarrhea, and/or lethargy) and mortality. The animals were weighed before the administration of the oil and at the end of the trial. Finally, the mice were sacrificed by dislocation, removing the heart, liver, kidneys, and spleen for observation and weighing.

Fatty acids profile

The fatty acids profile of M. oleifera crude and refined oils for the saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids was determined by gas chromatography, following the methodology described by the AOCS Ce 1h-05 (2005). A gas chromatographer (Agilent 7890 B, Mexico City, Mexico) equipped with a flame ionization detector (FID), an HP-88 column (100m*0.25m*0.20μm, Agilent, USA), and a data acquisition software (Chemstation version B.04.01.) was used for the determination. For the temperature program, the initial oven temperature (180 °C) was held for 10 min, then, increased to 220 °C at a rate of 3 °C/min, and finally held at 220 °C during 17 min. Helium was used as the carrier gas at a flow rate of 2 mL/min with an injection volume of 1 μL. The qualitative composition of the fatty acids was determined by comparing the retention times of the peaks obtained for the sample with a standard (EMAG C4-C22, Supelco® 37 Component Fatty Acid Methyl Esters Mix).

Physicochemical properties

Iodine index, saponification index, peroxide index and titratable acidity were determine for the crude and refined oil, following the methodology described by the AOCS (1997).

β-carotene content and antioxidant capacity

The β-carotene content was determined with the methodology proposed by Barros, Ferreira, Queirós Ferreira & Baptista (2007). 100 µL of oil were diluted with 10 mL of a mixture of acetone: hexane (4:6). The absorbance (A) of the samples was measured at 453, 505, and 663 nm using a spectrophotometer (Genesys 10S UV-VIS, Thermo Scientific, USA). The β-carotene content was calculated using Equation 3.

(3)
β-carotene (mg of β-carotene/ 100 g of oil) = 0.216 A663- 0.304 A505 + 0.452 A453         

The antioxidant capacity was determined using the methodology described by Brand-Williams, Cuvelier & Berset (1995). The oil was diluted with 1 mL of a mixture of ethanol: hexane (1:1), followed by the addition of 0.5 mL of 2,2-diphenyl-1-picrylhydrazyl (DPPH) 0.3 mol/L. Finally, these samples were left to stand in the dark for 15 min. The absorbance was measured at 540 nm using a spectrophotometer (Genesys 10S UV-VIS, Thermo Scientific, USA).

Oil density and viscosity

The density (ρ) of the crude and refined oils was determined by weighing 50 mL of the oil at 20 °C. The viscosity was determined utilizing a viscometer (RST CC, Brookfield Engineering Labs Inc., USA), using a concentric cylinder geometry at ambient temperature (Sánchez-Machado et al., 2015).

Results and discussions

Seed oil extraction

The total oil content in M. oleifera seeds was 36.52%. The extraction yield obtained by mechanical pressing was 61% with respect to the oil content of the seed determined by Soxhlet method; this result is in accordance with the value reported by Lalas & Tsaknis (2002) who obtained 60.6% of oil through this extraction method. Mechanical pressing was selected as the oil extraction method because it avoids the use of organic solvents, which are difficult to remove from the extracted oil (Ruttarattanamongkol, Siebenhandl, Schreiner & Petrasch, 2014).

Oil refining process

The oil recovery yield for each of the refining process stages is shown in Table I. At the end of this process, the recovery yield was 54.66%, which implies a total loss of 45.33%. Degumming, neutralization, and bleaching were the refining stages with the highest oil losses.

Table I

M. oleifera oil recovery yield during the refining process.

Refining process stage Oil recovery yield (%)
Crude oil 100
Degumming 81.34±2.20
Neutralization 69.74±2.05
Washing 66.67±2.56
Bleaching 54.66±2.54

[i] Values represent the average of three repetitions ± standard deviation.

During the first stage of the refining process, the degumming stage, hydratable and non-hydratable phospholipids are eliminated from the oil. The former are eliminated by sedimentation or centrifugation of the heated mixture of oil with water. To remove the non-hydratable phospholipids from the oil, acid must be added, which could sometimes forms salts with the metallic complex present in these types of compounds, thus, increasing its solubility in water and its removal.

The elimination of phospholipids improves the sensory quality and hydrolytic stability of the oil. The percentage of oil loss during the degumming stage was 18.66% and probably corresponds to the phospholipid content and to a portion of the oil that remains bound to these compounds (Gupta, 2017).

During the neutralization stage, free fatty acids are eliminated from the oil. These compounds are precursors of oxidation reactions; therefore, their elimination increases the oxidative stability of the oil. Free fatty acids react with the sodium hydroxide added, forming soap, which is separated from the oil by centrifugation and during the washing stage, after the neutralization (Gupta, 2017). The percentage of oil loss during the neutralization stage was 11.66% and corresponds to the free fatty acids content.

During the bleaching stage, part of the natural pigments of the oil is eliminated because they are trapped in the activated carbon that is removed from the oil (Gupta, 2017). Some of the pigments present in the oil, such as carotenes, act as natural antioxidants and as bioactive compounds; therefore, their elimination can reduce the oxidative stability and the nutritional quality of M. oleifera oil (Sánchez-Machado et al., 2015). The percentage of oil loss during the bleaching stage was 12.01%.

Acute toxicity of M. oleifera seed oil

After the single oral administration of the crude and refined M. oleifera oil (300 and 2,000 mg/kg), the animals showed no lethal effect of mortality during the trial period (Table II). Their behaviour and morphological characteristics remained normal. Animals showed no tremors, convulsions, salivation, diarrhoea, and/or lethargy; and no significant differences were observed in their weight (Figure 1).

Table II

Toxicity signals and mortality for the acute toxicity study of crude and refined M. oleifera oil.

Group Dose (mg/kg) Type of oil Toxicity signals (TS/NB)a Mortality (D/A)a
A 2,000 Refined 0/3 0/3
B 2,000 Crude 0/3 0/3
C 300 Crude 0/3 0/3

a Values expressed as number of animals. TS: toxicity signals, NB: normal behavior, D: dead, A: alive.

Figure 1

Body weight of mice at the beginning (day 1) and end of the trial (day 14), A: refined oil (2,000 mg/kg), B: crude oil (2,000 mg/kg body weight), and C: crude oil (300 mg/kg body weight).

1405-888X-tip-23-e20200264-gf1.jpg

At the time of the sacrifice, no anatomical changes were observed in the organs of the animals (heart, liver, kidneys, and spleen). Additionally, there was no significant difference in the relative weight of the organs between the different study groups (Figure 2). Due to these results and according to the OECD No. 423 (2001), the M. oleifera oil can be considered a safe compound for human consumption.

Figure 2

Relative weight of the mice organs in each administration group, A: refined oil (2,000 mg/kg), B: crude oil (2,000 mg/kg), and C: crude oil (300 mg/kg).

1405-888X-tip-23-e20200264-gf2.jpg

The acute toxicity was determined because some previous studies (Al-Anizi et al., 2014; Chivapat et al., 2012) reported that the M. oleifera seeds present toxicity, which could be associated to the presence of non-lipid compounds (alkaloids, glycosides, and enzymes) associated to oil. In contrast, the results obtained in the present work indicate that the crude and refined M. oleifera oil showed no toxicity. This could be attributed to the absence of these compounds in the M. oleifera seeds employed for oil extraction. Ukwueze et al. (2019) has been informed that the presence of compounds as alkaloids depends on the weather conditions and the geographical location of growth of the plant.

The results obtained in this work suggested that the oil obtained from M. oleifera seeds from Mexico, is safe for human consumption. In addition to toxicity, the composition and physicochemical properties of the oil are important to be considered before to use as edible vegetable oil.

Fatty acids profile

The fatty acids profile of the crude and refined M. oleifera oil is shown in Table III. The refining process did not cause significant changes (p < 0.05) in the fatty acids content of the oil. Sánchez-Machado et al., (2015) obtained similar results when evaluating the effect of the refining process on the quality of this oil.

Table III

Fatty acids profile (g /100 g of fatty acids) of the crude and refined M. oleifera oil.

Fatty acid Crude oil Refined oil
Saturated (SFA) 26.615±0.124a 26.295±0.461a
Myristic acid (14:0) 0.097 ± 0.009a 0.089 ± 0.003a
Palmitic acid (16:0) 5.968 ± 0.061a 5.936 ± 0.066a
Stearic acid (18:0) 7.510 ± 0.020a 7.477 ± 0.139a
Arachidic acid (20:0) 4.624 ± 0.007a 4.573 ± 0.051a
Behenic acid (22:0) 7.399 ± 0.021a 7.240 ± 0.160a
Lignoceric acid (24:0) 1.017 ± 0.006a 0.980 ± 0.042a
Monounsaturated (MUFA) 70.595±0.08a 70.965±0.243a
Cis-Palmitoleic acid (16:1) 1.754 ± 0.006a 1.781 ± 0.026a
Oleic acid (cis) (18:1) 68.841 ± 0.074a 69.184 ± 0.217a
Polyunsaturated (PUFA) 2.705±0.012a 2.701±0.022a
Linoleic acid (cis) (18:2) 0.735 ± 0.005a 0.747 ± 0.006a
α-Linolenic Acid (18:3) 1.970 ± 0.007a 1.954 ± 0.016a

[i] Values represent the average of three repetitions ± standard deviation. Same letters indicate no significant difference between the columns (t-test, p <0.05).

The content of saturated fatty acids of the crude (26.62%) and refined (26.30%) M. oleifera oil is appropriate according to the recommendations of the FAO and the European Cardiology Society, who establish that the percentage of these fatty acids in edible oils should not exceed 33% (Eilander, Harika & Zock, 2015).

Oleic acid is the fatty acid present in greater proportion (69%) in M. oleifera seed oil; this percentage is similar to the values reported by several authors (Anwar et al., 2006; Bhutada, Jadhav, Pinjari, Nemade & Jain, 2016; Sánchez-Machado et al., 2015; Sulaiman, Ahmad, Mariod, Mathäus & Salaheldeen, 2017). Since the oleic acid content in M. oleifera oil is greater than 60%, it can be classified as a highly monounsaturated vegetable oil (Chiou & Kalogeropoulos, 2017).

In the same classification are olive (78-83% of oleic acid) (Rodrigues et al., 2018) and avocado oil (57-60% of oleic acid) (Rodríguez-Carpena, Morcuende & Estévez, 2012). The consumption of olive oil is related to the reduction of total cholesterol and low-density lipoproteins (LDL) in blood, therefore, the consumption of vegetables oils with high percentages of this fatty acid is recommended (Mensink, Zock, Kester & Katan, 2003).

In addition to the oleic acid content, from a nutritional point of view, it is also important to consider the quantity and ratio of linoleic acid (ω6) and α-linolenic acid (ω3) present in the oil. The consumption of these two fatty acids is important because they cannot be synthesized by the organism and because from them, other fatty acids can be synthesized (arachidonic acid, from linoleic; eicosapentaenoic and docosahexaenoic acids from α-linolenic), which develop specific functions in the maintenance of the homeostasis. In order for these fatty acids to generate positive effects on health, they must be consumed in a ω6:ω3 ratio in the range of 1:1 - 2:1 (Saini & Keum, 2018). The analyzed M. oleifera oil contains a ω6:ω3 ratio of 0.4:1; thus, the quantity of linoleic acid present in this oil is lower than the recommended quantity (Saini & Keum, 2018). However, in most highly monounsaturated vegetable oils, the quantity of ω6 fatty acids is quite higher than ω3 fatty acids. For example, in olive oil the ratio is 15:1 (ω6:ω3) (Rodrigues et al., 2018) and in avocado oil the ratio is 10:1(ω6:ω3) (Rodríguez-Carpena et al., 2012). Therefore, the combined consumption of M. oleifera oil with olive oil and/or avocado oil could help to reach the recommended fatty acids ratio ω6:ω3.

The plasma cholesterol concentration has been reported to increase if oils with a combined myristic and palmitic acid content of 25% are consumed (Zock, De Vries & Katan, 1994). The combined content of these fatty acids in the crude and refined M. oleifera oil is of ~7% in both cases. Therefore, the consumption of the crude or refined M. oleifera oil does not increase the plasmatic cholesterol concentration. Another of the saturated fatty acids present in the M. oleifera oil is the behenic acid, which is poorly absorbed in the organism (between 11-24%) due to the length of its hydrocarbon chain; thus, its consumption has no significant effect on the plasmatic cholesterol concentration (Cater & Denke, 2001).

Physicochemical characteristics of the oil Iodine value

The iodine value (Table IV) of crude M. oleifera oil is similar to the value reported by Anwar et al., (2006) of 66.54 g I/100 g of oil; Sánchez-Machado et al., (2015) of 63.9 g I / 100 g of oil; and Leone et al., (2016) of 65.86 g I/100 g of oil. The refining process increases the iodine value (Table IV). This increase could be due to the loss of some compounds during the refining process, such as phospholipids, which interfere in the binding of iodine with the double bonds of the fatty acids.

Table IV

Physicochemical characterization of the crude and refined M. oleifera oil.

Assay Crude oil Refined oil
Iodine value (g I/100 g of oil) 65.11± 0.45a 70.88 ± 0.54b
Saponification value (mg KOH/g of oil) 194.46 ± 3.2a 238.46 ± 4.2b
Free fatty acids (% oleic acid) 1.87 ± 0.002a 0.37 ± 0.0001b
Peroxide value (meq/kg) 0.91 ± 0.001a 0.65 ± 0.002b
β- carotene (mg of β- carotene/ kg of oil) 2.18 ± 0.22a 0.66 ± 0.02b
Antioxidant capacity DPPH (% of inhibition) 37.24 ± 1.94a 15.16 ± 0.47b
Density (g/mL) 0.9060 ± 0.003a 0.9061± 0.002 a
Viscosity (mPa.s) 70 ± 2.3a 69 ± 2.7a

[i] Values represent the average of three repetitions ± standard deviation. Results with a different letter for each assay are significantly different (p < 0.05).

Vegetable oils can be classified in three categories, based on the iodine value. Non-drying oils have an iodine value <100, semi-drying oils between 100 and 140, and drying oils >140 (Gupta, 2017). Therefore, based on this classification, the crude and refined M. oleifera oil is non-drying. In these types of oils, the unsaturated fatty acid content is not enough to form impermeable films in the intestines, which prevent the absorption of nutrients. Such effect is only observed in drying oils, hence, non-drying oils are recommended for human consumption.

Saponification value

The saponification value (Table IV) of the crude M. oleifera oil is similar to the value reported for the same oil by Anwar et al., (2006) (179-199 mg KOH/g of oil) and by Leone et al., (2016) (178-188 mg de KOH /g of oil). After the refining process, the saponification value increased ~23% (Table III), which can be attributed to the removal of compounds with high molecular weight during the degumming stage, specifically phospholipids.

β-carotene content and antioxidant capacity

The β-carotene content (Table IV) of crude M. oleifera oil is lower than the value reported by Boukandoul, Casal, Cruz, Pinho & Zaidi (2017), 3.7 ± 0.1 mg of β-carotene/kg of oil. This difference may be due to the variety and to the environmental conditions of the plant development in each case. β-carotene content decreased approximately 70% (Table IV) as a result of the refining process, which can be attributed to the conditions used during such process. During the degumming and neutralization stages, the increase of the oil temperature and the modification of its pH caused oxidation of the carotenes; hence, decreasing the concentration of these compounds in the oil. Additionally, during the bleaching stage, the carotenes are absorbed in the added activated carbon, thus, separating from the oil (Gupta, 2017). Carotenes are pigments that protect oils against oxidation; therefore, the loss of these compounds could increase the degree of oil oxidation (Boukandoul et al., 2017).

The antioxidant capacity of the crude and refined M. oleifera oil was evaluated by the inhibition of the DPPH radical and expressed as percentage of inhibition. The result obtained for the crude oil (Table IV) is similar to the value reported by Ogbunugafor et al., (2011), 48.18 ± 0.01%. The antioxidant capacity of the oil decreased with the refining process (Table IV); this could be due to the reduction of antioxidant compounds content, such as carotenes, tocopherols, and sterols, mainly during the degumming, neutralization, and bleaching stages (Anwar et al., 2006).

Oil density and viscosity

The density of the crude and refined M. oleifera oil was 0.906 g/mL in both cases, similar to the values reported by Anwar et al. (2006) and Sánchez-Machado et al., (2015). The density of vegetable oils depends on the degree of unsaturation of the fatty acids that comprise them. Since the fatty acids composition of the oil was not modified during the refining process, the density remained constant.

Viscosity is the measure of the resistance of oils to flow; therefore, it must be considered for the design of processing and transport equipment. It also influences the sensory attributes of the oil, such as palatability. This parameter increases with increasing molecular weight and decreases as the degree of unsaturation of fatty acids present in the oil increases. The viscosity of the crude oil (Table IV) is within the limit values (43-103 mPa.s) reported by Leone et al. (2016) for M. oleifera oil extracted by cold pressing. The viscosity of the refined oil (Table IV) showed no significant difference (p < 0.05) from the viscosity of the crude oil because during the refining process, neither the degree of unsaturation nor the molecular weight of the fatty acids present in the oil were modified.

Free fatty acids (% oleic acid)

The free fatty acids content in the crude M. oleifera oil (Table IV) was similar to the value reported by Leone et al. (2016) for the same oil, 1-3.5%. The free fatty acids content of the refined oil decreased 80%, due to the reduction of these fatty acids during the neutralization stage. Sánchez-Machado et al. (2015) also reported an acidity reduction of M. oleifera oil as a result of the refining process, indicating that this reduction increases the oxidative stability of the oil. The acidity percentages obtained in this work for the crude and refined M. oleifera oil (Table III) are lower than the maximum limit allowed by the FAO/WHO, 2015 4% and 0.6%, respectively. Considering this standard, the analyzed oils can be used for human consumption.

Peroxide value

The peroxide value obtained for the crude M. oleifera oil (Table III) is within the range reported by Anwar et al. (2006) and Sánchez-Machado et al. (2015), 0.81-1.83 meq/kg. The peroxide value of the refined oil decreased because during the neutralization stage, free fatty acids, which are precursors of these compounds, are removed (Sánchez-Machado et al., 2015). The peroxide values obtained for the crude and refined M. oleifera oil were lower than the maximum limit allowed (15 meq/kg), established by standard for edible fats and oils not regulated by individual standards. Thus, it can be used for human consumption.

A similar composition is observed when comparing the values of the free fatty acids content and physicochemical characteristics of the analyzed M. oleifera oil to the values reported for the olive oil (Allalout et al., 2009). Olive oil has a higher polyunsaturated fatty acids content; therefore, this oil presents higher iodine and peroxide values than the analyzed M. oleifera oil. Based on these results, M. oleifera oil could be used as an alternative of consumption for highly monounsaturated vegetable oils.

Conclusions

The characterization of the crude and refined oil extracted from the M. oleifera seeds from Mexico did not present acute toxicity in a murine model, however, clinical studies are suggested to confirm the security of oil human consumption.

The crude and refined M. oleifera seed oil showed that due to their oleic acid content, both could be used as an alternative for the consumption of highly monounsaturated vegetable oils. The content and ratio ω6:ω3 of fatty acids in the M. oleifera seed oil could also contribute to reaching the recommended consumption ratio of these fatty acids, generating positive effects on human health. Even though the refining process did not modify the fatty acids content of the oil, it induced the loss of carotenes and other compounds with antioxidant capacity. The oil loss percentage during this process was 45.33%. Therefore, the use of crude oil is suggested, or that during refining, the bleaching process is not carried out, thus avoiding the loss of compounds with antioxidant activity, which allow greater stability to the oil.

The methodology used can be considered useful for the quality control of this natural oil; although, of course, more analysis are necessary.

Acknowledgments

Author Viridiana Pérez-Pérez wishes to express her gratitude to Consejo Nacional de Ciencia y Tecnología CONACYT for the support provided through the scholarship program. The authors wish to thank the Instituto Politécnico Nacional - México (National Polytechnic Institute) for the financial support provided through the SIP Projects: 20196648, 20200351. and Keren Toledo Madrid for the editing and translation of this article

References

1 

Al-Anizi, A. A., Hellyer, M. T. & Zhang, D. (2014). Toxicity assessment and modelling of Moringa oleifera seeds in water purification by whole cell bioreporter. Water Res., 56, 77-87. https://doi.org/10.1016/j.watres.2014.02.045

A. A. Al-Anizi M. T. Hellyer D. Zhang 2014Toxicity assessment and modelling of Moringa oleifera seeds in water purification by whole cell bioreporterWater Res.56778710.1016/j.watres.2014.02.045

2 

Al-Said, M. S., Mothana, R. A., Al-Yahya, M. A., Al-Blowi, A. S., Al-Sohaibani, M., Ahmed, A. F. & Rafatullah, S. (2012). Edible oils for liver protection: Hepatoprotective potentiality of Moringa oleifera seed oil against chemicalinduced hepatitis in rats. J. Food Sci., 77, T124-T130. https://doi.org/10.1111/j.1750-3841.2012.02698.x

M. S. Al-Said R. A. Mothana M. A. Al-Yahya A. S. Al-Blowi M. Al-Sohaibani A. F. Ahmed S. Rafatullah 2012Edible oils for liver protection: Hepatoprotective potentiality of Moringa oleifera seed oil against chemicalinduced hepatitis in ratsJ. Food Sci.,77T124T13010.1111/j.1750-3841.2012.02698.x

3 

Allalout, A., Krichène, D., Methenni, K., Taamalli, A., Oueslati, I., Daoud, D. & Zarrouk, M. (2009). Characterization of virgin olive oil from Super Intensive Spanish and Greek varieties grown in northern Tunisia. Sci. Hortic., 120, 77- 83. https://doi.org/10.1016/j.scienta.2008.10.006

A. Allalout D. Krichène K. Methenni A. Taamalli I. Oueslati D. Daoud M. Zarrouk 2009Characterization of virgin olive oil from Super Intensive Spanish and Greek varieties grown in northern TunisiaSci. Hortic.,12077 8310.1016/j.scienta.2008.10.006

4 

Anwar, F., Zafar, S. N. & Rashid, U. (2006). Characterization of Moringa oleifera seed oil from drought and irrigated regions of Punjab, Pakistan. Grasas y Aceites, 57, 160-168. https://doi.org/10.3989/gya.2006.v57.i2.32

F. Anwar S. N. Zafar U. Rashid 2006Characterization of Moringa oleifera seed oil from drought and irrigated regions of Punjab, PakistanGrasas y Aceites57,16016810.3989/gya.2006.v57.i2.32

5 

AOCS (1997) Official Methods and Recommended Practices of the American Oil Chemists’ Society, 4th edn., edited by D. Firestone, American Oil Chemists’ Society, Champaign, IL,USA.

AOCS 1997Official Methods and Recommended Practices of the American Oil Chemists’ Society4th edn D. Firestone American Oil Chemists’ SocietyChampaign, IL,USA

6 

AOCS (2005). Official methods and recommended practices of the AOCS. 6th Ed. AOCS, Champaign, IL, USA.

AOCS 2005Official methods and recommended practices of the AOCS6th EdAOCSChampaign, IL, USA

7 

Barros, L., Ferreira, M. J., Queirós, B., Ferreira, I. C. F. R. & Baptista, P. (2007). Total phenols, ascorbic acid, β-carotene and lycopene in Portuguese wild edible mushrooms and theirantioxidant activities. Food Chem., 103, 413-419. https://doi.org/10.1016/j.foodchem.2006.07.038

L. Barros M. J. Ferreira B. Queirós I. C. F. R. Ferreira P. Baptista 2007Total phenols, ascorbic acid, β-carotene and lycopene in Portuguese wild edible mushrooms and theirantioxidant activitiesFood Chem.10341341910.1016/j.foodchem.2006.07.038

8 

Bhutada, P. R., Jadhav, A.J., Pinjari, D. V., Nemade, P. R. & Jain, R. D. (2016). Solvent assisted extraction of oil from Moringa oleifera Lam. seeds. Ind. Crops Prod., 82, 74-80. https://doi.org/10.1016/j.indcrop.2015.12.004

P. R. Bhutada A.J. Jadhav D. V. Pinjari P. R. Nemade R. D. Jain 2016Solvent assisted extraction of oil from Moringa oleifera Lam. seedsInd. Crops Prod82748010.1016/j.indcrop.2015.12.004

9 

Boukandoul, S., Casal, S., Cruz, R., Pinho, C. & Zaidi, F. (2017). Algerian Moringa oleifera whole seeds and kernels oils: Characterization, oxidative stability, and antioxidant capacity. Eur. J. Lipid Sci. Tech., 119, 1-11. https://doi.org/10.1002/ejlt.201600410

S. Boukandoul S. Casal R. Cruz C. Pinho F. Zaidi 2017Algerian Moringa oleifera whole seeds and kernels oils: Characterization, oxidative stability, and antioxidant capacityEur. J. Lipid Sci. Tech.11911110.1002/ejlt.201600410

10 

Brand-Williams, W., Cuvelier, M. E. & Berset, C. (1995). Use of a free radical method to evaluate antioxidant activity. LWT-Food Sci. Tech., 28(1), 25-30.

W. Brand-Williams M. E. Cuvelier C. Berset 1995Use of a free radical method to evaluate antioxidant activityLWT-Food Sci. Tech.28(1)2530

11 

Cater, N. B. & Denke, M. A. (2001). Behenic acid is a cholesterol-raising saturated fatty acid in humans. Am. J. Clin. Nutr., 73, 41-44. https://doi.org/10.1093/ajcn/73.1.41

N. B. Cater M. A. Denke 2001Behenic acid is a cholesterol-raising saturated fatty acid in humansAm. J. Clin. Nutr.73414410.1093/ajcn/73.1.41

12 

Chiou, A. & Kalogeropoulos, N. (2017). Virgin Olive Oil as Frying Oil. Comp. Rev. Foods Sci. Food F., 16, 632-646. https://doi.org/10.1111/1541-4337.12268

A. Chiou N. Kalogeropoulos 2017Virgin Olive Oil as Frying OilComp. Rev. Foods Sci. Food F1663264610.1111/1541-4337.12268

13 

Chivapat, S., Sincharoenpokai, P., Suppajariyawat, P., Rungsipipat, A., Phattarapornchaiwat, S. & Chantarateptawan, V. (2012). Safety evaluations of ethanolic extract of Moringa oleifera Lam. seed in experimental animals. Thai J. Vet. Med., 42(3), 343-352.

S. Chivapat P. Sincharoenpokai P. Suppajariyawat A. Rungsipipat S. Phattarapornchaiwat V. Chantarateptawan 2012Safety evaluations of ethanolic extract of Moringa oleifera Lam. seed in experimental animalsThai J. Vet. Med.42(3)343352

14 

Crexi, V. T., Monte, M. L., Soares, L. A. de S. & Pinto, L. A. A. (2010). Production and refinement of oil from carp (Cyprinus carpio) viscera. Food Chem. , 119, 945-950.

V. T. Crexi M. L. Monte L. A. de S. Soares L. A. A. Pinto 2010Production and refinement of oil from carp (Cyprinus carpio) visceraFood Chem.119945950

15 

Durmaz, G. & Gökmen, V. (2019). Effect of refining on bioactive composition and oxidative stability of hazelnut oil. Food Res. Int. 116, 586-591. https://doi.org/10.1016/j. foodchem.2009.07.050

G. Durmaz V. Gökmen 2019Effect of refining on bioactive composition and oxidative stability of hazelnut oilFood Res. Int.11658659110.1016/j. foodchem.2009.07.050

16 

Eilander, A., Harika, R. K. & Zock, P. L. (2015). Intake and sources of dietary fatty acids in Europe: Are current population intakes of fats aligned with dietary recommendations?. Eur. J. Lipid Sci. Tech. , 117, 1370-1377. https://doi.org/10.1002/ejlt.201400513

A. Eilander R. K. Harika P. L. Zock 2015Intake and sources of dietary fatty acids in Europe: Are current population intakes of fats aligned with dietary recommendations?Eur. J. Lipid Sci. Tech.1171370137710.1002/ejlt.201400513

17 

FAO/WHO (2015). Norma para Grasas y Aceites Comestibles no Regulados por Normas Individuales (CODEX STAN 19-1981). Codex Alimentarius. Normas Internacionales de los alimentos. http://www.fao.org/input/download/standards/74/CXS_019s_2015.pdf

FAO WHO 2015Norma para Grasas y Aceites Comestibles no Regulados por Normas Individuales (CODEX STAN 19-1981). Codex Alimentarius. Normas Internacionales de los alimentoshttp://www.fao.org/input/download/standards/74/CXS_019s_2015.pdf

18 

Gupta, M. K. (2017). Practical guide to vegetable oil processing. Champaign, IL, USA: AOCS Press.

M. K. Gupta 2017Practical guide to vegetable oil processingChampaign, IL, USAAOCS Press

19 

Ilesanmi, J. O., Gungula, D. T. & Nadro, M. S. (2017). Acute toxicity evaluation of mixture of neem (Azadirachta indica) and moringa (Moringa oleifera) seed oils in rats. Afr. Food Sci., 11(11), 369-375. DOI: 10.5897/AJFS2017.1619

J. O. Ilesanmi D. T. Gungula M. S. Nadro 2017Acute toxicity evaluation of mixture of neem (Azadirachta indica) and moringa (Moringa oleifera) seed oils in ratsAfr. Food Sci.11(11)36937510.5897/AJFS2017.1619

20 

Lalas, S. & Tsaknis, J. (2002). Characterization of Moringa oleifera Seed Oil Variety “Periyakulam 1.” J. Food Compos Anal, 15, 65-77. DOI:10.1006/jfca.2001.1042

S. Lalas J. Tsaknis 2002Characterization of Moringa oleifera Seed Oil Variety “Periyakulam 1J. Food Compos Anal15657710.1006/jfca.2001.1042

21 

Leone, A., Spada, A., Battezzati, A., Schiraldi, A., Aristil, J. & Bertoli, S. (2016). Moringa oleifera seeds and oil: Characteristics and uses for human health. Int. J. Mol. Sci., 17, 1-14. https://doi.org/10.3390/ijms17122141

A. Leone A. Spada A. Battezzati A. Schiraldi J. Aristil S. Bertoli 2016Moringa oleifera seeds and oil: Characteristics and uses for human healthInt. J. Mol. Sci.1711410.3390/ijms17122141

22 

Mensink, R. P., Zock, P. L., Kester, A. D. M. & Katan, M. B. (2003). Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: A meta-analysis of 60 controlled trials. Am. J. Clin. Nutr. , 77, 1146-1155. https://doi.org/10.1093/ajcn/77.5.1146

R. P. Mensink P. L. Zock A. D. M. Kester M. B. Katan 2003Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: A meta-analysis of 60 controlled trialsAm. J. Clin. Nutr.771146115510.1093/ajcn/77.5.1146

23 

OECD 423 (2001). Guidelines for the testing of chemicals. Acute oral toxicity-Fixed-dose procedure. Animals. doi.org/ 10.1787/20745788.

OECD 2001Guidelines for the testing of chemicals. Acute oral toxicity-Fixed-dose procedureAnimals10.1787/20745788

24 

Ogbunugafor, H. A., Eneh, F. U., Ozumba, A. N., IgwoEzikpe, M. N., Okpuzor, J., Igwilo, I. O., Adenekan, S. O. & Onyekwelu, O. A. (2011). Physico-chemical and antioxidant properties of Moringa oleifera seed oil. Pak J. Nutr., 10, 409-414.

H. A. Ogbunugafor F. U. Eneh A. N. Ozumba M. N. IgwoEzikpe J. Okpuzor I. O. Igwilo S. O. Adenekan O. A. Onyekwelu 2011Physico-chemical and antioxidant properties of Moringa oleifera seed oilPak J. Nutr.10409414

25 

Orsavova, J., Misurcova, L., Vavra Ambrozova, J., Vicha, R. & Mlcek, J. (2015). Fatty acids composition of vegetable oils and its contribution to dietary energy intake and dependence of cardiovascular mortality on dietary intake of fatty acids. Int. J. Mol. Sci. , 16, 12871-12890. https://doi.org/ 10.3390/ijms160612871

J. Orsavova L. Misurcova J. Vavra Ambrozova R. Vicha J. Mlcek 2015Fatty acids composition of vegetable oils and its contribution to dietary energy intake and dependence of cardiovascular mortality on dietary intake of fatty acidsInt. J. Mol. Sci.16128711289010.3390/ijms160612871

26 

Rodrigues, N., Casal, S., Peres, A. M., Baptista, P., Bento, A., Martín, H., Asensio-S.-Manzanera, M. C. & Pereira, J. A. (2018). Effect of olive trees density on the quality and composition of olive oil from cv. Arbequina. Sci. Hortic. , 238, 222-233. https://doi.org/10.1016/j.scienta.2018.04.059

N. Rodrigues S. Casal A. M. Peres P. Baptista A. Bento H. Martín M. C. Asensio-S.-Manzanera J. A. Pereira 2018Effect of olive trees density on the quality and composition of olive oil from cv. ArbequinaSci. Hortic.23822223310.1016/j.scienta.2018.04.059

27 

Rodríguez-Carpena, J. G., Morcuende, D. & Estévez, M. (2012). Avocado, sunflower and olive oils as replacers of pork back-fat in burger patties: Effect on lipid composition, oxidative stability and quality traits. Meat Sci., 90, 106-115. https://doi.org/10.1016/j.meatsci.2011.06.007

J. G. Rodríguez-Carpena D. Morcuende M. Estévez 2012Avocado, sunflower and olive oils as replacers of pork back-fat in burger patties: Effect on lipid composition, oxidative stability and quality traitsMeat Sci.9010611510.1016/j.meatsci.2011.06.007

28 

Ruttarattanamongkol, K., Siebenhandl-Ehn, S., Schreiner, M. & Petrasch, A. M. (2014). Pilot-scale supercritical carbon dioxide extraction, physico-chemical roperties and profile characterization of Moringa oleifera seed oil in comparison with conventional extraction methods. Ind. Crops Prod ., 58, 68-77. https://doi.org/10.1016/j. indcrop.2014.03.020

K. Ruttarattanamongkol S. Siebenhandl-Ehn M. Schreiner A. M. Petrasch 2014Pilot-scale supercritical carbon dioxide extraction, physico-chemical roperties and profile characterization of Moringa oleifera seed oil in comparison with conventional extraction methodsInd. Crops Prod58687710.1016/j. indcrop.2014.03.020

29 

Saini, R. K. & Keum, Y. (2018). Omega-3 and omega-6 polyunsaturated fatty acids : Dietary sources , metabolism , and significance - A review. Life Sci., 203, 255-267. https://doi.org/10.1016/j.lfs.2018.04.049

R. K. Saini Y. Keum 2018Omega-3 and omega-6 polyunsaturated fatty acids : Dietary sources , metabolism , and significance - A reviewLife Sci.20325526710.1016/j.lfs.2018.04.049

30 

Sánchez-Machado, D. I., López-Cervantes, J., Núñez-Gastélum, J. A., Servín De La Mora-López, G., LópezHernández, J. & Paseiro-Losada, P. (2015). Effect of the refining process on Moringa oleifera seed oil quality. Food Chem. , 187, 53-57. https://doi.org/10.1016/j.foodchem.2015.04.031

D. I. Sánchez-Machado J. López-Cervantes J. A. Núñez-Gastélum G. Servín De La Mora-López J. LópezHernández P. Paseiro-Losada 2015Effect of the refining process on Moringa oleifera seed oil qualityFood Chem.187535710.1016/j.foodchem.2015.04.031

31 

Siano, F., Straccia, M. C., Paolucci, M., Fasulo, G., Boscaino, F. & Volpe, M. G. (2016). Physico-chemical properties and fatty acid composition of pomegranate, cherry and pumpkin seed oils. J. Sci. Food Agric., 96, 1730-1735. https://doi.org/10.1002/jsfa.7279

F. Siano M. C. Straccia M. Paolucci G. Fasulo F. Boscaino M. G. Volpe 2016Physico-chemical properties and fatty acid composition of pomegranate, cherry and pumpkin seed oilsJ. Sci. Food Agric.96,1730173510.1002/jsfa.7279

32 

Srivastava, S. & Bhargava, A. (2012). Functional foods and nutraceuticals, Biotechnology: New Ideas, New Developments (A Textbook of Modern Technology). New York , USA: Springer.

S. Srivastava A. Bhargava 2012Functional foods and nutraceuticals, Biotechnology: New Ideas, New Developments (A Textbook of Modern Technology)New York , USASpringer

33 

Sulaiman, H. A., Ahmad, E. E. M., Mariod, A. A., Mathäus, B. & Salaheldeen, M. (2017). Effect of pretreatment on the proximate composition, physicochemical characteristics and stability of Moringa peregrina oil. Grasas y Aceites , 68 (4), e227. https://doi.org/10.3989/gya.0444171

H. A. Sulaiman E. E. M. Ahmad A. A. Mariod B. Mathäus M. Salaheldeen 2017Effect of pretreatment on the proximate composition, physicochemical characteristics and stability of Moringa peregrina oilGrasas y Aceites68(4)e22710.3989/gya.0444171

34 

Ukwueze, C. K., Okogwu, O. I., Ebem, E. C., Nwonumara, G. N. & Nwodo, J. N. (2019). Evaluation of the Influence of Geographical Location on Phytochemical Composition of Moringa oleifera Seeds. World Appl. Sci. J., 37 (3), 196-201.

C. K. Ukwueze O. I. Okogwu E. C. Ebem G. N. Nwonumara J. N. Nwodo 2019Evaluation of the Influence of Geographical Location on Phytochemical Composition of Moringa oleifera SeedsWorld Appl. Sci. J.37(3)196201

35 

Vaisali, C., Charanyaa, S., Belur, P. D. & Regupathi, I. (2015). Refining of edible oils: A critical appraisal of current and potential technologies. Int. J. Food Sci. Tech. , 50, 13-23. https://doi.org/10.1111/ijfs.12657

C. Vaisali S. Charanyaa P. D. Belur I. Regupathi 2015Refining of edible oils: A critical appraisal of current and potential technologiesInt. J. Food Sci. Tech.50132310.1111/ijfs.12657

36 

Zock, P. L., De Vries, J. H. M. & Katan, M. B. (1994). Impact of myristic acid versus palmitic acid on serum lipid and lipoprotein levels in healthy women and men. Arterioscler Thromb., 14, 567-575. DOI: 10.1161/01.atv.14.4.567

P. L. Zock J. H. M. De Vries M. B. Katan 1994Impact of myristic acid versus palmitic acid on serum lipid and lipoprotein levels in healthy women and menArterioscler Thromb.1456757510.1161/01.atv.14.4.567

37 

Zulkurnain, M., Lai, O. M., Latip, R. A., Nehdi, I. A., Ling, T. C. & Tan, C. P. (2012). The effects of physical refining on the formation of 3-monochloropropane-1, 2-diol esters in relation to palm oil minor components. Food Chem., 135, 799-805. https://doi.org/10.1016/j.foodchem.2012.04.144

M. Zulkurnain O. M. Lai R. A. Latip I. A. Nehdi T. C. Ling C. P. Tan 2012The effects of physical refining on the formation of 3-monochloropropane-1, 2-diol esters in relation to palm oil minor componentsFood Chem.13579980510.1016/j.foodchem.2012.04.144



This display is generated from NISO JATS XML with jats-html.xsl. The XSLT engine is libxslt.

Enlaces refback

  • No hay ningún enlace refback.


Financiado por:

 

Proyecto C-297282

Licencia Creative Commons
TIP Revista Especializada en Ciencias Químico-Biológicas está distribuido bajo una Licencia Creative Commons Atribución-NoComercial-SinDerivar 4.0 Internacional.

TIP REVISTA ESPECIALIZADA EN CIENCIAS QUÍMICO-BIOLÓGICAS, Volumen 24, 2021, es una publicación editada por la Universidad Nacional Autónoma de México, Ciudad Universitaria, Deleg. Coyoacán, C.P. 04510, Ciudad de México, México, a través de la Facultad de Estudios Superiores Zaragoza, Campus I, Av. Guelatao # 66, Col. Ejército de Oriente, Deleg. Iztapalapa, C.P. 09230, Ciudad de México, México, Teléfono: 55.56.23.05.27, http://tip.zaragoza.unam.mx, Correo electrónico revistatip@yahoo.com, Editor responsable: Dra. Martha Asunción Sánchez Rodríguez, Certificado de Reserva de Derechos al Uso Exclusivo del Título No. 04-2014-062612263300-203, ISSN impreso: 1405-888X, ISSN electrónico: 2395-8723, otorgados por el Instituto Nacional del Derecho de Autor, Responsable de la última actualización de este número Claudia Ahumada Ballesteros, Facultad de Estudios Superiores Zaragoza, Av. Guelatao # 66, Col. Ejército de Oriente, Deleg. Iztapalapa, C.P. 09230, Ciudad de México, México, fecha de la última modificación, 4 de febrero de 2021.

Esta página puede ser reproducida con fines no lucrativos, siempre y cuando no se mutile, se cite la fuente completa y su dirección electrónica. De otra forma requiere permiso previo de la institución.