Hybrid palm oil (Elaeis oleifera ... - Wiley Online Library

Eur. J. Lipid Sci. Technol. 2017, 119, 1600070

1600070 (1 of 8)

Research Article Hybrid palm oil (Elaeis oleifera Elaeis guineensis) supplementation improves plasma antioxidant capacity in humans Myriam Ojeda1, Martha Borrero1, Gonzalo Sequeda2, Ofelia Diez3, Vivian Castro1, Angela Garcıa1, 4 5 5 5 6 Alvaro Ruiz , Deborah Pacetti , Natale Frega , Riccardo Gagliardi and Paolo Lucci 1

2 3 4 5 6

Faculty of Sciences, Department of Nutrition and Biochemistry, Pontificia Universidad Javeriana, Bogota D.C., Colombia Faculty of Sciences, Department of Chemistry, Pontificia Universidad Javeriana, Bogota D.C., Colombia Faculty of Sciences, Department of Microbiology, Pontificia Universidad Javeriana, Bogota D.C., Colombia Department of Internal Medicine, School of Medicine, Pontificia Universidad Javeriana, Bogota D.C., Colombia Politecnica delle Marche, Ancona, Italy Department of Agricultural, Food, and Environmental Sciences, Universita Department of Agri-Food, Animal and Environmental Sciences, University of Udine, Udine, Italy

Hybrid palm oil obtained from interspecific hybrid Elaeis oleifera Elaeis guineensis palm (HPO) has been recently proved to have a favorable impact on human plasma lipids related to cardiovascular disease risk factors. In the present work, we describe for the first time, the functional effect of crude HPO supplementation on human antioxidant plasma/serum status as assessed by the total phenolic content (Folin–Ciocalteu), ORAC and TEAC assays. One hundred sixty eligible participants (>50 years) were randomized and assigned to one of the two treatments: 25 mL hybrid palm oil (HPO group) or 25 mL extra virgin olive oil (EVOO group) daily for 3 months. This study showed that supplementation of 25 mL of HPO for a period of 3 months significantly increased (p < 0.01) the total phenolic content (19.2%) as well as the antioxidant capacity of human plasma measured by both ORAC (92.1%) and TEAC (42.9%) methods. Furthermore, no significant differences were found between HPO and EVOO groups in a repeated measures analysis of variance for TPC (p ¼ 0.344), TEAC (p ¼ 0.217), and ORAC (p ¼ 0.318) values. These results confirm that HPO can be considered a promising tropical edible oil with potential beneficial health effects. Practical applications: The understanding of the antioxidant properties of an edible oil in vivo is of primary importance when evaluating its nutritional/functional characteristics and/or its potentiality to serve as an active ingredient for functional food preparations. The results of this study confirm that HPO can be considered a promising tropical edible oil with beneficial health properties since it is able to improve the antioxidant status of plasma in humans. Keywords: Dietary antioxidants / Extra virgin olive oil / Functional ingredient / Hybrid palm oil / Phenols

Received: February 5, 2016 / Revised: April 18, 2016 / Accepted: April 28, 2016 DOI: 10.1002/ejlt.201600070 Correspondence: Paolo Lucci, Department of Agri-Food, Animal and Environmental Sciences, University of Udine, via Sondrio 2/a, 33100 Udine, Italy E-mail: [email protected]; [email protected] Fax: þ39 0432 558130 Abbreviations: AAPH, 2,20 -azobis(2-amidinopropane)dihydrochloride; ABTS, 2,20 -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid); ANOVA, analysis of variance; BMI, body mass index; CVD, cardiovascular diseases; EVOO, extra virgin olive oil; GAE, gallic acid equivalents; HPO, hybrid palm oil; ORAC, oxygen radical absorbance capacity; TEAC, trolox equivalent antioxidant capacity; TPC, total phenolic content ß 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

1 Introduction Antioxidants are compounds that can prevent or delay the oxidation of other molecules by inhibiting the initiation or propagation of oxidizing chain reactions [1, 2]; this allows The study was conducted in accordance with the guidelines from the Declaration of Helsinki, and all procedures involving human participants were approved by the Research Ethics Committee of the Pontificia Universidad Javeriana (Acta # 11; 21-06-2011).

www.ejlst.com

1600070 (2 of 8)

M. Ojeda et al.

them to protect the body from possibly harmful effects of free radicals and other reactive oxygen species [3]. According to their origin, antioxidants can be mainly divided into two groups: endogenous, those synthesized by the body, or exogenous, which are delivered through the intake of food. Over the last two decades, there has been considerable scientific interest in the role of dietary antioxidants in human health and disease. The evidence now suggests that antioxidants ingested orally via the diet play an important role in decreasing the development of the most prevalent chronic diseases worldwide, such as cardiovascular, neoplastic, and neurodegenerative disease [4]. The food substances to which have mainly been attributed this action are vitamin E, vitamin C, b-carotene, lycopene, and polyphenols, among others. Within this context, edible oils, which are an integral part of human diets, may have strong implications for health and nutrition. In general, unrefined vegetable oils can provide significant levels of antioxidants and other bioactive compounds with functional properties. Among these vegetable oils, extra-virgin olive oil (EVOO) stands out as an extraordinary source of nutraceutical antioxidants, such as polyphenols, that have been proven to play an important role in the prevention of diseases associated with oxidative damage such as cardiovascular diseases, stroke, atherosclerosis, cancer, infarction, chronic inflammation, septic shock, aging, and other degenerative diseases in humans [5–11]. On the other hand, recent advances in research on hybrid palm oil (HPO) are providing evidence to support the concept that HPO, a crude oil obtained from the fruits of the interspecific hybrid (Elaeis oleifera Elaeis guineensis) palm, can be seen as the “tropical equivalent of olive oil” [12]. In our previous investigation, we found that HPO consumption had a favorable effect on plasma lipids pattern related to cardiovascular risk factors and that this effect was not statistically different from that of EVOO [13]. Such positive result can be largely attributed not only to the high percentage of oleic acid and low saturated fatty acid content of HPO but also to the high amount of dietary antioxidant compounds it may provide, such as carotenes, tocopherols, and tocotrienols. For instance, the latter compounds, which are now recognized for their superior antioxidant activity, account for 24 mg/100 g of HPO and constitute 90% of the total HPO tocol fraction [14, 15]. Recently, HPO extracts have also been shown to possess good levels of phenolic compounds, as well as significant antioxidant activity in vitro [16]. On the other hand, HPLC-ESI-MS/ MS experiments revealed p-salicylic acid, syringic acid, syringaldehyde, and vanillic acid as predominant phenolic compounds. Therefore, in light of the previous findings, and in order to obtain additional information about the functional properties of this promising hybrid palm oil, the present study was undertaken to explore, for the first time, the potential beneficial impact of daily HPO consumption ß 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


(25 mL/day for 3 months) on plasma/serum antioxidant capacity (TEAC and ORAC assays) and total phenolic content (Folin–Ciocalteu) in adults aged 50–77 who are particularly vulnerable to heart disease. For this purpose, the results obtained were also compared to those achieved from individuals who received an equivalent amount of extravirgin olive oil, which is widely recognized for its beneficial effects on health, most of which are because of its antioxidant properties [17, 18].

2 Materials and methods 2.1 Subjects The participant enrollment and intervention procedures have already been described elsewhere [13]. Briefly, eligible participants were community-dwelling men and women, aged 50 years. The selection of subjects was based on the following inclusions criteria: (i) signed written informed consent; (ii) stable dose of statins (for patients receiving statin therapy). Exclusion criteria were desire to not participate in the study, prior cardiovascular disease, any severe chronic illness (not related to cardiovascular risk), drug or alcohol addiction, and history of allergy to olive or palm oils. Participants receiving statin were included in this study because the treatment of dyslipidemia, which is a wellestablished risk factor for developing CVD, may prevent development and progression of the heart disease. Therefore, in addition to therapeutic strategies (i.e., statin therapy), appropriate management and treatment of dyslipidemia, including dietary recommendations and guidelines, is essential. Enrollment was performed at the Polideportivo La Andrea, in the locality of USME (Bogota – Colombia). Eligible subjects provided written-informed consent and were then randomized to one of two supplementation groups and scheduled for the baseline visit (see Section 2.2). The study was conducted in accordance with the guidelines from the Declaration of Helsinki, and all procedures involving human participants were approved by the institutional ethical committee of the Pontificia Universidad Javeriana (Acta # 11; 21-06-2011).

2.2 Intervention Participants (n ¼ 160) were randomly assigned following simple randomization table to a rich extra-virgin oil (EVOO) diet (n ¼ 82), or hybrid palm oil-rich (HPO) diet (n ¼ 78). During the interventional period, the participants were required to take 25 mL/day of crude HPO or EVOO, depending on the group assignment. The duration of supplementation trial was 3 months. Oil supplements, that were not submitted to any cooking or thermal processes, were added to lunch and dinner meals, always paying special attention to consume the entire amount of oil added. The www.ejlst.com


O G palm oil improves human plasma antioxidant status

volunteers were advised to maintain their usual diet. Thus, as also expected considering the typical Colombian diet of the study population, data from interviews with participants showed that HPO or EVOO were mainly incorporated into ready meals such as rice, meat, vegetable, and bread. Individual visits were repeated every 1 month. Each baseline and follow-up visit included: (i) a simplified assessment of adherence to the supplementation diet; (ii) 24-h recall and food frequency questionnaire with foods plus vitamin supplements and alcohol consumption; (iii) physical activity questionnaire; (iv) measurement of weight, height, and waist circumference; (v) collection of fasting blood samples after an overnight fast of 12 h; (vi) a general questionnaire collecting information on medication use; and (vii) oil delivery.

1600070 (3 of 8)

standard, absorbance at l ¼ 734 nm was measured and the total antioxidant activities of samples were then expressed in Trolox equivalents (mM eq Trolox/L plasma).

2.4.3 Oxygen radical absorbance capacity (ORAC) assay

Blood sampling was performed in the morning after a 12-h overnight fast. Samples were drawn into EDTA tubes and centrifuged at 3000 rpm for 10 min at 4°C within 2 h of collection to separate cells from plasma. Plasma samples were then stored at 80°C for later analyses. All samples were analyzed blind in triplicate.

This assay was based on the decrease in fluorescein fluorescence caused by a peroxyl radical generating compound [20, 22]. The analysis was performed using a microplate spectrophotometer FLUOstar Optima (BMG Labtech), fluorescein as a target of free radical attack and AAPH as a peroxyl radical generator. Trolox was used as a control standard. For the analysis, serum samples (obtained as explained in Section 2.4.1) were diluted in a 75 mM phosphate buffer solution, pH 7.4. All the procedure ( 0.05). Apparently, in individuals who consumed HPO, ORAC values increased at a higher rate than in EVOO subjects. In all cases, regardless of the type of oil consumed, a final significant increase of ORAC measurements have been observed through the study (Fig. 3).

Table 1. Changes in total phenolic content and antioxidant capacity during the 3-months of HPO or EVOO oil supplementation

Baseline

Variable TPC mg GAE/L TEAC mmol eq Trolox/L ORAC mmol eq Trolox/L

Month 1

Month 2

Month 3

EVOO (n ¼ 82)

HPO (n ¼ 78)

EVOO (n ¼ 81)

HPO (n ¼ 73)

EVOO (n ¼ 76)

HPO (n ¼ 73)

EVOO (n ¼ 77)

HPO (n ¼ 68)

355 (34) 1926 (330) 2116 (532)a

359 (39) 1812 (390) 1886 (462)b

388 (39) 2112 (330) 2619 (444)

381 (48) 2040 (380) 2535 (548)

416 (35) 2343 (230) 3184 (476)

411 (39) 2304 (250) 3140 (629)

424 (36) 2564 (310) 3714 (618)

428 (37) 2590 (260) 3624 (609)

Baseline versus month 3 p-value

EVOO HPO p-Value •

•

0.344

•

•

0.217

•

•

0.318

Sample sizes in parenthesis; data are expressed as mean (standard deviation). EVOO, extra-virgin olive oil; HPO, hybrid palm oil. Different letters in the same row indicate statistical significance of differences between treatment groups at baseline (p < 0.05); number of participants who were receiving stable doses of statin across the study: EVOO (n ¼ 37), HPO (n ¼ 39). p-Value for univariate analysis [(considering only the treatment effect and not interactions; significance (p < 0.01) ¼ •]. p-Value for multivariate analysis [(considering interactions among visits and treatment; significance (p < 0.05)]. ß 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

www.ejlst.com



1600070 (5 of 8)

Figure 1. Changes in serum total phenolic content determined by using the Folin–Ciocalteu assay during the 3-months of EVOO or HPO oil supplementation; means without a common letter (a–d) indicate significantly different values (p < 0.05).

Finally, the repeated measures ANOVA shows that no differences were detected between HPO and EVOO groups for both TEAC (p ¼ 0.217) and ORAC (p ¼ 0.318) when the interaction between treatment and visits was taken into account (Table 1).

4 Discussion Recent studies have suggested that the consumption of foods rich in antioxidants is inversely related to the risk of cardiovascular disease, cancer, and other chronic diseases [23]. However, the consumption of a particular food with high antioxidant content is not necessarily indicative of highly attained levels of plasma antioxidant capacity in an individual. For instance, Prior et al. [24] found that after consuming meals rich in antioxidants (i.e., berries, grape, cherry, and strawberry), the antioxidant capacity of plasma increased significantly and concluded that this increase was probably dependent not only on the food antioxidant capacity, the type and quantity of the phytochemicals consumed via the food but also on the absorption and

metabolism of such dietary antioxidants. In fact, the bioavailability of these substances differ upon intestinal absorption and can both directly or indirectly affect antioxidant processes through signaling pathways, cytokine and receptors, among others that may protect cells from damage caused by free radicals. Therefore, the study of changes in the plasma antioxidant capacity and total phenolic content after supplementation with a particular food may provide usefulness information also on the absorption and bioavailability of its antioxidant compounds. In the present work, we describe for the first time, the functional effect of crude hybrid palm oil (E. oleifera E. guineensis) supplementation on human antioxidant plasma status. A daily supplementation with 25 mL of HPO for 3 months greatly improves the redox state of the studied subjects. The experimental evidence includes a remarkable improvement in serum levels of total phenolic compounds together with a considerable increase of antioxidant capacity measured by both TEAC and ORAC assays. Furthermore, HPO was shown to have similar effects to EVOO, which can be in many ways considered the “gold standard” among all edible oils because of its nutraceutical and functional properties. In fact,

Figure 2. Changes in plasma antioxidant capacity measured by TEAC assay during the 3-months of EVOO or HPO oil supplementation; means without a common letter (a–d) indicate significantly different values (p < 0.05). ß 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

www.ejlst.com

1600070 (6 of 8)

M. Ojeda et al.


Figure 3. Changes in serum antioxidant activity measured by ORAC assay during the 3-months of EVOO or HPO oil supplementation; means without a common letter (a–d) indicate significantly different values (p < 0.05).

in addition to the high content of oleic acid, EVOO also represent an extremely rich dietary source of antioxidants and numerous other phytochemicals. For instance, EVOO contains high quantities of phenolic compounds including simple phenols, lignans, and secoiridoids that are of considerable interest due to their antioxidant properties, and whose consumption has been associated with several biological activities [25]. On the other hand, palm oil, which is mainly extracted from the fruit of the African oil palm (E. guineensis Jacq.), was often held up as unhealthy edible oil and/or food ingredient because of its high content of saturated fatty acids. However, a new type of palm oil obtained from interspecific hybrid E. oleifera E. guineensis palm (HPO) is currently receiving increasing attention because it provides a crude oil that contains significantly higher amount of tocotrienols and oleic acid together with lower amounts of saturated fatty acids than the traditional African palm oil (E. guineensis) [12–16]. Furthermore, because of its higher degrees of unsaturation, HPO can be consumed without the need for refining and fractionation processes usually required for African palm oil to separate olein and stearin fractions. This also means that crude-unrefined HPO maintains all its health promoting and antioxidant compounds such as b-carotene, tocotrienols, tocopherols, and phenols whose protective effects against lipid peroxidation has already been reported [26]. Previous studies have also reported the use of red palm olein, a refined fraction of palm oil, for preparing antioxidant vitamins-rich (tocopherols and tocotrienols) functional foods [27, 28]. However, no information was available in the scientific literature on the functional effects of crude HPO consumption on phenol content neither on the antioxidant capacity of human plasma. And this study, which therefore represented a first attempt to fill this void, showed that dietary supplementation with 25 mL of crude HPO may increase serum TPC by approximately 19.2%. Our trial also demonstrated that the antioxidant capacity measured by TEAC and ORAC assays significantly increased in both HPO and EVOO groups. In ß 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

fact, TEAC values greatly increased (42.9%) in individuals who consumed 25 mL of HPO for 3 months. Interesting results were also recorded when performing ORAC assay: the results showed a final increase of 92.1 and of 75.5% for HPO and EVOO group, respectively. Other researchers have previously evaluated the intake of other types of antioxidantrich foods and increased plasma antioxidant capacity [29–32]. For instance, the daily intake of total antioxidants from fruit and vegetables in human subjects has been found to be significantly correlated with the fasting plasma ORAC, and that increasing consumption of fruit and vegetables from the usual five to the experimental ten servings/d resulted in a significant increase in plasma ORAC [33]. More recently, Oliveras-L opez et al. [34] evaluated the effects of EVOO consumption on antioxidant capacity (TAC) of plasma in elderly subjects, thus revealing that TAC in plasma significantly increased after the 6-week consumption of olive oil. However, it is somewhat difficult to compare our findings with other results published by other investigators because no studies have been specifically conducted on palm oil. Once again, however, one of the most interesting results of the study is that HPO had a similar effect on plasma/serum antioxidant capacity than EVOO. In fact, as already observed in TPC, there were no significant differences overall between the TEAC values observed in EVOO and HPO groups. On the other hand, while individuals randomly assigned to HPO had significantly lower initial ORAC values, final measurements at the end of the study revealed similar levels in both groups (without any statistical differences) as a result of the higher increase of ORAC values in HPO group (92.1%) than in EVOO group (75.5%) through the study.

5 Conclusions HPO has been recently showed to have a favorable impact on human plasma lipids related to CVD risk factors. With the present study, we showed that hybrid palm oil exerts an www.ejlst.com



additional beneficial biochemical effect such as the improvement of the antioxidant status and can serve as a promising tropical edible oil and/or ingredient for functional food preparations. The consumption of 25 mL of hybrid palm oil for a period of 3 months has been shown, for the first time, to significantly increase the total phenolic content as well as the antioxidant capacity of human plasma/serum in adults (aged 50–77), who represent a particularly vulnerable population as heart disease-related morbidity and mortality both increase with age. Furthermore, no statistical differences have been revealed comparing HPO behavior with that of EVOO, which is a worthy star of the healthy Mediterranean diet. However, also considering that palm oil is currently the most consumed edible oil in the worlds, further trials of longer duration should be conducted to confirm the effect of prolonged HPO consumption on antioxidant plasmatic status and its potentially cardiovascular protective properties. The authors acknowledge the project “PALM OIL AND CARDIOVASCULAR DISEASE: Effects of red palm oleinrich diet on plasma lipid pattern in hypercholesterolemic patients” [project ID 4735–Pontificia Universidad Javeriana (Bogot a – Colombia)] and the Hacienda La Caba~ na (Bogot a – Colombia) for their donation of oil samples. The authors would also like to thank Vanessa Olaya for her contribution to blood sample collection. The authors have declared no conflicts of interest.

References [1] Halliwell, B., Whiteman, M., Measuring reactive species and oxidative damage invivo and in cell culture: how should you do it and what do the results mean? Br. J. Pharmacol. 2004, 142, 231–255. [2] Gutteridge, J. M. C., Halliwell, B., Antioxidants: Molecules, medicines, and myths. Biochem. Bioph. Res. Commun. 2010, 393, 561–564. [3] Chaudiere, J., Ferrari-Iliou, R., Intracellular antioxidants: From chemical to biochemical mechanisms. Food. Chem. Toxicol. 1999, 37, 949–962. [4] N€alsen, C., Basu, S., Wolk, A., Vessby, B., The importance of dietary antioxidants on plasma antioxidant capacity and lipid peroxidation in vivo in middle-aged men. Scand. J. Food. Nutr. 2006, 50, 64–70. [5] Ninfali, P., Aluigi, G., Bacchiocca, M., Magnani, M., Antioxidant capacity of extra-virgin olive oils. J. Am. Oil Chem. Soc. 2001, 78, 243–247. [6] Visioli, F., Galli, C., Galli, G., Caruso, D., Biological activities and metabolic fate of olive oil phenols. Eur. J. Lipid Sci. Technol. 2002, 104, 677–684. [7] Stark, A. H., Madar, Z., Olive oil as a functional food: Epidemiology and nutritional approaches. Nutr. Rev. 2002, 60, 170–176. [8] Tuck, K. L. P., Hayball, J., Major phenolic compounds in olive oil: Metabolism and health effects. J. Nutr. Biochem. 2002, 13, 636–644. ß 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

1600070 (7 of 8)

[9] Caramia, G., Gori, A., Valli, E., Cerretani, L., Virgin olive oil in preventive medicine: From legend to epigenetics. Eur. J. Lipid Sci. Technol. 2012, 114, 375–388. [10] Wahrburg, W., Kratz, M., Cullen, P., Mediterranean diet, olive oil and health. Eur. J. Lipid Sci. Technol. 2002, 104, 698–705. [11] Huang, C. L., Sumpio, B. E., Olive oil, the Mediterranean diet, and cardiovascular health. J. Am. Coll. Surg. 2008, 207, 407–416. [12] Mozzon, M., Pacetti, D., Lucci, P., Balzano, M., Frega, N. G., Crude palm oil from interspecific hybrid Elaeis oleifera x Elaeis guineensis: Fatty acid regiodistribution and molecular species of glycerides. Food Chem. 2013, 141, 245–252. [13] Lucci, P, Borrero, M., Ruiz, A., Pacetti, D., et al., Palm oil and cardiovascular disease: A randomized trial of the effects of hybrid palm oil supplementation on human plasma lipid pattern. Food Funct. 2016, 7, 347–354. [14] Mozzon, M., Frega, N. G., Pacetti, D., Lucci, P., Crude palm oil from interspecific hybrid Elaeis oleifera Elaeis guineensis: Alcoholic constituents of unsaponificable matter. J. Am. Oil Chem. 2015, 141, 245–252. [15] Lucci, P., Pacetti, D., Frega, N. G., Mozzon, M., Phytonutrient concentration and unsaturation of glycerides predict optimal harvest time for Elaeis oleifera E. guineensis palm oil hybrids. Eur. J. Lipid Sci. Technol. 2015, 117, 1027–1036. ~ ez, O., et al., [16] Rodrıguez, J. C., G omez, D., Pacetti, D., N un Effects of the fruit ripening stage on antioxidant capacity, total phenolics, and polyphenolic composition of crude palm oil from interspecific hybrid Elaeis oleifera Elaeis guineensis. J. Agr. Food Chem. 2016, 64, 852–859. [17] Covas, M.-I., Ruiz-Gutierrez V., de la Torre, R., Kafatos, A., et al., Minor components of olive oil: Evidence to date of health benefits in humans. Nutr Rev. 2006, 64, S20–S30. [18] Cicerale, S., Lucas, L., Keast, R., Biological activities of phenolic compounds present in virgin olive oil. Int. J. Mol. Sci. 2010, 11, 458–479. [19] Singleton, V. L., Rossi, J. A., Colorimetry of total phenolics with phosphomolybdic-phosphotungstic acid reagents. Am. J. Enol. Viticult. 1965, 16, 144–158. [20] Cao, G., Russell, R. M., Lischner, N., Prior, R. L., Serum antioxidant capacity is increased by consumption of strawberries, spinach, red wine or vitamin C in elderly women. J. Nutr. 1998, 128, 2383–2390. [21] Miller, N. J., Rice-Evans, C. A., Davies, M. J., Gopinathan, V., Milner, A., A novel method for measuring antioxidant capacity and its application to monitoring antioxidant status in premature neonates. Clin. Sci. 1993, 84, 407–412. [22] Ou, B., Hampsch-Woodill, M., Prior, R. L., Development and validation of an improved oxygen radical absorbance capacity assay using fluorescein as the fluorescent probe. J. Agr. Food Chem. 2001, 49, 4619–4626. [23] Griep, L. M. O., Verschuren, W. M. M., Kromhout, D., Ocke, M. C., Geleijnse, J. M., Raw and processed fruit and vegetable consumption and 10-year stroke incidence in a population-based cohort study in the Netherlands. Eur. J. Clin. Nutr. 2011, 65, 791–779. [24] Prior, R. L., Gu, L., Wu, X., Jacob, R. A., et al., Plasma antioxidant capacity changes following a meal as a measure of the ability of a food to alter in vivo antioxidant status. J. Am. Coll. Nutr. 2007, 26, 170–181. www.ejlst.com

1600070 (8 of 8)

M. Ojeda et al.

[25] Servili, M., Esposto, S., Fabiani, R., Urbani, S., et al., Phenolic compounds in olive oil: Antioxidant, health and organoleptic activities according to their chemical structure. Inflammopharmacology 2009, 17, 76–84. [26] Jierong, Y., Andersen, M. L., Skibsted, L. H., Interactions between tocopherols, tocotrienols and carotenoids during autoxidation of mixed palm olein and fish oil. Food Chem. 2011, 127, 1792–1797. [27] El-Hadad Nesma, N. M., Youssef, M. M., Abd El-Aal, M. H., Abou-Gharbia, H. H., Utilisation of red palm olein in formulating functional chocolate spread. Food Chem. 2011, 124, 285–290. [28] Al-Saqer, J. M., Sidhu, J. S., Al-Hooti, S. N., Al-Amiri, H. A., et al. Developing functional foods using red palm olein. IV. Tocopherols and tocotrienols. Food Chem. 2004, 85, 579–583. [29] Fit o, M., De la Torre, R., Farre-Albaladejo, M., Khymenetz, O., et al., Bioavailability and antioxidant effects of olive oil phenolic compounds in humans: A review. An Sist Sanit Navar. 2007, 31, 375–381.

ß 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


[30] Natella, F., Nardini, M., Giannetti, I., Dattilo, C., Scaccini, C., Coffee drinking influences plasma antioxidant capacity in humans. J. Agr. Food Chem. 2002, 50, 6211–6216. [31] Schirrmacher, G., Skurk, T., Hauner, H., Grassmann, J., Effect of Spinacia oleraceae L. and Perilla frutescens L. on antioxidants and lipid peroxidation in an intervention study in healthy individuals. Plant Foods Hum. Nutr. 2010, 65, 71–76. [32] Dıaz-Rubio, M. E., Perez-Jimenez, J., Martınez-Bartolome, Alvarez, M. A., I., Saura-Calixto, F., Regular consumption of an antioxidant-rich juice improves oxidative status and causes metabolome changes in healthy adults. Plant Foods Hum. Nutr. 2015, 70, 9–14. [33] Cao, G., Booth, S. L., Sadowski, J. A., Prior, R. L., Increases in human plasma antioxidant capacity after consumption of controlled diets high in fruit and vegetables. Am. J. Clin. Nutr. 1998, 68, 1081–1087. [34] Oliveras-L opez, M. J., Molina, J. J., Mir, M. V., Rey, E. F., et al., Extra virgin olive oil (EVOO) consumption and antioxidant status in healthy institutionalized elderly humans. Arch. Gerontol. Geriatr. 2013, 57, 234–242.

www.ejlst.com