Evaluation of nutritional profile and total antioxidant capacity of the Mediterranean diet of southern Spain

Abstract The objective of this study was to determine the antioxidant capacity of a Mediterranean diet consisting typical dishes from southern Spain. For that, a 5‐day diet was developed with typical dishes of Murcia. The antioxidant capacity of the diet was measured using ORACHF, FRAP, and DPPH methods, and the total phenolic compound content of this diet was estimated by Folin–Ciocalteu. About 50% of the antioxidant capacity and 29% of the phenolic compounds per day came from sample 14 (artichokes with ham), whereas only 1% and a 4%, respectively, proceed from sample 16 (gypsy pot). The total antioxidant capacity of the diet was estimated as 9,506.33 ET/100 g/person/day by the ORACHF method, and the total phenolic consume was estimated as 1,839.05 mg GAE/person/day. The proposed diet can be considered an excellent strategy for improving the nutritional status of the population because of its high antioxidant activity and phenolic compound content.

and phenolic compounds, and trace elements such as selenium or zinc (Guo, 2013).
Previous studies have evaluated the antioxidant and nutritional value of various typical diets from different parts of the world. In the case of Finnish population, the intake of polyphenols was estimated as 863 ± 415 mg/day, based on individual food consumption records, mainly from berries, fruits, vegetables, grain products, and beverages (Ovaskainen et al., 2008).
Mexico is now the second country in the world for obesity in the adult population and fourth for obesity in children (Dávila-Torres, González-Izquierdo, & Barrera-Cruz, 2015). Hervert-Hernández, García, Rosado, and Goñi (2011) observed that the consumption of fruits and vegetables by obese women from Mexico was below the recommended dietary intake for fruits and vegetables; however, the diet provided polyphenols and had an antioxidant capacity similar to those of the Spanish diet. Saura-Calixto and Goñi (2006) reported than the Spanish Mediterranean diet is characterized by its high antioxidant capacity (6,014 ± 3,549 µmol ET), beverages being the major source, and to a lesser extent, vegetables and fruits, with a very low contribution from cereals.
To our knowledge, there are no studies on the antioxidant capacity of specific diets containing typical dishes from specific regions of the Mediterranean area. Therefore, the overall aim of the present study was to determine the antioxidant capacity and nutritional profile of the typical gastronomy of the Region of Murcia. Moreover, it was evaluated the phenolic compound content, nutritional profile, minerals, antioxidant compounds and the antioxidant capacity of the typical dishes of Mediterranean diet of the southern Spain.
TA B L E 1 Five days diet with typical Murcian gastronomy, based on Mediterranean Diet | 3855 GONZÁLEZ GARCÍA Et AL.

| Diet
A diet for 5 days (Table 1) was elaborated with reference to the "Pyramid of Healthy Eating," based on a variety of dishes of the Murcian cuisine. Each day was divided into five intakes (breakfast, brunch, lunch, afternoon snack and dinner) and provided 2000 kcal per day, with a macronutrients profile of 15%, 35% fat and 50% carbohydrates.
The databases BEDCA (Spanish Food Composition Database) were used for the development of the diet. • M6 (yogurt with kiwi) contained kiwi and yogurt.
• M8 (whole meal toast with tomato, olive oil, and salt) was composed by whole wheat toast, grated tomato, extra virgin olive oil, and iodized salt.
• M14 (artichokes with ham) was made from artichokes, ham, onion, lemon juice, extra virgin olive oil, and salt.
• M22 (coffee with milk) was composed by semi-skimmed milk and soluble coffee.
The liquefied and minced solid samples were stored in 100 ml jars and frozen at −18°C for a week until analysis.

| Food antioxidant extraction
The methodology described by Wu, Duckett, Neel, Fontenot, and Clapham (2008) with some modifications was followed up for sample extraction. Each sample was weighed into two grams in falcon tubes of 50 and 18.5 ml of 25% ethanol were added. The tubes were placed on a magnetic shaker (TENZO M-500) and shaken for 1 hr at 680 rpm. Then, the samples were centrifuged for 4 min at 3,500 g at 4°C, using a centrifuge (Kubota Corporation). The final solution obtained after the elimination of the precipitate was filtered through hydrophilic 0.45 µm nylon filters.

| Hydrophilic ORACassay
The methodology followed was described by Prior et al. (2003).

| DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay
The method described by Brand-Williams, Cuvelier, and Berset (1995) and Sánchez-Moreno, Larrauri, & Saura-Calixto (1998) was used to construct a pattern line from the 500 µM Trolox mother solution at 10, 50, 100, 250, and 500 µM. Then, in a similar 96-well microplate to that described above, 195 µl of DPPH working solution was mixed with 5 µl of the sample or Trolox solution and the absorbance was read at the absorption maximum of 515 nm after 30 min of mixing, in the microplate reader The whole process was carried out protecting the samples from the light in order to prevent oxidation.

| Folin-Ciocalteu index (Phenolic Content Quantification)
The method described by Singleton and Rossi (1965) was used to construct the pattern line with different concentrations of gallic acid 0-20-40-60-80-100. Finally, 85 µl of Na 2 CO 3 and 100 µl of Folin-Ciocalteu reagent were mixed with 5 µl of the sample or gallic acid solution in the 96-well microplate. After 1 hr of mixing, the absorbance was read at the absorption maximum of 750 nm in the microplate reader. Throughout the process, the samples were protected from the light to prevent oxidation.  The least antioxidant sample was nº 16, whose ingredients include potatoes. Several studies have shown that potato contain bioactive compounds with antioxidant properties, such as polyphenols, ascorbic acid, carotenoids, tocopherols, and selenium (Nimse & Pal, 2015;Venereo Gutiérrez, 2002). The ingredients also include tomato, which contains flavonoids, phenolic acids, carotenoids, ascorbic acid, and vitamin E, the last one responsible for the beneficial effects associated with this food (George, Kaur, Khurdiya, & Kapoor, 2004); garlic, whose therapeutical effects (hypolipidemic, antiatherosclerotic, hypoglycemic, anticoagulant, antihypertensive, antimicrobial, and hepatoprotective) may be due to the phenolic compounds and flavonoids it contains (Bozin, Mimica-Dukic, Samojlik, Goran, & Igic, 2008); carrots, which are a good source of antioxidant compounds containing carotenes, vitamin C and phenolic compounds (Alasalvar, Grigor, Zhang, Quantick, & Shahidi, 2001); turmeric, with a high antioxidant activity due a phenolic compound named curcumin (diferuloylmethane; Kaur & Kapoor, 2002); onion and extra virgin olive oil, whose antioxidant compounds have been mentioned above. Despite

| Antioxidant capacity of the diet
The results obtained for the antioxidant capacity and total phenolic compounds for each day of the diet are shown in Table 3 capacity and phenolic compound content are attained on day one, 5,873.18 ± 0.01 ET/100 g and 1,582.22 ± 0.01 GAE/100 g. González, Periago, and Alonso (2017) determined the average intake of phenolic compounds in Spanish people as 1,365,1 mg/day, which is clearly exceeded by the 1,839.05 GAE/100 g in the case of the diet of Murcia. In the same way, Ovaskainen et al. (2008)  phenolic compounds between these countries, then, seem to be due to the different consumption patterns of each country. Tables 4 and 5 show an evaluation of the macronutrients and micronutrients of each day of the diet and the total for the 5 days. Based on the nutritional objectives established by Bartrina and Majem (2011) for macronutrients, the mean overall intake of carbohydrates, fiber, proteins, total fat, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), saturated fatty acids (SFA), and cholesterol comply with the recommendations. First, the RDA of carbohydrates in a healthy Mediterranean diet is supposed to represent between 50% and 55% of the total energy intake, so that the average consumption of 47.25% represents 94.5% of the recommendation. In the case of fiber, it is advisable to consume more than 28 g per day because of its power to reduce cholesterol levels and cardiovascular risk; the mean consumption of fiber in our diet was 37.31 g, representing 100% of the recommendations (RDA). Protein is supposed to represent 15% of the total energy intake, so that the average consumption of the days (16,97%) again represents 100% of the RDA.

| Nutritional evaluation of the diet
Lastly, total fat consumption of a balanced diet is supposed to represent between 30% and 35% of the total energy intake; in our case, therefore, because the mean consumption of fat for all the days analyzed (37.25%), contributes 100% of the fat recommendation intake.  determined by Mathioudakis (2015). The total mean intake of vitamin A suprasses the RDA and so covers 100% of the recommendations.
Another point is that the consumption is below UL levels (Tolerable Upper Intake Level). In the case of vitamin E, the average intake was 15 mg, compared to the recommended 12 mg, so that the 100% of the RDA of this vitamin is covered with the diet. Nevertheless, this level is below the UL level. Vitamin C intake was well above the recommendations (338 mg compared with the recommended 80 mg), again contributing 100% of what is needed, although the UL level has not been established for this vitamin. The level of selenium was above that recommended, with a range from 55 to 115 µg, but, at the same time, it was far below the UL; in other words, the diet covered the 100% of the RDA. Finally, the RDA of zinc (10 mg/day) was covered by the diet, and, so once again, this represents the 100% of the RDA.

ACK N OWLED G EM ENT
Thank all those who have helped in carrying out the research.

CO N FLI C T O F I NTE R E S T
The authors declare that they do not have any conflict of interest.

E TH I C A L A PPROVA L
This study does not involve any human or animal testing. Note: Results are expressed as mean values ± standard deviation. a-e: Different letters in the same column indicate that there are significant differences between the samples (p < .05). Vitamin A = µg; Vitamin E = mg; Vitamin C = mg; Zinc = mg; Selenium = µg. Abbreviation: RDA, Recommended Daily Allowances.