Bioactive compounds in Spanish extra virgin olive oils: Migration and stability according to the culinary technique used.

Extra virgin olive oil (EVOO) is a basic food of the Mediterranean diet and an important source of bioactive compounds, especially phenolic substances. The culinary techniques to which the oil is subjected before consumption cause the migration of these compounds, hence the importance of studying their stability before and after culinary treatment. We determined the behaviour of the phenols present in EVOO and its total antioxidant capacity before and after the use of various culinary techniques such as deep frying, boiling (in a water/oil mixture (W/O) and sauteing, observing that the study parameters varied according to the variety of oil and the culinary technique used. Significant statistical differences were observed between the different varieties of EVOO according to the culinary technique used. But this was not the case with respect to polyphenol content, for which no statistically significant differences were observed among the different varieties of EVOO according to the culinary techniques employed (p > 0.05), except with the Arbequina variety (p < 0.05). With respect to the individual polyphenols - tyrosol, p-vainillin, vanillic acid, gallic acid, trans-caffeic acid, ferulic acid and luteolin - our analysis shows that although there were differences in content between raw EVOO and EVOO treated with each of the culinary techniques, these differences were not statistically significant (p > 0.05). There were significant losses of oleocanthal with the W/O boiling technique, but content increases were observed following sauteing and deep frying with respect to raw EVOO. Total antioxidant capacity presented a similar pattern in all samples, with increases after sauteing and decreases after W/O boiling and deep frying. ABTS was the most suitable technique for determining antioxidant capacity in EVOO. In short, the behaviour of the bioactive compounds in EVOO depends on the temperature and the cooking medium used.

Analysis and Screening of Commercialized Protein Supplements for Sports Practice.

Recent years have seen a rise in the popularity of the consumption of sports-related supplements. However, the hypothesis is raised that it is necessary to analyze the quality aspects of these supplements in relation to the information provided on the label, to avoid associated risks and obtain the greatest possible benefit from their consumption. Therefore, the aim of this study has been to carry out an analysis or screening of the protein supplements that are currently marketed in Spain. We analyzed the labels of 52 protein sports supplements available both in physical stores and online. The analysis consisted of addressing three relevant aspects considering the labeling: (a) the legislative framework in which the supplements are marketed, (b) the quality of the protein, and (c) the presence of other ingredients according to the specifications of the label. In the legislative context, there do not seem to be any specific regulations to guarantee consumer protection, which can lead to unfair practices and misleading advertising. Most of the supplements analyzed to comply with the requirements of their current regulations. However, claims about their benefits that are not allowed under European legislation have been found in some of them. Regarding composition and according to label information, the supplements have been found to provide a sufficient dose of protein in terms of recommended protein intake per serving. Regarding the presence of other ingredients and according to the information on the label, most of them, except for egg supplements, contain other ingredients. Colostrum was also found in one of the supplements evaluated. The conclusions of the study reveal that, due to a lack of knowledge or misleading advertising practices, supplements are often not used properly. The information provided is essential for both professionals and consumers to avoid the risks associated with consumption, such as unintentional doping, interactions between ingredients that reduce the quality of the supplement, and consumption of supplements inappropriately, among others.

Migration of Avocado Virgin Oil Functional Compounds during Domestic Cooking of Eggplant.

Avocado virgin oil (AVO) was used during eggplant deep-frying, boil, and boil in a water-oil mixture (W/O). There were measured the contents of moisture, dry matter, fat, total (TPC) and ten individual phenols, antioxidant activity (ABTS and DPPH), and total sterols; as well as the profiles of eight fatty acids and fourteen sterols/stanols. The values of raw and processed foods were compared and studied with multivariate analysis. The antioxidant capacity of AVO lowered after deep frying but augmented in eggplant and water after all treatments. The TPC was steady in AVO and raised in fried eggplant. Thermal treatments added to the initial profiles of the AVO, eggplant and water, nine, eight, and four phenols, respectively. Percentages of the main fatty acids (oleic, palmitic and linoleic), and sterols (ß-sitosterol, campesterol, and Δ5-avenasterol), remained unchanged between the raw and treated AVO; and the lipidic fractions from processed eggplant. Cooking leads to the movement of hydrophilic and lipophilic functional compounds between AVO, eggplant and water. Migration of sterols and unsaturated fatty acids from AVO to eggplant during deep frying and W/O boiling improved the functional properties of eggplant by adding the high biological value lipophilic fraction to the naturally occurring polyphenols.

Melatonin and metabolic regulation: a review.

Human life expectancy has increased over the past 50 years due to scientific and medical advances and higher food availability. However, overweight and obesity affect more than 50% of adults and 15% of infants and adolescents. There has also been a marked increase in the prevalence of metabolic syndrome in recent decades, which has been associated with a reduction in nocturnal pineal production of melatonin with aging and an increased risk of coronary diseases, type 2 diabetes mellitus (T2DM) and death. Melatonin is currently under intensive investigation in experimental animal models of diabetes, obesity and MS at pharmacological doses (between 5 and 20 mg kg(-1) body weight), demonstrating its capacity to ameliorate the total metabolic profile and its potential as an alternative to conventional drug therapies for the disorders associated with the MS, i.e. elevated systolic blood pressure, and impairment of glucose homeostasis, plasma lipid profile, inflammation, oxidative stress, and increased body weight. An especially significant finding is the induction by melatonin of white adipose tissue browning, which may be related to its effects against oxidative stress, uncoupling the mitochondrial bioenergetic process by enhancing the expression of uncoupled-protein-1 (UCP-1), which has been related to body weight reduction in experimental animals. Further research is required to improve knowledge of this mechanism. Clinical studies are needed with the administration of pharmacological melatonin doses, because the dose has ranged between 0.050 and 0.16 mg kg(-1) bw in most studies to date. Melatonin is a natural phytochemical, and it is also important to test its beneficial metabolic effects when consumed in functional foods.

Serum Zn levels and Cu/Zn ratios worsen in hemodialysis patients, implying increased cardiovascular risk: a 2-year longitudinal study.

The objective of this study was to analyze serum Zn and Cu concentrations and Cu/Zn ratios in 116 hemodialysis patients (HPs) over a 2-year longitudinal study at four time points (6-month intervals). The relation exerted on these values by 26 biochemical and nutritional indexes, the age and drug consumption of the patients, and the etiology of their disease were also evaluated. A healthy control group (n = 50) was also studied. Mean serum Zn concentrations were lower (p = 0.009) and the Cu/Zn ratios higher (p = 0.009) in HPs than in controls. Serum Cu levels in HP did not differ to those of controls. At all four sampling times, the mean serum Zn levels and Cu/Zn ratios were lower and higher, respectively, in HPs than in the controls. There was a significant reduction in serum Zn levels and an increase in Cu concentrations and Cu/Zn ratios in HPs from the second to the fourth sampling. Serum Zn levels of the HPs diminish with age older than 50 years. Serum Cu levels were significantly higher in patients consuming antihypercalcemic or anti-infarction drugs, whereas serum Cu levels and Cu/Zn ratios were significantly lower in those treated with diuretics. Diminished Zn levels were negatively correlated with low-density lipoprotein (LDL) cholesterol in HPs; however, enhanced Cu/Zn ratios were positively correlated with total cholesterol and LDL cholesterol. Both findings indicate an increased cardiovascular risk. We conclude that this study contributes the first evidence of a correlation between marked dyslipidemia and worsened Cu/Zn ratios in HPs, implying an increased risk of diseases associated with elevated oxidative stress, inflammation, and depressed immune function, such as cardiovascular diseases.

Melatonin administration in diabetes: regulation of plasma Cr, V, and Mg in young male Zucker diabetic fatty rats.

The use of melatonin, a neurohormone present in plants, represents an exciting approach for the maintenance of optimum health conditions. Melatonin administration ameliorates glucose homeostasis in Zucker diabetic fatty (ZDF) rats. The objective of this study was to investigate the effects of melatonin in diabetes in relation to the levels and regulation of plasma chromium (Cr), vanadium (V), and magnesium (Mg) in Zucker diabetic fatty (ZDF) and Zucker lean (ZL) rats. At the age of 6 weeks, ZDF (n = 30) and ZL (n = 30) groups were each subdivided into three groups: control (C) (n = 10), vehicle-treated (V') (n = 10) and melatonin-treated (M) (10 mg kg(-1) per day; n = 10) groups for a 6 week period. After treatment, plasma mineral concentrations were measured by flame (Mg) and electrothermal (Cr and V) atomic absorption spectrometry. No significant differences were found between the C and V' groups (p > 0.05). Plasma Mg levels were significantly lower in C-ZDF vs. C-ZL rats, demonstrating the presence of hypomagnesemia in this diabetes mellitus model. Plasma V and Cr levels were significantly higher in M-ZDF vs. C-ZDF rats. Plasma Mg levels in ZDF rats were not affected by melatonin treatment (p > 0.05). Melatonin administration ameliorates the diabetic status of ZDF rats by enhancing plasma Cr and V concentrations. This appears to be the first report of a beneficial effect of melatonin treatment on plasma Cr and V regulation in ZDF rats.

Antioxidant activity of melatonin in diabetes in relation to the regulation and levels of plasma Cu, Zn, Fe, Mn, and Se in Zucker diabetic fatty rats.

OBJECTIVE: To study the antioxidant activity of melatonin in diabetes in relation to the regulation and levels of plasma copper (Cu), zinc (Zn), iron (Fe), manganese (Mn), and selenium (Se) in Zucker diabetic fatty (ZDF) and lean (ZL) rats. METHODS: At 6 wk of age, both ZDF (n = 30) and ZL (n = 30) animals were subdivided into three groups: control (C) (n = 10), vehicle (V) (n = 10), and melatonin-treated (M) (10 mg/kg/d; n = 10) rats for a 6-wk period. At the end of treatment period, plasma mineral levels were measured by flame (Cu, Zn, and Fe), electrothermal (Mn), and hydride generation (Se) atomic absorption spectrometry. RESULTS: ZDF rats had significantly higher Cu, Fe, and Mn plasma levels than did ZL rats (P < 0.05). No significant differences were found between control and vehicle groups (P > 0.05). Melatonin treatment did not influence plasma levels of these antioxidant minerals (Cu, Zn, Fe, and Mn) in ZDF groups (M-ZDF versus C-ZDF group) and ZL (M-ZL versus C-ZL group) rats with the exception of Zn, whose mean plasma level was lower in the M-ZL versus C-ZL group. However, plasma Se levels increased significantly (P < 0.05) after melatonin supplementation in both groups (M-ZDF and M-ZL). CONCLUSION: The higher mean plasma Cu, Fe, and Mn levels in the ZDF group are related to the enhanced oxidative stress in diabetes and obesity. Melatonin administration significantly enhanced plasma Se levels in both groups (M-ZDF and M-ZL). This is the first study to report that melatonin treatment increases plasma Se levels.