Nalda Romero

Study of some physicochemical and functional properties of quinoa (Chenopodium quinoa willd) protein isolates

The amino acid composition and the physicochemical and functional properties of quinoa protein isolates were evaluated. Protein isolates were prepared from quinoa seed by alkaline solubilization (at pH 9, called Q9, and at pH 11, called Q11) followed by isoelectric precipitation and spray drying. Q9 and Q11 had high levels of essential amino acids, with high levels of lysine. Both isolates showed similar patterns in native/SDS-PAGE and SEM. The pH effect on fluorescence measurements showed decreasing fluorescence intensity and a shift in the maximum of emission of both isolates. Q9 showed an endotherm with a denaturation temperature of 98.1 degrees C and a denaturation enthalpy of 12.7 J/g, while Q11 showed no endotherm. The protein solubility of Q11 was lower than that of Q9 at pH above 5.0 but similar at the pH range 3.0-4.0. The water holding capacity (WHC) was similar in both isolates and was not affected by pH. The water imbibing capacity (WIC) was double for Q11 (3.5 mL of water/g isolate). Analysis of DSC, fluorescence, and solubility data suggests that there is apparently denaturation due to pH. Some differences were found that could be attributed to the extreme pH treatments in protein isolates and the nature of quinoa proteins. Q9 and Q11 can be used as a valuable source of nutrition for infants and children. Q9 may be used as an ingredient in nutritive beverages, and Q11 may be used as an ingredient in sauces, sausages, and soups.

Comparative study of virgin olive oil quality from single varieties cultivated in Chile and Spain

Olive tree varieties that were cultivated only in the Mediterranean basin a few decades ago are now planted in the Southern Hemisphere as well. The chemical composition of the oils produced in countries as far distant as Spain and Chile are affected by differences in latitude and climate. In this work, seven monovarietal virgin olive oils from Chile (Arbequina, Barnea, Frantoio, Koroneiki, Leccino, Manzanilla and Picual) have been characterized by the chemical compounds responsible for taste (phenols) and aroma (volatiles). The oils were produced in five regions of Chile, and the concentration values of some chemical compounds were related to the geographical location of the olive tree orchards. Virgin olive oils from the major cultivars, Arbequina and Picual, were characterized in comparison with the same monovarietal oils produced in Spain. The concentration values of fourteen volatile compounds showed significant differences (p < 0.05) between the oils produced in Spain and Chile. Concerning the phenol composition, main differences were found on the secoiridoids derivatives of oleuropein and ligstroside, apigenin and luteolin.

Influence of agroclimatic parameters on phenolic and volatile compounds of Chilean virgin olive oils and characterization based on geographical origin, cultivar and ripening stage

BACKGROUND This study involved two commercial orchards located in Limarí Valley and Molina from two important Chilean production zones of extra virgin olive oil (EVOO). The investigation evaluated the effects of climate, soil composition, agricultural practices (fertilization and irrigation) and variety (considering two harvests) on the compounds responsible for the flavor of EVOO (volatiles and phenols) and how these compounds can explain the differences in chemical profiles by geographical origin, cultivar and fruit ripeness stage. RESULTS Varieties from the Limarí Valley presented the highest content of phenolic compounds. A significant relationship (P < 0.05) between volatile compounds and climate indicated that the compounds produced via the lipoxygenase cascade were affected by the maximum temperature and, to a lesser extent, by evapo-transpiration and irrigation. The selection of different individual phenolic and volatile compounds independently allowed the significant differentiation of EVOOs, principally by geographical origin, crop season, fruit ripeness stage and, in a few cases, by cultivar. CONCLUSION Soil and climate of the Chilean regions have much more influence than cultivars on the concentration of sensory quality compounds. Difference in latitude between orchards increases the importance of the geographical origin on the virgin olive oil chemical composition while full irrigation decreases the impact of the cultivar.

Supplementation with Docosahexaenoic Acid and Extra Virgin Olive Oil Prevents Liver Steatosis Induced by a High-Fat Diet in Mice through PPAR-α and Nrf2 Upregulation with Concomitant SREBP-1c and NF-kB Downregulation

SCOPE Nonalcoholic fatty liver disease is the most common cause of liver disease, for which there is no validated drug therapy at present time. In this respect, the PUFA docosahexaenoic acid (DHA; C22:6 n-3) modulate lipid metabolism in the liver, and extra virgin olive oil (EVOO) has hepatoprotective effects. METHODS AND RESULTS The effect of combined DHA (C22:6 n-3) and EVOO administration to mice on oxidative stress and metabolic disturbances induced by high-fat diet (HFD) is evaluated. Male C57BL/6J mice are fed with a control diet (10% fat, 20% protein, and 70% carbohydrates) or an HFD (60% fat, 20% protein, and 20% carbohydrates) for 12 weeks. Animals are supplemented with DHA (50 mg/kg/day), EVOO (50 mg/kg/day), or DHA + EVOO through oral route. DHA + EVOO cosupplementation results in greater protection (p < 0.05) over that elicited by DHA or EVOO supply alone, when compared to the damage induced by HFD. DHA + EVOO significantly reduces hepatic steatosis, oxidative stress, systemic inflammation, and insulin resistance. CONCLUSION Synergistic beneficial effects of DHA + EVOO supplementation are associated with the activation/inactivation of key transcription factors involved in the above-mentioned processes. Data presented indicate that dietary supplementation with DHA + EVOO drastically reduces the development of nonalcoholic fatty liver disease.

Anti-steatotic effects of an n-3 LCPUFA and extra virgin olive oil mixture in the liver of mice subjected to high-fat diet

Non-alcoholic fatty liver disease (NAFLD) is characterized by liver steatosis, oxidative stress, and drastic depletion of n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA), namely, eicosapentaenoic acid (C20:5 n-3, EPA) and docosahexaenoic acid (C22:6 n-3, DHA), which trigger lipolysis stimulation and lipogenesis inhibition. Extra virgin olive oil (EVOO) has important antioxidant effects. This study evaluated the anti-steatotic effects of n-3 LCPUFA plus EVOO in the liver of male C57BL/6J mice subjected to a control diet (CD) (10% fat, 20% protein, 70% carbohydrate) or high fat diet (HFD) (60% fat, 20% protein, 20% carbohydrate), without and with supplementation with n-3 LCPUFA (100 mg per kg per day) plus EVOO (100 mg per kg per day) for 12 weeks. HFD induced (i) liver steatosis (increased total fat, triacylglycerols, and free fatty acid total contents), (ii) higher fasting serum glucose and insulin levels and HOMA index, total cholesterol, triacylglycerols and TNF-α and IL-6, (iii) liver and plasma oxidative stress enhancement, (iv) depletion of the n-3 LCPUFA hepatic content, and (v) increment in lipogenic enzyme activity and reduction in lipolytic enzyme activity. These changes were either reduced (p < 0.05) or normalized to control the values in animals subjected to HFD supplemented with n-3 LCPUFA plus EVOO. In conclusion, n-3 LCPUFA plus EVOO intervention exerts anti-steatotic effects underlying antioxidant and anti-inflammatory responses, improved insulin sensitivity, and recovery of the lipolytic/lipogenic status of the liver altered by HFD, and supports the potential therapeutic use of n-3 LCPUFA plus EVOO supplementation in the treatment of human liver steatosis induced by nutritional factors or other etiologies.

Effect of the composition of extra virgin olive oils on the differentiation and antioxidant capacities of twelve monovarietals

The effect of the composition of twelve varieties of extra virgin olive oils (EVOOs) on their differentiation based in agronomic criteria and on the antioxidant capacity was studied. Principal component analysis permitted an overview of the samples and their compositions, showing evidence of grouping and correlation between antioxidant capacity, oleuropein and ligstroside derivatives (OLD) and specific extinction at 270. Oleic and linoleic acids, 3,4-DHPEA-EA and p-HPEA-EDA (OLD), unsaturated/saturated ratio and induction time (IT) allowed the correct classification of samples according to year of harvest, ripening stage and variety. The antioxidant capacity of EVOOs was satisfactory predicted through a partial least square model based on ΔK, hydroxytyrosol, pinoresinol, oleuropein derivate and IT. Validation of the model gave a correlation R>0.83 and an error of 7% for independent samples. This model could be a useful tool for the olive industry to highlight the nutritional quality of EVOOs and improve their marketing.

Role of dietary α- and γ-tocopherol from Rosa mosqueta oil in the prevention of alterations induced by high-fat diet in a murine model

OBJECTIVE The aim of this study was to evaluate the contribution of tocopherols present in Rosa mosqueta oil (RM) in the prevention of high-fat diet (HFD)-induced alterations. METHODS Male C57 BL/6 J mice (n = 9/group) were fed for 12 wk and divided into four groups: control (CD; 10% kcal fat, 20% kcal protein, 70% kcal carbohydrates); HFD (60% as fat, 20% kcal protein, 20% kcal carbohydrates); HFD + RM (0.01 mL/g body weight/d); and HFD + RM- without tocopherols (0.01 mL/g body weight/d). Parameters of obesity, liver steatosis (histology, triacylglycerols content), inflammation (adipose NLRP3 inflammasome, tumor necrosis factor-α and interleukin-1 β expression, hepatic nuclear factor-κB) and oxidative stress (hepatic Nrf2 activation, carbonylated proteins) were evaluated. RESULTS Liver steatosis, inflammatory, and oxidative stress parameters were significantly (P < 0.05) increased in the HFD + RM- compared with the HFD + RM, with no differences between HFD and HFD + RM-. CONCLUSION The present study suggests that α- and γ-tocopherols from RM may have an important role in the prevention of alterations induced by HFD.

Molecular mechanisms related to the hepatoprotective effects of antioxidant-rich extra virgin olive oil supplementation in rats subjected to short-term iron administration

Abstract Enhanced iron levels in liver are associated with oxidative stress development and damage with increased fat accumulation. The aim of this work was to assess the hypothesis that antioxidant‐rich extra virgin olive oil (AR‐EVOO) counteracts iron‐rich diet (IRD)‐induced oxidative stress hindering hepatic steatosis. Male Wistar rats were fed and IRD (200 mg iron/kg diet) versus a control diet (CD; 50 mg iron/kg diet) with alternate AR‐EVOO supplementation (100 mg/day) for 21 days. IRD induced liver steatosis and oxidative stress (higher levels of protein oxidation and lipid peroxidation with glutathione depletion), mitochondrial dysfunction (decreased citrate synthase and complex I and II activities) and loss of polyunsaturated fatty acids (PUFAs), with a drastic enhancement in the sterol regulatory element‐binding protein‐1c (SREBP‐1c)/peroxisome proliferator‐activated receptor‐&agr; (PPAR‐&agr;) ratio upregulating the expression of lipogenic enzymes (acetyl‐CoA carboxylase, fatty acid (FA) synthase and stearoyl desaturase 2) and downregulating those involved in FA oxidation (carnitine palmitoyl transferase and acyl‐CoA oxidase) over values in the CD group. IRD also upregulated nuclear factor erythroid 2‐related factor 2 (Nrf2) and its target genes. AR‐EVOO supplementation alone did not modify the studied parameters, however, IRD combined with AR‐EVOO administration returned IRD‐induced changes to baseline levels of the CD group. It is concluded that IRD‐induced non‐alcoholic fatty liver disease (NAFLD) is prevented by AR‐EVOO supplementation, which might be related to the protective effects of its components such as hydroxytyrosol, oleic acid, tocopherols and/or PUFAs, thus representing a suitable anti‐steatotic strategy to avoid progression into more severe stages of the disease, underlying NAFLD associated with iron overloading pathologies or obesity. Graphical abstract Figure. No caption available. HighlightsIron (Fe) overload triggers liver oxidative stress and LCPUFA depletion.Low LCPUFAs decreases FA oxidation and upregulates lipogenesis inducing steatosis.Antioxidant‐rich extra virgin olive oil (AR‐EVOO) abrogates Fe‐induced hepatotoxicity.Steatosis prevention by AR‐EVOO may avoid progression into the inflammatory stage.