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Background and objectives Hypertension is associated with the overproduction of free radicals, generating oxidative stress, which could contribute to the lipid peroxidation, altering the blood lipid levels, and to the development of diseases such as diabetes. The aim of this work was to evaluate the bioactivity of cooked red and black quinoa over blood lipids, oxidative stress and glucose levels in hypertension‐induced rats by the supply of the drug N (ω)‐nitro‐L‐arginine methyl ester (L‐NAME). Findings The consumption of red quinoa increased significantly (p < .05) the levels of high‐density lipoprotein (HDL). In addition, the quinoa consumption, regardless of the variety, not only increased the activity of antioxidant enzymes (superoxide dismutase and catalase), but also reduced blood glucose levels. The total phenolic compounds and total flavonoids content were higher in red than in black quinoa while this latter obtained better values for the total antioxidant activity. Conclusions The presence of bioactive compounds in quinoa could be the responsible for its capacity to improve the HDL levels, the in vivo antioxidant activity and the levels of fasting blood glucose in hypertension‐induced rats. Significance and novelty Findings from this study could promote the consumption of quinoa, which seems to be a good source in the development of functional foods, in order to take advantages of its bioactivities.

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... Quinoa contains fiber, 20HE, phenolic, tocopherols, protein, and bioactive peptide contents, which may contribute to its antidiabetic potential (Ayyash et al., 2018;Cisneros-Yupanqui et al., 2020;de Oliveira Lopes et al., 2019;Hemalatha et al., 2016;. Phenolic compounds from several plants have been shown to exert in vitro α-amylase and α-glucosidase inhibitory effect (Hemalatha et al., 2016). ...
... Furthermore, saponins have been reported to have hypoglycemic potential (Marrelli et al., 2016;Ren et al., 2017;Singh et al., 2017). The high protein content of quinoa is also thought to help slow down the process of digestion and gastric emptying (Cisneros-Yupanqui et al., 2020). ...
... Many in vitro studies have also found the hypoglycemic potential of quinoa (Al-Qabba et al., 2020;Ayyash et al., 2018;Cisneros-Yupanqui et al., 2020;Graf et al., 2014;Hemalatha et al., 2016;Noratto et al., 2019;. Hemalatha et al. (2016) reported the enzyme inhibitory activities of quinoa extract on α-amylase and α-glucosidase. ...
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The seed of quinoa (Chenopodium quinoa) is a pseudocereal well known for its high nutritive value. The purpose of this review is to evaluate the potential for it to be used as a functional food. The nutritional composition, phytochemicals, and experimental evidence on its bioactivities are introduced to evaluate the physiological effects of consuming quinoa, including its antioxidant, hypolipidemic, immunomodulatory, weight‐regulating, hypoglycemic, hypotensive, probiotic, antitumor, and hormone‐regulating effects. The antinutrients, allergenicity, and toxicity of quinoa are then discussed. Overall, many studies and evidences have suggested the functional properties of quinoa, with most of them focusing on the antioxidant and hypolipidemic ability. Compared with the potential benefits, the risk of consuming quinoa is relatively low and easy to be managed. Therefore, quinoa can be considered to have great potential to be promoted as a healthy/functional food. More investigations are needed to confirm the effective intake of quinoa for achieving certain health effects. Beneficial effects of consuming quinoa
... Diet supplemented with quinoa and amaranth seeds reduced oxidative stress in the plasma, heart, kidney, liver, spleen, lung, testis and pancreas of fructose administered rats [46]. Cisneros-Yupanqui et al. [48] reported that activity of superoxide dismutase (an enzyme that catalyzes the dissociation of the free radical in water and hydrogen peroxide) was increased when quinoa seeds were supplied to hypertension-induced rats. In addition, the free phenolic and PUFA fractions of cooked quinoa showed strong antioxidant ability based on Caco-2 cell-based antioxidant activity assay. ...
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Amaranth and quinoa are classed as pseudocereals that do not belong to the grass family, meaning they are not technically a grain. Both of them are seeds with tremendous nutritional value; compared to other cereals, they contain much more fat. The aim of the study was to present the parameters characterizing thermal properties of amaranth and quinoa oils, such as: oxidation induction time, oxidation kinetic parameters, and melting profile. In isolated oils, the peroxide value, oxidative stability by the Rancimat test (in 120 °C) and the pressure differential scanning calorimetry (PDSC) method (at 100, 110, 120, 130, 140 °C), fatty acids composition, and their distribution between the triacylglycerol positions were determined. The kinetic parameters of the oxidation process (activation energy, pre-exponential factor, and reaction rate constants) were calculated using the Ozawa–Flynn–Wall method and the Arrhenius equation. To measure the melting profile, the differential scanning calorimetry (DSC) method was used. Both types of seeds are a good source of unsaturated fatty acids. Induction time of oxidation suggests that amaranth oil may have better resistance to oxidation than quinoa oil. The melting characteristics of the oils show the presence of low-melting triacylglycerol fractions, mainly containing unsaturated fatty acids, which means that a small amount of energy is required to melt the fats.
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Consumers are becoming increasingly conscious of adopting a healthy lifestyle and demanding food with high nutritional values. Quinoa (Chenopodium quinoa Willd.) has attracted considerable attention and is consumed worldwide in the form of a variety of whole and processed products owing to its excellent nutritional features, including richness in micronutrients and bioactive phytochemicals, well-balanced amino acids composition, and gluten-free properties. Recent studies have indicated that the diverse utilization and final product quality of this pseudo-grain are closely related to the processing technologies used, which can result in variations in nutritional profiles and health benefits. This review comprehensively summarizes the nutritional properties, processing technologies, and potential health benefits of quinoa, suggesting that quinoa plays a promising role in enhancing the nutrition of processed food. In particular, the effects of different processing technologies on the nutritional profile and health benefits of quinoa are highlighted, which can provide a foundation for the updating and upgrading of the quinoa processing industry. It further discusses the present quinoa-based food products containing quinoa as partial or whole substitute for traditional grains.
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The present study aimed to investigate the effects of different cooking conditions - atmospheric (100 °C) and pressure cooking (115 °C) - on the phenolic composition and antioxidant activity of methanolic extracts of four Phaseolus vulgaris varieties and soy (Glycine max). Contrary to soy, in P. vulgaris varieties both cooking methods increased drastically the total phenolic, flavonoid, and ortho-diphenol content, as well as antioxidant capacity. These results were corroborated by HPLC analysis, where an overall increase of phenolic acids and flavonoids was detected in processed samples. However, draining the cooking water significantly decreased phenolic acids, flavonoids and antioxidant activity in all P. vulgaris varieties and as well as soy. The hypothesis that cooking increases the compound accessibility and nutritional value through increased release of phytochemicals was verified in the present study for P. vulgaris varieties. Keeping the cooking water is crucial to the increased nutritional value of all Phaseolus varieties. Overall, compared with the tested varieties of Phaseolus, soy, to which many health benefits are attributed, is not the best legume source of antioxidants.
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Background: Hypertension is an exceptionally common condition which every now and again remains undiscovered until generally late in its course, prompting an assortment of other hazardous conditions. Around 91.3% of the hypertensive patients had no less than one related cardiovascular hazard factor. Our investigation plans to estimate the relationship of hazard factor with cardiovascular Disease. Materials and methods: This is observational and follows up investigation which focused 145 patients from Indira Gandhi Memorial Hospital over a time of one year (July 2016 to October 2017). Out of 145, 127 Patients could enrolled in the study for actual biochemical Estimation. We followed the modified NCEP ATP-III criteria of metabolic Syndrome for categorization of the patients. Result: Among 127 patients, 90 (78.26%) patients were found to be having metabolic disorder and without metabolic disorder were 25 (21.73%) and frequency rate was high in the age assemble between 51 and 60. Prevalence rate was high in farmer housewives having 4-6 years length of hypertension. Most common combination of lifted levels of parameters found to be HbA1c, triglyceride and waist circumference and it was 33.33% in both male and female. Lipid profile and was abnormal during baseline, and significant variation was found during follow up after patient counseling and proper treatment. Conclusion: The study justifies the view that all hypertensive patients should be screened for metabolic syndrome and those who diagnosed as a positive should be put on the proper treatment to protect them from CVS risk.
Article
This study aimed to investigate the in-vitro cytotoxicity activity against two cancer cell lines, α-amylase and α-glucosidase inhibitions, ACE-inhibition, antioxidant and proteolytic activities of whole-grain lupin, quinoa and wheat fermented by three species of Bifidobacterium spp. B. animalis, B. breve and B. longum were employed in solid-state fermentation (SSF) 37 °C for 72 h. The ranges of total phenolic contents in fermented lupin (FL), quinoa (FQ) and wheat (FW) were ∼17.0 to 44.0, ∼11.0 to 36.0, ∼5.0–29.0 mg GAE/g, respectively, relative to the unfermented control. α-Glucosidase inhibition increased significantly (p < 0.05) in FL and FQ after 24 h of fermentation. The cereals fermented by B. breve and B. longum had markedly increased ACE-inhibition activities. The magnitude of the cytotoxicity activities in FL was greater (p < 0.05) by approximately 5-fold and 3-fold against colon cancer cell (Caco-2) and breast cancer cell (MCF-7), respectively than in FQ and FW. The findings suggest that health properties of grains could be enhanced by probiotic fermentation and such enhancements depend on grain type and probiotic species. The inclusion of grains fermented by probiotics into foods could improve health benefits of these product.
Chapter
The classical negative correlation between HDL-cholesterol and coronary artery disease is due to HDL role in reverse cholesterol transport and many other atheroprotective functions, such as vasodilation, antiapoptosis, antioxidant, antiinflammatory, antithrombotic, and cytoprotective actions. Cigarette smoking, infections, diabetes mellitus, and other conditions may alter HDL composition and structure and thereby HDL may become dysfunctional and even proatherogenic. Clinical reproducible assays of cholesterol efflux, monocyte chemotaxis, endothelial inflammation, oxidation, NO production, and thrombosis permit assessment of several HDL functions. Lipid transfers among lipoproteins, mediated by transfer proteins CETP and PLTP, are part of HDL metabolism and an in vitro method was developed to assess lipid transfers to HDL and significance to atherosclerosis. HDL carries microRNAs and may influence gene expression. HDL and apo A-I have antidiabetogenic properties as they increase pancreatic beta cells function and insulin sensitivity. HDL-cholesterol may be increased by anticholesterolemic drugs and HDL-cholesterol increases by CETP inhibitors are under evaluation.
Article
Protocatechuic acid (PCA) is a natural antioxidant with beneficial cardiovascular properties. In this study, the effect of supplementation with PCA was investigated in deoxycorticosterone acetate (DOCA)-salt hypertension. Male Wistar rats received DOCA (25 mg/kg, s.c.) twice weekly and 1% NaCl in drinking water and simultaneously treated with PCA (50, 100 and 200 mg/kg, p.o.) for 4 weeks. Systolic blood pressure (SBP) was detected using tail-cuff method. Electrolytes including Na+, K+ and chloride, catalase activity, glutathione, total antioxidant capacity, malondialdehyde (MDA) and hydroperoxides concentration were measured in serum samples. Body and organs weight, water intake and, kidney and heart histopathology were also evaluated. Administration of PCA reversed the changes caused by DOCA-salt approximately at all doses. At the lowest dose, PCA significantly decreased SBP (132.5 ± 4.0 vs 152.3 ± 4.5 mmHg, P < .05), serum sodium (138.5 ± 1.52 vs 141 ± 1.50, P < .05) and chloride level (101.6 ± 1.47 vs 110 ± 1.39, P < .01) and raised serum potassium level (3.8 ± 0.09 vs 3.1 ± 0.17, P < .05) compared with DOCA-salt hypertensive rats. PCA increased serum catalase activity, total antioxidant capacity and glutathione concentration and reduced MDA and hydroperoxides levels. PCA also improved organ weight changes, reduced water intake and moderately prevented histopathological changes of kidney and heart upon DOCA-salt administration. The present study indicates the antihypertensive and antioxidant effects of PCA against DOCA-salt hypertension.
Article
In the recent years, quinoa has gained a renewed relevance as an alternative crop to cereals due to its excellent nutritional value. Thus, the aims of this work were to determine the physico-chemical, techno-functional and in vitro antioxidant properties as well as the total phenolic and flavonid contents of six quinoa flours. On the different samples proximal compositions and polyphenolic, sugar and organic acids profiles were also determined. Quinoa flours showed a protein content ranged between 11.62 and 13.66 g/100 g while the fat content was comprised between 4.87 and 6.48 g/100 g. The TDF content ranged from 12.71 to 18.59 g/100 g with ratios IDF:SDF higher than 8:1. In all samples analyzed four organic acids (oxalic, ciltric, malic, and succinic) and three sugars (sucrose, glucose, and fructose) were determined. As regards to techno-functional propreties, all quinoa flours showed lower water and oil holding capacities with values of 1.44–1.80 g water/g sample and 0.89–1.04 g oil/g sample, respectively. However, all samples showed a high swelling capacity with values ranged from 8.55 to 9.57 mL/g. The chemical profiles identification allowed to exposed major concentrations of 4-hydroxibenzoic acid and interesting concentrations of the other phenolic compounds and interesting contents of Ω3 fatty acids, compounds with renewed biological properties in terms of antioxidant activity and control diseases. In addition, the antioxidant activity assessed allowed to establish their antioxidant capacity of this product and the good correlations with total phenolic and flavonoid contents. The results of this study suggested that quinoa flours is a valid source of natural compounds with significant antioxidant activity and biological properties. Further investigations should be undertaken in respect of target product, anyhow the present study allowed to increase the knowledge about this Andean region species.
Article
Because of the continuous and direct interaction between the digestive tract and foods, dietary compounds represent an interesting source of chemopreventive agents for gastrointestinal health. In this study, the influence of a standardized static in vitro gastrointestinal digestion model on the release of peptides with chemopreventive potential from quinoa protein was investigated. Gastroduodenal digests and fractions collected by ultrafiltration were evaluated for their in plate oxygen radical absorbance capacity and in vitro colon cancer cell viability inhibitory activity. Highest effects were observed in the digests obtained during the intestinal phase, with fraction containing peptides < 5 kDa as the main responsible for the antioxidant activity and peptides ˃ 5 kDa showing the greatest anti-cancer effects. Seventeen potential bioactive peptides derived from quinoa proteins have been identified. These proteins might be utilized as new ingredients in the development of functional foods or nutraceuticals with the aim of reducing oxidative stress-associated diseases, including cancer.
Article
The beneficial health effects of taurine on hypertension have been demonstrated previously in both experimental and epidemiological studies. However, the role of taurine in reproductive dysfunction associated with hypertension has not been investigated. The present study evaluated the therapeutic efficacy of taurine on reproductive deficits in N-nitro-l-arginine methyl ester (L-NAME)-induced hypertensive rats. Sixty male Wistar rats were randomly assigned into six groups namely control, taurine alone, L-NAME alone (40mg/kg) or L-NAME treated with either taurine (100 and 200mg/kg) or reference drug atenolol (10mg/kg) for 28 consecutive days. Results indicated that taurine treatment significantly abrogated L-NAME-induced increase in systolic, diastolic and mean arterial pressures when compared with hypertensive control. Administration of taurine markedly increased antioxidant enzymes activities and glutathione level whereas it suppressed the increase in biomarkers of oxidative stress in the testes and epididymis of L-NAME-induced hypertensive rats. Moreover, taurine significantly reversed hypertension mediated decreases in circulatory concentrations of luteinizing hormone, follicle-stimulating hormone and testosterone whereas it increased testicular sperm number, epididymal sperm number and sperm progressive motility in the hypertensive rats. Furthermore, taurine abrogated the suppression of marker enzymes of testicular function namely acid phosphatase, alkaline phosphatase and lactate dehydrogenase and preserved the histo-architectures of the testes and epididymis in L-NAME-induced hypertensive rats. Taken together, the findings from this study highlight the beneficial role of taurine in reproductive system of L-NAME-induced male hypertensive rats. Taurine supplementation may be a good clinical approach to prevent reproductive deficits in male hypertensive patients.
Article
Objectives The relationship between the renin–angiotensin system (RAS) and diabetes has been studied for many years. However, studies that assessed RAS components comprehensively were limited. We hypothesized that serum RAS components, especially the effector peptide angiotensin-II, might be closely associated with glucose metabolism status and diabetic complications. Methods We investigated the association of individual RAS component with albuminuria in 407 subjects with normal glucose metabolism (NGM), prediabetes, or type 2 diabetes mellitus (T2DM). Anthropometric and biochemical parameters, including glucose homeostasis, albuminuria, and RAS-related parameters such as plasma renin activity (PRA), aldosterone, angiotensin-converting enzyme (ACE), and angiotensin-II levels, were measured. Results The mean ± standard deviation (SD) age and body mass index were 57.1 ± 11.1 years and 24.7 ± 3.3 kg/m², respectively. There were 54 subjects with NGM, 102 with prediabetes, and 251 with T2DM. The mean ± SD angiotensin-II levels in these groups were 9.32 ± 6.89, 12.89 ± 10.39, and 17.00 ± 15.28 pg/mL, and the respective urinary albumin-to-creatinine ratios (ACRs) were 8.1 ± 5.3, 13.3 ± 17.3, and 30.7 ± 51.9 mg/g, which were significantly different among the groups. The serum angiotensin-II levels were correlated with levels of PRA, insulin resistance, C-reactive protein, and urinary ACR. Among RAS-related parameters, only the angiotensin-II level was significantly associated with urinary ACR after adjusting for relevant risk factors. Conclusions Angiotensin-II may play an important role in the development of albuminuria, particularly in subjects with impaired glucose metabolism.
Article
Quinoa was the traditional grain crop used by the prehispanic civilizations in America. Grains are white, black, yellow, and red-violet and plants are cultivated in vast areas of Peru, Bolivia and Ecuador. The recent description of the betacyanin pigment betanin in red-violet varieties is here further analyzed detecting the presence of amaranthin not previously identified in quinoa grains. Yellow-orange grains are characterized for the first time and up to four different betaxanthins are found to be responsible for this coloration. The native fluorescence of the identified betaxanthins makes the surface of the yellow quinoa grains glow with green fluorescent light. The presence of betalains is correlated with high antioxidant and free radical scavenging activities measured under the FRAP, ABTS and ORAC assays in grain extracts of 29 Peruvian varieties. TEAC equivalence is as high as 44.1 and 47.4 mmol Trolox/kg for the yellow and red-violet varieties analyzed respectively.
Article
In this research, coloured quinoa seeds were subjected to a modified oncom-type processing (pre-cooking followed by solid- state fermentation with Neurospora intermedia) to obtain convenient food products of improved parameters. As compared to raw material, the products contained a higher level of protein (on average by 44 %, of the advantageous essential amino acid profile) and fibre (by 71%) but a lower amount of inositol phosphates (by 50%, with an increased share of InsP3 fraction in the profile). Fermented quinoa was enriched in carotenoids (6.5 fold), and riboflavin (5 fold). The antioxidant potential of oncom was also improved in respect of antiradical activity (on average by 39%) and reducing power. Of the red and black quinoa, the former substrate was processed into a product of better quality, containing a higher level of protein (214 g kg-1 DM), fibre (234 g kg-1 DM), carotenoids (81 mg kg-1 DM) and riboflavin (8 mg kg-1 DM), as well as antiradical activity (IC50 in ABTS•+ and DPPH• assay - 0.4 and 3 mg DM, respectively). This was associated with a 50% higher level of fungal glucosamine in this oncom. Therefore, the activity of N. intermedia can be considered as beneficial for biotreatment of quinoa seeds.
Article
Oxidative stress is associated with the pathogenesis of hypertension. Decreased bioavailability of nitric oxide (NO) is one of the mechanisms involved in the pathogenesis. It has been suggested that physical exercise could be a potential non-pharmacological strategy in treatment of hypertension because of its beneficial effects on oxidative stress and endothelial function. The aim of this review is to investigate the effect of oxidative stress in relation to hypertension and physical exercise, including the role of NO in the pathogenesis of hypertension. Endothelial dysfunction and decreased NO levels have been found to have the adverse effects in the correlation between oxidative stress and hypertension. Most of the previous studies found that aerobic exercise significantly decreased blood pressure and oxidative stress in hypertensive subjects, but the intense aerobic exercise can also injure endothelial cells. Isometric exercise decreases normally only systolic blood pressure. An alternative exercise, Tai chi significantly decreases blood pressure and oxidative stress in normotensive elderly, but the effect in hypertensive subjects has not yet been studied. Physical exercise and especially aerobic training can be suggested as an effective intervention in the prevention and treatment of hypertension and cardiovascular disease via reduction in oxidative stress.
Article
Body weight is related to fat mass, which is associated with obesity. Our study explored the effect of fat-1 gene on body weight in fat-1 transgenic mice. In present study, we observed that the weight/length ratio of fat-1 transgenic mice was lower than that of wild-type mice. The serum levels of triglycerides (TG), cholesterol (CT), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c) and blood glucose (BG) in fat-1 transgenic mice were all decreased. The weights of peri-bowels fat, perirenal fat and peri-testicular fat in fat-1 transgenic mice were reduced. We hypothesized that increase of n-3 PUFAs might alter the expression of hypothalamic neuropeptide genes and lead to loss of body weight in fat-1 transgenic mice. Therefore, we measured mRNA levels of appetite neuropeptides, Neuropeptide Y (NPY), Agouti-related peptides (AgRP), Proopiomelanocortin (POMC), Cocaine and amphetamine regulated transcript (CART), ghrelin and nesfatin-1 in hypothalamus by Real-Time PCR. Compared with wild-type mice, the mRNA levels of CART, POMC and ghrelin were higher, while the mRNA levels of NPY, AgRP and nesfatin-1 were lower in fat-1 transgenic mice. The results indicate that fat-1 gene or n-3 PUFAs participates in regulation of body weight, and the mechanism of this phenomenon involves the expression of appetite neuropeptides and lipoproteins in fat-1 transgenic mice.
Article
Flavonoids, with various biological activities, are considered as key compounds in propolis. In this study, quantitative determinations of flavonoids in propolis were conducted by two complementary colorimetric methods, aluminum chloride method and 2,4-dinitrophenylhydrazine method. Results suggested that the sum of flavonoid contents determined by the above two individual methods may represent the real content of total flavonoids. In this work, six raw propolis samples were investigated and the total contents of flavonoids ranged from 10.38 ± 0.14% to 24.91 ± 0.53%. As for the 12 commercial propolis products examined, the levels of total flavonoids in tinctures were all below 7% and those in powdery products varied from 2.97 ± 0.05% to 22.73 ± 0.72%.
Article
Recent technological advances have created great interest in the use of biologically active peptides. Bioactive peptides can be defined as specific portions of proteins with 2 to 20 amino acids that have desirable biological activities, including antioxidant, anti-hypertensive, antithrombotic, anti-adipogenic, antimicrobial and anti-inflammatory effects. Specific characteristics, including low toxicity and high specificity, make these molecules of particular interest to the food and pharmaceutical industries. This review focuses on the production of bioactive peptides, with special emphasis on fermentation and enzymatic hydrolysis. The combination of different technologies and the use of auxiliary processes are also addressed. A survey of isolation, purification and peptide characterization methods was conducted to identify the major techniques used to determine the structures of bioactive peptides. Finally, the antioxidant, antimicrobial, anti-hypertensive, anti-adipogenic activities and probiotic-bacterial growth-promoting aspects of various peptides are discussed.
Article
Quinoa (Chenopodium quinoa Willd., Amaranthaceae) is a grain-like, stress-tolerant food crop that has provided subsistence, nutrition, and medicine for Andean indigenous cultures for thousands of years. Quinoa contains a high content of health-beneficial phytochemicals, including amino acids, fiber, polyunsaturated fatty acids, vitamins, minerals, saponins, phytosterols, phytoecdysteroids, phenolics, betalains, and glycine betaine. Over the past 2 decades, numerous food and nutraceutical products and processes have been developed from quinoa. Furthermore, 4 clinical studies have demonstrated that quinoa supplementation exerts significant, positive effects on metabolic, cardiovascular, and gastrointestinal health in humans. However, vast challenges and opportunities remain within the scientific, agricultural, and development sectors to optimize quinoa's role in the promotion of global human health and nutrition
Article
Physical features, bioactive compounds and total antioxidant capacity (TAC) of coloured quinoa varieties (Chenopodium quinoa Willd.) from Peruvian Altiplano were studied. Quinoa seeds did not show a pure red colour, but a mixture which corresponded to different fractal colour values (51.0-71.8), and they varied from small to large size. Regarding bioactive compounds, total phenolic (1.23-3.24mg gallic acid equivalents/g) and flavonol contents (0.47-2.55mg quercetin equivalents/g) were highly correlated (r=0.910). Betalains content (0.15-6.10mg/100g) was correlated with L colour parameter (r=-0.569), total phenolics (r=0.703) and flavonols content (r=0.718). Ratio of betaxanthins to betacyanins (0.0-1.41) was negatively correlated with L value (r=-0.744). Whereas, high TAC values (119.8-335.9mmol Trolox equivalents/kg) were negatively correlated with L value (r=-0.779), but positively with betalains (r=0.730), as well as with free (r=0.639), bound (r=0.558) and total phenolic compounds (r=0.676). Unexploited coloured quinoa seeds are proposed as a valuable natural source of phenolics and betalains with high antioxidant capacity. Copyright © 2015 Elsevier Ltd. All rights reserved.
Book
Antioxidants in Food, Vitamins and Supplements bridges the gap between books aimed at consumers and technical volumes written for investigators in antioxidant research. It explores the role of oxidative stress in the pathophysiology of various diseases as well as antioxidant foods, vitamins, and all antioxidant supplements, including herbal supplements. It offers healthcare professionals a rich resource of key clinical information and basic scientific explanations relevant to the development and prevention of specific diseases. The book is written at an intermediate level, and can be easily understood by readers with a college level chemistry and biology background.
Article
The gastrointestinal (GI) tract and specifically the most distal part of the small intestine, the ileum, has become a renewed focus of interest for mechanisms targeting appetite suppression. The 'ileal brake' is stimulated when energy-containing nutrients are delivered beyond the duodenum and jejunum and into the ileum, and is named for the feedback loop which slows or 'brakes' gastric emptying and duodenojejunal motility. More recently it has been hypothesised that the ileal brake also promotes secretion of satiety-enhancing GI peptides and suppresses hunger, placing a 'brake' on food intake. Postprandial delivery of macronutrients to the ileum, other than unavailable carbohydrates (CHO) which bypass absorption in the small intestine en route to fermentation in the large bowel, is an uncommon event and hence this brake mechanism is rarely activated following a meal. However the ability to place a 'brake' on food intake through delivery of protected nutrients to the ileum is both intriguing and challenging. This review summarizes the current clinical and experimental evidence for activation of the ileal brake by the three food macronutrients, with emphasis on eating behavior and satiety as well as GI function. Whilst clinical studies have shown that exposure of the ileum to lipids, CHOs and proteins may activate GI components of the ileal brake, such as decreased gut motility, gastric emptying and secretion of GI peptides, there is less evidence as yet to support a causal relationship between activation of the GI brake by these macronutrients and the suppression of food intake. The predominance of evidence for an ileal brake on eating comes from lipid studies, where direct lipid infusion into the ileum suppresses both hunger and food intake. Outcomes from oral feeding studies are less conclusive with no evidence that 'protected' lipids have been successfully delivered into the ileum in order to trigger the brake. Whether CHO or protein may induce the ileal brake and suppress food intake has to date been little investigated, although both clearly have GI mediated effects. This review provides an overview of the mechanisms and mediators of activation of the ileal brake and assesses whether it may play an important role in appetite suppression.
Article
The antioxidant activity and the relationship between total antioxidant activity and the main classes of antioxidants in the seeds of bitter and sweet Chenopodium quinoa seeds were measured before and after boiling, in order to establish which one showed the best antioxidant property and how a traditional cooking method could affect it. Our results, obtained by using DPPH (1,1-diphenyl-2-picrilhydrazyl) and FRAP (Ferric Reducing/Antioxidant Power) methods, showed that antioxidant activity of bitter seeds was higher than that of sweet seeds. This activity principally depended on phenols and flavonoids in bitter seeds, while it was mainly due to phenol, flavonoid and carotenoid compounds in sweet seeds. Moreover, boiling caused a significant loss of antioxidant capacity in water.
Article
The autoxidation of pyrogallol was investigated in the presence of EDTA in the pH range 7.9–10.6. The rate of autoxidation increases with increasing pH. At pH 7.9 the reaction is inhibited to 99% by superoxide dismutase, indicating an almost total dependence on the participation of the superoxide anion radical, O2·−, in the reaction. Up to pH 9.1 the reaction is still inhibited to over 90% by superoxide dismutase, but at higher alkalinity, O2·− -independent mechanisms rapidly become dominant. Catalase has no effect on the autoxidation but decreases the oxygen consumption by half, showing that H2O2 is the stable product of oxygen and that H2O2 is not involved in the autoxidation mechanism. A simple and rapid method for the assay of superoxide dismutase is described, based on the ability of the enzyme to inhibit the autoxidation of pyrogallol. A plausible explanation is given for the non-competitive part of the inhibition of catechol O-methyltransferase brought about by pyrogallol.
Article
The ABTS/H2O2/HRP decoloration method permits the evaluation of the antioxidant activity of complex food samples. This method, with slight modifications, is capable of determining both hydrophilic and lipophilic antioxidant properties, thus, it is possible estimate the antioxidant activity of both antioxidant types in the same sample. The method is easy, accurate and rapid to apply. Its application to three vegetable soups provided data on hydrophilic and lipophilic antioxidant activity, and the values reflect the contribution of the particular antioxidants (ascorbic acid and carotenoids) to the total antioxidant activity of the samples.
Article
Bioactive peptides, as products of hydrolysis of diverse food proteins, are the focus of current research. They exert various biological roles, one of the most crucial of which is the antioxidant activity. Reverse relationship between antioxidant intake and diseases has been approved through plenty of studies. Antioxidant activity of bioactive peptides can be attributed to their radical scavenging, inhibition of lipid peroxidation and metal ion chelation properties of peptides. It also has been proposed that peptide structure and its amino acid sequence can affect its antioxidative properties. This paper reviews bioactive peptides from food sources concerning their antioxidant activities. Additionally, specific characteristics of antioxidative bioactive peptides, enzymatic production, methods to evaluate antioxidant capacity, bioavailability, and safety concerns of peptides are reviewed.