Iza F. Pérez-Ramírez

Effect of stevia and citric acid on the stability of phenolic compounds and in vitro antioxidant and antidiabetic capacity of a roselle (Hibiscus sabdariffa L.) beverage.

Plant infusions are consumed due to their beneficial effects on health, which is attributed to their bioactive compounds content. However, these compounds are susceptible to degradation during processing and storage. The objective of this research was to evaluate the effect of stevia and citric acid on the stability of phenolic compounds, antioxidant capacity and carbohydrate-hydrolysing enzyme inhibitory activity of roselle beverages during storage. The optimum extraction conditions of roselle polyphenolic compounds was of 95 °C/60 min, which was obtained by a second order experimental design. The incorporation of stevia increased the stability of colour and some polyphenols, such as quercetin, gallic acid and rosmarinic acid, during storage. In addition, stevia decreased the loss of ABTS, DPPH scavenging activity and α-amylase inhibitory capacity, whereas the incorporation of citric acid showed no effect. These results may contribute to the improvement of technological processes for the elaboration of hypocaloric and functional beverages.

Cooked common beans (Phaseolus vulgaris L.) modulate renal genes in streptozotocin-induced diabetic rats

Food consumption with different bioactive compounds could reduce the risk of diabetic complications. This study was designed to evaluate the effect of cooked common beans on differentially expressed genes in whole kidney homogenates of streptozotocin-induced diabetic rats. After 4weeks of treatment with a cooked bean supplemented (10%) diet, animals fed with Flor de Mayo bean (FMB) exerted the greatest protective effect, since they presented the lowest blood glucose levels, consistent with an increase in blood insulin levels, a decrease in urine albumin and urea levels and an increase in creatinine clearance (P≤.05). Regarding the gene expression of kidneys evaluated using expressed sequence tag, consumption of cooked beans improved the expression of Glu1, Cps1, Ipmk, Cacna1c, Camk1, Pdhb, Ptbp3 and Pim1, which are related to the elimination of ammonium groups, the regulation of inflammatory and oxidative response, as well as cell signaling and apoptosis. In addition, the beneficial effects observed were not related to their polyphenolic and saponin profile, suggesting the activity of other bioactive compounds or the synergistic interaction of these compounds. These results suggest that the consumption of cooked common beans (FMB) might be used as an alternative for the regulation of genes related to renal alterations.

Comprehensive Characterization of Extractable and Nonextractable Phenolic Compounds by High-Performance Liquid Chromatography–Electrospray Ionization–Quadrupole Time-of-Flight of a Grape/Pomegranate Pomace Dietary Supplement

Grape and pomegranate are rich sources of phenolic compounds, and their derived products could be used as ingredients for the development of functional foods and dietary supplements. However, the profile of nonextractable or macromolecular phenolic compounds in these samples has not been evaluated. Here, we show a comprehensive characterization of extractable and nonextractable phenolic compounds of a grape/pomegranate pomace dietary supplement using high-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight (HPLC-ESI-QTOF) and matrix-assisted laser desorption/ionization (MALDI)-TOF techniques. The main extractable phenolic compounds were several anthocyanins (principally malvidin 3-O-glucoside) as well as gallotannins and gallagyl derivatives; some phenolic compounds were reported in grape or pomegranate for the first time. Additionally, there was a high proportion of nonextractable phenolic compounds, including vanillic acid, and dihydroxybenzoic acid. Unidentified polymeric structures were detected by MALDI-TOF MS analysis. This study shows that mixed grape and pomegranate pomaces are a source of different classes of phenolic compounds including a high proportion of nonextractable phenolic compounds.

Phytochemical characterization and effect of Calendula officinalis, Hypericum perforatum, and Salvia officinalis infusions on obesity-associated cardiovascular risk

Abstract Medicinal herb infusions can be used for the treatment of obesity-related metabolic alterations. The aim of this study was to characterize the phytochemical profile and to evaluate the effect of Hypericum perforatum, Salvia officinalis, and Calendula officinalis on the cardiovascular risk developed in diet-induced obese rats. All infusions decreased body weight and abdominal fat mass and reduced serum triglycerides (TG), total cholesterol, low-density lipoproteins, and C-reactive protein levels. The anti-obesogenic and hypolipidemic effect of C. officinalis and H. perforatum were associated with the inhibition of triglycerides digestion and absorption. Conversely, the hypolipidemic effect of S. officinalis was not associated with this mechanism. Moreover, seven phenolic acids and nine flavonoids were quantified by HPLC–UV/VIS, hesperidin and epigallocatechin gallate were the majoritarian compounds of H. perforatum and C. officinalis, whereas rosmarinic and ellagic acids were the main compounds in S. officinalis. Additionally, we used HPLC–DAD–MSD to identify 45 phytochemicals, such as anthraquinone and phloroglucinol derivatives, phytosterols, saponins, and alkaloids. Total flavonoids, phytosterols, and alkaloids content were highly correlated with TG levels, AUC values from the oil tolerance test, and pancreatic lipase inhibition. These results suggest that these phytochemical-rich infusions may be used as an alternative for obesity-related cardiovascular risk treatment.

Metabolite profile, antioxidant capacity, and inhibition of digestive enzymes in infusions of peppermint (Mentha piperita) grown under drought stress.

Peppermint (Mentha piperita) infusions represent an important source of antioxidants, which can be enhanced by inducing abiotic stress in plants. The aim of this study was to evaluate the effect of drought stress on peppermint cultivation as well as the metabolite profile, antioxidant capacity, and inhibition of digestive enzymes of resulting infusions. At 45 days after planting, irrigation was suppressed until 85 (control), 65, 35, 24, and 12% soil moisture (SM) was reached. The results showed that 35, 24, and 12% SM decreased fresh (20%) and dry (5%) weight. The 35 and 24% SM treatments significantly increased total phenolic and flavonoid contents as well as antioxidant capacity. Coumaric acid, quercetin, luteolin, and naringenin were detected only in some drought treatments; however, in these infusions, fewer amino acids and unsaturated fatty acids were identified. The 24 and 12% SM treatments slightly improved inhibition of pancreatic lipase and α-amylase activity. Therefore, induction of moderate water stress in peppermint is recommended to enhance its biological properties.

Phytochemical composition and in vitro analysis of nopal (O. ficus-indica) cladodes at different stages of maturity

ABSTRACT This study aimed to determine the phytochemical profile and nutraceutical properties of nopal cladodes (Opuntia ficus-indica) at different stages of maturity. Medium-age cladodes showed the highest total saponins, phytosterols, and indigestible fiber, as well as the highest in vitro antioxidant capacity and digestive enzymes inhibitory activity. Furthermore, these cladodes presented the highest content of p-hydroxybenzoic acid, p-coumaric acid, rutin, narcissin, nicotiflorin, β-sitosterol, and sitosteryl-3-β-glucopyranoside, as well as several amino acids, organic acids, and fatty acids. Whereas young cladodes contained the highest concentration of condensed and hydrolyzable tannins. These results demonstrated that maturity affects the nutritional and nutraceutical properties of nopal cladodes.

Cookies elaborated with oat and common bean flours improved serum markers in diabetic rats

BACKGROUND Common beans have been associated with anti-diabetic effects, due to its high content of bioactive compounds. Nevertheless, its consumption has decreased worldwide. Therefore, there is an increasing interest in the development of novel functional foods elaborated with common beans. The aim of this study was to evaluate the anti-diabetic effect of oat-bean flour cookies, and to analyze its bioactive composition, using commercial oat-wheat cookies for comparative purposes. RESULTS Oat-bean cookies (1.2 g kg-1 ) slightly decreased serum glucose levels (∼1.1-fold) and increased insulin levels (∼1.2-fold) in diabetic rats, reducing the hyperglycemic peak in healthy rats (∼1.1-fold). Oat-bean cookies (0.8 and 1.2 g kg-1 ) exerted a greater hypolipidemic effect than commercial oat-wheat cookies (1.2 g kg-1 ), as observed in decreased serum triglycerides and low-density lipoprotein cholesterol. Furthermore, the supplementation with 1.2 g kg-1 oat-bean cookies decreased atherogenic index and serum C-reactive protein levels, suggesting their cardioprotective potential. The beneficial effect of oat-bean cookies was associated with their high content of dietary fiber and galacto oligosaccharides, as well as chlorogenic acid, rutin, protocatechuic acid, β-sitosterol and soyasaponins. CONCLUSION These results suggest that common beans can be used as functional ingredients for the elaboration of cookies with anti-diabetic effects.

Improvement of physico-chemical properties and phenolic compounds bioavailability by concentrating dietary fiber of peach (Prunus persica) juice by-product: Improvements of peach juice by-product

BACKGROUND This study aimed to concentrate dietary fiber (DF) from peach (Prunus persica) juice by-product (PJBP), to improve its functional properties, and its polyphenols bioavailability. The dietary fiber concentrates (DFCs) were obtained from PJBP using water/ethanol treatments (100:0, 20:80, 50:50, 80:20, and 0:100, v/v) at 1:5 ratio (wet weight/solvent, w/v) for 5 and 20 min at 21 °C. RESULTS All treatments concentrated condensed tannins, total and insoluble DF, with the highest content found with 100% H2 O treatment. The major polyphenols of DFC were 4-O-caffeoylquinic, chlorogenic, and 1,5-di-O-caffeoylquinic acids. Water and oil retention capacity and maximum glucose diffusion rate were improved mainly with 100% H2 O treatment. Healthy rats were fed with a standard diet supplemented with 8% of PJBP, DFC obtained with 100% H2 O for 5 min, or DFC obtained with 20% EtOH for 5 min. Gastrointestinal digesta weight and viscosity were increased in animals supplemented with 100% H2 O DFC. Moreover, the urinary excretion of polyphenol metabolites, mainly glucuronide and sulfate conjugates, was increased with this treatment, indicating a greater bioavailability of PJBP polyphenols, which was associated with an increased dietary fiber porosity. CONCLUSION Water treatment could be used to potentiate PJBP functional properties and polyphenols bioavailability.

The main beneficial effect of roselle (Hibiscus sabdariffa) on obesity is not only related to its anthocyanin content: Antiobesogenic effect of roselle (Hibiscus sabdariffa) extratcs

BACKGROUND The calyxes of roselle (Hibiscus sabdariffa) are recognized for their high nutraceutical value because they decrease body weight and obesity complications. These effects have been attributed mainly to anthocyanins. However, the calyxes comprise important concentration of flavonoids, phenolic, and organic acids, which could also contribute to these effects. The objective of this work was to determine the effect of the Alma Blanca white roselle variety on obesity and hepatic steatosis in high-fat, high-fructose, diet-fed rats and compare its beneficial effects with the red variety (Criolla), which has been more extensively studied. RESULTS Aqueous and methanolic extracts were prepared from two roselle varieties, Alma Blanca (white) and Criolla (red). The phytochemical profiles were determined using high-performance liquid chromatography-mass spectrometry (HPLC-MS). Criolla extracts contain principally anthocyanins, phenolic acids, and flavonoids. Anthocyanins were not detected in Alma Blanca. The aqueous extracts of both varieties prevented body-weight gain and decreased adipocytes hyperplasia on rats fed a hypercaloric diet. These extracts also protected against hepatic steatosis. These benefits were associated with hibiscus, dimethyl hibiscus, and hydroxycitric acid. CONCLUSION These results demonstrated that calyxes from Hibiscus sabdariffa contain compounds that are different from anthocyanins, with potential benefits to health. The organic acids were strongly associated with these beneficial health effects.