Bertha Irene Juárez-Flores

Quantitative characterization of nonstructural carbohydrates of mezcal Agave (Agave salmiana Otto ex Salm-Dick).

Fructans are the reserve carbohydrates in Agave spp. plants. In mezcal factories, fructans undergoes thermal hydrolysis to release fructose and glucose, which are the basis to produce this spirit. Carbohydrate content determines the yield of the final product, which depends on plant organ, ripeness stage, and thermal hydrolysis. Thus, a qualitative and quantitative characterization of nonstructural carbohydrates was conducted in raw and hydrolyzed juices extracted from Agave salmiana stems and leaves under three ripeness stages. By high-performance liquid chromatography (HPLC), fructose, glucose, sucrose, xylose, and maltose were identified in agave juice. Only the plant fraction with hydrolysis interaction was found to be significant in the glucose concentration plant. Interactions of the fraction with hydrolysis and ripeness with hydrolysis were statistically significant in fructose concentration. Fructose concentration rose considerably with hydrolysis, but only in juice extracted from ripe agave stems (early mature and castrated). This increase was statistically significant only with acid hydrolysis.

Effects of different sources of fructans on body weight, blood metabolites and fecal bacteria in normal and obese non-diabetic and diabetic rats.

Fructans contribute significantly to dietary fiber with beneficial effects on gastrointestinal physiology in healthy individuals and offer a promising approach to treating some diseases. Two experiments (Experiment 1 = rats with normal weight; Experiment 2 = obese rats) were developed to compare the effects of three fructan sources (Cichorium intybus L. Asteraceae, Helianthus tuberosus L. Asteraceae and Agave angustifolia ssp. tequilana Haw, Agavaceae) on body weight change, blood metabolites and fecal bacteria in non-diabetic (ND) and diabetic (D) rats. In Experiment 1 total body weight gain and daily feed intake in D and ND rats decreased (P < 0.05) with supplements of fructan. Only in D rats, blood glucose concentrations, fecal Clostrodium spp. counts, and liver steatosis decreased, while blood HDL concentrations and fecal Lactobacillus spp. and Bifidobacterium spp. counts increased due to fructans. In Experiment 2, total body weight gain and feed intake in ND and D rats were also decreased by fructans. In ND rats, fructan decreased blood glucose concentrations. In D rats, fructans from A. angustifolia ssp. tequilana decreased blood cholesterol and LDL and liver steatosis. For both ND and D rats, fecal Lactobacillus spp. and Bifidobacterium spp. counts were higher (P < 0.05) with fructan supplements.

Effect of prebiotics of Agave salmiana fed to healthy Wistar rats

BACKGROUND Inulin and other fructans are synthesized and stored in mezcal agave (Agave salmiana). Fructans provide several health benefits and have excellent technological properties, but only few data report their physiological effect when added in the diet. RESULTS Here, we studied the physiological effects of fructans obtained from A. salmiana when added in the diet of Wistar rats. Results showed favorable changes on Wistar rats when the fructans was added to their diet, including the decrease of the pH in the feces and the increase of the number of lactic acid bacteria (CFU g-1 ) (Lactobacillus spp. and Bifidobacterium spp.), even these changes were enhanced with the synbiotic diet (fructans plus B. animalis subsp. lactis). Synbiotic diet, developed changes in the reduction of cholesterol and triglycerides concentrations in serum, with statistical differences (P < 0.05). Histological analysis of colon sections showed that synbiotic diet promoted colon cells growth suggesting that fructans from A. salmiana confer beneficial health effects through gut microbiota modulation. CONCLUSION Our data underline the advantage of targeting the gut microbiota by colonic nutrients like specific structure of fructans from A. salmiana, with their beneficial effects. More studies are necessary to define the role of fructans to develop more solid therapeutic solutions in humans.

Aflatoxins Contamination in Maize Products from Rural Communities in San Luis Potosi, Mexico

Background: Aflatoxins are a group of mycotoxins that have been associated with hepatic damage and cancer. Aflatoxins B1 and B2 are secondary metabolites produced by fungi Aspergillus. These toxins can be found in a variety of commodities, especially in maize, and have been studied around the world due to their effects in human health. The Latin American population is especially exposed to aflatoxins given that maize products can be found in traditional diets all over the continent. Interestingly, in Mexico, chronic hepatic diseases and cirrhosis are leading causes of death in adult population. Methods: In order to observe the effect of physical variables like temperature and humidity, this study was conducted collecting samples in four different seasons, in two communities in the State of San Luis Potosi, in Mexico. The content of aflatoxins in tortillas was measured using immunoaffinity columns prior to HPLC-FLD analysis. Findings: Results showed that 18% of samples exceeded the Mexican limits for AFB1; whereas, 26% of the samples exceeded the limits of the European Union for AFB1. The AFB1 was detected in 80% of samples in one site and higher concentrations were found in samples collected during fall and winter seasons. Conclusions: Lack of control in storing practices is the principal cause for the contamination of maize. Considering that maize products are part of the staple diet of Mexican population, our results show that AFB1 detection has to be declared a public health priority. Detection and prevention of aflatoxins through a surveillance program, may avoid chronic health effects.

Consumption of Amaranth Induces the Accumulation of the Antioxidant Protein Paraoxonase/Arylesterase 1 and Modulates Dipeptidyl Peptidase IV Activity in Plasma of Streptozotocin-Induced Hyperglycemic Rats

Background/Aim: Amaranth is a source of several bioactive compounds, among which peptides with inhibitory activity upon dipeptidyl peptidase IV (DPP-IV) have been reported. However, there is no information about the action of amaranth DPP-IV-inhibitory peptides using in vivo models. The aim of this work was to evaluate the effect of amaranth consumption on plasma and kidney DPP-IV activity as well the changes in plasma proteome profile of streptozotocin (STZ)-induced hyperglycemic rats. Methods: Rats were fed for 12 weeks with a diet containing 20% popped amaranth grain. Kidneys and blood samples were collected for lipid profile, DPP-IV activity and expression, and proteomic analysis. Results: Total cholesterol and DPP-IV activity in plasma was increased in hyperglycemic rats, but this effect was reverted by amaranth consumption. Triacylglycerols were increased in the hyperglycemic group fed amaranth, and the highest levels of high-density lipoproteins were also observed in this group. These data correlated with the accumulation of apolipoprotein A-II in plasma. Accumulation of the antioxidant protein paraoxonase/arylesterase 1 in STZ-induced hyperglycemic rats was observed when amaranth was supplied in the diet. Conclusion: This study provides new insights into the molecular mechanisms by which amaranth exerts its beneficial health action in a hyperglycemic state.