Rosalía Reynoso-Camacho

Chemical Composition and In Vitro Polysaccharide Fermentation of Different Beans (Phaseolus vulgaris L.)

The composition of bioactives including polysaccharide yield and resistant starch (RS) content of 4 raw and cooked bean (Phaseolus vulgaris L.) cultivars was evaluated. Polysaccharide was fermented in vitro by incubation with human gut flora under anaerobic conditions and short-chain fatty acids (SCFAs) production was compared at 6, 12, and 24 h by gas chromatography. Polysaccharide and soluble fiber contents increased upon cooking with stachyose as the major oligosaccharide. Cooked bean of cultivar Bayo Madero had the highest yield of polysaccharides (55%) and resistant starch (37%), followed by those of Negro 8025 (48% and 32%, respectively). Acetate was the most abundant SCFAs formed in all bean varieties. The concentration of SCFAs was cultivar-dependent; Bayo Madero and Negro 8025 displayed the highest concentration of butyrate (15 mmol/L), while Azufrado Higuera had the lowest and highest concentrations of acetate (39 mmol/L) and propionate (14 mmol/L), respectively. The results suggest that the common bean is an excellent source of polysaccharides that can be fermented in the colon and produce SCFAs, compounds previously reported to exert health benefits.

Purification and acute toxicity of a lectin extracted from tepary bean (Phaseolus acutifolius)

Lectins are proteins or glycoproteins known for their ability to agglutinate cells, especially erythrocytes. Several lectins are toxic to mammalian cells both in vitro and in vivo, inhibit growth when incorporated into the diet and are toxic when injected into animals. On the other hand, the use of lectins has been suggested as an alternative in cancer treatment. The objective of the present study was to evaluate the acute toxicity of a lectin extracted and purified from tepary bean (Phaseolus acutifolius, G-400-34) on CD-1 mice. Fetuin affinity chromatography, electrophoretic pattern and Western-immunoblot techniques were used to purify and partially characterize the lectin. This tepary bean line presented high levels of lectin activity. Western blot revealed that the sera reacted with the known PHA subunits in the 34-40 kD range. Four major lectin and lectin-related glycopolypeptides were identified. The purified lectin from tepary bean was a tetrameric one that ran at about 115-120 kD. The LD(50) (ip) was 1100 mg/kg body weight for males and 1120 mg/kg body weight for females. The body weight of experimental animals decreased in a dose-dependent manner. The main target organs affected were small intestine, spleen and thymus. The lectin isolated from tepary bean showed affinity towards fetuin, with high agglutination values and low acute toxicity.

Composition and Chemopreventive Effect of Polysaccharides from Common Beans (Phaseolus vulgaris L.) on Azoxymethane-Induced Colon Cancer

Common beans ( Phaseolus vulgaris L.) contain a high proportion of undigested carbohydrates (NDC) that can be fermented in the large intestine to produce short-chain fatty acids (SCFA) such as acetate, propionate, and butyrate. The objective of the present study was to evaluate the composition and chemopreventive effect of a polysaccharide extract (PE) from cooked common beans ( P. vulgaris L) cv. Negro 8025 on azoxymethane (AOM) induced colon cancer in rats. The PE induced SCFA production with the highest butyrate concentrated in the cecum zone: 6.7 +/- 0.06 mmol/g of sample for PE treatment and 5.29 +/- 0.24 mmol/g of sample for PE + AOM treatment. The number of aberrant crypt foci (ACF) and the transcriptional expression of bax and caspase-3 were increased, and rb expression was decreased. The data suggest that PE decreased ACF and had an influence on the expression of genes involved in colon cancer for the action of butyrate concentration.

Physicochemical, Nutritional, and Functional Characterization of Fruits Xoconostle (Opuntia matudae) Pears from Central‐México Region

Xoconostle cv. Cuaresmeño (Opuntia matudae) has attracted domestic and international industry attention; however, variations of composition from xoconostle structures have not been evaluated. Industries discard the pulp (endocarp) and peel (pericarp) as wastes and utilize the skin (mesocarp), which is the edible portion. The physicochemical, nutritional, and functional characterization of structures from xoconostle pear from 3 major sites of production in Mexico were assessed. Skin yield ranged from 58% to 64% and was higher to that of peel (22% to 24%) and pulp (12% to 18%) yields. pH, degrees Brix, and acidity were similar among xoconostle structures. Total fiber showed by peel (18.23% to 20.37%) was 2-fold higher than that of skin. Protein and ether extract were higher in xoconostle pulp compared to that showed by peel and skin. Iron content of xoconostle peel (6 to 9.6 mg/100 g, DWB) was higher to that of skin and pulp and prickly pear pulp. Soluble phenols of peel (840 to 863 mg GAE/100 g, DWB) were almost similar to that of skin (919 to 986 mg GAE/100 g, dry weigh basis); meanwhile, ascorbic acid concentration of skin was 2-fold higher compared to that of peel. The phenolic fraction of xoconostle structures consisted of gallic, vanillic, and 4-hydroxybenzoic acids; catechin, epicatechin, and vanillin were also identified by high-performance liquid chromatography-didoe array detection (HPLC-DAD). Xoconostle peel showed higher antioxidant activity (TEAC) compared to that of skin (2-fold) and pulp (6-fold) of commonly consumed fruits and vegetables. The potential of xoconostle peel and pulp for the production of feed or food is promissory. Practical Application: Outstanding nutritional and functional properties of xoconostle cv. Cuaresmeño fruits are demonstrated. Increased consumption could contribute positively to improve the diet of rural and urban consumers. The high fiber, mineral, and antioxidant components of xoconostle peel and pulp suggest that these fruit structures, which are currently discarded as waste, have promissory use as feed or food by industry.

In vitro fermentability and antioxidant capacity of the indigestible fraction of cooked black beans (Phaseolus vulgaris L.), lentils (Lens culinaris L.) and chickpeas (Cicer arietinum L.).

BACKGROUND Pulses represent an important source of protein, as well as digestible and indigestible carbohydrates. Little information is available on the indigestible carbohydrates and antioxidant capacity of legume seeds. The cooked seeds of three pulses (black bean, chickpea and lentil) were evaluated for their indigestible fraction (IF), polyphenols content, antioxidant capacity and in vitro fermentability, including short-chain fatty acid production. RESULTS The insoluble indigestible fraction (IIF) was higher than the soluble counterpart (soluble indigestible fraction, SIF). The SIF value was highest in black beans, while no difference was observed between chickpeas and lentils. Black beans and lentils had higher polyphenols content than chickpeas. The IF of black beans exhibited the lowest and chickpeas the highest associated polyphenols content. Condensed tannins were retained to some extent in the IF that exhibited significant antioxidant capacity. The total IF of the three pulses produced short chain fatty acids (SCFA) after 24 h of in vitro fermentation by human colonic microflora. IF from black bean and lentil were best substrates for the fermentative production of butyric acid. CONCLUSIONS It is concluded that the IF of pulses might be an important source of bioactive compounds.

Functional and technological potential of dehydrated Phaseolus vulgaris L. flours.

The effect of cooking followed by dehydration was evaluated on the bioactive composition, antioxidant activity and technological properties of two varieties (Negro 8025 and Bayo Madero) of common beans. Quercetin, rutin, and phenolic acids were the most abundant phenolics found. Cooking processes resulted in decreased values of some phenolic compounds and antioxidant capacity. A subsequent dehydration increased TEAC values, resistant starch content and decreased starch digestibility. Oligosaccharides and dietary fibre were preserved in both treatments. Variety had a strong impact on phytochemical profile, being Negro 8025 that exhibited the highest content of most of the compounds assessed. Water absorption index (WAI) and oil absorption capacity (OAC) were determined in order to measure technological suitability. Dehydration produced flours with stable WAI and low oil pick up. The results suggest that the flours of Negro 8025 beans have a good potential to be considered as functional ingredient for healthy food products.

Effect of chemical elicitors on peppermint (Mentha piperita) plants and their impact on the metabolite profile and antioxidant capacity of resulting infusions.

Infusions are widely consumed all over the world and are a source of dietary antioxidants, which can be improved in plants using elicitors. The aim of this study was to evaluate the foliar application of salicylic acid (SA) (0.5, 1 and 2mM) or hydrogen peroxide (H2O2) (0.05, 0.1 and 0.5mM) on peppermint (Mentha piperita) plants and its effect on the metabolite profile and antioxidant capacity of resulting infusions. Whereas 2mM SA treatment improved plant growth parameters and metabolite profile (carbohydrates and amino acids), 0.5 and 1mM SA treatments increased phenolic compound concentration. Sinapic acid, rutin and naringin were detected only in SA treatments; antioxidant capacity was also improved. Regarding H2O2 treatments, no differences in plant growth parameters, metabolite profile or antioxidant capacity were found. Therefore, the application of SA to peppermint is recommended in order to improve bioactive compounds and the antioxidant capacity of infusions.

Dietary Supplementation of Lutein Reduces Colon Carcinogenesis in DMH-Treated Rats by Modulating K-ras, PKB, and β-catenin Proteins

In colon cancer, disturbances have been detected in genes coding for proteins involved in cellular proliferation, such as K-ras, β-catenin, extracellular signal-regulated kinases (ERKs), and the protein kinase B (PKB). Although carotenoids such as lutein have an important role to prevent and treat some types of cancer, there are very few studies about the effect of lutein against colon cancer and its activity at the molecular level. Therefore, the aim of this study was to evaluate the chemoprotective activity of lutein against colon cancer induced by dimethylhydrazine (DMH). The results showed a significant increase in protein expression for K-ras and β-catenin in tumors of DMH-treated rats. Simultaneously, we detected changes in the phosphorylation state of ERK1/2 and PKB in DMH-treated animals. Lutein given in the diet (0.002%), before (prevention) and after (treatment) DMH administration, diminished the number of tumors by 55% and 32%, respectively. Moreover, lutein significantly decreased in tumors the expression of K-ras (25%) and β-catenin (28%) and the amount of pPKB (32%), during the prevention, and 39%, 26%, and 26% during the treatment stage, respectively. This study demonstrates the chemoprotective effect of lutein against colon cancer by modulating the proliferative activity of K-ras, PKB, and β-catenin proteins.

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.

Non-digestible fraction of cooked bean (Phaseolus vulgaris L.) cultivar Bayo Madero suppresses colonic aberrant crypt foci in azoxymethane-induced rats

The non-digestible fraction (NDF) of common bean (Phaseolus vulgaris L.) cultivar Bayo Madero was evaluated for its chemopreventive effect on azoxymethane (AOM) induced aberrant crypt foci (ACF) in rats. Diets containing cooked beans (CB) or its non-digestible fraction (NDF) were fed to 72 male rats after 2 azoxymethane injections (15 mg kg(-1) of body weight once a week for 2 weeks). ACF number, short chain fatty acids (SCFA) and β-glucuronidase activity were measured in colon sections from rats sacrificed 7 weeks after the last AOM injection. Food intake and weight gain of rats were unaffected by CB and NDF. CB and NDF suppressed the AOM-induced formation of ACF (0.8 and 1.5 ACF/distal zone, respectively vs. 6.6 ACF/distal zone based on methylene blue stain) and lowered β-glucuronidase activity in cecal, colonic and fecal content compared to AOM group. SCFA production was not significantly different among fecal, cecal and colonic content. These results indicate that CB and NDF from Bayo Madero provide direct chemoprotection against early stage of azoxymethane (AOM)-induced colon cancer in rats.