Physicochemical Characterization of Resistant Starch Type-III (RS3) Obtained by Autoclaving Malanga (Xanthosoma sagittifolium) Flour and Corn Starch.

The feasibility of obtaining resistant starch type III (RS3) from malanga flour (Xanthosoma sagittifolium), as an unconventional source of starch, was evaluated using the hydrothermal treatment of autoclaving. The physicochemical characterization of RS3 made from malanga flour was carried out through the evaluation of the chemical composition, color attributes, and thermal properties. In addition, the contents of the total starch, available starch, resistant starch, and retrograded resistant starch were determined by in vitro enzymatic tests. A commercial corn starch sample was used to produce RS3 and utilized to compare all of the analyses. The results showed that native malanga flour behaved differently in most of the evaluations performed, compared to the commercial corn starch. These results could be explained by the presence of minor components that could interfere with the physicochemical and functional properties of the flour; however, the RS3 samples obtained from malanga flour and corn starch were similar in their thermal and morphological features, which may be related to their similarities in the content and molecular weight of amylose, in both of the samples. Furthermore, the yields for obtaining the autoclaved powders from corn starch and malanga flour were similar (≈89%), which showed that the malanga flour is an attractive raw material for obtaining RS3 with adequate yields, to be considered in the subsequent research.

Effect of extracts of Luffa cylindrica, Xanthosoma sagittifolium and Momordica charantia on Saprolegnia spp. mycelial growth / Efeito de extratos de Luffa cylindrica, Xanthosoma sagittifolium e Momordica charantia sobre o crescimento mycelial de Saprolegnia spp / Efecto de extractos de Luffa cylindrica, Xanthosoma sagittifolium y Momordica charantia en el crecimiento mycelial de Saprolegnia spp

Among the major infectious diseases in fish, those caused by zoosporic organisms are important, especially saprolegniasis. These diseases can affect few animals or even the entire population of the production environment. The use of alternative treatments for infectious diseases in aquatic animals has proven to be effective. It prevents the mortality of part of the crop, as well as the contamination of water by chemical components. Within this scenario, the use of plants stands out, mainly unconventional food plants (UFPs). The objective of this work was to evaluate the effect of the aqueous extracts of Luffa cylindrica, Xanthosoma sagittifolium and Momordica charantia on the mycelial growth of Saprolegnia spp. The extracts obtained from the maceration of dry and ground leaves were incorporated into the potato agar dextrose (PDA), at concentrations of 0, 5, 15, 25 and 50%. Later, filter paper disks containing the mycelium of Saprolegnia spp. were applied on the agar and incubated at 25°C. Evaluations were performed every 24 hours, for 10 days. In the study, all concentrations of M. charantia extract had an inhibitory action on the mycelial growth in the order of 75% of Saprolegnia spp. and can be considered a promising alternative for controlling this pathogen.(AU)

Entre as principais doenças infecciosas em peixes, as causadas por organismos zoospóricos são importantes, especialmente a saprolegníase. Essas doenças podem afetar poucos animais ou até mesmo toda a população do ambiente de produção. O uso de tratamentos alternativos para doenças infecciosas em animais aquáticos tem se mostrado eficaz. Evita a mortalidade de parte da cultura, bem como a contaminação da água por componentes químicos. Dentro deste cenário, destaca-se o uso de plantas, principalmente plantas alimentícias não convencionais (PANCs). O objetivo deste trabalho foi avaliar o efeito dos extratos aquosos de Luffa cylindrica, Xanthosoma sagittifolium e Momordica charantia sobre o crescimento micelial de Saprolegnia spp. Os extratos obtidos da maceração de folhas secas e moídas foram incorporados em ágar batata dextrose (BDA), nas concentrações de 0, 5, 15, 25 e 50%. Mais tarde, os discos de papel de filtro contendo o micélio de Saprolegnia spp. foram aplicados no ágar e incubados a 25°C. As avaliações foram realizadas a cada 24 horas, por 10 dias. No estudo, todas as concentrações do extrato de M. charantia tiveram ação inibitória sobre o crescimento micelial da ordem de 75% de Saprolegnia spp., podendo ser considerada uma alternativa promissora para o controle desse patógeno.(AU)

Entre las principales enfermedades infecciosas en los peces, las causadas por organismos zoospóricos son importantes, especialmente la saprolegniasis. Estas enfermedades pueden afectar a pocos animales o incluso a toda la población del entorno de producción. El uso de tratamientos alternativos para enfermedades infecciosas en animales acuáticos ha demostrado ser efectivo. Previene la mortalidad de parte del cultivo, así como la contaminación del agua por componentes químicos. Dentro de este escenario, se destaca el uso de plantas, principalmente plantas alimenticias no convencionales (PANCs). El objetivo de este trabajo fue evaluar el efecto de los extractos acuosos de Luffa cylindrica, Xanthosoma sagittifolium y Momordica charantia sobre el crecimiento micelial de Saprolegnia spp. Los extractos obtenidos de la maceración de hojas secas y molidas se incorporaron a la papa dextrose agar (PDA), a concentraciones de 0, 5, 15, 25 y 50%. Más tarde, filtre los discos de papel que contienen el micelio de Saprolegnia spp. se aplicaron sobre el agar y se incubaron a 25°C. Las evaluaciones se realizaron cada 24 horas, durante 10 días. En el estudio, todas las concentraciones de extracto de M. charantia tuvieron una acción inhibitoria sobre el crecimiento micelial del orden del 75% de Saprolegnia spp. y puede considerarse una alternativa prometedora para controlar este patógeno.(AU)

Effect of extracts of Luffa cylindrica, Xanthosoma sagittifolium and Momordica charantia on Saprolegnia spp. mycelial growth / Efeito de extratos de Luffa cylindrica, Xanthosoma sagittifolium e Momordica charantia sobre o crescimento mycelial de Saprolegnia spp / Efecto de extractos de Luffa cylindrica, Xanthosoma sagittifolium y Momordica charantia en el crecimiento mycelial de Saprolegnia spp

Among the major infectious diseases in fish, those caused by zoosporic organisms are important, especially saprolegniasis. These diseases can affect few animals or even the entire population of the production environment. The use of alternative treatments for infectious diseases in aquatic animals has proven to be effective. It prevents the mortality of part of the crop, as well as the contamination of water by chemical components. Within this scenario, the use of plants stands out, mainly unconventional food plants (UFPs). The objective of this work was to evaluate the effect of the aqueous extracts of Luffa cylindrica, Xanthosoma sagittifolium and Momordica charantia on the mycelial growth of Saprolegnia spp. The extracts obtained from the maceration of dry and ground leaves were incorporated into the potato agar dextrose (PDA), at concentrations of 0, 5, 15, 25 and 50%. Later, filter paper disks containing the mycelium of Saprolegnia spp. were applied on the agar and incubated at 25°C. Evaluations were performed every 24 hours, for 10 days. In the study, all concentrations of M. charantia extract had an inhibitory action on the mycelial growth in the order of 75% of Saprolegnia spp. and can be considered a promising alternative for controlling this pathogen.

Entre as principais doenças infecciosas em peixes, as causadas por organismos zoospóricos são importantes, especialmente a saprolegníase. Essas doenças podem afetar poucos animais ou até mesmo toda a população do ambiente de produção. O uso de tratamentos alternativos para doenças infecciosas em animais aquáticos tem se mostrado eficaz. Evita a mortalidade de parte da cultura, bem como a contaminação da água por componentes químicos. Dentro deste cenário, destaca-se o uso de plantas, principalmente plantas alimentícias não convencionais (PANCs). O objetivo deste trabalho foi avaliar o efeito dos extratos aquosos de Luffa cylindrica, Xanthosoma sagittifolium e Momordica charantia sobre o crescimento micelial de Saprolegnia spp. Os extratos obtidos da maceração de folhas secas e moídas foram incorporados em ágar batata dextrose (BDA), nas concentrações de 0, 5, 15, 25 e 50%. Mais tarde, os discos de papel de filtro contendo o micélio de Saprolegnia spp. foram aplicados no ágar e incubados a 25°C. As avaliações foram realizadas a cada 24 horas, por 10 dias. No estudo, todas as concentrações do extrato de M. charantia tiveram ação inibitória sobre o crescimento micelial da ordem de 75% de Saprolegnia spp., podendo ser considerada uma alternativa promissora para o controle desse patógeno.

Entre las principales enfermedades infecciosas en los peces, las causadas por organismos zoospóricos son importantes, especialmente la saprolegniasis. Estas enfermedades pueden afectar a pocos animales o incluso a toda la población del entorno de producción. El uso de tratamientos alternativos para enfermedades infecciosas en animales acuáticos ha demostrado ser efectivo. Previene la mortalidad de parte del cultivo, así como la contaminación del agua por componentes químicos. Dentro de este escenario, se destaca el uso de plantas, principalmente plantas alimenticias no convencionales (PANCs). El objetivo de este trabajo fue evaluar el efecto de los extractos acuosos de Luffa cylindrica, Xanthosoma sagittifolium y Momordica charantia sobre el crecimiento micelial de Saprolegnia spp. Los extractos obtenidos de la maceración de hojas secas y molidas se incorporaron a la papa dextrose agar (PDA), a concentraciones de 0, 5, 15, 25 y 50%. Más tarde, filtre los discos de papel que contienen el micelio de Saprolegnia spp. se aplicaron sobre el agar y se incubaron a 25°C. Las evaluaciones se realizaron cada 24 horas, durante 10 días. En el estudio, todas las concentraciones de extracto de M. charantia tuvieron una acción inhibitoria sobre el crecimiento micelial del orden del 75% de Saprolegnia spp. y puede considerarse una alternativa prometedora para controlar este patógeno.

Physicochemical and rheological properties of purees based on Mafafa (Xanthosoma robustum) and quinoa (Chenopodium quinoa Willd.) with the addition of cryoprotectants.

Growing interest in processed frozen products with similar characteristics to natural products has generated the study of new products in the food industry field. The characteristics of each matrix, the process of elaboration, composition, and structure of the additives and the interactions amongst these modify the food's texture, structure, physical and sensory properties and, hence, interfere directly with consumer acceptance. This research studied the effect of adding cryoprotectors during frozen storage on the rheological, physicochemical, structural, and microbiological properties in a Mafafa-quinoa-olive oil puree. To carry out the study, the rheological properties were determined through dynamic oscillatory tests and in steady state; likewise, the physicochemical properties (humidity, color, pH, and syneresis) were analyzed. Regarding physicochemical properties, the humidity content in the purees formulated varied between 57 and 74%, without important variation (p > .05) with respect to the formulation, however, in the storage during the freezing/thawing process, this parameter diminished in greater proportion in those purees containing carrageenan as cryoconservant. Both the addition of cryoconservants and the storage time affected significantly (p < .05) the puree's syneresis, with the degree of exudation being lower in the formulation containing xanthan gum at 1% w/w. During the freezing/thawing process, decreased apparent viscosity was noted. Additionally, the analysis of the viscoelastic properties of the purees evidences that already described, given that a significant effect (p < .05) was observed of the formulation of purees in the elastic component G', in contrast with a notable decrease in the viscous component G″.

Nutritional Evaluation of Non-Conventional Vegetables in Brazil.

The objective of this study was to characterize the nutritional compounds of interest present in vegetables known as non-conventional, in Brazil. The following evaluations were carried out: antioxidant activity, phenolic compounds, vitamin C, calories, carbohydrates, humidity, lipids, proteins, fiber, acidity and quantification of minerals (P, K, Ca, Mg, S, Cu, Fe, Mn, Zn and B). The species studied were Amaranthus hybridus L., Amaranthus viridis L., Basella alba L., Eryngium campestre L., Hibiscus sabdariffa L., Lactuca canadensis L., Rumex acetosa L., Stachys byzantina K. Koch, Tropaeolum majus L. and Xanthosoma sagittifolium L. Representative samples of plant structures of interest were harvested from each species suitable for human consumption such as leaves, flowers and flower buds. The results were submitted to multivariate analysis - principal components analysis (PCA). All the species present nutritional compounds of interest in different levels among the evaluated structures.

Physicochemical, morphological, and rheological characterization of Xanthosoma robustum Lego-like starch.

This work presents the physicochemical and pasting characterization of isolated mafafa starch and mafafa flour (Xanthosoma robustum). According to SEM images of mafafa starches in the tuber, these starches form Lego-like shaped structures with diameters between 8 and 35 µm conformed by several starch granules of wedge shape that range from 2 to 7 µm. The isolated mafafa starch is characterized by its low contents of protein, fat, and ash. The starch content in isolated starch was found to be 88.58% while the amylose content obtained was 35.43%. X-ray diffraction studies confirm that isolated starch is composed mainly by amylopectin. These results were confirmed by differential scanning calorimetry and thermo gravimetric analysis. This is the first report of the molecular parameters for mafafa starch: molar mass that ranged between 2×10(8) and 4×10(8) g/mol, size (Rg) value between 279 and 295 nm, and molecular density value between 9.2 and 9.7 g/(mol nm(3)). This study indicates that mafafa starch shows long chains of amylopectin this fact contributes to higher viscosity development and higher gel stability. The obtained gel phase is transparent in the UV-vis region. The viscosity, gel stability and optical properties suggest that there is potential for mafafa starch applications in the food industry.

Taioba (Xanthosoma sagittifolium) leaves: nutrient composition and physiological effects on healthy rats.

Several studies have shown that fruits and vegetables contribute to protect against degenerative pathologies such as cardiovascular diseases, diabetes, and cancer, mainly due to the presence of dietary fiber (DF) and polyphenols. Taioba (Xanthosoma sagittifolium) is an edible aroid widely grown in many parts of Africa, America, and Asia. The tubers portions of taioba are widely consumed; however, the leafy portions are generally discarded, despite their high nutritive value. In this study, we have partly characterized the DF of lyophiized taioba leaf (LTL), and assessed the possible protective effects on biochemical parameters and on bile acid (BA) production in colon and cecum, when fed to healthy rats for 4 wk. Forty-five Wistar rats were assigned to either of 5 groups: group 1 received AIN 93G diet (CG: Control); group 2 received AIN 93G containing 2.5% of cellulose + 2.5% inulin (CEIN_5%); group 3 received AIN 93G containing 2.5% of cellulose + 2.5% taioba fiber (CETA_5%); group 4 received AIN 93G containing 5% cellulose + 2.5% taioba fiber (CETA_7.5%); group 5 received AIN 93G containing 5% cellulose + 2.5% of inulin (CEIN_7.5%). LTL showed high contents of total fiber, predominantly comprising insoluble DF with glucose as the major monomer. Rats receiving LTL had increased fecal mass and fat excretion, and improved BA profiles by diminishing the proportion of secondary acids, thus suggesting that consumption of taioba leaf may have the property of lowering the risk of colon cancer.

A Kunitz proteinase inhibitor from corms of Xanthosoma blandum with bactericidal activity.

Bacterial infections directly affect the world's population, and this situation has been aggravated by indiscriminate use of antimicrobial agents, which can generate resistant microorganisms. In this report, an initial screening of proteins with antibacterial activity from corms of 15 species of the Xanthosoma genus was conducted. Since Xanthosoma blandum corms showed enhanced activity toward bacteria, a novel protein with bactericidal activity was isolated from this particular species. Edman degradation was used for protein N-termini determination; the primary structure showed similarities with Kunitz inhibitors, and this protein was named Xb-KTI. This protein was further challenged against serine proteinases from different sources, showing clear inhibitory activities. Otherwise, no hemolytic activity was observed for Xb-KTI. The results demonstrate the biotechnological potential of Xb-KTI, the first proteinase inhibitor with antimicrobial activity described in the Xanthosoma genus.

Carotenoids from malanga (Xanthosoma sagittifolium) leaves protect cells against oxidative stress in rats.

The present study investigated the effect of malanga leaf powder and its carotenoids oil extract on oxidative damage in rat tissues. A group of rats received AIN-93G diet devoid of vitamin A (AD) and three other groups were treated with AD diet supplied with synthetic beta-carotene (beta-car) or malanga leaf powder (MP) or malanga carotenoids extract (CE). The diets' carotenoids bioavailability was determined through carotenoids intake/liver retinol content. Lipid thiobarbituric acid reactive substances (TBARS) and protein (carbonyl) oxidation, and reduced (GSH) and oxidized (GSSG) glutathione concentrations were determined in liver, heart, and brain. Synthetic beta-carotene bioavailability was higher than that of pro-vitamin A carotenoids from MP and CE diets, and no difference was observed between the latter two groups. Liver and heart lipid peroxidation was lower in the beta-car and CE groups than the AD group, while no difference was observed for the MP group. The beta-car, MP, and CE groups showed lower liver protein oxidation than the AD group, and only the CE group had lower heart protein oxidation in relation to AD. The MP group had a lower liver GSSG concentration and higher GSH/GSSG ratio than the AD group, while no difference was observed for heart glutathione concentration among the groups. The results indicate that at physiological levels, beta-car, malanga carotenoids extract, and malanga leaf powder have antioxidant effects in rats.

Malanga (Xanthosoma sagittifolium) and purslane (Portulaca oleracea) leaves reduce oxidative stress in vitamin A-deficient rats.

AIM: This study examined the ability of tropical vegetables to reduce oxidative stress induced by vitamin A deficiency. METHODS: Vitamin A-deficient male Wistar rats were divided into four groups which were treated for 30 days with different diets: AIN-93G vitamin A-deficient diet (DD), DD supplemented with pure beta-carotene (beta-D) and DD supplemented with malanga (Xanthosoma sagittifolium) (MD) or purslane (Portulaca oleracea) (PD) leaves as the only source of vitamin A. The thiobarbituric acid-reactive substances (TBARS), reduced (GSH) and oxidized (GSSG) glutathione, and antioxidant enzyme activities were determined in the heart and liver. RESULTS: The rats fed beta-D, MDand PD showed liver and heart TBARS concentrations lower than did DD rats. The liver GSH concentration of beta-D, MD and PD rats was lower compared to DD rats. The heart GSSG concentration of the vegetable groups was significantly lower than in DD rats. Liver and heart catalase activities were not significantly different among the groups, nor was heart glutathione peroxidase (GPX) activity, however the beta-D rats showed the highest liver GPX activity. There was no difference in liver glutathione-S-transferase level among the groups, while heart activity was higher in rats fed the vegetable leaves. CONCLUSION: This study evidences that the ingestion of purslane or malanga leaves may have a protective effect against oxidative stress caused by vitamin A deficiency.

Preparation of indigestible pyrodextrins from different starch sources.

Starch-modifying processes, such as pyrodextrinization, are potential ways to alter the nutritional features of this polysaccharide. A widely used method for pyrodextrinizing maize starch was also applied to lentil, sorghum, cocoyam, sagu, and cassava starches, and the in vitro digestibility of the products was evaluated. Pyrodextrins were produced by heating starch at 140 degrees C for 3 h, with catalytic amounts of HCl. The enzymatically available starch content of all preparations decreased by 55-65% after modification. Thus, pyrodextrinization seems to be an effective way to produce indigestible glucans from different starches. Pyrodextrins obtained were complex mixtures of starch derivatives with a wide range of molecular weight as estimated by gel filtration chromatography. Both their molecular weight profiles and contents of indigestible fractions varied with starch source. Experiments with lentil and cassava starches showed that changing dextrinization conditions also affects the susceptibility to enzymatic hydrolysis of the product.