raffinose and verbascose

A modelling approach was developed to better understand the behavior of the flatulence-causing oligosaccharides in cowpea seeds during isothermal water soaking-cooking process. Concentrations of verbascose, stachyose and raffinose were measured both in the seed and in the soaking water during the process (T=30, 60 and 95°C). A reaction-diffusion model was built for the three considered alpha-galactosides both in the seed and in the soaking water, together with a model of water transport in the seed. The model reproduced coupled reaction-diffusion of alpha-galactosides during the soaking-cooking process with a good fit. Produced, diffused and degraded alpha-galactoside fractions were identified by performing a mass balance. During soaking at 30°C, degradation predominated (maximum found for raffinose degradation rate constant of 3.22×10

Topics: Carbohydrate Metabolism; Cooking; Diffusion; Galactosides; Hot Temperature; Models, Theoretical; Oligosaccharides; Raffinose; Seeds; Transition Temperature; Vigna; Water

In Ajuga reptans, raffinose oligosaccharides accumulated during winter. Stachyose, verbascose, and higher RFO oligomers were exclusively found in the vacuole whereas one-fourth of raffinose was localized in the stroma. The evergreen labiate Ajuga reptans L. can grow at low temperature. The carbohydrate metabolism changes during the cold phase, e.g., raffinose family oligosaccharides (RFOs) accumulate. Additionally, A. reptans translocates RFOs in the phloem. In the present study, subcellular concentrations of metabolites were studied in summer and winter leaves of A. reptans to gain further insight into regulatory instances involved in the cold acclimation process and into the function of RFOs. Subcellular metabolite concentrations were determined by non-aqueous fractionation. Volumes of the subcellular compartments of summer and winter leaves were analyzed by morphometric measurements. The metabolite content varied strongly between summer and winter leaves. Soluble metabolites increased up to tenfold during winter whereas the starch content was decreased. In winter leaves, the subcellular distribution showed a shift of carbohydrates from cytoplasm to vacuole and chloroplast. Despite this, the metabolite concentration was higher in all compartments in winter leaves compared to summer leaves because of the much higher total metabolite content in winter leaves. The different oligosaccharides did show different compartmentations. Stachyose, verbascose, and higher RFO oligomers were almost exclusively found in the vacuole whereas one-fourth of raffinose was localized in the stroma. Apparently, the subcellular distribution of the RFOs differs because they fulfill different functions in plant metabolism during winter. Raffinose might function in protecting chloroplast membranes during freezing, whereas higher RFO oligomers may exert protective effects on vacuolar membranes. In addition, the high content of RFOs in winter leaves may also result from reduced consumption of assimilates.

Topics: Adaptation, Physiological; Ajuga; Biological Transport; Carbohydrate Metabolism; Chloroplasts; Cold Temperature; Cytoplasm; Freezing; Microscopy, Electron, Transmission; Oligosaccharides; Plant Leaves; Raffinose; Seasons; Subcellular Fractions

To develop genetic improvement strategies to modulate raffinose family oligosaccharides (RFO) concentration in chickpea ( Cicer arietinum L.) seeds, RFO and their precursor concentrations were analyzed in 171 chickpea genotypes from diverse geographical origins. The genotypes were grown in replicated trials over two years in the field (Patancheru, India) and in the greenhouse (Saskatoon, Canada). Analysis of variance revealed a significant impact of genotype, environment, and their interaction on RFO concentration in chickpea seeds. Total RFO concentration ranged from 1.58 to 5.31 mmol/100 g and from 2.11 to 5.83 mmol/100 g in desi and kabuli genotypes, respectively. Sucrose (0.60-3.59 g/100 g) and stachyose (0.18-2.38 g/100 g) were distinguished as the major soluble sugar and RFO, respectively. Correlation analysis revealed a significant positive correlation between substrate and product concentration in RFO biosynthesis. In chickpea seeds, raffinose, stachyose, and verbascose showed a moderate broad sense heritability (0.25-0.56), suggesting the use of a multilocation trials based approach in chickpea seed quality improvement programs.

Topics: Africa; Asia; Cicer; Environment; Genotype; Oligosaccharides; Raffinose; Seeds; South America; Sucrose

Rice bean, a less known and underutilized legume, has emerged as a potential legume because of its nutritional potential. The nutritional quality of rice bean is higher as compared to many other legumes of Vigna family. In the present study, 16 diverse rice bean genotypes were evaluated for major nutritional constituents viz; protein content, total lipids, dietary fiber, total carbohydrates, vitamins, minerals, protein fractions, amino acid, and fatty acid profile. The protein content to the extent of 25.57% was observed in the genotype BRS-2 with in vitro digestibility of 54.23%. The fatty acid profile revealed the higher percentage of unsaturated fatty viz., linoleic and linolenic acid, which are nutritionally desirable in the diet. Albumins (6.13% to 7.47%) and globulins (13.11% to 15.56%) constituted the major portion of proteins. Anti-nutritional factors were in the range of: total phenolics (1.63% to 1.82%), total tannins (1.37% to 1.55%), condensed tannins (0.75% to 0.80%), hydrolysable tannins (0.56% to 0.79%), trypsin inhibitor (24.55 to 37.23 mg/g), phytic acid (7.32 to 8.17 mg/g), lipoxygenase activity (703 to 950 units/mg), and saponin content (1.2 to 3.1 mg/100 g). The oligosaccharides associated with the production of flatulence viz., raffinose, stachyose, and verbascose were in the limits of 1.66% to 2.58%, 0.94% to 1.88%, and 0.85% to 1.23%, respectively. In vitro protein digestibility up to 55.57% was observed in rice bean genotypes. The present study has revealed that rice bean is a nutritionally rich legume as compared to many other legumes of the category. Among different genotypes BRS-2 was observed superior and could be advocated for consumption as well as for inclusion in crop improvement programs.. Rice bean is nutritionally rich legume, but despite its nutritional excellence, it has been put in underutilized category. Because of this and several other reasons the people are not aware of its nutritional benefits. Moreover, the complete nutritional details are also not available on this pulse. The present study gives the vivid description of nutritional attributes of this legume for making people aware of its nutritional excellence and provoking improved work in rice bean.

Topics: Amino Acids; Ascorbic Acid; Dietary Carbohydrates; Dietary Fiber; Dietary Proteins; Fabaceae; Fatty Acids; Genotype; Lipoxygenase; Niacin; Nutritive Value; Oligosaccharides; Phenols; Phytic Acid; Raffinose; Saponins; Tannins; Trace Elements; Trypsin Inhibitors; Vitamins

Raffinose family oligosaccharides (RFOs) in food are considered anti-nutritional factors. This study elucidated the role of α-galactosidase (α-Gal), levansucrase, and sucrose phosphorylase for conversion of RFOs by lactobacilli. Quantification of gene expression by reverse-transcriptase quantitative PCR revealed that expression of levansucrase and sucrose phosphorylase by Lactobacillus reuteri is increased more than 100 fold when sucrose or raffinose are available. Fava bean (Vicia faba) or field pea (Pisum sativum) flours were fermented with α-Gal positive L. reuteri or α-Gal negative Lactobacillus sanfranciscensis. Isogenic strains lacking levansucrase activity, a L. reuteri ftfA mutant and a L. sanfranciscensis levS mutant, were used for comparison. During growth in pulse flours, L. sanfranciscensis accumulated melibiose and α-galactooligosaccharides (α-GOSs); the levansucrase-negative strain did not grow. L. reuteri metabolized raffinose, stachyose, and verbascose by levansucrase activity and accumulated α-GOSs as metabolic intermediates. Oligosaccharide metabolism in the levansucrase-negative mutant was slower, and accumulation of α-GOSs was not observed. The use of sorghum sourdough fermented with L. reuteri LTH5448 and bean flour in gluten-free baking converted RFOs to α-GOSs by levansucrase and invertase activities. In conclusion, the elucidation of the role levansucrase in RFO metabolism by lactobacilli allowed the conversion or hydrolysis of RFOs in food fermentations.

Topics: Bacterial Proteins; Fermentation; Glucosyltransferases; Hexosyltransferases; Lactobacillus; Oligosaccharides; Raffinose; Sucrose