Improved method to obtain pure a-galactosides from lupin seeds

Improvement of a previously described method of purification of α-galactosides, members of the raffinose family of oligosaccharides (RFOs), has been developed for lupins. The considerable amount of sucrose present in the RFO preparations obtained by the previous method has been removed by modifying the purification stage on diatomaceous earth and charcoal. The present method allows for the preparation of high-purity RFOs containing ∼99.4% of RFOs in the form of a white fine powder, which provides new perspectives for the production of pure α-galactoside preparations for their use as prebiotics in functional foods.Peer Reviewe

Food safety evaluation of broccoli and radish sprouts

Three cultivars of broccoli seeds (Brassica oleracea var. italica), cv. Tiburon, cv. Belstar and cv. Lucky, and two cultivars of radish seeds (Raphanus sativus), cv. Rebel and cv. Bolide, were germinated for three and five days and safety aspects such as microbiological counts and biogenic amines were investigated. Cytotoxicity evaluation was also carried out. Broccoli and radish sprouts contained numbers of mesophilic, psychrotrophic, total and faecal coliform bacteria which are the usual counts for minimally processed germinated seeds. Putrescine, cadaverine, histamine, tyramine, spermidine and spermine increased during sprout production although these levels were below those permitted by legislation (5 mg/100 g of edible food). Broccoli and radish sprouts demonstrated no toxic effects on proliferation and viability of HL-60 cells and should be included in our diets as healthy and safe fresh foods.This research was funded by Project AGL-2004-00886/ALI from the Spanish CYCYT. Dr. Piotr Gulewicz thanks the Spanish Ministry of Education and Science for a postdoctoral fellowship.Peer reviewe

Effect of germination on the protein fractional composition of different lupin species

Sweet lupin seeds (Lupinus luteus cv. 4486 and cv. 4492 and Lupinus angustifolius cv. troll and cv. zapaton) were germinated and investigated according to protein composition, nitrogen and amino acid content of Osborne fractions. In raw lupins, globulins (G) comprised the main fraction of lupins, followed by albumins (A) and glutelins+prolamines (Gt + P). Differences in the protein profile of the Osborne fractions were found among species whilst cultivars did not show electrophoretic differences. Amino acid content of protein fractions was also studied and differences among cultivars were found. In general, Glu, Gly, Arg and Ala (as non-essential amino acids, NEAA) and Lys (as essential amino acid, EAA) were predominant in the A fraction, Glu and Arg (NEAA) and Leu and Thr (EAA) were the main ones in the G fraction; while Asp, Glu, Gly and Arg (NEAA) and Leu and Lys (EAA) were the major components of the Gt + P fraction. Germination increased the protein content of L. luteus cv. 4486, L. angustifolius cv. troll and cv. zapaton and caused sharp changes in the protein profile of the Osborne fractions. After germination, the A fraction almost disappeared in the protein profile while G and Gt + P fractions were modified, depending on the lupin species and cultivarThis work was supported by AGL2004-00886/ALI and Dr. Piotr Gulewicz thanks the Spanish Ministry of Education for providing a postdoctoral fellowship.Peer reviewe

Assessment of protein fraction of three varieties of Pisum sativum L. Effect of germination

Protein composition, nitrogen and amino acid content of Osborne fractions in different cultivars of Pisum sativum L. (cv. ucero, cv. ramrod and cv. agra) seeds were investigated and the effect of germination on these parameters was also analysed. Albumins comprised the main protein fraction in raw seeds, globulins were constituted mainly by vicilin, with a smaller proportion of the glutelin and prolamine fractions. Regarding the amino acid profile of pea protein fractions, although differences among pea cultivars were found, in general albumin, glutelin and prolamine fractions presented Asp, Glu and Gly as the major non-essential amino acids (NEAA) and Lys as the main essential amino acid (EAA). The globulin fraction, however, presented Asp, Glu, Gly and Arg as the major NEAA and Leu, Phe, Lys, and Thr as the main EAA. In general, the albumin fraction accounted for more sulphur amino acids and Lys, followed by the glutelin + prolamine fraction. Germination caused an increase in the total protein content of P. sativum cv. ucero and P. sativum cv. ramrod. In the albumin fraction a wide number of proteins underwent degradation and convicilin disappeared from the globulin fraction of pea sprouts whilst vicilin and legumin decreased slightly. In general, all the Osborne fractions of pea sprouts presented higher EAA contents than raw seeds. The estimated essential amino acid indexes of protein fractions for P. sativum cv. ucero (EAAIadult and EAAIegg) improved with the germination process whilst for P. ativum cv. ramrod and P. sativum cv. agra depended on the Osborne fraction.This work was supported by AGL2004-00886/ ALI and Dr. Piotr Gulewicz acknowledges the Spanish Education Ministry for providing a postdoctoral fellowship.Peer reviewe

Simple method of isolation and purification of α-galactosides from legumes

A simple method for the isolation and purification of α-galactosides, raffinose family oligosaccharides (RFOs), from legumes has been developed. The method includes (i) imbibition of seeds, (ii) extraction with 50% ethanol, (iii) precipitation of RFOs, (iv) purification of RFOs on diatomaceous earth and charcoal, and (v) cation-exchange chromatography. The described method allows one to obtain high purity RFO preparations (90% for lentil and 80% for pea seeds, determined by HPLC-RI analysis) in the form of white, fine powder. Yields of α-galactosides isolated from 100 g of seeds of lentil and pea were 5.6 and 4.3 g, respectively.Peer Reviewe

Biological activity of α-galactoside preparations from Lupinus angustifolius L. and Pisum sativum L. seeds

Biological activity tests were performed on α-galactoside preparations obtained from Lupinus angustifolius L. cv. Mirela (alkaloid-rich) and Pisum sativum L. cv. Opal seeds. The studies included the following tests: acute toxicity, cytotoxic test, delayed type hypersensitivity (DTH), plaque-forming cell number (IgM-PFC), and influence on the growth of bifidobacteia and coliform presence in rat colon. Results of these studies showed that α-galactosides from lupin and pea seeds were essentially nontoxic. Their acute toxicity (LD50) in mice was >4000 mg kg-1 of body weight. α-Galactoside preparations were not cytotoxic for mouse thymocytes in vitro. The in vitro test shows that oligosaccharides from lupin and pea are utilized by selected beneficial colon bacterium strains. The in vivo experiment demonstrated that α-galactosides from legume significantly influenced the growth of bifidobacteria in rats colon. Simultaneously, the decrease of the coliform presence was observed. The chemical composition of the tested preparations had no significant effect on their biological activity.Peer Reviewe

Biogenic amines and HL60 citotoxicity of alfalfa and fenugreek sprouts

The use of germinated seeds as food originated in far east countries and has recently spread to the western world where they are seen as fresh and healthy ingredients. While sprouted alfalfa is widely consumed, sprouted fenugreek seeds are not commonly produced, yet could be active ingredients for blood glucose and cholesterol control. As part of a safety evaluation of sprouted alfalfa and fenugreek flours, as novel ingredients for use in functional foods, their contents of biogenic amines and HL60 cytotoxicity were studied. Alfalfa (Medicago sativa) and fenugreek (Trigonella foenum-graecum) were germinated or 4 days at 20 °C and 30 °C, with and without light. Ungerminated seeds contained putrescine, cadaverine, histamine, tyramine, spermidine and spermine. Bioactive amine levels found in alfalfa sprouts were twice higher than those found in raw seeds and germination at 20 °C without light provided the lowest levels of total biogenic amines. In sprouted fenugreek, only putrescine and cadaverine increased during germination and temperature and light exposure brought about little change. The amount of biogenic amines in sprout seeds was always below acceptable healthy levels. Results obtained in HL60 leukemic cells showed apoptosis, cell proliferation and cell viability values similar to those found for distilled water and no toxic effects were found. The results provide support for the use of germinated alfalfa and fenugreek seeds as ingredients in functional foods.This work was funded by the AGL-2004-00886/ALI project for financial support. Dr. P. Gulewicz acknowledges the Spanish Ministry of Education and Science for a postdoctoral fellowship.Peer reviewe

Sprouted garden cress enriched with selenium

Resumen del trabajo presentado al EuroFoodChem XV: Food for the future, celebrado del 5 al 8 de julio de 2009 en Copenhague (Dinamarca).The effect of different selenium solutions on the content of total selenium, protein, total antioxidant capacity and HL-60 cytotoxicity during germination of garden cress (Lepidium sativum) has been studied. The content of total Se in cress sprouts increased during germination in the presence of Se solutions and the highest Se content was obtained with 8 mg/L. Protein content rose during germination, TEAC suffered the highest increment after Se germination and slight changes between NazSe03 or NazSe04 solutions were observed. Glucotropeolin was the dorninant GLS in raw garden cress and its content decreased after germination, being lower this decrease when Se germination was carried out with NazSe03 solution. Garden cress-Se sprouts caused no cytotoxic effects on HL- 60 cells.This work has been funded by the Spanish Commission of Science and Technology AGL2007- 62044 project.Peer reviewe

Influence of germination with different selenium solutions on nutritional value and cytotoxicity of lupin seeds

The effect of different selenium solutions during germination of lupin seeds (Lupinus angustifolius L. cv. Zapaton) on the content of total selenium, protein, amino acids, soluble carbohydrates, total antioxidant activity, and cytotoxicity on HL-60 human leukemic cell line has been studied. Seeds were germinated in the presence of selenite (Na2SeO3) or selenate (Na2SeO4) solutions at different concentrations (0, 2, 4, 6, and 8 mg/L) for 5 days at either 20 or 25 °C. The addition of inorganic Se forms significantly increased Se content in lupin sprouts in a dose-dependent manner. The highest Se content in lupin sprouts was observed when germination was carried out with selenate solutions at 20 °C (11 μg/g of dw) or 25 °C (14 μg/g of dw). The Se-enriched sprouts presented an improvement in antioxidant activity (up to 117.8 and 103.5 μmol of Trolox/g of dw) as well as in essential amino acid content, and no cytotoxicity was observed on HL-60 human leukemic cells. Lupin seeds germinated with 8 mg/L selenate solutions for 5 days at 20 °C exhibited a higher germination rate (>90%) and a higher concentration of some essential amino acids than those obtained in selenite solutions in the same germination conditions. Therefore, the employment of selenate solutions at a concentration of 8 mg/L and germination for 5 days at 20 °C may be suggested for the production of Se-enriched lupin sproutsWe are indebted to Dr. H. Zieliníski for helpful discussion.Peer reviewe