Ispitivanje fermentacijskih svojstava smeđe riže i rižinih mekinja radi uzgoja Lactobacillus plantarum NCIMB 8826

The growth on rice-based media of the probiotic strain Lactobacillus plantarum NCIMB 8826 isolated from the human gut has been investigated. Fermentation broths were obtained from the whole grain brown rice and rice bran of two Thai rice cultivars, RD6 (glutinous) and RD17 (nonglutinous). The rice used was not germinated and fermentations were carried out in a single step without growth supplementation. L. plantarum grew well in all tested broths, and a final biomass value of approx. 10.4 log CFU/mL was obtained. In addition, biomass production and substrate depletion were satisfactorily modelled using an unstructured mathematical model. There were no statistical differences observed among the four rice media. The results confirm that brown rice and rice bran are suitable substrates for the culture of the probiotic L. plantarum NCIMB 8826. Rice bran, currently a by-product of the traditional cereal processing industry, has shown similar fermentability to brown rice. This indicates that rice bran or rice bran extracts could be used in new probiotic food developments, while probably still maintaining other functional properties of the bran.U radu je ispitan rast soja mliječno-kiselih probiotičkih bakterija Lactobacillus plantarum NCIMB 8826, izoliranog iz crijeva čovjeka, u podlogama s rižom. Pripremljene su podloge od integralne (smeđe) riže i mekinja dvaju kultivara tajlandske riže, RD6 i RD17. Upotrijebljena je nenaklijala riža, a fermentacija je provedena u jednom koraku i bez dodatka stimulatora rasta. Soj L. plantarum rastao je dobro u svim podlogama, pa je postignut maksimalni prinos biomase od 10,4 log CFU/mL. Proizvodnja biomase i potrošnja supstrata uspješno su modelirane pomoću nestrukturiranoga matematičkog modela. Nije uočena statistički bitna razlika između rezultata dobivenih uzgojem soja u četiri različite podloge. Rezultati potvrđuju da su tajlandska integralna riža i rižine mekinje prikladne podloge za uzgoj probiotičkoga soja Lactobacillus plantarum NCIMB 8826. Utvrđeno je da rižine mekinje, nusproizvod dobivanja ljuštene (bijele) riže, imaju slična fermentacijska svojstva kao i smeđa riža. Stoga je zaključeno da se rižine mekinje ili ekstrakt rižinih mekinja mogu uspješno upotrijebiti za dobivanje novih probiotičkih proizvoda, a da pritom ne izgube ostala funkcionalna svojstva

Controlled germination to enhance the functional properties of rice

6 páginas, 4 figurasThe production of prebiotic oligosaccharides during germination of rice has been investigated. Germination of waxy (RD6) and non-waxy (RD17) rice was compared by evaluating the total reducing sugars, free amino nitrogen, pH and enzyme activities over a 7-day period. An increment of amylolytic enzymes and chemical changes were observed in both varieties. RD6 showed higher levels of total reducing sugars and also higher amylolytic activities including α-amylase and α-glucosidase, which reached maximum values at the third day of germination. However, the amount of free amino nitrogen in RD6 was lower than in RD17. Sugar analysis indicates that RD6 produces higher concentration of sugars and oligosaccharides during germination. Based on these results, germinated RD6 at different times was used to produce malted rice syrup through mashing. After saccharification, the malted rice syrup contained different concentrations of sugars and oligosaccharides, particularly isomaltose, panose and isomaltotriose, which have been reported to have prebiotic propertiesThis research was carried out with the financial support of The Royal Thai Government ScholarshipPeer reviewe

Evaluation of the fermentability of oat fractions obtained by debranning using lactic acid bacteria

11 páginas, 5 tablas, 4 figurasAims: The overall kinetics of the fermentation of four oat fractions obtained by debranning using three potentially probiotic lactic acid bacteria were investigated. The main objective was to study the suitability of these fractions as fermentation media for the growth and the metabolic production of bacteria isolated from human intestine. Methods and Results: The cell growth, lactic acid production and substrate uptakes of the three lactobacilli was monitored for 30 h. An unstructured mathematical model was used to describe and fit the experimental data. In the medium from fraction B (1–3% pearlings or β-glucan-rich fraction) all strains reached the highest cell populations, maximum growth rates and maximum lactic acid productions. This could be because of the high levels of total fibre and β-glucan of this fraction. Limited growth and lactic acid formation was found in medium A (0–1% pearlings or bran-rich fraction). Conclusions: Medium B (1–3% pearling fraction) is the most suitable for fermentation and produces considerably higher probiotic cell concentrations. Significance and Impact of the Study: Debranning technology could be used to separate fractions from cereal grains for the production of functional formulations with higher probiotic levels than the ones that were obtained with the whole grainPeer reviewe

Enzymatic digestion and in vitro fermentation of coat fractions by human lactobacillus strains

7 páginas, 4 tablas, 3 figurasOats have received considerable interest for their high content of soluble and insoluble fibre and for their high fermentability with probiotic lactic acid bacteria. However, these fibres are not uniformly distributed within the oat kernel. Oat fractions were obtained by debranning technology and the pearlings generated were hydrolysed in vitro using gastric and pancreatic enzymes of human origin. The indigestible part was separated using dialysis and the soluble and insoluble fibre was obtained by precipitation with ethanol. The suspensions were later fermented by lactic acid bacteria of human origin to evaluate the prebiotic potential of the oat fractions and flours in vitro. Of the three probiotic strains tested, Lactobacillus plantarum showed in all media a higher maximum growth. The 1–3% pearling oat sample has higher fermentation ability and the indigestible components of this fraction showed the highest growth of lactobacilliPeer reviewe

Fermentability of whole oat flour, PeriTec flour and bran by Lactobacillus plantarum

4 páginas, 2 tablas, 1 figuraWhole oat flour obtained by hammer milling was fermented with Lactobacillus plantarum along with white flour and bran in order to compare the suitability of these substrates for the production of a probiotic beverage. The three substrates show a viable cell concentration at the end of fermentation above the minimum required in a probiotic product. The highest cell concentration was observed in white flour (9.16 Log10 CFU/mL) and the lowest in the bran sample (8.17 Log10 CFU/mL)Peer reviewe

Kinetics of daidzin and genistin transformations and water absorption during soybean soaking at different temperatures

7 páginas, 7 tablas, 5 figurasThe kinetics of the isoflavone transformations (diadzin, diadzein, genistin and genistein) and moisture content in soaked soybeans were studied in the temperature range 30–85 °C. The evolution of the moisture was described by Peleg’s model, and a modified first order kinetic equation was used to predict the transformation profiles of different isoflavones in the soaked soybeans. The dependency, on temperature, of the kinetic parameter was modelled by the Arrhenius equation and empirical equations. The measured β-glucosidase activity at different temperatures justifies the experimental profiles of isoflavone conversionThe authors wish to thank the SPMU-TPSDP Diponegoro University (Indonesia) for the grant awarded to Dyah Hesti Wardhani to do this research (ADB Loan No. 1792-INO). Dr. José Antonio Vázquez Álvarez has been awarded a postdoctoral grant (Bolsas para estadías fóra de Galicia, 2007) by the dirección Xeral de Investigación, Desenvolvemento e Innovación, Xunta de Galicia, Spain.Peer reviewe

Optimisation of antioxidants extraction from soybeans fermented by Aspergillus oryzae

4 figuras, 7 tablasThe extraction of antioxidant compounds from soybeansfermented with Aspergillusoryzae was optimised using a factorial design. A kinetic study of the total phenolic production and DPPH radical scavenging activity was first performed at the points selected in the factorial design. In both cases, the experimental profiles were fitted to a modified first-order kinetic model. To investigate the combined effects of temperature and solvent concentration on the extraction, the parameters obtained from the fitted kinetic models were used as response variables in a rotatable second-order design with quintuple replications in the centre of the experimental domain. The results obtained indicate that temperature had the most significant effect. The response surfaces show a maximum in the experimental domain studied. The optimum conditions for the extraction of total phenolic content were 65.3 °C and 73.1% ethanol, in which 56.2 mg of GAE/g were predicted. A scavenging activity of 81.6% DPPH radical was predicted at the optimum conditions of 61.6 °C and 60% ethanolDrs. Pablo Fuciños and José Antonio Vázquez has been awarded a postdoctoral grant (Programa de bolsas para estadías fóra de Galicia, 2007 and 2008 respectively) by the Dirección Xeral de Investigación, Desenvolvemento e Innovación, Xunta de Galicia, Spain.Peer reviewe