Effect of lactic acid and UV irradiation on the cassava and corn starches

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Osteointegration of poly(L-lactic acid)PLLA and poly(L-lactic acid)PLLA/poly(ethylene oxide)PEO implants in rat tibiae

Natural or synthetic materials may be used to aid tissue repair of fracture or pathologies where there has been a loss of bone mass. Polymeric materials have been widely studied, aiming at their use in orthopaedics and aesthetic plastic surgery. Polymeric biodegradable blends formed from two or more kinds of polymers could present faster degradation rate than homopolymers. The purpose of this work was to compare the biological response of two biomaterials: poly(L-lactic acid)PLLA and poly(L-lactic acid)PLLA/poly(ethylene oxide)PEO blend. Forty four-week-old rats were divided into two groups of 20 animals, of which one group received PLLA and the other PLLA/PEO implants. In each of the animals, one of the biomaterials was implanted in the proximal epiphysis of the right tibia. Each group was divided into subgroups of 5 animals, and sacrificed 2, 4, 8 and 16 weeks after surgery, respectively. Samples were then processed for analysis by light microscopy. Newly formed bone was found around both PLLA and PLLA/PEO implants. PLLA/PEO blends had a porous morphology after immersion in a buffer solution and in vivo implantation. The proportion 50/50 PLLA/PEO blend was adequate to promote this porous morphology, which resulted in gradual bone tissue growth into the implant.

Screening for yeast with antibacterial properties from an ethanol distillery

A general screening for the expression of antibacterial activity and non-flocculating type of yeast strains from must and fermented broth of alcohol distilleries was performed. From 60 strains only Saccharomyces sp. M26 presented a inhibitory halo in Lactobacillus fermentum culture and significant reduction in the culture turbidity (71%) and specific growth rate (56%) when compared to the control. Freezing did not affect the antibacterial activity of the Saccharomyces sp. M26 extract and heating at 90°C for 20 min completely destroyed this activity. It is expected the decrease of lactic acid bacteria growth in the S. cerevisiae alcoholic fermentation should allow for better control of these bacteria in the process. © 2003 Elsevier Ltd. All rights reserved.

L(+) Lactic acid production by new Lactobacillus rhamnosus B 103

L(+) Lactic acid fermentation was studied by Lactobacillus rhamnosus sp. under the effects of pH control and a lowcost nutritional medium (sugarcane juice and corn steep liquor-CSL). Central composite design (CCD) was employed to determine maximum lactic acid production at optimum values for process variables and a satisfactory fit model was realized. Statistical analysis of the results showed that the linear and quadratic terms of two variables (sugarcane juice and pH) had significant effects. The interactions between the three variables were found to contribute to the response at a significant level. A second-order polynomial regression model estimated that the maximum lactic acid production of 86.36 g/L was obtained when the optimum values of sucrose, CSL and pH were 112.65 g/L, 29.88 g/L and 6.2, respectively. Verification of the optimization showed that L(+) lactic acid production was of 85.06 g/L. Under these conditions, Y P/S and Q P values of 0.85 g/g and 1.77 g/Lh, respectively, were obtained after 48 h fermentation, with a maximal productivity of 2.2 g/L h at 30 h of process. © 2010 de Lima CJB, et al.

Aperfeiçoamento do processo de fermentação láctica em diferentes hortaliças e avaliação de aspectos econômicos e energéticos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo in situ de culturas autóctones de Lactobacillus helveticus autolíticus sobre a dinâmica bioquímica e sensorial do queijo Paramesão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da suplementação alimentar com bactéria probiótica no crescimento e sanidade de Arapaima gigas em sistema de recirculação de água

As bactérias acido lácticas tem se destacado por desempenhar efeitos benéficos ao hospedeiro, entre eles destacam-se a ativação no sistema imunológico, desempenho zootécnico e eficiência alimentar. O objetivo deste trabalho foi selecionar e a avaliar bactérias potencialmente probiótica no crescimento e sanidade de Arapaima gigas. A primeira etapa foi o isolamento e seleção de bactérias com potencial probiótico a partir de 10 juvenis de A. gigas sendo submetidas a testes in vitro de inibição de patógenos bacterianos conhecidos para aquicultura, e a segunda etapa consistiu em testes in vivo avaliando a colonização do trato intestinal pela cepa bacteriana e sua relação com a hematologia. A cepa com melhor halo de inibição foi identificada com o kit API50 CH como Lactobacillus paracasei (99.9%). Para avaliação in vivo, os animais foram alimentados durante 120 dias com dieta contendo somente leite estéril (T1), dieta controle sem bactéria (T2), dieta com 105 L. paracasei (T3) e dieta com 106 L. paracasei(T4). Após este período os peixes foram submetidos três tratamentos: injeção intraperitoneal com Aeromonas hydrophila, injeção de solução salina e peixes não injetados. Ao final de 24 horas de desafio foi observado elevada mortalidade dos peixes pertencentes ao grupo T3, T4 em relação ao T1. Os resultados nos permite concluir que a cepa utilizada nos testes in vivo não influenciou o desempenho zootécnico, além de ser ineficaz na proteção contra a infecção por Aeromonas.

Rehydration of corn grain with acid whey improves the silage quality

Our objective was to investigate the effects of rehydration with acid whey or water at three moisture levels, as well as the effects of bacterial inoculation, on the fermentation, chemical composition and aerobic stability of corn grain silages. The trial was conducted in a completely randomized design with four replicates in a factorial arrangement as follows: 3 (rehydration with three different moisture levels: 300,350 and 400 mL/kg of corn grain)x 2 (silage inoculated with bacteria or not inoculated (control))x 2 (liquid used in the rehydration: acid whey or water). Overall, corn grain silages rehydrated with acid whey produced more lactic acid than the silages rehydrated with water (13.8 vs. 12.6 g/kg of dry matter (DM), respectively). In addition, increases in the rehydration of corn grain silages promoted decreases (linear) in lactic acid concentration as well as in production of total acids. Although inoculated silages had higher pH as consequence of the rehydration using water at the three levels, these treatments presented high DM recovery. In general, neutral detergent fiber (aNDFom) decreased if inoculant was applied in corn grain silages rehydrated with acid whey. After silos opening, silages rehydrated with 350 or 400 mL/kg (independent of the liquid) had lower aerobic stability than silages rehydrated with 300 mL/kg. Overall, we found that the inoculant did not promote significant changes in the composition of the corn grain silage. In contrast, the potential of the use of acid whey in ensiling corn grain is high, as its addition leads to improvements in the fermentation process and aerobic stability of the silages. (C) 2014 Elsevier B.V. All rights reserved.

Leuconostoc mesenteroides SJRP55: a potential probiotic strain isolated from Brazilian water buffalo mozzarella cheese

The probiotic potential of Leuconostoc mesenteroides subsp. mesenteroides SJRP55 isolated from water buffalo mozzarella cheese was evaluated. The microorganism presented resistance to stressful conditions that simulated the gastrointestinal tract, and to the best of our knowledge Leuconostoc mesenteroides SJRP55 was the first of this species with the ability to deconjugate bile salts. Tolerance to NaCl was temperature dependent, as well the results obtained by aggregation capacity. The strain presented good adhesion properties, β galactosidase activity, viability in fermented milk during storage, non-active against Streptococcus thermophilus and sensible to most of the tested antibiotics. Some analgesic medications inhibited the growth of the strain. Leuconostoc mesenteroides SJRP55 exhibited in vitro probiotic potential, and it can be better characterized through future in vivo tests. This bacterium presents higher functional properties compared to other studied strains, and therefore it is a potential candidate for the application as a probiotic strain, which could be used by industries in the manufacture of functional milk-based products.

Nanoelectrocatalytic oxidation of lactic acid using nickel nanoparticles

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Zidovudine-poly (L-lactic acid) solid dispersions with improved intestinal permeability prepared by supercritical antisolvent process

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desenvolvimento de um embutido cárneo fermentado, com teores reduzidos de gordura e sais de cura, através da utilização de culturas probióticas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Lactobacillus sakei 2a and its Concentrated Acid Extract on Inhibition of Food-Borne Salmonella strains

Lactic acid bacteria are used in food production to provide desirable organoleptic characteristics, and can also act as biopreservatives, controlling the growth of undesirable microorganisms. In this study, we examined the antimicrobial action of Lactobacillus sakei 2a and its concentrated acid extract against food-borne Salmonella spp. The extract was obtained by acid extraction from culture broth of L. sakei 2a and was designated extract 2a. We determined that extract 2a had significant activity (approximately 500 AU ml(-1)). We used different antimicrobial substances alone or in combination with extract 2a to evaluate the inhibitory activity of the various treatments on a pool of five Salmonella strains. The pathogen Listeria monocytogenes Scott A Cm-r Em(r) was used as an indicator strain of inhibitory activity. In summary, all antimicrobials substances that were tested showed an inhibitory effect against the growth of Salmonella, andthis action was enhanced in the presence of extract 2a. Moreover, among the treatments applied, the combination of extract 2a and 0.1% lactic acid exhibited the most potent inhibitory effect towards the pool of Salmonella strains. Our findings indicate that L. sakei 2a and extract 2a, especially in combination with other antimicrobials, present potential technological application in the control of salmonellae in foods.

Influence of milk type and addition of passion fruit peel powder on fermentation kinetics, texture profile and bacterial viability in probiotic yoghurts

The effect of the addition of passion fruit peel powder (PFPP) on the fermentation kinetics and texture parameters, post-acidification and bacteria counts of probiotic yoghurts made with two milk types were evaluated during 28 days of storage at 4 degrees C. Milks were fermented by Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (CY340), and one strain of probiotic bacteria: Lactobacillus acidophilus (L10 and NCFM), Bifidobacterium animalis subsp. lactis (8104 and HN019). The addition of PFPP reduced significantly fermentation time of skim milk co-fermented by the strains L10, NCFM and HN019. At the end of 28-day shelf-life, counts of B. lactis Bl04 were about 1 Log CFU mL(-1) higher in whole yoghurt fermented with PFPP regarding its control but, in general, the addition of PFPP had less influence on counts than the milk type itself. The titratable acidity in yoghurts with PFPP was significantly higher than in their respective controls, and in skim yoghurts higher than in the whole ones. The PFPP increased firmness, consistency (except for the NCFM strain of L acidophilus) and cohesiveness of all skim yoghurts. The results point out the suitability of using passion fruit by-product in the formulation of both skim and whole probiotic yoghurts. (C) 2012 Elsevier Ltd. All rights reserved.

Multi-Walled Carbon Nanotubes and Poly(lactic acid) Nanocomposite Fibrous Membranes Prepared by Solution Blow Spinning

Nanocomposite fibers based on multi-walled carbon nanotubes (MWCNT) and poly(lactic acid) (PLA) were prepared by solution blow spinning (SBS). Fiber morphology was characterized by scanning electron microscopy (SEM) and optical microscopy (OM). Electrical, thermal, surface and crystalline properties of the spun fibers were evaluated, respectively, by conductivity measurements (4-point probe), thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), contact angle and X-ray diffraction (XRD). OM analysis of the spun mats showed a poor dispersion of MWCNT in the matrix, however dispersion in solution was increased during spinning where droplets of PLA in solution loaded with MWCNT were pulled by the pressure drop at the nozzle, producing PLA fibers filled with MWCNT. Good electrical conductivity and hydrophobicity can be achieved at low carbon nanotube contents. When only 1 wt% MWCNT was added to low-crystalline PLA, surface conductivity of the composites increased from 5 x 10(-8) to 0.46 S/cm. Addition of MWCNT can slightly influence the degree of crystallinity of PLA fibers as studied by XRD and DSC. Thermogravimetric analyses showed that MWCNT loading can decrease the onset degradation temperature of the composites which was attributed to the catalytic effect of metallic residues in MWCNT. Moreover, it was demonstrated that hydrophilicity slightly increased with an increase in MWCNT content. These results show that solution blow spinning can also be used to produce nanocomposite fibers with many potential applications such as in sensors and biosensors.