Perfil sensorial e aceitação de bolos de laranja formulados com prebióticos

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Desenvolvimento de néctar à base de mamão (Carica papaya L.) adicionado de inulina e oligofrutose

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Características químicas, físicas e sensoriais de bolos de laranja e pães adicionados de inulina e oligofrutose

Inulin and oligofructose are fructans that can change important characteristics in original products when added in food. Two formulations of orange cakes (one containing 77.7g of inulin and another one 77.7g of oligofructose/inulin) and two formulations of breads (one containing 130g of inulin and another one 175g of oligofructose/inulin) were compared to the respective standard formulations (with no fructans) in relation to chemical composition, texture, volume, color and sensory acceptability with a nine-point hedonic scale. The cakes and breads with inulin and oligofructose/inulin showed greater amount of total dietary fiber in relation to standard products. The orange cake with inulin had lower cohesiveness and yellower dough when compared to the standard cake, but the addition of inulin and oligofructose/inulin reduced the acceptability for appearance, texture and flavor and the overall acceptability, although the acceptability for aroma was the same for the three products. The breads with inulin and oligofructose/inulin were harder and less cohesive than the standard bread, and bread with inulin showed minor volume in relation to the standard. The bread with inulin also presented crust with lower luminosity, dough with higher intensity of redness and yellowness and higher intensity of color in relation to standard, besides different hue. In relation to sensory acceptability, the bread with oligofructose/inulin had higher overall acceptability and flavor when compared to standard bread.

Papaya nectar formulated with prebiotics: Chemical characterization and sensory acceptability

Mixture modeling methodology was used to investigate interactions of sugar, oligofructose and inulin in papaya nectars as related to sensory liking and chemical characteristics. Mixing sugar and inulin and increasing the sugar proportion raised the liking of flavor and sweetness and the overall acceptability of papaya nectars. Addition of the three components, along with raising the sugar proportion, increased the ash and soluble solids content in papaya nectars. The internal preference mappings showed that all nectars with oligofructose and inulin were as well liked as nectar containing sugar alone, except for some formulations with lower quantities of sugar. Formulations with 6 g/100 g sugar and 6 g/100 g inulin, or with 8 g/100 g sugar, 2 g/100 g inulin and 2 g/100 g oligofructose, can be considered to be the best formulations to produce, with regard to sensory liking and adequacy of chemical parameters, besides all papaya nectars with addition of oligofructose and inulin can potentially be claimed as prebiotic. (C) 2015 Elsevier Ltd. All rights reserved.

Effect of the consumption of a symbiotic shake on the intestinal microflora of erdely people

The consumption of foods containing probiotic and prebiotic ingredients is growing consistently every year, and in view of the limited number of studies investigating their effect in the elderly. Objective The objective of this study was to evaluate the effect of the consumption of a symbiotic shake containing Lactobacillus acidophilus, Bifidobacterium bifidum and fructooligosaccharides on glycemia and cholesterol levels in elderly people. Methods A randomized, double-blind, placebo-controlled study was conducted on twenty volunteers (ten for placebo group and ten for symbiotic group), aged 50 to 60 years. The criteria for inclusion in the study were: total cholesterol > 200 mg/dL; triglycerides > 200 mg/dL and glycemia > 110 mg/dL. Over a total test period of 30 days, 10 individuals (the symbiotic group) consumed a daily dose of 200 mL of a symbiotic shake containing 108 UFC/mL Lactobacillus acidophilus, 108 UFC/mL Bifidobacterium bifidum and 2 g oligofructose, while 10 other volunteers (the placebo group) drank daily the same amount of a shake that did not contain any symbiotic bacteria. Blood samples were collected 15 days prior to the start of the experiment and at 10-day intervals after the beginning of the shake intake. The standard lipid profile (total cholesterol, triglycerides and HDL cholesterol) and glycemia, or blood sugar levels, were evaluated by an enzyme colorimetric assay. Results The results of the symbiotic group showed a non-significant reduction (P > 0.05) in total cholesterol and triglycerides, a significant increase (P < 0.05) in HDL cholesterol and a significant reduction (P < 0.05) in fasting glycemia. No significant changes were observed in the placebo group. Conclusion The consumption of symbiotic shake resulted in a significant increase in HDL and a significant decrease of glycemia.

In Vitro Evaluation of the Probiotic Potential of Bacteriocin Producer Lactobacillus sakei 1

Lactobacillus sakei 1 is a food isolate that produces a heat-stable antimicrobial peptide (sakacin 1, a class ha bacteriocin) inhibitory to the opportunistic pathogen Listeria monocytogenes. Bacterial isolates with antimicrobial activity may be useful for food biopreservation and also for developing probiotics. To evaluate the probiotic potential of L. sakei I, it was tested for (i) in vitro gastric resistance (with synthetic gastric juice adjusted to pH 2.0, 2.5, or 3.0); (ii) survival and bacteriocin production in the presence of bile salts and commercial prebiotics (inulin and oligofructose); (iii) adhesion to Caco-2 cells; and (iv) effect on the adhesion of L. monocytogenes to Caco-2 cells and invasion of these cells by the organism. The results showed that L. sakei I survival in gastric environment varied according to pH, with the maximum survival achieved at pH 3.0, despite a 4-log reduction of the population after 3 h. Regarding the bile salt tolerance and influence of prebiotics, it was observed that L. sakei 1 survival rates were similar (P > 0.05) for all de Man Rogosa Shame (MRS) broth formulations when tests were done after 4 h of incubation. However, after incubation for 24 h, the survival of L. sakei 1 in MRS broth was reduced by 1.8 log (P < 0.001), when glucose was replaced by either inulin or oligofructose (without Oxgall). L. sakei 1 was unable to deconjugate bile salts, and there was a significant decrease (1.4 log) of the L. sakei 1 population in regular MRS broth plus Oxgall (P < 0.05). In spite of this, tolerance levels of L. sakei 1 to bile salts were similar in regular MRS broth and in MRS broth with oligofructose. Lower bacteriocin production was observed in MRS broth when inulin (3,200 AU/ml) or oligofructose (2,400 AU/ml) was used instead of glucose (6,400 AU/ml). L. sakei I adhered to Caco-2 cells, and its cell-free pH-neutralized supernatant containing sakacin I led to a significant reduction of in vitro listerial invasion of human intestinal Caco-2 cells.

Equine laminitis: cleavage of laminin 5 associated with basement membrane dysadhesion

Reasons for performing study: The key lesion of laminitis is separation at the hoof lamellar dermal-epidermal interface. For this to happen the structural and adhesion proteins of the basement membrane zone must be altered. Which proteins and how damage to them leads to the lamellar separation of laminitis is unknown. Objectives: To investigate lamellar hemidesmosome and cytoskeleton damage and basement membrane dysadhesion using light microscopy (LM) and immunofluorescence microscopy (IFM). Methods: Cryostat sections of lamellar tissues from 2 control and 6 Standardbred horses with oligofructose induced laminitis were studied using LM and IFM. Plectin, integrin alpha(6) and BP230 antibody was used to label hemidesmosome intracellular plaque proteins and anti-BP180 and anti-laminin 5 (L5) was used to label anchoring filament (AF) proteins. Cytoskeleton intermediate filaments were labelled using anti-cytokeratin 14. The primary antibodies of selected sections were double labelled to show protein co-localisation. Results: Laminitis caused reduction of transmembrane integrin alpha(6), the AF proteins BP180 and L5,and failure of co-localisation of BP180 and L5. Proteins of the inner hemidesmosomal plaque, plectin and BP230, were unaffected. Conclusions: Loss of co-localisation of L5 and BP180 suggests that, during the acute phase of laminitis, L5 is cleaved and therefore, the AFs connecting the epidermis to the dermis, fail. Without a full complement of AFs separation at the lamellar dermo-epidermal junction occurs. Potential relevance: Suppressing or inhibiting metalloproteinase activity may prevent L5 cleavage and therefore the lamellar dermo-epidermal separation of laminitis.

Production of bioactive metabolites by intestinal bacteria

The adult intestinal microbiota comprises a microbial ecosystem of approximately 100 trillion microorganisms, with specific bacterial communities holding distinct metabolic capabilities. Bacteria produce a range of bioactive compounds to survive unfavourable stimuli and to interact with other organisms, and generate several bioactive products during degradation of dietary constituents the host is not capable of digesting. This thesis addressed the impact of feeding potential probiotic bacteria and other dietary strategies such as pure fatty acids and prebiotics, on gut microbiota composition, short chain fatty acid (SCFA) production and modulation of metabolism in animal models. In the first experimental chapter (Chapter 2) a gas chromatography method for the quantification of SCFA was optimized and applied in the analysis of caecal samples obtained in animal studies described in other chapters of this thesis. In Chapter 3, t10, c12 CLA supplementation was shown to significantly alter murine gut microbiota composition and SCFA production rather than no supplementation. These changes were suggested to be extra factors affecting host lipid metabolism. Chapter 4 described the contrasting effects of CLA-producing strains, Bifidobacterium breve DPC 6330 and B. breve NCIMB 702258, on murine fat distribution/composition and gut microbiota composition, suggesting that these changes were most likely strain-dependent. In Chapter 5, dietary GABA-producing strain Lactobacillus brevis DPC 6108 was shown to significantly increase (p<0.05) serum insulin in healthy rats, leading to a second experiment using a type 1 diabetes rat model. Lb. brevis DPC 6108 administration did not change insulin levels in diabetic rats, but attenuated high levels of glucose when compared to diabetic control. However, an auto-immune-induced diabetes model was suggested as a better model to study GABA-related effects on diabetes. In Chapter 6 bovine milk oligosaccharides, 6’sialyllactose and Beneo Orafti P95 oligofructose supplementations were associated with depletion or reduction of less favourable bacteria, demonstrating that ingestion of these oligosaccharides might be a safe and effective approach to modulate populations of the intestinal microbiota. In Chapter 7 (General discussion) the major findings of all studies were reviewed and discussed.