Marinara-type sauces were created using three natural antimicrobials, as well as two combination treatments (natamycin, propionic acid, cultured dextrose, natamycin-propionic acid, and natamycin-cultured dextrose) and two controls (sodium benzoate-potassium sorbate, no preservatives). Samples were subjected to a shelf-life study at 20 C with both non-inoculated sauce and sauces that were either inoculated with Zygosaccharomyces bailii or a cocktail of thermophilic fermentative organisms. Natamycin and Natamycin-propionic acid treatments had fewer log colony counts (CFU/g) of yeast and lactic acid bacteria than the negative control after 42 days of storage and performed as well or better than the positive control throughout the storage period. No sensory differences were detected (P>0.05) between the natamycin treatment when compared to the industry standard (positive control), but the natamycin-propionic acid treatment was different (P<0.05). Results indicate that natamycin and/or natamycin-propionic acid could be used as a natural alternative in the formulation of marinara sauce.

No description available.

Type 2 diabetes is a worldwide and costly disease that requires complex cellular metabolic breakdown for its development. The onset of this disease is indicated by an abnormal elevated blood glucose level (hyperglycemia) and coexistence with hypertension. Apple and blueberry are the two popular fruits in the U.S. that are high in bioactive phenolic compounds. The objectives of this thesis were to investigate the synergistic health benefits of apple cider and blueberry juice for potential management of early stages of type 2 diabetes using in vitro enzyme assay models and enhance their synergistic effects through fermentation using probiotic strains of lactic acid bacteria. Apple cider and whole blueberry juice were combined at 5 different ratios. Synergistic interaction of the phenolic bioactives between the two juice sources was observed in all assays. For maintenance of high α-glucosidase, α-amylase and ACE inhibition activities, a proportion of 80% apple cider and 20% whole blueberry juice was selected as the optimum combination reflecting maximum health benefits to potentially manage hyperglycemia and hypertension associated with type 2 diabetes. The 80/20 apple cider and blueberry juice combination was fermented at 24 and 48 h using Lactobacillus helveticus R0052 and Bifidobacterium longum isolate. High inhibition of α-glucosidase, α-amylase and ACE enzymes was observed in apple cider/blueberry juice combination. Strong antimicrobial activity against H. pylori was exerted by L. helveticus- and B. longum-fermented sample at 48 h. A possible mode of action through the synergy between lactic acid and proline oxidation pathway was suggested.

No description available.

Yes / Highly oriented poly(lactic acid) (PLA)/thermoplastic polyurethane (TPU) blends were fabricated through solid hot stretching technology in an effort to improve the mechanical properties and blood biocompatibility of PLA as blood-contacting medical devices. It was found that the tensile strength and modulus of the blends can be improved dramatically by stretching. With the increase of draw ratio, the cold crystallization peak became smaller, and the glass transition and the melting peak moved to high temperature, while the crystallinity increased, and the grain size of PLA decreased, indicating of the stress-induced crystallization during drawing. The oriented blends exhibited structures with longitudinal striations which indicate the presence of micro-fibers. TPU phase was finely and homogeneously dispersed in the PLA, and after drawing, TPU domains were elongated to ellipsoid. The introduction of TPU and orientation could enhance the blood compatibility of PLA by prolonging kinetic clotting time, and decreasing hemolysis ratio and platelet activation.

Yes / Highly-oriented poly (lactic acid) (PLA) with bionic fibrillar structure and micro-grooves was fabricated through solid hot drawing technology for further improving the mechanical properties and blood biocompatibility of PLA as blood-contacting medical devices. In order to enhance the melt strength and thus obtain high orientation degree, PLA was first chain branched with pentaerythritol polyglycidyl ether (PGE). The branching degree as high as 12.69 mol% can be obtained at 0.5 wt% PGE content. The complex viscosity, elastic and viscous modulus for chain branched PLA were improved resulting from the enhancement of molecular entanglement, and consequently higher draw ratio can be achieved during the subsequent hot stretching. The stress-induced crystallization of PLA occurred during stretching, and the crystal structure of the oriented PLA can be attributed to the α′ crystalline form. The tensile strength and modulus of PLA were improved dramatically by drawing. Chain branching and orientation could significantly enhance the blood compatibility of PLA by prolonging clotting time and decreasing hemolysis ratio, protein adsorption and platelet activation. Fibrous structure as well as micro-grooves can be observed for the oriented PLA which were similar to intimal layer of blood vessel, and this bionic structure was considered to be beneficial to decrease the activation and/or adhesion of platelets.

Yes / Highly-oriented poly (lactic acid) (PLA) with bionic micro-grooves was fabricated through solid hot drawing technology for further improving the mechanical properties and blood biocompatibility of PLA. In order to enhance the melt strength and thus obtain high orientation degree, long chain branched PLA (LCB-PLA) was prepared at first through a two-step ring-opening reaction during processing. Linear viscoelasticity combined with branch-on-branch (BOB) model was used to predict probable compositions and chain topologies of the products, and it was found that the molecular weight of PLA increased and topological structures with star like chain with three arms and tree-like chain with two generations formed during reactive processing, and consequently draw ratio as high as1200% can be achieved during the subsequent hot stretching. With the increase of draw ratio, the tensile strength and orientation degree of PLA increased dramatically. Long chain branching and orientation could significantly enhance the blood compatibility of PLA by prolonging clotting time and decreasing platelet activation. Micro-grooves can be observed on the surface of the oriented PLA which were similar to the intimal layer of blood vessel, and such bionic structure resulted from the formation of the oriented shish kebab-like crystals along the draw direction.

Yes / Highly oriented poly(lactic acid) (PLA)/multi-walled carbon nanotubes (MWNTs) composites were fabricated through solid hot drawing technology in an effort to improve the mechanical properties and blood biocompatibility of PLA as blood-contacting medical devices. It was found that proper MWNTs content and drawing orientation can improve the tensile strength and modulus of PLA dramatically. With the increase in draw ratio, the cold crystallization peak became smaller, and the glass transition and the melting peak of PLA moved to high temperature, while the crystallinity increased, and the grain size decreased, indicating the stress-induced crystallization of PLA during drawing. MWNTs showed a nucleation effect on PLA, leading to the rise in the melting temperature, increase in crystallinity and reduction of spherulite size for the composites. Moreover, the intensity of (002) diffraction of MWNTs increased with draw ratio, indicating that MWNTs were preferentially aligned and oriented during drawing. Microstructure observation demonstrated that PLA matrix had an ordered fibrillar bundle structure, and MWNTs in the composite tended to align parallel to the drawing direction. In addition, the dispersion of MWNTs in PLA was also improved by orientation. Introduction of MWNTs and drawing orientation could significantly enhance the blood compatibility of PLA by prolonging kinetic clotting time, reducing hemolysis ratio and platelet activation.

No description available.

Synthesized polymer from bio-based and renewable resources reported as an attractive substitution for fossil-fuel based polymers. Therefore, this work has focused on using sustainable material for production of elastomers to reduce the environmental impact of fossil-based elastomers and overcome the shortage of non-renewable fuels. In this research (as thesis work) bio-based elastomers (resins synthesized by reacting of lactic acid with 1,4-butanediol in presence of toluene and methanesulfonic acid as solvent and catalyst, respectively. To trace the reaction, the Fourier transform infrared (FT-IR) spectrometer was used for structural characterization of the products. Furthermore, the degree of reaction followed by measuring of the acid value using alkali titration method. To achieve the desirable results, both condensed resins were reacted with caprolactone for ring opening polymerization. The produced resins were finally functionalized using methacrylic anhydride and the structures and thermal properties of the produced resin were characterized using FT-IR, DSC and TGA. In addition, the viscoelastic properties of the resins were investigated using dynamic mechanical analysis (DMA); and elasticity and viscosity of the elastomers measured using tensile testing machine and viscometer, respectively. The important result such as viscosity showed the resin with chain length n= 5 had higher viscosity when compared to the resin chain length n=3. This makes the resin (n=5) suitable for applications that need high viscosities. The resin with chain length n=3 had lower viscosity that is suitable for processing at room temperature. Furthermore, the tensile strength results show maximum elongation for resin with chain length n=3 is almost double compared to resin with chain length n=5. The results showed that these bio-based resins are compatible with petrochemical-based resins, due to desirable rubbery properties, melting temperature, also acceptable viscosity, and other good mechanical properties as will be mentioned below.