Glyceryl monostearate-based oleogels as a new fat substitute in meat emulsion.

Bologna sausages were produced with 25, 50, 75 and 100% of their pork fat content replaced by monoglyceride based-oleogels prepared from conventional or high oleic sunflower oils. Physicochemical, technological, and sensory properties of Bologna sausages were evaluated. Emulsion stability was little affected by fat replacement. All treatments batters exhibited characteristic rheological properties of gels (G' > G″). Overall, the addition of oleogel as a fat substitute made the sausages lighter and a small increase in hardness was observed in the sausages with total fat replacement by oleogels. The sliceability was affected by the reformulation and a higher number of slices were obtained in samples with oleogels in relation to the control. These results were associated to the product structure that became more compact as the amount of pork fat was reduced. However, all samples showed good acceptance by the consumers and no significant difference was observed between treatments. The results showed that monostearate-based oleogel can be a potential fat replacer with higher amount of unsaturated fatty acids to be used in meat products, but retaining the desired characteristics of the traditional products.

Antibiofilm activity in the culture supernatant of a marine Pseudomonas sp. bacterium.

In the marine environment, most solid surfaces are covered by microbial biofilms, mainly composed of bacteria and diatoms. The negative effects of biofilms on materials and equipment are numerous and pose a major problem for industry and human activities. Since marine micro-organisms are an important source of bioactive metabolites, it is possible that they synthesize natural ecofriendly molecules that inhibit the adhesion of organisms. In this work, the antibiofilm potential of marine bacteria was investigated using Flavobacterium sp. II2003 as a target. This strain is potentially a pioneer strain of bacteria that was previously selected from marine biofilms for its strong biofilm-forming ability. The culture supernatants of 86 marine heterotrophic bacteria were tested for their ability to inhibit Flavobacterium sp. II2003 biofilm formation and the Pseudomonas sp. IV2006 strain was identified as producing a strong antibiofilm activity. The Pseudomonas sp. IV2006 culture supernatant (SNIV2006) inhibited Flavobacterium sp. II2003 adhesion without killing the bacteria or inhibiting its growth. Moreover, SNIV2006 had no effect on the Flavobacterium sp. II2003 cell surface hydrophilic/hydrophobic and general Lewis acid-base characteristics, but modified the surface properties of glass, making it on the whole more hydrophilic and more alkaline and significantly reducing bacterial cell adhesion. The glass-coating molecules produced by Pseudomonas sp. IV2006 were found to probably be polysaccharides, whereas the antibiofilm molecules contained in SNIV2006 and acting during the 2 h adhesion step on glass and polystyrene surfaces would be proteinaceous. Finally, SNIV2006 exhibited a broad spectrum of antibiofilm activity on other marine bacteria such as Flavobacterium species that are pathogenic for fish, and human pathogens in both the medical environment, such as Staphylococcus aureus and Pseudomonas aeruginosa, and in the food industry, such as Yersinia enterocolitica. Thus, a wide range of applications could be envisaged for the SNIV2006 compounds, both in aquaculture and human health.

Role of the oil on glyceryl monostearate based oleogels.

The high consumption of saturated and trans fats, used in the formulation of lipid-based foods, is associated with incidence of health problems. Organogels or oleogels are a novel class of structured lipids formed from liquid oil as continuous phase entrapped within network of structuring molecules. The aim of this study was to understand the role of oils with different composition on the formation of glyceryl monostearate (GM) gel network. Glyceryl monostearate-based oleogels were produced with the minimal concentration of 5 wt% in sunflower (SF), high oleic sunflower oil (HOS) and coconut oil (CO). The influence of the oil type on the physicochemical properties of the gel was analyzed. The GM gels showed a solid-like behavior using either high oleic sunflower or sunflower oils but did not form a true gel with coconut oil. Although different oils could affect the crystal formation, all gels exhibited needle-like crystal morphology regardless solvent quality. The GM crystals arranged in a lamellar configuration are responsible for entrapping both SF and HOS oils. Degree of saturation of oils might affect GM oleogel properties. Long chain monounsaturated fatty acids favored the packing of GM crystals in a cohesive gel. Furthermore polymorphism with preferential crystalline ß' form of GM was formed using a medium containing one and two unsaturation. In conclusion, it was observed that the type of oil influenced the formation of the GM gel network. These findings allow the better understanding of GM-based oleogels, providing opportunity to design for food products with improved technological and nutritional properties.

Validation of an Ultraviolet-visible (UV-Vis) technique for the quantitative determination of curcumin in poly(L-lactic acid) nanoparticles.

Curcumin is a natural yellow-orange pigment extracted from turmeric and is a potential substitute of health-dangerous artificial dyes. Nanoencapsulation in biodegradable polymers is a promising alternative to improve curcumin stability and water solubility but curcumin concentration inside the nanoparticles must be precisely known. A reliable method to determine the actual curcumin concentration must be validated since the validation procedures warrant that the method is adequate and sufficient for the specific application involved. This work describes the validation parameters given by the International Conference on Harmonisation (ICH) guidelines to adopt an analytical method based on Ultraviolet-visible spectroscopy for the quantitative determination of curcumin encapsulated in poly(l-lactic acid) nanoparticles. This method was validated in respect to linearity, detection limit, quantification limit, accuracy and precision. Studies on the analytical procedure validation warranted safety in final results obtained for the curcumin concentration in the nanoparticles.