Simone Hickmann Flôres

Edible film production from chia seed mucilage: Effect of glycerol concentration on its physicochemical and mechanical properties

This study investigated the physicochemical and mechanical properties of a novel edible film based on chia mucilage (CM) hydrocolloid. CM (1% w/v) films were prepared by incorporation of three concentrations of glycerol (25%, 50%, and 75% w/w, based on CM weight). As glycerol concentration increased, water vapor permeability (WVP), elongation at break (EB), and water solubility of CM films increased while their tensile strength (TS), and Youngs modulus (YM) decreased significantly (p<0.05). CM films containing a high concentration of glycerol were slightly reddish and yellowish in color but still had a transparent appearance. CM films exhibited excellent absorption of ultraviolet light, and good thermal stability. The scanning electron micrographs showed that all CM films had a uniform appearance. This study demonstrated that the chia mucilage hydrocolloid has important properties and potential as an edible film, or coating.

Development of active biofilms of quinoa (Chenopodium quinoa W.) starch containing gold nanoparticles and evaluation of antimicrobial activity.

Active biofilms of quinoa (Chenopodium quinoa, W.) starch were prepared by incorporating gold nanoparticles stabilised by an ionic silsesquioxane that contains the 1,4-diazoniabicyclo[2.2.2]octane chloride group. The biofilms were characterised and their antimicrobial activity was evaluated against Escherichiacoli and Staphylococcusaureus. The presence of gold nanoparticles produces an improvement in the mechanical, optical and morphological properties, maintaining the thermal and barrier properties unchanged when compared to the standard biofilm. The active biofilms exhibited strong antibacterial activity against food-borne pathogens with inhibition percentages of 99% against E. coli and 98% against S. aureus. These quinoa starch biofilms containing gold nanoparticles are very promising to be used as active food packaging for the maintenance of food safety and extension of the shelf life of packaged foods.

Effect of cooking on the concentration of bioactive compounds in broccoli (Brassica oleracea var. Avenger) and cauliflower (Brassica oleracea var. Alphina F1) grown in an organic system.

Brassica vegetables have been shown to have antioxidant capacities due to the presence of carotenoids, flavonoids and vitamins. This study evaluates the influence of different processing conditions (boiling, steaming, microwaving and sous vide) on the stability of flavonoids, carotenoids and vitamin A in broccoli and cauliflower inflorescences grown in an organic system. Results indicated that sous vide processing resulted in greater antioxidant capacity and that all processes contributed in some way to an increased content of antioxidant compounds in both cauliflower and broccoli.

Nisin production from Lactococcus lactis A.T.C.C. 7962 using supplemented whey permeate.

The influence of pH control and aeration (20% dissolved oxygen) on nisin production in a supplemented cheese whey permeate was examined during batch fermentation with Lactococcus lactis subsp. lactis A.T.C.C. 7962. A maximum nisin activity of 5280 i.u./ml of medium was observed in the raw extract of nisin after 9 h of fermentation with a constant pH at 4.9. However, the fermentation was continued until 24 h, when a decrease in the nisin activity was observed. The pH control did not influence the nisin production and aeration of the culture medium increased cell growth (biomass) but not nisin activity. The yeast Kluyveromyces marxianus, used as an alternative method to control pH, has not been efficient.

The optimization of biohydrogen production by bacteria using residual glycerol from biodiesel synthesis

In this research the production of hydrogen by Klebsiella pneumoniae BLb01 using residual glycerol discharged from a biodiesel fuel production plant was investigated. Klebsiella pneumoniae BLb01 was isolated from a bacteria-rich sludge of an upflow anaerobic sludge blanket reactor (UASB) of a soybean processing plant. A Plackett–Burman design (P-B) and Response Surface Methodology (RSM) were employed to determine the optimal condition for enhanced hydrogen production. The maximal hydrogen production, which was 45.0 mol % and with 98% of glycerol degradation, was achieved with the optimized medium with the following composition: 30 g L−1 glycerol; 3 g L−1 yeast ex tract 3 g L−1 K2HPO4; 1 g L−1 KH2PO4; temperature 39°C and pH 9.0. These results show the ability of this new strain of effectively converting residual glycerol into value-added energy products.

Hydroethanolic extracts from different genotypes of açaí (Euterpe oleracea) presented antioxidant potential and protected human neuron-like cells (SH-SY5Y)

Fruit breeding programs have resulted in bioactive compounds increase and health effects. Thus, this study aimed to evaluate the antioxidant activity and neuroprotective effects of the hydroethanolic extracts from six açaí (Euterpe oleracea) genotypes using ABTS, deoxyribose, and glutathione oxidation assays, as well as, SH-SY5Y cells insulted with H2O2. L22P13 genotype showed the highest total content of anthocyanins, while L06P13 showed a high content of total carotenoids. However, the genotypes showed no difference in the antioxidant activity by ABTS and deoxyribose assays. The hydroethanolic extracts from different genotypes of açaí showed a protective effect (13-62%) on SH-SY5Y cells insulted by H2O2 at a concentration of 50μg/mL by DCFH-DA assay. Except L04P16, no genotypes showed cytotoxicity in the SRB assay. These results indicate that açaí genotypes have antioxidant effect against reactive species generated in SH-SY5Y cells, suggesting a neuroprotective effect of the hydroethanolic extracts from these fruits.

Nanoencapsulation of chia seed oil with chia mucilage (Salvia hispanica L.) as wall material: Characterization and stability evaluation

In this study, chia seed oil was nanoencapsulated utilizing chia seed mucilage (CSM) as wall material. The viscosity, encapsulation efficiency, loading capacity, transmission electron microscopy, FT-IR spectroscopy and thermal properties of chia seed oil nanoparticles (CSO-NP) were performed after preparation. Particle size, zeta potential, span value, and pH of CSO-NP and oxidation stability of nanoencapsulated and unencapsulated oil were evaluated during 28days of storage at accelerated conditions (40°C). The CSO-NP showed spherical shape, an average size of 205±4.24nm and zeta potential of -11.58±1.87mV. The encapsulation efficiency (82.8%), loading capacity (35.38%) and FT-IR spectroscopy demonstrated the interaction between oil and mucilage. Furthermore, CSO-NP were thermally stable at temperatures up 300°C and nanoencapsulated oil showed higher stability against oxidation than unencapsulated oil. The results suggest that chia seed mucilage represents a promising alternative to substitute synthetic polymers in nanoencapsulation.

Effects of orange by-product fiber incorporation on the functional and technological properties of pasta

The incorporation of fiber into products consumed every day by the general population is important and viable. The aim of the present work was to evaluate the impact of incorporating orange juice industry dietary fiber byproducts in fettuccini of fresh pasta. Three different fiber concentrations were added to fresh pastas (25 g/kg, 50 g/kg and 75 g/kg). The results showed a significant increase in solid loss content when the incorporation of orange fiber was greater than 50 g/kg. This difference did not occur regarding weight increase values and color parameters. The pasta with 75 g/kg orange fiber can be considered a “high fiber” product, with the total dietary fiber content of the pasta increasing by 99% compared to control pasta. The carotenoid and phenolic contents of pasta increased significantly with the incorporation of fiber at 75 g/kg, but only the pasta formulation with 25 g/kg of orange fiber did not differ from control pasta in relation to all of the sensory attributes and presented an acceptance greater than 75%. The addition of orange fiber byproducts to pastas is an interesting alternative because fiber has a high nutritional value and an abundance of antioxidants.

Rheological modelling, microstructure and physical stability of custard-like soy-based desserts enriched with guava pulp

Search for food products containing functional ingredients such as soy derivatives and pulp fruits has stimulated the development of new formulations of desserts. The aim of this study was to evaluate the influence of the addition of water-soluble soy extract, modified starch and guava pulp on the rheological parameters, microstructure, water-holding capacity (WHC), creaming index, pH and soluble solid content of creamy soy-based desserts. Rheologically, the samples were characterized as no time-dependent, shear-thinning weak gel-like systems. The physicochemical and rheological parameters evaluated varied in a wide range as a function of the soy, starch and guava pulp contents, with the soy extract content being the variable that most affected these properties. There was a link between the microscopic analysis and the WHC, and a strong correlation between WHC and the rheological parameter Q was observed.

Protective effect of guabiju (Myrcianthes pungens (O. Berg) D. Legrand) and red guava (Psidium cattleyanum Sabine) against cisplatin-induced hypercholesterolemia in rats

O presente estudo foi o primeiro realizado para avaliar o efeito protetor e o potencial antioxidante de duas frutas nativas do sul do Brasil, conhecidas como Guabiju (Myrcianthes pungens (O. Berg) D. Legrand) e araca vermelho (Psidium cattleyanum Sabine), em relacao a reduzir os efeitos da hipercolesterolemia induzida pela cisplatina em ratos Wistar machos. Os animais tratados com a cisplatina apresentaram elevada taxa de glicose, altos niveis de colesterol LDL, colesterol LDL oxidado e colesterol total. Os frutos nativos atuaram protegendo os animais pela reducao destes parâmetros. Os niveis de gordura no figado melhoraram com a suplementacao pelos frutos e nao houve diferencas nas substâncias reativas ao acido tiobarbiturico (TBARS) e niveis de creatina, ureia e colesterol HDL e, tambem, no peso dos orgaos analisados, indicando que a dose utilizada nao foi capaz de afetar tais marcadores.