Radio-frequency electrical characterization of viable-cell suspensions

Suspended viable cells significantly influence the relative complex permittivity (dielectric constant) of the suspension. This influence depends on the concentration, viability, size, and even the cell shape. Hence, by measuring the permittivity, various fermentation processes can be monitored (e.g., in wine making and preparation of milk products). Thereby, the complex impedance (or admittance) between electrodes immersed into the suspension is measured and the permittivity is obtained by a suitable de-embedding procedure. There exist various data in the literature on this influence, but they do not provide sufficient information for wide implementation of the technique. The aim of the paper was to experimentally investigate various aspects of the measurement procedures and establish practical guidelines and limitations. Measurements were performed using an LCR meter, a classical vector network analyzer, and a nanoVNA analyzer, in the frequency range from 10 Hz to 100 MHz. Various suspension containers and systems of electrodes were designed and manufactured. Bipolar systems of electrodes were found to be more suitable for higher frequencies than tetrapolar ones. Open electrode systems were found to be more prone to the influence of the environment than shielded systems (e.g., coaxial). Good results were obtained for simple yeast suspensions. However, the presence of other cells and dispersed solids (e.g., in pressed grape juice) was found to completely overshadow the yeast cells. Electrochemical effects on the electrodes were found to be insignificant above around 200 kHz. Bubbles on electrodes, delamination, high concentrations of ions, and even temperature variations significantly hindered measurements in many cases

Maltose-mediated, long-term stabilization of freeze- and spray-dried forms of bovine and porcine hemoglobin

Slaughterhouse blood represents a valuable source of hemoglobin, which can be used in the production of heme-iron based supplements for the prevention/treatment of iron-deficiency anemia. In order to obtain a stable solid-state formulation, the effect of maltose addition (30 %) on the stability and storage of bovine and porcine hemoglobin in powders obtained by spray-and freeze-drying (without maltose: Hb; with maltose: HbM) were investigated. Differential scanning calorimetry of spray- and freeze-dried powders indicated satisfying quality of the formulation prepared with maltose on dissolving back into solution. After two-year storage at room temperature (20 +/- 5 degrees C) in solid forms, protected from moisture and light, rehydrated spray- and freeze- dried HbM were red, while Hb were brown. Dynamic light scattering showed the presence of native hemoglobin monomers in rehydrated spray- and freeze- dried HbM, but their agglomerates in Hb samples. UV-Vis spectrophotometry confirmed an absence of significant hemoglobin denaturation and methemoglobin formation in HbM freeze-dried powders. In spray-dried HbM, an increased level of methemoglobin was detected. The results confirmed the stabilizing effect of maltose, and suggested its use in the production of long-term stable solid-state formulations of hemoglobin, along with drying processes optimization

Urban transformation with TURAS open innovations; opportunities for transitioning through transdisciplinarity

Transitioning is a unidirectional process of mainstreaming sustainability within normative societal behaviour, which communities hope will build resilience, reduce our dependence on distant resources and lead to the transformation towards more sustainable living as an end product. Throughout Europe there are numerous examples and pilot or demonstration projects that illustrate tools, practices, mechanisms, pathways and policies for how transitioning can be guided and a transformation can be achieved. This paper draws on the experience of the TURAS project by illustrating some of the diverse open innovation opportunities that have been derived using novel transdisciplinary approaches. The paper concludes with identifying possible ways forward by utilising the TURAS innovations to enable the transformation of urban communities

Biotechnological production of γ-decalactone, a peach like aroma, by Yarrowia lipolytica

The request for new flavourings increases every year. Consumer perception that everything natural is better is causing an increase demand for natural aroma additives. Biotechnology has become a way to get natural products. γ-Decalactone is a peach-like aroma widely used in dairy products, beverages and others food industries. In more recent years, more and more studies and industrial processes were endorsed to cost-effect this compound production. One of the best-known methods to produce -decalactone is from ricinoleic acid catalyzed by Yarrowia lipolytica, a generally regarded as safe status yeast. As yet, several factors affecting -decalactone production remain to be fully understood and optimized. In this review, we focus on the aromatic compound -decalactone and its production by Y. lipolytica. The metabolic pathway of lactone production and degradation are addressed. Critical analysis of novel strategies of bioprocess engineering, metabolic and genetic engineering and other strategies for the enhancement of the aroma productivity are presented.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684)

Clinical significance and MDCT angiographic presentation of the mesenteric collateral circulation of the colon

© 2017, Serbian Medical Society. All rights reserved. Developed mesenterial collateral system provides adequate perfusion of the colon in conditions and diseases where blood flow is disabled or compromised. MDCT angiography is the optimal method, providing an adequate review of the blood vessels in a high resolution image, which is of great importance in the diagnosis of various anatomical variations, diseases and conditions

Encapsulation of flavors and aromas: Controlled release

Ongoing research on biodegradable/edible lms is being made, and there is a great interest to make this knowledge more widely available and used. In the last 30 years, considerable progress has been made in developing these materials driven by the increasing consumer demand for safe, high-quality, convenient food with long shelf lives, along with an ecological awareness of the limited natural resources and the environmental impact of packaging waste (Janjarasskul and Krochta 2010; Kester and Fennema 1986). Nevertheless, the use of edible lms or coatings to extend storage life of food is an ancient human practice of food preservation. Some examples of those old practices are fruit waxing used since the twelfth century in China, meat larding used in England since the sixteenth century (Kester and Fennema 1986), and the production of soy lms from soy milk (yuba) traditionally employed in the Orient to wrap and shape ground meats or vegetables (Gennadios and Weller 1991).Fil: Bertuzzi, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; ArgentinaFil: Slavutsky, Anibal Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones para la Industria Química. Universidad Nacional de Salta. Facultad de Ingeniería. Instituto de Investigaciones para la Industria Química; Argentina. Universidad Nacional de Salta. Facultad de Ingeniería; Argentin