Growth of Chlorella in vanillin enriched medium

In this work the effect of different concentration of vanillin on the growth of Chlorella culture was evaluated. Two concentrations of vanillin: 60 mg/L and 300 mg/L in Bold Basal Medium (BBM) were tested and an inoculum from a two month Chlorella sp. (CCBA) culture was used. Vanillin at concentration of 60 mg/L showed to possess stimulating effect on Chlorella growth during 11 days of cultivation. Stimulation of Chlorella started on 3rd day of growth and was accompanied by 87% decrease of vanillin concentration within first 3 days of cultivation and its complete removal from growth media after 7 days. The acceleration of Chlorella growth in vanillin containing medium was detected due to biomass density, up to 1.2 times bigger than in the control culture, but also by measurement of chlorophyll content. Increased amount of chlorophyll content, up to 1.35 times higher than in control, was found between 4th and 11th day of cultivation. The response of Chlorella towards higher concentration of vanillin (300 mg/L) was different when compared to experiments where only 60 mg/L was used. During first 4 days of cultivation, strong inhibition of Chlorella exposed to 300 mg/L vanillin was observed and vanillin concentration maintained at the same initial concentration. During next days, a recovery effect occurred as biomass density and chlorophyll content gradually increased in comparison to the onset of growth and vanillin concentration decreased to 2 % of its initial value. Biomass density measured in Chlorella culture on 11th day was much higher than at the beginning of cultivation but still by 40% smaller than in control and by 50% smaller than in the culture growing in medium with 60 mg/L of vanillin. Chlorophyll content at the end of cultivation constituted 50% of control value and 35% of chlorophyll culture with 60 mg/L vanillin in medium

Effect of Metals, Metalloids and Metallic Nanoparticles on Microalgae Growth and Industrial Product Biosynthesis: A Review

peer reviewedMicroalgae are a source of numerous compounds that can be used in many branches of industry. Synthesis of such compounds in microalgal cells can be amplified under stress conditions. Exposure to various metals can be one of methods applied to induce cell stress and synthesis of target products in microalgae cultures. In this review, the potential of producing diverse biocompounds (pigments, lipids, exopolymers, peptides, phytohormones, arsenoorganics, nanoparticles) from microalgae cultures upon exposure to various metals, is evaluated. Additionally, different methods to alter microalgae response towards metals and metal stress are described. Finally, possibilities to sustain high growth rates and productivity of microalgal cultures in the presence of metals are discussed

The potential of gastronomic mediation to promote “Entre-Sambre-et-Meuse” wines

With climate change, improvement of the technics and the use of more adapted grape varieties, Belgian viticulture is currently booming. Wines from the “Entre-Sambre-Et-Meuse” terroir are getting particularly more attention, with some sparkling wines winning international medals (e.g. “Le chant d’Eole” or “Ruffus”). Although, there is still a long way to go to raise the public perception of this emerging terroir. The goal of this project is to study the potential of gastronomic mediation to raise the public perception of “Entre-Sambre-Et-Meuse” wines and promote this terroir. Gastronomic mediation is a concept of pedagogic tool using gastronomy as an intermediary between the producer and the consumer by communicating about a product, its specifities, its preparation and tasting, through experience and knowledge sharing. Therefore, gastronomic mediation workshops will be created around specific thematics that are currently selected. To achieve so, interviews of the “Entre-Sambre-et-Meuse” and similar terroirs experts are conducted to list the criteria that have an impact on the terroir perception. Then a statistical hierarchisation will help to select the most impacting criteria which will be used in the workshops. After development, workshops will then be tested with public to analyse their impact on “EntreSambre-Et-Meuse” terroir perception. The goal will be to measure the difference of perception before and after the workshops, and characterize which criteria improve the perception the most. With these results, we aim to help producers of this emerging terroir to reach consumers through a new tool to improve the perception of their product and savoir-faire

Développement de boissons fonctionnelles fermentées répondant aux besoins du consommateur

Ce projet de recherche est axé sur la formulation et l’étude d’un panel de boissons fonctionnelles de types kombucha. Il intègre la dimension sociale par la prise en considération des besoins et préférences du consommateur en termes de boissonsalternatives thérapeutiques. En effet, par la caractérisation physico chimique des boissons fonctionnelles, les thématiques liées au bien être physique et mental peuvent être considérées. L’étude des cinétiques de composants majoritaires synthétisés par le consortium microbien présent dans le milieu fermentaire mais également celle des arômes développés au cours de la fermentation permet le monitoring de la fermentation et de moduler les flaveurs finales des boissons en fonction du substrat utilisé et des paramètres de fermentation. À l’aube d’une transition alimentaire encourageant sans cesse la consommation d’aliments fonctionnels sains et durables, cette étude assure ainsi la proposition d’un panel de boissons naturelles et soucieuses de la santé du consommateur

Analyse des caractéristiques nutritionnelles, organoleptiques et de cuisson de pâtes enrichies avec de la biomasse microbienne fraîche et sèche

There are ecological and environmental reasons to reduce the consumption of animal proteins. Alternatives are therefore required. Besides plant-based alternatives, microbial biomass from species such as spirulina (Arthrospira platensis) appear promising. Indeed, from a nutritional point of view, its high protein content and diversity together with high levels of vitamins, minerals and antioxidants makes it an attractive food. Pasta is a widely consumed food product and fresh pasta market is growing to respond to the consumer’s willingness to consume less transformed and artisanal products. Also, as fresh pasta is a product with a rather simple composition and a quite high water content, it could constitute a relevant model for experimentation on food enrichment with microbial biomass. The fresh tagliatelle model was therefore chosen for this study. The tagliatelle recipes were formulated with dry spirulina biomass and with fresh spirulina biomass (77% moisture) from a single supplier and in different proportions (range from 9 to 50% of fresh biomass, corresponding to 2 to 12% of rehydrated dry biomass). The culinary methods (food and cooking recipes) were established as follows: the ingredients are mixed and kneaded for 10 minutes. The mixture is left in the fridge for 30 minutes before being rolled out and cut into tagliatelle. Ten grams of tagliatelle are then cooked in 100 ml of boiling water. The experimental approaches used to compare recipes formulated with fresh spirulina biomass or dry spirulina biomass were: (1) moisture preservation dynamic by measuring dry matter, water activity, weight increase and cooking loss; (2) texture profile analysis to determine the firmness, adhesiveness and chewiness of cooked product; (3) organoleptic parameters by instrumental methods: colour of raw and cooked product and sensory analysis (hedonic test) of cooked product ; and (4) analysis of the nutritional value by measuring the protein content of the formulations of the raw and cooked product. In particular, sensory analysis allows to determine the formulation preferences but also the consumer's acceptance of eating products based on microbial biomass

Study and development of a functional fermented drink based on Sobacha: A Japanese infusion of roasted buckwheat seeds

peer reviewedNowadays, consumer’s demand for the development of functional foods on the market, i.e., satisfying hunger and nutrient intake, but also preventing chronic diseases and improving physical and mental health, is constantly increasing. At the dawn of a food transition encouraging the consumption of healthy and sustainable non-dairy probiotic products, the development of a functional drink based on Sobacha is considered. This cereal matrix is an infusion of roasted buckwheat seeds widely consumed in Asian countries for its health benefits. Resulting from a Japanese expertise of buckwheat roasting, the matrix presents anti-inflammatory and antioxidant properties. Moreover, kombucha has gained immense popularity in recent years due to its many health benefits. As fermentation improve the nutritional and organoleptic status of grain products, the mixed fermentation process involved in the development of Hakko Sobacha is conducted by inoculating a symbiotic culture of bacteria and yeasts into the cereal matrix. Considering the beverage characterization, the kinetics of volatile organic compounds (VOCs) were determined using stir bar sorptive extraction—gas chromatography—mass spectrometry. Odor-active compounds were theoretically calculated to estimate consumer perception. Finally, sensory analyses highlighted the appreciation and preferences of the consumer towards the beverages. The fermentative yield differences observed between the two buckwheat concentration modalities are due to the number of sugars available for fermentation but also to the nutrients available from the complex sugars of the starch matrix. The study of volatile organic compounds shows the analysis of production kinetics of potentially aromatic compounds such as esters, aldehydes, ketones, terpenes, ... from carboxylic acids and alcohols. The synthesis of these aromas evolves during fermentation, reflecting the activity of microorganisms to use multiple fermentative pathways in search of an optimal environment for their development. Consumers appreciate the beverage with the highest buckwheat concentration for its fruity (citrus), green, creamy, and spicy (from esters, ketones, and phenols) aromas, as well as for its acidity, predominant roasted hazelnut aroma (from pyrazines of sobacha). Opposite consumers appreciate the drink less concentrated in buckwheat for its sour, floral, grilled, fruity (melon), green notes (from carboxylic acids, esters, and alcohols mainly) but also for its color, freshness, and sparkle. As this study allowed to characterize Hakko Sobacha, an insight for the development of new drinks by controlling the fermentation process was suggested. Such a methodology should allow a better control and optimization of their sensory profile, which could in turn lead to greater consumer acceptance.Win4Excellence MICROBoos

Characterization of Aroma Active Compound Production during Kombucha Fermentation: Towards the Control of Sensory Profiles

peer reviewedSince the sensorial profile is the cornerstone for the development of kombucha as a beverage with mass market appeal, advanced analytical tools are needed to gain a better understanding of the kinetics of aromatic compounds during the fermentation process to control the sensory profiles of the drink. The kinetics of volatile organic compounds (VOCs) was determined using stir bar sorptive extraction—gas chromatography—mass spectrometry, and odor-active compounds were considered to estimate consumer perception. A total of 87 VOCs were detected in kombucha during the fermentation stages. The synthesis of mainly phenethyl alcohol and isoamyl alcohol probably by Saccharomyces genus led to ester formation. Moreover, the terpene synthesis occurring at the beginning of fermentation (∆-3-carene, α-phellandrene, γ-terpinene, m- and p-cymene) could be related to yeast activity as well. Principal component analysis identified classes that allowed the major variability explanation, which are carboxylic acids, alcohols, and terpenes. The aromatic analysis accounted for 17 aroma-active compounds. These changes in the evolution of VOCs led to flavor variations: from citrus-floral-sweet notes (geraniol and linalool domination), and fermentation brought intense citrusherbal-lavender-bergamot notes (α-farnesene). Finally, sweet-floral-bready-honey notes dominated the kombucha flavor (2-phenylethanol). As this study allowed to estimate kombucha sensory profiles, an insight for the development of new drinks by controlling the fermentation process was suggested. Such a methodology should allow a better control and optimization of their sensory profile, which could in turn lead to greater consumer acceptance

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)