22 research outputs found
Development of fermented sauce-based salads : assessment of safety and stability
Sauce-based delicatessen salads, composed of solid ingredients, such as potatoes, vegetables, fish, meat and an oil-in-water emulsion containing acidulants (acetic and lactic acids) and chemical preservatives (sorbic and benzoic acids) can be subject to microbial and chemical changes and physical deterioration. In this thesis a new method of salad preparation is presented which meets consumer demands for salads without chemical preservatives and with a less sour taste and by which the major microbiological and chemical problems of the present-day salads can be controlled. Conditions for operation and the microbiological and chemical aspects that are relevant for the process have been investigated. It is shown that preparation of salads by the new process, i.e. fermentation in their package with lactic acid bacteria at higher temperatures (≥42°C) in a short time (≤8 hours), followed by cooling to below 7°C, is feasible. Salads produced according to this procedure have a mildly sour taste and are microbially stable for 5-6 weeks at 7°C, i.e. yeasts and other spoilage organisms are inhibited, provided that measures are taken to assure low initial contamination with these microorganisms. Moreover, fermented salads, subjected to light exposure, are protected for lipid photo-oxidation. This protection is apparently due to the oxygen scavenging and reducing effects of the fermentation. The salads could be regarded as safe, as growth of pathogenic microorganisms and production of biogenic amines are inhibited
Contribution to the study of resistance to drying of lactic acid bacteria (lyophilization)
Ibourahema COULIBALY (2010). Contribution à l’étude de la résistance au séchage des bactéries lactiques (thèse de doctorat en français) ; Université de Liège, Gembloux Agro-Bio Tech, (Belgique), 260 p., 22 tableaux, 39 figures.RésuméL’utilisation de souches lactiques, à l’échelle industrielle, nécessite une sélection sur base des propriétés technologiques, physiologiques et biochimiques, ainsi que la mise enoeuvre de procédés biotechnologiques bien maîtrisés pour leur production et leur conservation. A cet effet, le séchage est une étape importante. Sous forme sèche, le produit est plus facilement manipulable. Cependant au cours du séchage, les microorganismessubissent un stress thermique et/ou osmotique qui se traduit par une perte de viabilité pendant le stockage. L’utilisation d’agents protecteurs au cours du stockage a permis d’obtenir une bonne viabilité. En effet, les bactéries sont soumises pendant la lyophilisation et au cours du stockage à une mortalité liée en grande partie à l’oxydation des acides gras membranaires. L’analyse de ces acides au cours des différents procédés defabrication et de stockage permet de noter la présence des hydroperoxydes. Cette oxydation est engendrée par l’action de l’oxygène sur les acides gras polyinsaturés principalement l’acide linoléique (C18:2) et linolénique (C18:3) ce qui engendre la formation des hydroperoxydes : acide hydroperoxyoctadecadienoique (HPOD) et acide hydroperoxyoctadecatrienoique(HPOT) méthylés ou non en position 13- et 9-. Une analyse des composés secondaires émanant des poudres de bactéries lactiques indique la présence de composés volatils. Parmi ceux-ci, apparaissent des molécules volatiles (principalement des aldéhydes), qui modifient la flaveur d’origine des corps gras. Les études menées au niveau des constituants phospholipidiques de la membrane montrent un lien entre le degré d’oxydation et la mortalité cellulaire au cours du stockage. Les différents phospholipides déterminés au nombre de sept (7) subissent tous cette oxydation à des degrés divers.L’utilisation d’antioxydant au cours du stockage permet d’inhiber les phénomènes de peroxydation des lipides et permet également de maintenir la valeur nutritionnelle (teneur en AGPI, réduction des dérivés peroxydés nocifs) du produit.Ibourahema COULIBALY (2010). Contribution to the study of resistance of lactic acid bacteria subject to drying. (Dissertation in French) ; University of Liège, Gembloux Agro-Bio Tech , (Belgium), p. 260 p., 22 tables, 39 figures.SummaryThe use of lactic strains in industrial scale requires selection on the basis oftechnological, physiological and biochemical properties, as the implementation of biotechnological processes under control for their production and conservation. At this effect drying process is an important step. In dry form, the product is more easily manipulated. However during the drying process, microorganisms undergo heat stress and/or osmotic resulting in a loss of viability during storage. The use of protective agents during storage has resulted in a good viability. In fact, the bacteria are subjected during lyophilization and during storage to a mortality largely oxidation the membrane fatty acids. The analysis of these acids during the process helps to note the presence of hydroperoxydes which are the cause of this mortality. This oxidation is caused by the action of oxygen on polyunsaturated acids linoleic acid (C18:2) and linolenic (C18:3) mostly, causing the formation of hydroperoxydes: hydroperoxyoctadecadienoic acid (HPOD) and hydroperoxyoctadeca-trienoic acid (HPOT) at position 13 - and 9 - methyl or not. An analysis of secondary compounds from the powders indicates the presence of birds.These products appear volatile compounds (mainly aldehydes), hydrocarbons, alcohols, acids etc., which altered the original flavour of fat. Studies in phospholipids constituents of the membrane show a link between the degree of oxidation and cell death during storage. The various phospholipids determined, seven (7) are all undergo this oxidation to various degrees. The use of antioxidants during storage can inhibit the process of lipid peroxydation and helps also to maintain the nutritional value (PUFA content, reduction of harmful peroxide-derived) product
Gut Microorganisms of Aquatic Animals 2.0
This is a collection of scientific research articles focusing on the associations and/or interactions of various aquatic animals with their microorganisms, focusing mostly on fish and, in particular, gut bacterial communities
Chapter 34 - Biocompatibility of nanocellulose: Emerging biomedical applications
Nanocellulose already proved to be a highly relevant material for biomedical
applications, ensued by its outstanding mechanical properties and, more importantly, its biocompatibility. Nevertheless, despite their previous intensive
research, a notable number of emerging applications are still being developed.
Interestingly, this drive is not solely based on the nanocellulose features, but also
heavily dependent on sustainability. The three core nanocelluloses encompass
cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and bacterial nanocellulose (BNC). All these different types of nanocellulose display highly interesting biomedical properties per se, after modification and when used in
composite formulations. Novel applications that use nanocellulose includewell-known areas, namely, wound dressings, implants, indwelling medical
devices, scaffolds, and novel printed scaffolds. Their cytotoxicity and biocompatibility using recent methodologies are thoroughly analyzed to reinforce their
near future applicability. By analyzing the pristine core nanocellulose, none
display cytotoxicity. However, CNF has the highest potential to fail long-term
biocompatibility since it tends to trigger inflammation. On the other hand, neverdried BNC displays a remarkable biocompatibility. Despite this, all nanocelluloses clearly represent a flag bearer of future superior biomaterials, being
elite materials in the urgent replacement of our petrochemical dependence
Lignocellulosic Biomass
Recently, there has been a growing awareness of the need to make better use of natural resources. Hence, the utilization of biomass has led to so-called biorefinery, consisting of the fractionation or separation of the different components of the lignocellulosic materials in order to achieve a total utilization of the same, and not only of the cellulosic fraction for paper production. The use of plant biomass as a basic raw material implies a shift from an economy based on the exploitation of non-renewable fossil fuels, with limited reserves or with regeneration cycles far below the rates of exploitation, to a bioeconomy based on the use of renewable organic natural resources, with balanced regeneration and extraction cycles. To make this change, profound readjustments in existing technologies are necessary, as well as the application of new approaches in research, development, and production."Biorefinery" is the term used to describe the technology for the fractionation of plant biomass into energy, chemicals, and consumer goods. The future generation of biorefinery will include treatments, leading to high-value-added compounds. The use of green chemistry technologies and principles in biorefineries, such as solvent and reagent recovery and the minimization of effluent and gas emissions, is essential to define an economically and environmentally sustainable process.In particular, the biorefinery of lignocellulosic materials to produce biofuels, chemicals and materials is presented as a solid alternative to the current petrochemical platform and a possible solution to the accumulation of greenhouse gases
Continuing professional development - challenge for professional organization
Professions, as one of key sectors of social systems,
bear a leading role in the existing social work organization.
Free professions take up a special place and significance,
all the way from Roman artes liberales to our times.
Pharmaceutical profession, as one of the oldest, led by
ethical principles, is regulated by postulates accepted by
the profession members, and in modern times established
through legislations. Typical determinants of the regulated
professions, which also refer to pharmacists, as chamber
members, are as follows: following ethical principles,
specific skills and knowledge, professional development,
autonomy at work, continuing improvement, competencies
development, professional associations, licensing