Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). 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, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

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Not AvailableHot extruded spent hen meat puffed products (SHPP) are made of spent hen meat mixed with flours and additives subjected to a maturing andextrusion process. This study was undertaken to evaluate the hygienic quality, the organoleptic characteristics, physico-chemical, proximate and microbial status during shelf life of SHPP in ambient temperature. Growth models, developed and validated on hot extruded spent hen meat puffed products (SHPP)were used to predict the growth of microorganisms. Temperature data were obtained from retail and home refrigerators. Shelf life was greatly influenced by storage temperature, but initial microbial load had a smaller effect. The expiration date of hot extruded spent hen meat puffed products must be based only on the growth of the spoilage microorganisms. Only when product contamination with bacteria cell concentrations is high, the product fraction poses health risks for consumers. Sensitivity analysis confirmed that storage temperature and temperature variability were the most important factors for the duration of shelf life.Not Availabl

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Not AvailableThe availability of culled and spent hens has also increased many folds with rapid development of poultry layer industry. The meat from spent hen is generally tough, less tender which reduces the market value. Better use of this meat could provide economic profits. The present study was aimed to produce a value added Hot Extruded puffed product by incorporation of spent hen meat emulsion in the flour in various proportions. Spent hen meat emulsion and two flour mixtures (Corn flour and Rice flour) were admixed in 15:85 (T1), 20:80 (T2) and 25:75 (T3) proportions to obtained emulsion based dough to produce hot extruded puffed product. Hot extruded puffed products thus obtained by twin screw hot extruder were rich in protein because of incorporation of spent hen meat which possessed almost 10-15% protein. Puffed product from flour mixture admixed with spent hen meat emulsion in different proportion can be effectively manufactured by using twin screw hot extruder.Not Availabl

The proteasome system in health and disease.

The proteasome is involved in the regulation of all cellular pathways and consequently plays a central role in the control of cellular homeostasis. Together with its regulators, it is at the frontline, both as an actor and as a target, in human health and when homeostasis is disturbed in disease. In this review, we aim to provide an overview of the many levels at which the functions of the proteasome and its regulators can be regulated to cope with cellular needs or are altered in pathological conditions