Effect of deacetylation degree of chitosan on rheological properties and physical chemical characteristics of genipin-crosslinked chitosan beads

2020 ◽  
Vol 106 ◽  
pp. 105876 ◽  
Author(s):  
Loleny Tavares ◽  
Elí Emanuel Esparza Flores ◽  
Rafael Costa Rodrigues ◽  
Plinho Francisco Hertz ◽  
Caciano Pelayo Zapata Noreña
2018 ◽  
Vol 40 (2) ◽  
Author(s):  
Paula Nogueira Curi ◽  
Givago Coutinho ◽  
Mariana Matos ◽  
Rafael Pio ◽  
Francielly Corrêa Albergaria ◽  
...  

Abstract With the purpose of adding value to the final product and aiming to identify which cultivars implanted in tropical regions are more appropriate for the processing of marmelade, the objective of this study was to characterize and evaluate the influence of different cultivars of quince (‘Fuller’, ‘Smyrna’, ‘Portugal’, ‘Provence’, ‘Mendonza Inta-37’, ‘Alaranjado’, ‘Lajeado’, ‘CTS 207’, ‘D’Angers’ and ‘Bereczy’) grown in tropical Brazilian regions, on the physical-chemical characteristics, rheological properties and the consumer acceptance of the obtained marmelade. The different quince cultivars presented great variability among themselves in relation to physical and physicochemical characteristics. However, the cultivars studied gave rise to marmelades that were similar to each other, which had a high sensory acceptance, except for the cultivar Mendonza Inta-37, which resulted in a less accepted marmelade.


2021 ◽  
Vol 11 (10) ◽  
pp. 4417
Author(s):  
Veronica Vendramin ◽  
Gaia Spinato ◽  
Simone Vincenzi

Chitosan is a chitin-derived fiber, extracted from the shellfish shells, a by-product of the fish industry, or from fungi grown in bioreactors. In oenology, it is used for the control of Brettanomyces spp., for the prevention of ferric, copper, and protein casse and for clarification. The International Organisation of Vine and Wine established the exclusive utilization of fungal chitosan to avoid the eventuality of allergic reactions. This work focuses on the differences between two chitosan categories, fungal and animal chitosan, characterizing several samples in terms of chitin content and degree of deacetylation. In addition, different acids were used to dissolve chitosans, and their effect on viscosity and on the efficacy in wine clarification were observed. The results demonstrated that even if fungal and animal chitosans shared similar chemical properties (deacetylation degree and chitin content), they showed different viscosity depending on their molecular weight but also on the acid used to dissolve them. A significant difference was discovered on their fining properties, as animal chitosans showed a faster and greater sedimentation compared to the fungal ones, independently from the acid used for their dissolution. This suggests that physical–chemical differences in the molecular structure occur between the two chitosan categories and that this significantly affects their technologic (oenological) properties.


Author(s):  
Camilo A S Ballesteros ◽  
Luiza Mercante ◽  
Augusto Alvarenga ◽  
Murilo Henrique Moreira Facure ◽  
Rodrigo Schneider ◽  
...  

A large variety of engineered nanostructures possessing enzyme-like activities have been proposed recently, which unique physical-chemical characteristics enable remarkable technological advances. In this review, we survey recent advances on nanozymes...


2009 ◽  
Vol 33 ◽  
pp. 264-280 ◽  
Author(s):  
TATIANA BEATRIS TRIBESS ◽  
MARIA AUXILIADORA DE BRITO RODAS ◽  
JUSSARA CARVALHO DE MOURA DELLA TORRE ◽  
CARMEN CECILIA TADINI

2016 ◽  
Vol 869 ◽  
pp. 112-115 ◽  
Author(s):  
Francisca Pereira de Araújo ◽  
Edson Cavalcanti Silva Filho ◽  
João Sammy Nery de Souza ◽  
Josy Anteveli Osajima ◽  
Marcelo Barbosa Furtini

Soil-cement bricks are good examples of environmentally friendly products. This brick is the combination of soil with compacted cement with no combustion in its production. In this work the physical chemical characteristics of the soil from Piaui for producing this material were investigated. Samples of the soil were collected in three potteries from the county of Bom Jesus and pH analysis were carried out, as well as the rate of organic matter, texture, particle density, limits of liquidity and plasticity rates. The results have shown that the soils have acid tones (pH 5,49 a 6,11), which can be neutralized by adding cement, and organic matter percentages up to 1%. The samples have shown predominantly clay-rich textures with adequate plasticity limits, however, values of liquidity limits and particle density above recommended. Altogether, these soils tend to present viability concerning soil-cement brick production, provided that corrections with additives are made in order to minimize this effect.


Author(s):  
Берик Картанбаевич Саяхов ◽  
Александр Геннадьевич Дидух ◽  
Гульнара Амангельдиевна Габсаттарова ◽  
Марат Давлетович Насибулин ◽  
Жасулан Канатович Наурузбеков

На начальных участках магистрального нефтепровода Узень - Атырау - Самара формируются партии низкозастывающих бузачинских и высокозастывающих мангышлакских нефтей. По маршруту транспортировки осуществляются дополнительные подкачки нефтей с различными физико-химическими и реологическими характеристиками, что может оказывать существенное влияние на свойства перекачиваемых нефтесмесей. Цель настоящей работы - исследование физико-химических и реологических свойств бузачинской и мангышлакской нефтесмесей на маршруте поставки Узень - Атырау, а также диапазона и причин изменений характеристик бузачинской нефти (основной в компонентном составе нефтесмесей, перекачиваемых по нефтепроводу Узень - Атырау - Самара). По результатам исследований установлено, что свойства мангышлакской нефтесмеси изменяются в незначительных пределах. Для бузачинской нефтесмеси свойственна нестабильность реологических параметров, которые могут изменяться в широком диапазоне в результате путевой подкачки на различных участках нефтепровода. Колебания реологических параметров наиболее показательных проб партий бузачинской нефтесмеси рекомендуется учитывать для решения задач повышения текучести высоковязких нефтей и оптимизации технологических режимов работы трубопроводов, по которым осуществляется перекачка таких нефтей. Методами газохроматографического анализа молекулярно-массового распределения тугоплавких парафинов и поляризационной микроскопии определена температура нагрева бузачинской и мангышлакской нефтесмесей, оптимальная для ввода депрессорной присадки. At the initial sections of the Uzen - Atyrau - Samara main oil pipeline, batches of low pour point Buzachinsky and high pour point Mangyshlak oils are formed. Additional pumping of oils with different physical, chemical and rheological characteristics is carried out along the transportation route, which can have a significant effect on the properties of the pumped oil mixtures. The purpose of this study is to examine the physical, chemical and rheological properties of Buzachi and Mangyshlak oil mixtures on the Uzen - Atyrau supply route, as well as the range and causes of changes in the characteristics of Buzachinsky oil (the main oil mixture in the blend composition pumped through the Uzen - Atyrau - Samara pipeline). According to the research results, it was found that the properties of the Mangyshlak oil mixture vary within insignificant limits. The Buzachinsky oil mixture is characterized by instability of rheological parameters, which can vary in a wide range as a result of route pumping at different pipeline sections. Fluctuations of the rheological parameters of the most indicative samples of batches of the Buzachinsky oil mixture are recommended to be taken into account in order to increase the fluidity of high-viscosity oils and optimize the process modes of operation of pipelines through which such oils are pumped. Using the methods of gas chromatographic analysis of the molecular weight distribution of high-melting-point paraffins, as well as polarization microscopy, the optimal heating temperature for the introduction of a pour point depressant into the Buzachinsky and Mangyshlak oil mixtures has been determined.


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