Properties of Portland Cement Mortar with Substitutions of Natural and Expanded Perlite

The present research deals with the feasibility of using high-temperature pozzolans such as Natural Perlite (NP) and Expanded Perlite (EP), different dosagues of additions were made to mortars in order to perform their mechanical properties. Mortars were subjected to destructive tests in hardened state: compression, tension, flexion and adhesion strength; as well as non-destructive tests in hardened state: ultrasonic pulse velocity (UPV), electrical resistivity (ER), density (ρ) and total porosity (PT); in addition to attack by sodium sulfate at 90 days. The percentages of the substitutions were 5%, 10%, 15%, 20% and 30% by weight of Portland cement mass (PC) relative to a control mortar (cement-sand-water). With the partial replacement of the cement and according to the tests carried out, it can be observed that the problem of durability and CO2 emissions is significantly reduced and, consequently, an energy saving and a lower environmental impact are promoted

Effect of Bovine Plasma Protein on Autolysis and Gelation of Protein Extracted from Giant Squid (Dosidicus gigas) Mantle

The effect of bovine plasma protein (BPP) on the inhibition of autolytic activity and its effect on the gelling properties of a protein concentrate (PC) obtained from jumbo squid (Dosidicus gigas) mantle were investigated. Sols and gels were prepared from the PC by adding different amounts of BPP (0, 1, and 2%). Dynamic oscillatory measurements indicated that systems with 1% BPP had a higher elastic modulus ( ), in which hydrophobic interactions were favored. Concerning the technological and textural quality of the gels, BPP caused a greater water holding capacity (WHC), force, cohesiveness, and elasticity, probably due to improvement of the electrostatic and hydrophobic interactions during gel formation. Scanning electron microscopy (SEM) allowed visualization of the formation of more rigid and ordered gels with less porosity when BPP was added. Therefore, the addition of BPP improved the gelling capacity of proteins extracted from giant squid

Contribución del aplanado de morteros de cal para restauración sobre muretes de mampostería

Los morteros con base cal, han sido materiales descritos en los tratados antiguos de arquitectura, permitidos en muchos documentos que rigen los trabajos de restauración de bienes inmuebles patrimoniales y actualmente son los materiales más empleados en la restauración y conservación del patrimonio de mampostería natural en muchos sitios del mundo. La cal puede ser normalizada o bien puede ser apagada en sitio como describe Vitrubio en sus Libros de Arquitectura; los áridos pueden ser ígneos, metamórficos o sedimentarios; para modificar las propiedades físicas y mecánicas básicas de los morteros de cal suelen agregarse aditivos orgánicos e inorgánicos. La restauración y conservación de los edificios de mampostería coloniales es un reto en México. Tenemos 9 ciudades coloniales cuyos centros históricos están en el listado de Patrimonio de la Humanidad de la Unesco. Todas edificadas con mamposterías de rocas naturales y aplanadas con morteros de cal y aditivos orgánicos. Inicialmente se recubrían las rocas que carecían de labrado, cánones dictados por la arquitectura en boga. Con la modernización y masificación del transporte, los residuos vertidos a la atmósfera han deteriorado la calidad del aire ambiental resultando en pátinas, costras negras, daño antropogénico en superficies expuestas, devitrificación de la matriz de las rocas. Del uso sugerido de emplear morteros como protección en los monumentos arquitectónicos coloniales, método relativamente simple y económico, se ha revisado también su efecto sobre la resistencia mecánica. Este trabajo hace una comparación entre pilas de mampostería de arcilla recocida adheridas con mortero de cal adicionado con fibras desecadas y pulverizadas de nopal cactus opuntia y pilas con las mismas características, pero recubiertas en ambas caras con el mortero mencionado.Tópico 4.- Morteros de cal, materiales cálcicos y cementíceos. Evaluación de propiedades y composición. Mampostería de ladrillos. Caracterización. Evaluación de patologías y Refuerzo

Preservative effect of jumbo squid (dosidicus gigas) skin extract as glazing material during the frozen storage of atlantic chub mackerel (scomber colias)

7 pages, 2 tables, 2 figures[EN] The present research was focused on the quality loss of Atlantic Chub mackerel (Scomber colias) during the frozen storage. Its basic objective was to investigate the effect of including a lipophilic extract of jumbo squid (Dosidicus gigas) skin (JSS) in the glazing system applied previously to the frozen storage. For it, two different concentrations of skin extracts were tested and compared with two control treatments (water glazing and non-glazing conditions). Quality changes were monitored for a 8-month frozen storage by sensory (odour and taste) and chemical (lipid hydrolysis and oxidation development) evaluation. An inhibitory effect (p<0.05) of skin extracts on lipid hydrolysis (free fatty acid formation) evolution was observed; furthermore, lower average values for lipid oxidation indices (peroxide and fluorescent compounds formation) were observed in fish samples corresponding to the highest JSS presence in the glazing system. Some sensory quality enhancement was evident in mackerel as a result of including JSS extracts in the glazing medium, especially for raw-flesh and cooked-flesh odours; as for chemical indices, an increasing effect was implied by increasing the skin extract presence in the glazing medium. Under the conditions tested in the present study, the JSS extract has shown promising antioxidant properties that could be applied to enhance the seafood quality during the commercialisation in frozen conditions. Further research would be necessary to optimise its use in the glazing system.[BU] В настоящата работа са изследвани промените в качеството на атлантическа скумрия (Scomber colias) по време на съхранението й в замразено състояние. Проследено е влиянието на липофилен екстракт от кожа на гигантски калмари (Dosidicus gigas) (JSS) в глазиращата система, приложена преди замразяване. Тествани са две концентрации от кожни екстракти и са сравнени с две контролни обработки (глазиране с вода и без глазиране). Промените в качеството са проследени в продължение на 8-месечно съхранение в замразено състояние чрез сензорна (мирис и вкус) и химическа (хидролиза и окисление на липидите) оценка. Установен е инхибиторен ефект (p<0.05) на JSS екстрактите върху хидролизата на липидите (образуване на свободни мастни киселини), като по-ниски средни стойности на липидните окислителни индекси (образуване на пероксидни и флуоресцентни съединения) са наблюдавани при рибните проби с по-висока концентрация на JSS в глазиращата система. Установено е повишение на сензорното качество на скумрията в резултат на включване на JSS екстракти в глазиращата система., особено по отношение на мириса на суровото и свареното месо. Установено е и повишение на химическите индекси с увеличаване концентрацията на JSS екстракта в глазиращата система. При изследваните условия, JSS екстрактът е демонстрирал перспективни антиоксидационни свойства, които биха намерили приложение за повишаване на качеството на морската храна при търговията в замразено състояние. Предстоят изследвания за оптимизиране на употребата на JSS в глазиращата система.This work was supported by the CONACYT-Mexico grant 154046, by the Consejo Superior de Investigaciones Científicas (CSIC) through the Research Project 201370E001 and by the University of Sonora grant USO31302163.Peer reviewe

Effect of previous chilling storage on quality loss in frozen (&#8211;20 &#176;C) sierra (Scomberomorus sierra) muscle packed with a low-density polyethylene film containing butylated hydroxytoluene

Rancidity development during frozen storage (&#8211;20 &#176;C) of sierra fish (Scomberomorus sierra) was studied. Fillets were packed in low-density polyethylene films with and without butylated hydroxytoluene added (BHT-LDPE and LDPE respectively). Fillets stored with no package were used as control. Special attention was given to the effect of previous ice storage (0, 3, 6, 9 and 15 days) on the quality of the frozen fish. Physical (pH and texture) and chemical (peroxide value, PV and thiobarbituric acid index, TBA-i) analyses were carried out. Lipid oxidation increased with ice storage time in fish muscle without film packing, being greater than the film packed muscle (with and without antioxidant). An effect of previous ice storage time was observed on the frozen product (in all treatments). However, fish muscle with film packing containing antioxidant showed less lipid deterioration. Under the conditions applied in this study, the plastic films with antioxidant prevented the lipids oxidation during the cold handling of the sierra muscle

Quality changes during frozen storage of blue shrimp (Litopenaeus stylirostris) with antioxidant, &#945;-tocopherol, under different conditions

Fresh blue shrimp (Litopenaeus stylirostris) muscle was stored with antioxidants under different conditions: ANTIOX 2%, packed in bilayer film of polyamide-low density polyethylene film (PA-LDPE) with 2% &#945;-tocopherol; ANTIOX 4%, packed in PA-LDPE film with 4% &#945;-tocopherol; and ANTIOX-GLAZED, samples stored glazed with 2% &#945;-tocopherol. Shrimps packed in PA-LDPE without &#945;-tocopherol were used as CONTROL. All samples were stored at &#8211;20 &#176;C for 120 days. As compared to the CONTROL, the shrimp stored with the antioxidant showed lower lipid oxidation (0.10-0.14 vs 1.58 mgMA/kg of muscle), lost less firmness and astaxanthin content. ANTIOX 2% and ANTIOX-GLAZED showed the lowest concentrations of formaldehyde (0.081-0.083 &#956;M/g). There were no significant differences in color and sensory properties, but differences in the integrity of the muscle fibers were observed. The treatments with &#945;-tocopherol maintained the shrimp muscle quality during frozen storage. However, no significant differences were found between these treatments

Effect of Bovine Plasma Protein on Autolysis and Gelation of Protein Extracted from Giant Squid (Dosidicus gigas) Mantle

The effect of bovine plasma protein (BPP) on the inhibition of autolytic activity and its effect on the gelling properties of a protein concentrate (PC) obtained from jumbo squid (Dosidicus gigas) mantle were investigated. Sols and gels were prepared from the PC by adding different amounts of BPP (0, 1, and 2%). Dynamic oscillatory measurements indicated that systems with 1% BPP had a higher elastic modulus (G′), in which hydrophobic interactions were favored. Concerning the technological and textural quality of the gels, BPP caused a greater water holding capacity (WHC), force, cohesiveness, and elasticity, probably due to improvement of the electrostatic and hydrophobic interactions during gel formation. Scanning electron microscopy (SEM) allowed visualization of the formation of more rigid and ordered gels with less porosity when BPP was added. Therefore, the addition of BPP improved the gelling capacity of proteins extracted from giant squid