The influence of frozen and canned storage on the chemical freshness parameters, determined in golden kingclip (Genypterus blacodes)

Changes in pH, total volatile basic nitrogen (TVB-N) and K-value were determined in golden kingclip species (Genypterus blacodes) frozen and stored at -18 °C and -30 °C for 6 months and golden kingclip canned fish in two different filling media. In frozen fish, pH values ranged from 6.4 to 6.8 and TVB-N varied from 8 to 14 mg of N/100 g. In canned fish, pH values varied from 6.5 to 7.0 and TVB-N from 9 to 22 mg of N/100 g. In frozen fish, the K-value was the most demanding index for determining freshness, namely, below 20%, while in canned fish it varied from 8% to 55%

Caracterización funcional y bioquímica de la carne del manto de jibia (Dosidicus gigas)

En el presente trabajo se realizó la caracterización funcional y bioquímica de la carne del manto de jibia (Dosiducus gigas) almacenada a _ 25°C por 6 meses. Se estudiaron la capacidad emulsionante, capacidad de retención de agua y la capacidad de gelificación. Además se buscaron las condiociones óptimas para la separación y diferenciación de las proteínas miofibrilares de las sarcoplasmáticas. Dentro de las propiedades funcionales se encontró que la carne descongelada del manto de jibia es capaz de emulsionar 2.817,4 g aceite/g proteína, de retener 3,64 g agua/g proteína. La capacidad de formar geles fue nula, lo cual se atribuyó al tiempo de almacenamiento. Respecto a la obtención de proteínas miofibrilares de carne del manto de jibia, se concluyó que con dos lavados a baja fuerza iónica (I=0,05), las proteínas sarcoplasmáticas son eliminadas de la matriz proteica. Mediante la realización de PAGE-SDS, de los extractos de carne de manto de jibia obtenidos a dos fuerzas iónicas diferentes (I=0,5 y I=0,05), se logró difrenciar las proteínas miofibrilares de las sarcoplasmáticas. Del estudio realizado se deduce que las proteínas del manto de jibia poseen una buena capacidad de emulsionar y retener agua, por lo que se puede considerar una muy buena materia prima para el desarrollo de productos parea untar. En el caso de productos gelificados, es necesario realizar estudios complementarios en la carne fresca para poder inferir en relación a esta propiedad funcional.Biochemistry and functional characterization of squid mantle meat (Dosidicus gigas). A study for the characterization of frozen giant squid mantle (meat) protein stored at _25°C for 8 month was started. In the present research, the folowing functional properties were investigate: emulsifying, water holding and gel forming capacities. Optimal conditions for the separation and differentiation of miofibrillar and sarcoplasmmatic proteins were also studied. It was found that the unfrozen giant squid mantle meat es capable of emulifying 2.817,4 g of oil/g of protein and holding capacity was 3,64 g of water/g of protein. Related to the gel forming capacity, it was not obtain, probably due to excessive storage of the meat. With regard to miofibrilar protein obtention of the squid mantle meat, it was found that two low ionic strength washings (I=0,05), the sarcoplasmic proteins were practically eliminated from the protein matrix. The differentiation of miofibrilar and sarcoplasmatic proteins was obtained by PAGE-SDS of the squid mantle meat extracted at two differents ionic strength (I=0,05 and I=0,5). This work demonstrates that the giant squid mantle protein has a high emulsifying and water holding capacity, and it can be used, as a raw material, for the improvement of sausage products. About the gelling products, more studies will be necessary with fresh squid mantle meat to conclude about this functional property

Effect of quinoa and potato flours on the thermomechanical and breadmaking properties ofwheat flour

The thermomechanical properties of dough and the physical characteristics of bread from quinoa-wheat and potato-wheat composite flours at 10 and 20% substitution level were evaluated. The functional properties of flours were measured by the water absorption index (WAI), water solubility index (WSI) and swelling power (SP). The thermomechanical properties of wheat and composite flours were assessed using a Mixolab and the baking quality characteristics of breads were weight, height, width, and specific volume. The results showed that the higher values of WAI (4.48), WSI (7.45%), and SP (4.84) were for potato flour. The quinoa-wheat composite flour presented lower setback and cooking stability data, which are a good indicator of shelf life of bread. On the other hand, the potato-wheat composite flour showed lower stability, minimum torque and peak torque, and higher water absorption. Weight, height, width, and specific volume of wheat bread were most similar to samples of potato-wheat composite flour at 10% substitution level