Ontogenetic changes in energetic reserves, digestive enzymes, amino acid and energy content of Lithodes santolla (Anomura: Lithodidae): Baseline for culture.

The southern king crab (SKC) Lithodes santolla is an important commercial species in southern South America. Fishing pressure has caused the deterioration of its stocks. Currently, culture techniques are being developed for producing SKC juveniles to enhance the natural population and to recover the fishing stock. Therefore, it is necessary to know about physiology, energetic and nutritional requirements for SKC maintenance in hatchery. Thus, this study aims to evaluate the biochemical and physiological changes in the midgut gland, muscle and hemolymph of juveniles, pre-adults and adults of wild SKC. The energetic reserves, digestive enzymes activity, amino acid profile and energy were quantified in twelve juveniles, ten pre-adult, and ten adult crabs. Juveniles showed high glycogen and low lipids in the midgut gland, and low proteins and low lactate in muscle. In the hemolymph, juveniles had high lipids. Pre-adults had high glycogen and lipids in the midgut gland, and both high protein and lactate in muscle. In the hemolymph, pre-adults had high lipids. Adults had low glycogen and high lipids in midgut gland, and both high proteins and high lactate in muscle. In hemolymph, adults had high glucose and lactate. Juveniles and pre-adults had high proteinase activity, whereas adults had high lipase activity. Major essential amino acids of SKC were arginine, methionine, and tryptophan, and the non-essential amino acids were glycine, aspartic acid and glutamic acid. On another hand, SKC had similar energy in the midgut gland and muscle, regardless of the ontogenetic stage. Moreover, we demonstrated that the biochemical energy calculation underestimates the actual measured values by a calorimeter. Thus, our results help to understand the physiological changes, energetic and nutritional requirements of L. santolla, and this study is a baseline for research on diet formulation for maintaining this species under culture conditions.

Evaluación de las condiciones de desamargado en húmedo de quinoa (Chenopodium quinoa Willd) / Evaluation of wet de-bittering conditions of quinoa (Chenopodium quinoa Willd)

Introducción: los granos de quinoa presentan en su episperma saponinas, compuestos con actividad antinutricional y que le otorgan sabor amargo al grano, por lo que deben desamargarse previo a su consumo. La falta de precisión acerca de las condiciones más adecuadas para realizarlo por método húmedo, evidencia la necesidad de contar con información que aporte claridad. Objetivo: el objetivo del trabajo fue evaluar las condiciones de desamargado vía húmeda en granos de quinoa, con el fin de comparar su efectividad con un método cuantitativo. Materiales y métodos: se evaluaron como variables el tiempo, relación agua/granos y temperatura. Para determinar el contenido de saponinas residuales, se utilizó el método de la espuma (estimación afrosimétrica) y se compararon los resultados con espectrofotometría. Resultados y discusión: todas las variables ejercieron un efecto significativo y una correlación negativa sobre el contenido de saponinas. La interacción de las variables permitió establecer las condiciones de extracción que tuvieron mayor eficiencia: 6 minutos, relación masa granos/solvente 10 mL/g, independientemente de la temperatura. Por espectrofotometría, se observó la misma tendencia. Conclusiones: la conjugación de estas condiciones permite realizar lavados en tiempos breves, con una cantidad de agua determinada y sin la necesidad de aplicar temperatura. El método demostró ser sencillo, práctico y eficiente para la remoción de las saponinas

Introduction: quinoa grains present in its episperm saponins, compounds with antinutritional activity that give bitter flavor to the grain. Therefore, they must be previously removed for their consumption. The lack of precision about the most appropriate conditions to perform it by wet method, demonstrates the need to have information that provides clarity. Aim: the aim of this work was to evaluate the conditions of wet de-bittering in grains of quinoa, in order to compare its effectiveness with a quantitative method. Materials and methods: Time, water/grain mass ratio and temperature were evaluated as variables. To determine the content of saponins, foam method (afrosimetric estimation) was used and the data obtained by spectrophotometric method was used to compare. Results and discussion: All the variables presented a significant effect and a negative correlation on the saponin content. The interaction between the variables allowed establishing the conditions of extraction that had greater efficiency: 6 minutes, solvent/grain mass ratio 10:1, independently of the temperature. The same tendency was observed by spectrophotometry. Conclusions: the conjugation of these conditions enables to carry out washes in short periods of time, with a certain amount of water and without the need to apply temperature. The method proved to be simple, practical and efficient for the removal of saponins

Calidad nutricional y propiedades físicas de panes libres de gluten / Nutritional quality and physical properties of gluten-free breads

Introducción: los panificados libres de gluten (LG) presentan dificultades tecnológicas en su elaboración, una textura muy diferente a sus homólogos con gluten y una calidad nutricional muchas veces deficiente por el uso de harinas refinadas y almidones, que proveen alta densidad energética y bajos valores nutricionales. Objetivo: evaluar las características nutricionales y físicas de panes libres de gluten empleando mezclas de harinas y almidones. Materiales y métodos: Los panes fueron elaborados con harina integral de quinoa (HQ), harina de arroz (HA), harina de lupino blanco (HL), almidones de maíz (MZ) y mandioca (MA). Se aplicó un diseño experimental de mezclas D-optimal ajustándose a una ecuación de segundo orden y considerando como variables predictoras el contenido de carbohidratos, proteínas, lípidos y minerales. Fueron elaboradas 20 formulaciones donde se analizaron el volumen específico, la dureza y uniformidad alveolar. La formulación optimizada fue comparada su composición proximal y perfil de aminoácidos con panes LG comerciales. Resultados y discusiones: los panes con mezclas del 35- 41% HQ, 18% HL y HA entre 18 y 29%, mostraron un destacado contenido en proteínas (9%), lípidos (3%) y minerales totales (1,8%). Estas formulaciones de panes LG presentaron una dureza que varió entre 4,09 y 7,51 N, un volumen específico entre 1,53 y 1,95 cm3/g y una uniformidad alveolar entre 1,38 y 2,7. La formulación optimizada (P0) fue la compuesta por 41% HQ, 20% HA, 18% HL, 11% MZ y 10% MA. Al comparar P0 con los panes comerciales, se pudo observar diferencias significativas (P<0,05) en el contenido de proteínas (11,21%), lípidos (3%) y minerales totales (2,27%), destacándose P0 por presentar los mayores valores nutricionales. Conclusiones: Se logró un producto panificable apto para celíacos donde el uso HQ y HL, como principales componentes, tuvieron un efecto positivo sobre la calidad nutricional y características físicas de los panes evaluados

Introduction: The gluten free bread (GF) free bread have technological difficulties in its development, the texture is very different from their counterparts with gluten and the nutritional quality is often poor by the use of refined flours and starches, which provide high energy density and low nutritional values. Aim: Nutritional and physical characteristics evaluation of breads from mixtures of gluten-free flours and starches. Materials & methods: Quinoa flour (HQ), rice flour (HA), white lupine flour (HL), cornstarch (MZ) and starch from cassava (MA) were used to make the breads dough. It was applied an experimental design of mixing D-optimal, adjusting to a second order equation and considering the content of carbohydrates, proteins, lipids and minerals as predictor variables. Volume, hardness and alveolar uniformity of crumb were analysed in 20 formulations. The optimized formulation was compared by their proximate composition and profile of amino acids with GF commercial breads. Results and discussions: Breads with mixtures of 35- 41% HQ, 18% HL, 18-29% HA has presented an outstanding content in proteins (9%), lipids (3%), and total minerals (1.8%). The 20 LG bread formulations presented a hardness that ranged between 7.51 and 4.09 N, a specific volume ranging from 1.53 to 1.95 cm3/g and alveolar uniformity between 1.38 and 2.7. The optimized formulation (P0) was composed of 41% HQ, 20%, 18% HL, 11% MZ and 10% MA. Comparing the P0 with the LG commercial bread loaf, significant differences could be observed (P<0.05) in the content of proteins (11.21%), lipids (3%) and total minerals (2.27%), highlighting the bread of the P0 by presenting the highest nutritional values. Conclusions: It was achieved a suitable gluten-free product where the use of quinoa and sweet lupine flours as main components had a positive effect on the nutritional quality and to the physical properties of testing bread loafs