Efecto de reemplazar estearina por oleína de palma en galletas de papa horneadas

Potato cookies were formulated by replacing red palm stearin (RPS) by red palm olein (RPOL) at 0, 17 and 35%, and then baked at 160, 180 and 200 °C for 10, 12 and 15 min. The sensory analysis, using an orthogonal test, showed that a RPS-RPOL ratio of 65:35, baking temperature of 160 ºC, and baking time 12 min were the optimal conditions. Cookies made from 65% RPS + 35% RPOL composition exhibited 0.6 times less squalene, but 1.5 times more β-carotene, tocopherols and tocotrienols than the mixture of RPS and RPOL at 100:0. In addition, cookies with superior oxidative stability were obtained at a lower temperature (160 ºC) and short baking time (10 min). This study demonstrates that the application of RPOL and RPS blending can positively enhance the nutritional properties and oxidative stability of baked food, and that using potato in the baking processing may be beneficial.Las galletas de papa fueron formuladas reemplazando estearina de palma roja (RPS) por oleina de palma roja (RPOL) al 0, 17 y 35%, y posteriormente horneadas a 160, 180 y 200°C durante 10, 12 y 15 min. El análisis sensorial utilizando una prueba ortogonal mostró que la relación RPS-RPOL 65:35, la temperatura de horneado 160 ºC, y el tiempo de horneado 12 min fueron las condiciones óptimas. Las galletas hechas de 65% RPS + 35% RPOL presentan 0,6 veces menos de escualeno, pero 1,5 veces más β-caroteno, tocoferoles y tocotrienoles que la mezcla de RPS y RPOL en 100:0. Por otra parte, las galletas con mayor estabilidad oxidativa se obtuvieron a menor temperatura (160 ºC) y menor tiempo de horneado (10 min). Este estudio demuestra que la mezcla RPOL y RPS puede mejorar positivamente las propiedades nutricionales y la estabilidad oxidativa de los alimentos horneados, y que el uso de papa en el procesamiento de hornear puede ser beneficioso

Instability and stability properties of traveling waves for the double dispersion equation

In this article we are concerned with the instability and stability properties of traveling wave solutions of the double dispersion equation $~u_{tt} -u_{xx}+a u_{xxxx}-bu_{xxtt} = - (|u|^{p-1}u)_{xx}~$ for $~p>1$, $~a\geq b>0$. The main characteristic of this equation is the existence of two sources of dispersion, characterized by the terms $u_{xxxx}$ and $u_{xxtt}$. We obtain an explicit condition in terms of $a$, $b$ and $p$ on wave velocities ensuring that traveling wave solutions of the double dispersion equation are strongly unstable by blow up. In the special case of the Boussinesq equation ($b=0$), our condition reduces to the one given in the literature. For the double dispersion equation, we also investigate orbital stability of traveling waves by considering the convexity of a scalar function. We provide both analytical and numerical results on the variation of the stability region of wave velocities with $a$, $b$ and $p$ and then state explicitly the conditions under which the traveling waves are orbitally stable.Comment: 16 pages, 4 figure

Preparación de sustitutos de grasa de leche humana y mejora de su estabilidad oxidativa

1,3-Dioleoyl-2-palmitoylglycerol (OPO) was synthesized by enzymatic interesterification using palm stearin rich in tripalmitin (PPP) and ethyl oleate. Enzymatic interesterification parameters such as temperature, water content, enzyme load, and substrate molar ratio were optimized. High contents of C52 (primarily OPO and its isomeric compounds) production (46.7%) and sn-2 palmitic acid (PA) content of 75.3% were detected. In addition, OPO-human milk fat substitute (HMFS) was blended with coconut, soybean, algal and microbial oils at a weight ratio of 0.70:0.18:0.11:0.004:0.007 to simulate fatty acids in human milk fat (HMF) according to the mathematical model. The main and important fatty acids in the Final-HMFS were within the ranges of those present in HMF. The Final-HMFS could promote the absorption of fats and minerals and the development of retina tissues in infants. The mixture of L-ascorbyl palmitate (L-AP) and vitamin E (VE) resulted in a synergistic antioxidant effect both in OPO-HMFS and OPO-HMFS emulsions. This finding has great significance in improving the quality and extending shelf-life of HMFS.Se sintetizó el 1,3-dioleoil-2-palmitoilglicerol (OPO), utilizando estearina de palma rica en tripalmitina (PPP) y oleato de etilo, mediante interesterificación enzimática. Se optimizaron los parámetros de la interesterificación enzimática, como la temperatura, el contenido de agua, la carga de enzimas y la relación molar del sustrato. Se lograron altos rendimientos de C52 (principalmente OPO y sus isómeros, 46,7%) y un contenido de ácido palmítico (PA) en sn-2 del 75,3%. Además, el sustituto graso de leche humana OPO (HMFS), se mezcló con aceites de coco, soja, algas y microbianos, en una proporción en peso de 0,70:0,18:0,11:0,004:0,007 para simular los ácidos grasos de la leche humana (HMF) de acuerdo con un modelo matemático. Los ácidos grasos principales e importantes en HMFS-Final estaban casi dentro de los rangos de los presentes en HMF. El HMFS-Final podría promover la absorción de grasas y minerales y el desarrollo de los tejidos de la retina en los bebés. La mezcla de palmitato de L-ascorbilo (L-AP) y vitamina E (VE) resultó tener un efecto antioxidante sinérgico, tanto en la emulsión OPO-HMFS como en la OPO-HMFS. Este hallazgo tiene una gran importancia para mejorar la calidad y prolongar la vida útil de HMFS

Efecto de diferentes técnicas de horneado en la calidad de las nueces y su aceite

The baking conditions of walnut kernels were optimized based on different cultivars and baking methods. The influence of the different baking techniques on the chemical properties of walnut oils was determined. The results showed that acid value, peroxide value and induction period (IP) all significantly increased in the baked samples compared to the unbaked ones. The highest increase in IP was from 6 to 17 h indicating that baking can improve the oxidative stability of walnut oils and prolong their shelf-life. Several aroma components increased after baking. However, among the different baking conditions, the strongest aroma in walnut oil was observed after baking was done for 20 min with sucrose (107%) at 153 ℃. Nevertheless, baking had little effect on the fatty acid composition of walnuts.Las condiciones de horneado de los granos de nueces se optimizaron en base a diferentes cultivares y métodos de horneado. Se determinó la influencia de las diferentes técnicas de horneado sobre las propiedades químicas de los aceites de nuez. Los resultados mostraron que el índice de acidez, el índice de peróxido y el período de inducción (PI) aumentaron significativamente en las muestras horneadas en comparación con las no horneadas. El mayor aumento en el PI fue de 6 a 17 h, lo que indica que el horneado puede mejorar la estabilidad oxidativa de los aceites de nuez y prolongar su vida útil. Varios componentes del aroma aumentaron después del horneado, sin embargo, entre las diferentes condiciones de horneado, se observó el aroma más fuerte en el aceite de nuez después del horneado durante 20 minutos con sacarosa (107%) a 153 ℃. Sin embargo, el horneado tuvo poco efecto sobre la composición de ácidos grasos de las nueces

Refactoring Process Models in Large Process Repositories.

With the increasing adoption of process-aware information systems (PAIS), large process model repositories have emerged. Over time respective models have to be re-aligned to the real-world business processes through customization or adaptation. This bears the risk that model redundancies are introduced and complexity is increased. If no continuous investment is made in keeping models simple, changes are becoming increasingly costly and error-prone. Though refactoring techniques are widely used in software engineering to address related problems, this does not yet constitute state-of-the art in business process management. Process designers either have to refactor process models by hand or cannot apply respective techniques at all. This paper proposes a set of behaviour-preserving techniques for refactoring large process repositories. This enables process designers to eectively deal with model complexity by making process models better understandable and easier to maintain

Preferred growth direction of III-V nanowires on differently oriented Si substrates

One of the nanowire characteristics is its preferred elongation direction. Here, we investigated the impact of Si substrate crystal orientation on the growth direction of GaAs nanowires. We first studied the self-catalyzed GaAs nanowire growth on Si (111) and Si (001) substrates. SEM observations show GaAs nanowires on Si (001) are grown along four directions without preference on one or some of them. This non-preferential nanowire growth on Si (001) is morphologically in contrast to the extensively reported vertical preferred GaAs nanowire growth on Si (111) substrates. We propose a model based on the initial condition of an ideal Ga droplet formation on Si substrates and the surface free energy calculation which takes into account the dangling bond surface density for different facets. This model provides further understanding of the different preferences in the growth of GaAs nanowires along selected directions depending on the Si substrate orientation. To verify the prevalence of the model, nanowires were grown on Si (311) substrates. The results are in good agreement with the three-dimensional mapping of surface free energy by our model. This general model can also be applied to predictions of nanowire preferred growth directions by the vapor-liquid-solid growth mode on other group IV and III-V substrates

Effect of boundaries on the force distributions in granular media

The effect of boundaries on the force distributions in granular media is illustrated by simulations of 2D packings of frictionless, Hertzian spheres. To elucidate discrepancies between experimental observations and theoretical predictions, we distinguish between the weight distribution {\cal P} (w) measured in experiments and analyzed in the q-model, and the distribution of interparticle forces P(f). The latter one is robust, while {\cal P}(w) can be obtained once the local packing geometry and P(f) are known. By manipulating the (boundary) geometry, we show that {\cal P}(w) can be varied drastically.Comment: 4 pages, 4 figure

Geometry of Frictionless and Frictional Sphere Packings

We study static packings of frictionless and frictional spheres in three dimensions, obtained via molecular dynamics simulations, in which we vary particle hardness, friction coefficient, and coefficient of restitution. Although frictionless packings of hard-spheres are always isostatic (with six contacts) regardless of construction history and restitution coefficient, frictional packings achieve a multitude of hyperstatic packings that depend on system parameters and construction history. Instead of immediately dropping to four, the coordination number reduces smoothly from $z=6$ as the friction coefficient $\mu$ between two particles is increased.Comment: 6 pages, 9 figures, submitted to Phys. Rev.

Neutron scattering and superconducting order parameter in YBa2Cu3O7

We discuss the origin of the neutron scattering peak at 41 meV observed in YBa$_2$Cu$_3$O$_7$ below $T_c$. The peak may occur due to spin-flip electron excitations across the superconducting gap which are enhanced by the antiferromagnetic interaction between Cu spins. In this picture, the experiment is most naturally explained if the superconducting order parameter has $s$-wave symmetry and opposite signs in the bonding and antibonding electron bands formed within a Cu$_2$O$_4$ bilayer.Comment: In this version, only few minor corrections and the update of references were done in order to make perfect correspondence with the published version. RevTeX, psfig, 5 pages, and 3 figure

Self-formed quantum wires and dots in GaAsP-GaAsP core-shell nanowires

Quantum structures designed using nanowires as a basis are excellent candidates to achieve novel design architectures. Here, triplets of quantum wires (QWRs) that form at the core–shell interface of GaAsP–GaAsP nanowires are reported. Their formation, on only three of the six vertices of the hexagonal nanowire, is governed by the three-fold symmetry of the cubic crystal on the (111) plane. In twinned nanowires, the QWRs are segmented, to alternating vertices, forming quantum dots (QDs). Simulations confirm the possibility of QWR and QD-like behavior from the respective regions. Optical measurements confirm the presence of two different types of quantum emitters in the twinned individual nanowires. The possibility to control the relative formation of QWRs or QDs, and resulting emission wavelengths of the QDs, by controlling the twinning of the nanowire core, opens up new possibilities for designing nanowire devices