Aplicaciones de las ondas electromagnéticas en productos alimenticios

High frequency waves have a great potential in Food technology, both at house-cooking or industrial use. At home, microwave oven is a widely used equipment at kitchens of developed world. By contrast, in the Food Industry, the use of microwave and radio-frequency techniques is relatively small as a consequence of the need of equipment and specialised staff. The low application of such technology is related to the poor knowledge of the heating process through high frequencies as well as their critical factors that determine the quality of the heating process (dielectric constants, product geometry, distribution in the packaging, etc.). This article intends to clarify the basis of this technology besides describing some applications.Las altas frecuencias tienen un gran potencial dentro de la tecnología de alimentos, tanto en el ámbito doméstico como en el industrial. En el ámbito doméstico, el horno microondas es un equipo conocido que hoy en día se ha convertido en un elemento importante en las cocinas del mundo desarrollado. En el caso de la industria alimentaria, el uso de las microondas y radiofrecuencias es todavía escaso debido a la necesidad de equipos y personal especializado. La falta de aplicación de esta tecnología viene relacionada con la falta de conocimiento de lo que es un calentamiento por altas frecuencias y el desconocimiento de los factores críticos que determinarán la calidad de este calentamiento (constantes dieléctricas, geometría del producto, distribución en el envase, etc.). Con este artículo se busca aclarar las bases de esta tecnología, además de describir algunas aplicaciones

Implementation of a quality by design approach in the potato chips frying process

The purpose of the article is to implement a holistic concept namely Quality by Design (QbD) approach for assessment of deep frying of potatoes chips. Critical quality attributes (CQAs), critical process parameters (CPPs) and quality target parameters (QTPs) were identified and measured all along the chips processing chain in 98 independent experiments. Temperature, time and oil quality usually used in the food industry were applied. Multilinear regression (MLR) was conducted to identify the variables (CQAs and CPPs) that could explain variation of the QTPs. An aggregation of significant QTPs was also performed in order to determine a single value that could express final products quality coupled to MLR analysis. It was possible to identify the main CQAs and CPPs that can explain the variation of some QTPs (colour a*, “flavour roast” sensory attribute, pentylfuran content and acrylamide content) as well as aggregated data.info:eu-repo/semantics/acceptedVersio

Shelf‐life extension of multi‐vegetables smoothies by high‐pressure processing compared with thermal treatment. Part I: Microbial and enzyme inhibition, antioxidant status, and physical stability

Consumer demand for minimally processed food products based on fruits and vegetables is associated with their “fresh‐like” qualities and a desire for convenience. Smoothies could help meet these needs and contribute to increasing fruit and vegetable intake. The first part of this study assesses microbial and enzyme inactivation, antioxidant status, and physical stability of a vegetable smoothie (apple, carrot, zucchini, pumpkin, and leek) stabilized (for up to 28 days at 4°C) by high‐pressure processing (HPP) (350 MPa/5 min/10°C). Compared with mild heating (85°C/7 min), HPP ensured microbial quality (aerobic mesophilic and psychotropic bacteria, yeasts and molds), inhibited peroxidase, and slightly enhanced polyphenol oxidase and pectinmethylesterase enzymes. Consequently, the pressurized smoothies underwent earlier clarification and oxidation as reflected in their values of turbidity, browning index, viscosity, and antioxidant capacity. Therefore, the pressurizing conditions and/or raw material selection need to be improved to achieve better stabilization by HPP.info:eu-repo/semantics/acceptedVersio

Shelf‐life extension of multi‐vegetables smoothies by high pressure processing compared with thermal treatment. Part II: Retention of selected nutrients and sensory quality

Consumers are increasingly demanding food products based on minimally processed fruit and vegetables (Part I), which are associated with “fresh‐like” qualities and convenience. Smoothies may well fit in these needs and contribute to increasing fruit and vegetable intake. In this Part II, the objective was to assess the sensory and nutritional quality for up to 28 days at 4°C in a vegetable smoothie with apple that was stabilized by high pressure processing (HPP) (350 MPa/10°C/5 min) or mild heating (85°C/7 min). HPP provided smoothies without a cooked fruit odor that maintained their “fresh‐like” characteristics for at least 14 days. Furthermore, HPP resulted in a higher retention of vitamin C but not of total phenols and flavonoids, while sucrose rapidly was degraded to glucose and fructose during storage. Thus, mild pressurizing may be used to obtain “fresh‐like” vegetable smoothies, although the treatment should be improved to retain their sensory traits and nutrients for longer.info:eu-repo/semantics/acceptedVersio

Radio frequency cooking of pork hams followed with conventional steam cooking

Radio frequency (RF) is a volumetric heating technology that reduces the time needed to cook foodstuffs, but heating is not evenly distributed. The aim of this work was to develop a two-step cooking process in a RF tunnel and in a steam oven (RF-ST) for pork hams and compare it to cooking in a steam oven (ST). The temperature distribution was monitored during cooking and the accumulated lethality was calculated. Cooking losses and physicochemical and sensory properties of the cooked product were analysed. Hot spots and overheating problems were identified during the RF cooking process and were reduced by shielding the ends of the hams with aluminium foil and by adjusting the times of both, RF and steam cooking. The total ST process time (360 min) was reduced by 50% in RF-ST (180 min). Hardly significant differences were observed in the technological and sensory quality of the final product. Regarding the food safety of the RF-ST process, the lowest accumulated lethality in RF-ST process was observed in the outer part of the hams, which can be increased by extending the ST processing time, obtaining a more evenly distributed accumulated lethality in comparison to the ST process.info:eu-repo/semantics/acceptedVersio

Radio frequency cooking of pork hams followed with conventional steam cooking

Radio frequency (RF) is a volumetric heating technology that reduces the time needed to cook foodstuffs, but heating is not evenly distributed. The aim of this work was to develop a two-step cooking process in a RF tunnel and in a steam oven (RF-ST) for pork hams and compare it to cooking in a steam oven (ST). The temperature distribution was monitored during cooking and the accumulated lethality was calculated. Cooking losses and physicochemical and sensory properties of the cooked product were analysed. Hot spots and overheating problems were identified during the RF cooking process and were reduced by shielding the ends of the hams with aluminium foil and by adjusting the times of both, RF and steam cooking. The total ST process time (360 min) was reduced by 50% in RF-ST (180 min). Hardly significant differences were observed in the technological and sensory quality of the final product. Regarding the food safety of the RF-ST process, the lowest accumulated lethality in RF-ST process was observed in the outer part of the hams, which can be increased by extending the ST processing time, obtaining a more evenly distributed accumulated lethality in comparison to the ST process.info:eu-repo/semantics/acceptedVersio

FIREBall-2: advancing TRL while doing proof-of-concept astrophysics on a suborbital platform

Here we discuss advances in UV technology over the last decade, with an emphasis on photon counting, low noise, high efficiency detectors in sub-orbital programs. We focus on the use of innovative UV detectors in a NASA astrophysics balloon telescope, FIREBall-2, which successfully flew in the Fall of 2018. The FIREBall-2 telescope is designed to make observations of distant galaxies to understand more about how they evolve by looking for diffuse hydrogen in the galactic halo. The payload utilizes a 1.0-meter class telescope with an ultraviolet multi-object spectrograph and is a joint collaboration between Caltech, JPL, LAM, CNES, Columbia, the University of Arizona, and NASA. The improved detector technology that was tested on FIREBall-2 can be applied to any UV mission. We discuss the results of the flight and detector performance. We will also discuss the utility of sub-orbital platforms (both balloon payloads and rockets) for testing new technologies and proof-of-concept scientific ideasComment: Submitted to the Proceedings of SPIE, Defense + Commercial Sensing (SI19

FIREBall-2: The Faint Intergalactic Medium Redshifted Emission Balloon Telescope

The Faint Intergalactic Medium Redshifted Emission Balloon (FIREBall) is a mission designed to observe faint emission from the circumgalactic medium of moderate redshift (z~0.7) galaxies for the first time. FIREBall observes a component of galaxies that plays a key role in how galaxies form and evolve, likely contains a significant amount of baryons, and has only recently been observed at higher redshifts in the visible. Here we report on the 2018 flight of the FIREBall-2 Balloon telescope, which occurred on September 22nd, 2018 from Fort Sumner, New Mexico. The flight was the culmination of a complete redesign of the spectrograph from the original FIREBall fiber-fed IFU to a wide-field multi-object spectrograph. The flight was terminated early due to a hole in the balloon, and our original science objectives were not achieved. The overall sensitivity of the instrument and telescope was 90,000 LU, due primarily to increased noise from stray light. We discuss the design of the FIREBall-2 spectrograph, modifications from the original FIREBall payload, and provide an overview of the performance of all systems. We were able to successfully flight test a new pointing control system, a UV-optimized, delta-doped and coated EMCCD, and an aspheric grating. The FIREBall-2 team is rebuilding the payload for another flight attempt in the Fall of 2021, delayed from 2020 due to COVID-19.Comment: 23 Pages, 14 Figures, Accepted for Publication in Ap