Advantages of ohmic cooking in the kilohertz range – Part II: Impact on textural changes and approaches to improve heating uniformity

Electron microscopy (EM), with the advent of computer control and image analysis techniques, is rapidly evolving from an interpretative science into a quantitative technique. Electron microscopy is potentially of value in two general aspects of environmental health: exposure and diagnosis.In diagnosis, electron microscopy is essentially an extension of optical microscopy. The goal is to characterize cellular changes induced by external agents. The external agent could be any foreign material, chemicals, or even stress. The use of electron microscopy as a diagnostic tool is well- developed, but computer-controlled electron microscopy (CCEM) has had only limited impact, mainly because it is fairly new and many institutions lack the resources to acquire the capability. In addition, major contributions to diagnosis will come from CCEM only when image analysis (IA) and processing algorithms are developed which allow the morphological and textural changes recognized by experienced medical practioners to be quantified. The application of IA techniques to compare cellular structure is still in a primitive state.

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An Integrated Approach of Mechanistic-Modeling and Machine-Learning for Thickness Optimization of Frozen Microwaveable Foods

Foods ◽

10.3390/foods10040763 ◽

2021 ◽

Vol 10 (4) ◽

pp. 763

Author(s):

Ran Yang ◽

Zhenbo Wang ◽

Jiajia Chen

Keyword(s):

Machine Learning ◽

Learning Algorithm ◽

Food Product ◽

Integrated Approach ◽

Mechanistic Modeling ◽

Bayesian Optimization ◽

Initial Training ◽

Thickness Optimization ◽

Heating Uniformity ◽

Food Design

Mechanistic-modeling has been a useful tool to help food scientists in understanding complicated microwave-food interactions, but it cannot be directly used by the food developers for food design due to its resource-intensive characteristic. This study developed and validated an integrated approach that coupled mechanistic-modeling and machine-learning to achieve efficient food product design (thickness optimization) with better heating uniformity. The mechanistic-modeling that incorporated electromagnetics and heat transfer was previously developed and validated extensively and was used directly in this study. A Bayesian optimization machine-learning algorithm was developed and integrated with the mechanistic-modeling. The integrated approach was validated by comparing the optimization performance with a parametric sweep approach, which is solely based on mechanistic-modeling. The results showed that the integrated approach had the capability and robustness to optimize the thickness of different-shape products using different initial training datasets with higher efficiency (45.9% to 62.1% improvement) than the parametric sweep approach. Three rectangular-shape trays with one optimized thickness (1.56 cm) and two non-optimized thicknesses (1.20 and 2.00 cm) were 3-D printed and used in microwave heating experiments, which confirmed the feasibility of the integrated approach in thickness optimization. The integrated approach can be further developed and extended as a platform to efficiently design complicated microwavable foods with multiple-parameter optimization.

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Softening of Processed Plant Virus Infected Cucumis sativus Fruits

Agronomy ◽

10.3390/agronomy11081451 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1451

Author(s):

Anne-Katrin Kersten ◽

Sabrina Scharf ◽

Martina Bandte ◽

Peer Martin ◽

Peter Meurer ◽

...

Keyword(s):

Cucumis Sativus ◽

Plant Virus ◽

Plant Viruses ◽

Economic Losses ◽

Symptom Expression ◽

Considerable Influence ◽

Mechanical Inoculation ◽

Morphological Alterations ◽

Texture Properties ◽

Textural Changes

Texture softening of pickled cucumbers does not meet consumers’ quality expectations and leads to economic losses. The factor(s) triggering this phenomenon is still unknown. We investigated the importance of plant viruses such as Cucumber green mottle mosaic tobamovirus (CGMMV) and Zucchini yellow mosaic potyvirus (ZYMV) in the context of softening of pickles. Cucumber plants (Cucumis sativus) were infected by mechanical inoculation, grown under greenhouse conditions and tested positive for the viral infection by ELISA. The severity of virus infection was reflected in yield and symptom expression. Histological and morphological alterations were observed. All fruits were pasteurized, separately stored in jars and subjected to texture measurements after four, six and 12 months. CGMMV-infections were asymptomatic or caused mild symptoms on leaves and fruit, and texture quality was comparable to control. At the same time, fruits of ZYMV-infected plants showed severe symptoms like deformations and discoloration, as well as a reduction in firmness and crunchiness after pasteurization. In addition, histological alterations were detected in such fruits, possibly causing textural changes. We conclude that plant viruses could have a considerable influence on the firmness and crunchiness of pickled cucumbers after pasteurization. It is possible that the severity of symptom expression has an influence on texture properties.

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Simulation of Thermal and Electric Field Distribution in Packaged Sausages Heated in a Stationary Versus a Rotating Microwave Oven

Foods ◽

10.3390/foods10071622 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1622

Author(s):

Wipawee Tepnatim ◽

Witchuda Daud ◽

Pitiya Kamonpatana

Keyword(s):

Temperature Distribution ◽

Electric Field ◽

Three Dimensional ◽

Development Stage ◽

Microwave Oven ◽

Computational Time ◽

Plastic Package ◽

Heating Uniformity ◽

The Cost ◽

Good Agreement

The microwave oven has become a standard appliance to reheat or cook meals in households and convenience stores. However, the main problem of microwave heating is the non-uniform temperature distribution, which may affect food quality and health safety. A three-dimensional mathematical model was developed to simulate the temperature distribution of four ready-to-eat sausages in a plastic package in a stationary versus a rotating microwave oven, and the model was validated experimentally. COMSOL software was applied to predict sausage temperatures at different orientations for the stationary microwave model, whereas COMSOL and COMSOL in combination with MATLAB software were used for a rotating microwave model. A sausage orientation at 135° with the waveguide was similar to that using the rotating microwave model regarding uniform thermal and electric field distributions. Both rotating models provided good agreement between the predicted and actual values and had greater precision than the stationary model. In addition, the computational time using COMSOL in combination with MATLAB was reduced by 60% compared to COMSOL alone. Consequently, the models could assist food producers and associations in designing packaging materials to prevent leakage of the packaging compound, developing new products and applications to improve product heating uniformity, and reducing the cost and time of the research and development stage.

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Effects of layer arrangement on heating uniformity and product quality after hot air assisted radio frequency drying of carrot

Innovative Food Science & Emerging Technologies ◽

10.1016/j.ifset.2021.102667 ◽

2021 ◽

Vol 69 ◽

pp. 102667

Author(s):

Chenchen Wang ◽

Xiaoxi Kou ◽

Xu Zhou ◽

Rui Li ◽

Shaojin Wang

Keyword(s):

Radio Frequency ◽

Product Quality ◽

Layer Arrangement ◽

Hot Air ◽

Heating Uniformity

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A Complete CDW Theory for the Single Ionization of Multielectronic Atoms by Bare Ion Impact

Atoms ◽

10.3390/atoms9010003 ◽

2021 ◽

Vol 9 (1) ◽

pp. 3

Author(s):

Juan M. Monti ◽

Michele A. Quinto ◽

Roberto D. Rivarola

Keyword(s):

Transition Amplitude ◽

Emission Spectra ◽

Heavy Ion ◽

Distorted Wave ◽

Single Ionization ◽

Complete Form ◽

Active Electron ◽

Ion Impact ◽

Range Part ◽

The Continuum

A complete form of the post version of the continuum distorted wave (CDW) theory is used to investigate the single ionization of multielectronic atoms by fast bare heavy ion beams. The influence of the non-ionized electrons on the dynamic evolution is included through a residual target potential considered as a non-Coulomb central potential through a GSZ parametric one. Divergences found in the transition amplitude containing the short-range part of the target potential are avoided by considering, in that term exclusively, an eikonal phase instead of the continuum factor as the initial channel distortion function. In this way, we achieve the inclusion of the interaction between the target active electron and the residual target, giving place to a more complete theory. The present analysis is supported by comparisons with existing experimental electron emission spectra and other distorted wave theories.

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