| 1. |
- Jha, Piyush, et al.
(författare)
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Benchmarking of techniques used to assess the freeze damage in potatoes
- 2019
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Ingår i: Journal of Food Engineering. - : Elsevier Ltd. - 0260-8774 .- 1873-5770. ; 262, s. 60-74
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Tidskriftsartikel (refereegranskat)abstract
- In this study, benchmarking of methods used for assessing freeze damage in potatoes was carried out. Initially, the samples were frozen by subjecting them to three different temperatures (i.e. at –18 °C, − 30 °C, and at −74 °C). Then, different analytical techniques comprising of focused methods (i.e. cryo-Scanning elctron microscopy-cryo-SEM, confocal laser scanning microscopy-CLSM)and global methods (i.e. texture analysis, low field nuclear magnetic resonance (NMR), exudate loss and colour change)were used to assess the impact of the freezing treatment from the different point of view addressed by each method. As a result, each of these methods were able to distinguish significantly fresh samples from the frozen-thawed samples. Focused methods like cryo-SEM and CLSM methods could differentiate the impact of all three different protocols. Meanwhile, texture analysis (including conventional method and novel method based on a touchless laser puff firmness tester), NMR and exudate loss could only determine the quality difference between −18 °C and − 74 °C freezing conditions. Colour analysis was found as an inappropriate parameter for comparing the three freezing protocols. Among all analytical techniques, cryo-SEM provides the most authentic information about the product as the analysis is performed in frozen state, while for other techniques the product is thawed prior to analysis.
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| 2. |
- Jha, Piyush, et al.
(författare)
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Effect of innovative microwave assisted freezing (MAF) on the quality attributes of apples and potatoes
- 2020
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Ingår i: Food Chemistry. - : Elsevier Ltd. - 0308-8146 .- 1873-7072. ; 309
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Tidskriftsartikel (refereegranskat)abstract
- This study considered the effect of low energy microwave assisted freezing (MAF) on freezing time and quality attributes (microstructure, texture, drip loss and colour) of apple and potato. MAF of apples and potatoes was performed by applying constant microwave (MW) power (167 W/kg) and pulsed MW power (500 and 667 W/kg with 10 s pulse width and 20 s pulse interval resulting in an average power of 167 and 222 W/kg) during the freezing process. The temperature profile was monitored during the freezing process, and the microstructure was examined using X-ray micro-tomography and cryo-SEM. Other quality parameters such as texture, drip loss and colour were evaluated with thawed samples. It appeared that the freezing time was not affected by the MAF process. It is the first time that a MAF process is used for freezing plant-based products and showed that the application of microwaves during freezing process caused less freeze damage than the control condition.
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| 3. |
- Jha, Piyush Kumar, et al.
(författare)
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Advances of electro-freezing in food processing
- 2018
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Ingår i: Current Opinion in Food Science. - : Elsevier BV. - 2214-7993 .- 2214-8000. ; 23, s. 85-89
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Tidskriftsartikel (refereegranskat)abstract
- Food freezing is a complex process, involving heat transfer and a series of physical and chemical changes which may profoundly affect the product quality. Several novel freezing methods have been developed in recent times taking into account the energy saving and/or quality preservation to a greater extent upon thawing. Electro-freezing technique, especially electric field assisted freezing is gaining momentum among them; it offers less energy intensive freezing conditions (higher set point ambient temperature, lower air velocity), and allows better quality retention. In the present short review article, a focused overview of the main findings and the latest studies regarding the applications of electro-freezing in food is given.
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| 4. |
- Jha, Piyush Kumar, et al.
(författare)
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An Overview on Magnetic Field and Electric Field interactions with Ice crystalization; Application in case of frozen food
- 2017
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Ingår i: Crystals. - : MDPI AG. - 2073-4352. ; 7:10
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Forskningsöversikt (refereegranskat)abstract
- Ice nucleation is a stochastic process and it is very difficult to be controlled. Freezing technologies and more specifically crystallisation assisted by magnetic, electric and electromagnetic fields have the capability to interact with nucleation. Static magnetic field (SMF) may affect matter crystallisation; however, this is still under debate in the literature. Static electric field (SEF) has a significant effect on crystallisation; this has been evidenced experimentally and confirmed by the theory. Oscillating magnetic field induces an oscillating electric field and is also expected to interact with water crystallisation. Oscillating electromagnetic fields interact with water, perturb and even disrupt hydrogen bonds, which in turn are thought to increase the degree of supercooling and to generate numerous fine ice crystals. Based on the literature, it seems that the frequency has an influence on the above-mentioned phenomena. This review article summarizes the fundamentals of freezing under magnetic, electric and electromagnetic fields, as well as their applicability and potentials within the food industry.
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| 5. |
- Jha, Piyush Kumar, et al.
(författare)
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Assessment of freeze damage in fruits and vegetables
- 2019
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Ingår i: Food Research International. - : Elsevier BV. - 0963-9969 .- 1873-7145. ; 121, s. 479-496
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Tidskriftsartikel (refereegranskat)abstract
- Freezing is an efficient and widely used method of food preservation. However, it can also cause irreversible damages at cellular level which in turn degrade the overall quality of the frozen food products. Therefore, qualitative and quantitative methods and technologies that will be able to evaluate with accuracy the freeze damage are of great importance. This review paper provides a comprehensive study of the methods that have been used to evaluate the freeze damage in fruits and vegetables. Further than the principles and the applications of those methods, the advantages and the limitations are also being discussed.
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| 6. |
- Jha, Piyush K., et al.
(författare)
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Freezewave H2020 project-microwaveassisted freezing of potato
- 2018
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Ingår i: Refrigeration Science and Technology. - 9782362150241 ; , s. 190-195
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Konferensbidrag (refereegranskat)abstract
- In the recent times, several novel freezing techniques have been attracting remarkable attention not only within the scientific community but also in the food industry due to their ability to enhance the formation of small size ice crystals and to prevent food products from freeze-damage. One of these is freezing assisted by electromagnetic waves. This short study was intended to investigate the impact freezing under low power microwaves (MWs) (2450 MHz) had on the freezing time and the microstructure of the potatoes. The time taken by the conventional freezing process to reach - 10°C from 6°C was 13.95 min, while the same temperature change was achieved within 37.53, 19.87 and 20.18 min for short pulse high power (SPHP), long pulse low power (LPLP) and constant microwave (MW) freezing conditions, respectively. Although that the application of MWs during freezing process, as it was expected, resulted in longer freezing time compared to conventional freezing condition, the image analysis (X-ray micro-computed tomography) results revealed that the application of MWs during freezing process produced better microstructure than the conventional method.
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| 7. |
- Le-Bail, A., et al.
(författare)
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Freezewave; A new European project on freezing under microwaves irradiation
- 2018
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Ingår i: Refrigeration Science and Technology. - 9782362150241 ; , s. 182-189
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Konferensbidrag (refereegranskat)abstract
- FREEZEWAVE project is an ERANET SUSFOOD project (May 2015 - Dec. 2018). It concerns the freezing of foods using a highly innovative technique combining freezing at slow rate with part time emission of microwaves (2450 MHz); this innovative concept has been investigated recently by ONIRIS and results showed that a 62% decrease of the average ice crystal size was acquired when samples were frozen under microwave irradiation compared to the control (Xanthakis et al., 2014, IFSET - study on pork meat). To improve the quality of frozen foods, fast freezing is usually recommended, resulting in a reduction of the ice crystals. However, a fast freezing increases the energy demand: low ambient temperature & high air velocity to enhance the rate of heat transfer are needed to achieve a fast freezing. FREEZEWAVE project aims at expanding & optimizing the concept to several foods (sauce, meat, vegetable & ready to eat meals) and also at designing industrial equipment. The novel concept concerns the freezing equipment sector thanks to a French SME partner (SAIREM) and the global frozen food sector. FREEZEWAVE will provide scientific knowledge and new scientific insights in food freezing. Project's outcomes may also be of interest for non-food applications such as biotechnology.
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| 8. |
- Le-Bail, Alain, et al.
(författare)
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Phase change under static electrical field; in the case of lipids
- 2016
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Ingår i: Refrigeration Science and Technology. - 9782362150142 ; , s. 138-143
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Konferensbidrag (refereegranskat)abstract
- Phase change in biological tissues may be affected by electrical and magnetic disturbances. Freezing under static electric field of water, aqueous solution and pork meat has been investigated by the authors, showing the ability of this process to refine ice crystals in frozen matrices. SEF affects the supercooling, which is usually reduced with SEF. SEF also triggers the nucleation. The use of radiofrequencies and microwaves has also been used recently by researchers to promote refined ice crystallization in food systems. A focus is proposed on recent experiments done on solidification of a vegetable fat mix (Vegetaline ® - France) under static electric field (SEF). Results showed that SEF affects the supercooling and the phase change temperature of the fat mix indicating a possible impact on the crystalline structure of the solidified fat.
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| 9. |
- Le-Bail, Alain, et al.
(författare)
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Review on the impact of electrical and magnetic disturbances during freezing
- 2018
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Ingår i: Refrigeration Science and Technology. - 9782362150241 ; , s. 225-232
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Konferensbidrag (refereegranskat)abstract
- Phase change in biological tissues may be affected by electrical and magnetic disturbances. This presentation proposes a review based on existing literature as well as some very recent results on freezing under static electric field (SEF), magnetic field (MF) and electromagnetic radiations. Freezing under static electric field of water, aqueous solution and pork meat has been investigated by the authors, showing the ability of this process to refine ice crystals in frozen matrices. SEF permits to lower the supercooling and to trigger the phase change of water to ice. Radiofrequencies and microwaves havebeen used recently by researchers to promote refined ice crystallization in food systems. Even though the energy optimization of the process is still in debate, the benefit in terms of size of ice crystals has been evidenced. © 2018 International Institute of Refrigeration. All rights reserved.
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