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1.	Elustondo, Diego, et al. (författare) Mathematical modeling of moisture evaporation from foodstuffs exposed to subatmospheric pressure superheated steam 2001 Ingår i: Journal of Food Engineering. - 0260-8774 .- 1873-5770. ; 49:1, s. 15-24 Tidskriftsartikel (refereegranskat)abstract In this work, a reduced expression to calculate the drying rate of foodstuffs being dried with low pressure superheated steam is developed. It is based on a theoretical drying mechanism which assumes that water removal is carried out by evaporation in a moving boundary making the vapor to flow through the dry layer built as drying proceeds. The theoretical model can be applied to any form and features dimensionless parameters to allow for the influence of form, shrinking effect and boiling point rise. To make the application easier, a simplified expression was derived, which has only two experimentally determined parameters and allows the calculation of the drying rate of a given product. Different foodstuffs were dried with this technique and the empirical parameters were calculated from the experimental data fitting equation. Interestingly, those parameters can be considered constant within the 10000-20000 Pa pressure range and the 60-90°C temperature range
2.	Elustondo, Diego, et al. (författare) New thermal conductivity probe design based on the analysis of error sources 2001 Ingår i: Journal of Food Engineering. - 0260-8774 .- 1873-5770. ; 48:4, s. 325-333 Tidskriftsartikel (refereegranskat)abstract The thermal conductivity determination by means of the thermal probe is a classical non-stationary method, suitable for foodstuffs because of the relatively short period of time and the small temperature rise required during experimental measurements. Even though its simplicity, this method has theoretical and practical implicit errors, their main sources being evaluated in this paper. The theoretical analysis shows that experimental errors can be kept within acceptable values, if the testing time period is within certain limits, out of which the errors grow quite rapidly. The error arising from the calculation of the thermal conductivity by means of an approximate equation is studied and a new way to express it is presented. Also, testing times were calculated for different probe dimensions. Finally, on the basis of two former probe which exhibits some advantages upon each other, a new probe design is proposed which recoveries those features.
3.	Funebo, Tomas, et al. (författare) Microwave heat treatment of apple before air dehydration : Effects on physical properties and microstructure 2000 Ingår i: Journal of Food Engineering. - 0260-8774 .- 1873-5770. ; 46:3, s. 173-182 Tidskriftsartikel (refereegranskat)abstract Golden delicious apple cubes were heated with microwave energy of high intensity (20 W/g), as a pre-treatment before air-dehydration at 40 °C, 60 °C and 80 °C. After the microwave treatment extending for 0.75 up to 5 min, the cubes were finish-dried with only forced air at 2 m/s. Dehydrated and rehydrated samples were analyzed with a puncture test using a texture analyzer. The microstructure of the samples was studied with confocal laser scanning microscopy (CLSM). Dried apple pieces were harder and more shrunk when pre-treated with microwaves, compared to only air dehydration. Despite the shrinkage and increased firmness, the rehydration capacity of microwave `blanched' apple cubes was higher than when they were only air-dehydrated. Image analysis of the rehydrated apples showed that large voids (up to 0.5 mm in diameter) had developed, and that these increased with air temperature. Higher magnification of the images revealed cell separation and disruption of cell walls, caused by the microwave heating.
4.	Prothon, F., et al. (författare) Application of the Guggenheim, Anderson and De Boer model to correlate water activity and moisture content during osmotic dehydration of apples 2004 Ingår i: Journal of Food Engineering. - 0260-8774 .- 1873-5770. ; 61:3, s. 467-470 Tidskriftsartikel (refereegranskat)abstract Water activity and moisture content are the most valuable characteristics for assessing the stability of dried foods. The aim of this work was to evaluate if a desorption isotherm model could be used to describe the relationship between the water activity and moisture content in the product during osmotic dehydration. This model can lead to a better understanding of how water activity of a product can be reduced during osmotic dehydration. The Guggenheim, Anderson and De Boer (GAB) model was chosen because it has been proven to best fit the desorption and adsorption of foods over a large range of water activities. The studied material was apple pieces, and the osmotic medium with a water activity of 0.939 was prepared with sucrose. The osmotic dehydration process was studied by collecting moisture content and water activity data at different temperatures and times. The model was shown to fit well the experimental points at temperatures 25, 45 and 55 °C. At 65 °C, however, the model is satisfactory if aw is below 0.970 but not above. The effect of temperature can be expressed on the C-parameter of the GAB model. © 2003 Elsevier Ltd. All rights reserved.
5.	Skjöldebrand, Christina, et al. (författare) A computer simulation program for evaluation of the continuous heat treatment of particulate food products. : Part 1: Design 1993 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 20:2, s. 149-165 Tidskriftsartikel (refereegranskat)abstract Computer simulation programs used by the food industry today are not very well developed, partly because few food processes ar easily described by mathematical equations. The heat treatment of food, however, is one group of processes for which mathematical modelling exists. Programs used for prediction of the time-temperature relationship for various food products during heat treatment have been developed at SIK. A specially designed program calculates the temperature in viscous liquid foods with discrete solid particles. This program facilitates study of the influence of processing conditions on the product quality in an aseptic processing system. The F value is a measure of the safety and a so-called C value (cook value) is a measure of the quality of the product. The simulation program has been further developed to take into account product flow rate, residence time distribution, particle size and geometry, equipment specifications, particle load and the thermal properties of the product. The simulation program makes it possible to analyse the entire sterilisation system, including cooling, and determine the required holding time to reach a desired lethality value in the centre of the fastest-moving particle. The design of the program is described in this paper, and some applications are treated in a following paper. © 1993.
6.	Skjöldebrand, Christina, et al. (författare) A computer simulation program for evaluation of the continuous heat treatment of particulate food products. : Part 2: Utilisation 1993 Ingår i: Journal of Food Engineering. - 0260-8774 .- 1873-5770. ; 20:2, s. 167-181 Tidskriftsartikel (refereegranskat)abstract A computer program for calculation of temperatures in a liquid containing particles during continuous heat treatment has been developed at the SIK. The program facilitates the study of the influence of processing on product quality in an aseptic processing system. The calculated F value is related to the safety, and the cook value (C value) is related to the quality of the product. In this paper, results of some calculations using the program are presented. They concentrate on the influence of the processing conditions on the process design. These results indicate that factors such as particle heat transfer coefficient, both in the holding tube and in the scraped surface heat exchangers (SSHEs), flow conditions, particle diameter and sterilisation temperature have consequences for the holding tube length, i.e. the processing time, for a given lethality. For example, for small particle heat transfer coefficients (< 100 W m2 K), a small change will have a large effect on the required processing time (i.e. the holding tube length). However, at particle heat transfer coefficients > 150-200 W m2 K a small change does not greatly affect the processing time (i.e. holding tube length). The program can thus be used to examine whether the surface heat transfer coefficient is the rate-limiting factor, or whether the heat conduction inside the particles is more important in the design of the process. © 1993.
7.	Skjöldebrand, Christina, et al. (författare) Optical properties of bread in the near-infrared range 1988 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 8:2, s. 129-139 Tidskriftsartikel (refereegranskat)abstract This paper reports on a method for determination of the optical properties of bread. The optical properties of white bread have been studied. The measurements were carried out for dough, crumb and crust. The transmission and reflection measurements were made with a Beckman spectrophotometer with an integrating sphere. Transmission functions and penetration depths were calculated and compared with previous investigations made at this institute (SIK). The influence of peak power wavelength and spectral range (800-1250 nm and 1250-2500 nm) on the penetration depth for crust and crumb have been determined. This study has shown that it is possible to calculate penetration depth for any radiator using transmission data in the range 800-2500 nm. © 1989.
8.	Thorvaldsson, K., et al. (författare) A model for simultaneous heat, water and vapour diffusion. 1999 Ingår i: Journal of Food Engineering. - 0260-8774 .- 1873-5770. ; 40:3, s. 167-172 Tidskriftsartikel (refereegranskat)abstract A model for simultaneous heat, water and vapour diffusion was developed to use for prediction of the diffusion of water inside foods during heat processing. The model is based on Fourier's and Fick's Laws. The diffusion of liquid water is separated from the diffusion of water vapour. The model was evaluated in a drying process. Slabs of bread crumbs, 12×12×2 cm3 in size, were dried in a conventional oven at 210 °C and the local water content and temperatures were measured during the drying in the centre, halfway to the centre and at the surface. From the measurements, the diffusion coefficient as a function of temperature and concentration and several other material parameters were estimated. The results show that the measured water content slowly increases in the centre of the sample. During the increase, the temperature remains on a plateau. When the centre starts to dry the temperature increases. Halfway to the centre the water content also increases slightly before it starts to dry out, while the surface starts drying immediately. The simulated water content levels and temperatures conform well to the experimental values and show that the evaporation and condensation model describes well the diffusion mechanisms in a porous food.
9.	Thorvaldsson, K., et al. (författare) Method and instrument for measuring local water content inside food 1996 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 29:1, s. 1-11 Tidskriftsartikel (refereegranskat)abstract A new method of measuring local water content inside food during heat processing has been evaluated. The method uses a fibre optic NIR-Instrument. The evaluation was mainly based on investigations of the influence of structure and temperature. The instrument was found to be very sensitive to both the structure and the temperature of the sample. The dependence on the temperature of the sample can be incorporated into the calibration and is thereby not an impediment to the measurements. The structural dependence makes quantitative measurements at different places in the sample difficult for inhomogeneous materials. However, measurements of dynamic changes in the water content in one spot work well for both homogenous and inhomogeneous materials and are probably the best application of the instrument. By using two or more optic fibres, the diffusion of water can also be measured. Copyright © 1996 Elsevier Science Limited.
10.	Thorvaldsson, K., et al. (författare) Water transport in meat during reheating 1996 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 29:1, s. 13-21 Tidskriftsartikel (refereegranskat)abstract A study of heat and water transport in meat during a heating process was conducted. The meat samples were heated from 10 to 100°C in a conventional oven at 175°C and local water content and temperatures were measured during the heating process. Using whole meat from bovine muscles, the mechanism behind water transport inside the sample during heating was investigated. The anisotropy of meat in terms of heat and water transport was also studied. The study yielded two main results: When heating commences, water moves towards the centre of the samples. At a centre temperature of ?70°C, water transport stops and changes direction. A theory for transport phenomena has been developed and is described in this paper. The results also indicate that, as expected, both water transport and heat transport are faster parallel to the meat fibres than perpendicular to them. Copyright © 1996 Elsevier Science Limited.
11.	Walkenström, Pernilla, et al. (författare) Effects of flow behaviour on the aggregation of whey protein suspensions, pure or mixed with xanthan 1999 Ingår i: Journal of Food Engineering. - 0260-8774 .- 1873-5770. ; 42:1, s. 15-26 Tidskriftsartikel (refereegranskat)abstract The effect of prior thermal treatment on radiation sensitization were investigated on proton irradiated Type 304 stainless steel (SS) of initially as-received (AR) and thermal-sensitized (SEN) conditions. The Cr depletion profiles were measured by field emission gun transmission electron microscopy/energy dispersive spectroscopy (FEGTEM, EDS), and were calculated by a radiation induced segregation (RIS) model. The different initial conditions were input in the RIS model calculations. For the as-received condition, the initial Cr profile was modeled by a uniform concentration distribution. Overall, the results show that radiation sensitization is characterized by a very narrow Cr depleted zone.
12.	Wählby, Urban, et al. (författare) Impact of impingement on cooking time and food quality 2000 Ingår i: Journal of Food Engineering. - 0260-8774 .- 1873-5770. ; 43:3, s. 179-187 Tidskriftsartikel (refereegranskat)abstract An experimental study has been made, with the objective to find the impact of directed forced convection (impingement) on food quality. Two different foods were chosen for the study, yeast buns (representing category bread) and pork cutlet (representing meats). The tests were made in an experimental oven intended for the domestic market. The main results were a shorter cooking time and more uniform browning for meat (a reduction by up to 50% at similar air temperature as recommended). For smaller pieces of meat, browning was a general problem, as centre temperature increased to rapidly, at the air temperatures tested here. Buns were slightly more uniform in browning on the surface. The cooking time was basically similar to a traditional oven, but at much lower air temperature setting.
13.	Wählby, Urban, et al. (författare) NIR-measurements of moisture changes in foods 2001 Ingår i: Journal of Food Engineering. - 0260-8774 .- 1873-5770. ; 47:4, s. 303-312 Tidskriftsartikel (refereegranskat)abstract Mass transfer and especially the movement and loss of water are important for the quality of cooked foods. Measurements of the water content changes during cooking are therefore valuable when it comes to controlling cooking processes. A near infrared reflection fibre optic probe is here used to measure water content changes inside pork meat and buns during heating. The results are compared with a moist porous brick (in the following called model food). Five different periods were seen locally in the centre. First a period of constant water content, then a period of constant decrease (constant rate period). The constant rate was followed by a period, an intermediate period where the temperature levelled at 100 °C, while the water content decrease was small. In the fourth period the slope of the water content vs time curve became steeper and the temperature began to increase above 100 °C. Finally, the water content moved to zero while the temperature rose towards the air temperature. The results for buns indicated that the water content near the surface began to decrease almost instantly and continued for the whole heating time in a falling rate manner. At the centre, the water content fell initially and then levelled. The major difference compared to the model food was the levelling off temperature, roughly 100 °C in the food and 75 °C in the model food.
14.	Wählby, Urban, et al. (författare) Reheating characteristics of crust formed on buns, and crust formation 2002 Ingår i: Journal of Food Engineering. - 0260-8774 .- 1873-5770. ; 53:2, s. 177-184 Tidskriftsartikel (refereegranskat)abstract The idea of this paper to examine some characteristics of crust formation during baking of yeast leavened dough. The aim is to find the impact of the crust on the heat and mass transfer rates. In a second test series, buns were baked under different conditions, and the rate of crust browning and thickness evolution was followed. The aim was further to see whether a baking at 145 °C under high convective boundary conditions could match traditional baking (hot air at 175 °C and top-bottom at 200 °C). Ready baked buns were reheated some with and some without (peeled off) crust. The results show a difference in heating behaviour. The temperature in buns heated with crust rose faster and levelled off at significantly higher temperatures than in buns without crust. The buns heated without crust lost weight at a rate about three times that of buns with crust. Air temperature and velocity influenced the loss rate for both kinds of buns. For the comparative study, it was found that although the internal heating rate of the buns was similar for the three heating technologies, the crust browning was faster and greater in the traditional processes. It was also found that the rate of browning is not significantly increased by impingement, even when varying the air velocity. © 2002 Elsevier Science Ltd. All rights reserved.
15.	Åström, Annika, et al. (författare) Heat transfer between fluid and particles in aseptic processing 1994 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 21:1, s. 97-125 Tidskriftsartikel (refereegranskat)abstract The particle heat transfer coefficient, hfp, is one of the critical factors, besides the residence time distribution, that has to be known for the design and development of continuous heat processes of particulate food products. In the present work, data and methods for determining hhp for conditions relevant to aseptic processing have been studied. The influence of product characteristics, such as size and composition of particles, fluid properties, temperature differences and fluid motion, have been investigated. Among the parameters investigated, the flow field around the particles was shown to be the most important for heat transfer but for special conditions the particle size, particle shape or thermal properties of the particle, as well as the apparent viscosity and the thermal properties of the fluid, are equally important for the value of hfp. For safety considerations, the present investigation indicates that hfp values corresponding to an Nu value of 5-6 should be relevant for medium-sized spherical particles transported by a highly viscous liquid. For the quality aspects, different conditions have to be considered. Particles at different positions in·the tube flow will experience different heat transfer. The few particles in the centre of the tube will experience a low heat transfer and hfp values corresponding to Nu values ranging between 5 and 10. The larger amounts of particles are transported in the liquid with a pronounced velocity gradient which yields Nu values of 10-17, while for extreme conditions occurring for sedimented particles, Nu values between 20 and 45 could be expected. © 1993.
16.	Andersson, Johanna, et al. (författare) Comparison of steaming and boiling of root vegetables for enhancing carbohydrate content and sensory profile 2022 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 312 Tidskriftsartikel (refereegranskat)abstract Root vegetables have unique techno-functional and nutritional properties however, their use in processed foods is limited to a few species, partially due to a lack of knowledge related to the impact of thermal treatments on the sensory properties. This study investigated the effect of steaming and boiling on the microstructure, mechanical properties, and sensory profile of three model root vegetables with distinct carbohydrate composition: Jerusalem artichoke (Helianthus tuberosus L.), parsnip (Pastinaca sativa), and beetroot (Beta vulgaris). Thermally treated Jerusalem artichoke and parsnip showed higher content of cell wall polysaccharides, particularly β-glucans (e.g. cellulose) and pectic components, compared to raw. Steaming produced more cell shrinkage and loss of cell-cell adhesion than boiling, leading to softer vegetables. Processed beetroot showed loss of cell turgor and drastic softening but not clear changes in overall carbohydrate content. The scores for several flavour and in-mouth attributes were higher for steamed vegetables compared to boiled. Our results give insights on the processability of root vegetables towards products with enhanced sensory and nutritional properties.
17.	Berta, M., et al. (författare) Correlation between in-line measurements of tomato ketchup shear viscosity and extensional viscosity 2016 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 173, s. 8-14 Tidskriftsartikel (refereegranskat)abstract The viscosity and shear thinning behavior are essential characteristics of tomato ketchup. A real-time monitoring of those characteristics during processing is important to obtain a good quality of the final product and to reduce production waste. This work investigates the measurement of rheological in-line flow properties of tomato ketchup, using a real-time technique that combines ultrasound velocity profiling (UVP) and pressure difference (PD) assessment. In-line data were compared to those obtained off-line using a rotational viscometer. There was a poor correlation with the Bostwick measurement, whereas the flow curves calculated from flow velocimetry data were very similar to those measured off-line. The extensional viscosity of ketchup was determined through the measurement of Hyperbolic Contraction Flow; the curve followed a trend similar to that for the shear viscosity over the deformation rate investigated.
18.	Bor, Yasemin, et al. (författare) Polylactide stereocomplexation leads to reduced migration during microwave heating in contact with food simulants 2014 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 134, s. 1-4 Tidskriftsartikel (refereegranskat)abstract The effect of stereocomplexation on the stability and migration resistance of polylactide during microwave and conventional heating in contact with different food simulants was evaluated. The heating effects were followed through mass loss measurements, molecular weight measurements and identification of the individual migrants by electrospray ionization-mass spectrometry (ESI-MS). Increased mass losses were observed as a function of time and temperature, but approximately 50% smaller mass losses were always measured for PLA stereocomplex as compared to the corresponding regular PLEA material. The stability of the stereocomplex material was, thus, significantly higher. Microwave heating increased the mass loss as compared to the conventional heating at the same time and temperature. This effect was especially significant when 10% ethanol was used as food simulant instead of water. The amount of water-soluble migrants was in most cases under the detection limits, but when heating temperature was increased to 95 C, ESI-MS revealed the formation of homologous series of linear lactic acid oligomers. Results indicate that PEA stereocomplex materials could have potential in single-use microwave applications.
19.	Botha, G.E., et al. (författare) Microwave assisted air drying of osmotically treated pineapple with variable power programmes 2012 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 108:2, s. 304-311 Tidskriftsartikel (refereegranskat)abstract Variable power programmes for microwave assisted air drying of pineapple were studied. The pineapple pieces were pre-treated by osmotic dehydration in a 55° Brix sucrose solution at 40 °C for 90 min. Variable power output programmes were designed and ran with different inlet air temperatures between 30 and 70 °C. Results indicated that the use of variable microwave power combined with low air temperatures can result in a fast drying process without significant charring of pineapple pieces. High microwave powers need to be reduced quickly, faster than the decrease in water content would suggest, to minimize charring. In this study an inlet air temperatures of 70 °C was found to be excessive when combined with microwave energy (5 W/g - after compensating for the moisture loss), resulting in fast temperature increase. Microwave power was found to be most effective in the first hour to 1.5 h of processing. It should then be reduced to 0.1 W/g (initial product weight) in the final stages of drying to avoid charring of the fruit pieces. The best microwave programme tested lead to 20% water content with just 1% losses due to charring, but the results allow to conclude that charring could be completely reduced by switching off microwave energy altogether after 1.5 h and then finish off drying with higher air temperatures. The use of low air temperatures (30-50 °C) is advantageous with microwave energy in the first stages of drying as it limits the peaks of specific energy absorption, but it slows down drying towards the end probably because of a too low point of equilibrium (saturation humidity of air). Microwave energy did not significantly influence the drying process towards the end, although drying rates showed a "memory effect", that is, drying rates in processes with the same conditions after a given time depended on the conditions up to that point. © 2011 Elsevier Ltd. All rights reserved.
20.	Dahlenborg, Hanna, et al. (författare) Effect of particle size in chocolate shell on oil migration and fat bloom development 2015 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 146, s. 172-181 Tidskriftsartikel (refereegranskat)abstract The effects of chocolate shell particle size were investigated by means of its influence on rate of oil migration and fat bloom development. The particle size of the non-fat particles in the chocolate, i.e. sugar and cocoa particles was varied between 15, 22 and 40 mu m. A novel set of analytical techniques was used and by combining migration results with surface topology results clear differences could be observed between the samples. At 23 degrees C storage the samples with a particle size of 15 mu m showed higher rate of oil migration and, further, the earliest development of fat bloom at the surface. This could be observed both macroscopically and microscopically. Thus, it appears as a larger specific surface area of the nonfat particles facilitates migration of filling oil, possibly due to a more heterogeneous and coarser crystal network with higher permeability. Molecular diffusion cannot explain the level of oil migration observed and, thus, convective flow is assumed to be an important contribution in addition to the molecular diffusion. (C) 2014 Elsevier Ltd. All rights reserved.
21.	Dalvi-Isfahan, Mohsen, et al. (författare) Review on identification, underlying mechanisms and evaluation of freezing damage 2019 Ingår i: Journal of Food Engineering. - : Elsevier Ltd. - 0260-8774 .- 1873-5770. ; 255, s. 50-60 Tidskriftsartikel (refereegranskat)abstract Although freezing is known as the best method of food preservation, physical and chemical changes that occur to the cellular structure during processing and storage may damage the quality of food products. Most freeze damages are associated with ice crystal morphology (size, number, shape and distribution) which in turn affects the microstructure of the frozen food. Therefore, the evaluation of frozen food microstructure provides opportunities for monitoring the ice crystal morphology and also identifies freeze damage at cellular level which can be linked with the final quality of frozen food products. In this review, the most important physical damages that occur during freezing and storage of food matrices are described. In addition, methods for evaluating and observing the morphology of ice crystals and microstructure of frozen food stuffs are comprehensively discussed. An understanding of the freeze damage and their relationship with ice crystal morphology can contribute to the improvement of the freezing process as well as to the frozen product quality.
22.	Dalvi-Isfahan, Mohsen, et al. (författare) Review on the control of ice nucleation by ultrasound waves, electric and magnetic fields 2017 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 195, s. 222-234 Tidskriftsartikel (refereegranskat)abstract Freezing is the most popular and widely used food preservation method of the modern times. The freezing process of food matrices is related to their high water content and its metamorphoses into ice on cooling. The final quality of the frozen product is highly depended on the ice crystal morphology because it can cause irreversible damage on the microstructure of the food matrix. Supercooling and ice nucleation temperature need to be controlled both in suppressing and inducing the solidification to improve technological processes such as freeze drying, freeze concentration, cryopreservation, ice formation and cold-energy storage both in food industry and domestic preservation. However, the mechanism of freezing is not yet well known and it is affected by several factors. Several emerging technologies have been recently proposed for ice nucleation control during freezing. This review article is focused on the alternative freezing methods such as ultrasound waves, magnetic, electric, and electromagnetic field assisted freezing. In addition, the properties, mechanism of action and possible applications of electrofreezing are extensively discussed.
23.	Erdogdu, S. Belgin, et al. (författare) Experimental determination of penetration depths of various spice commodities (black pepper seeds, paprika powder and oregano leaves) under infrared radiation 2015 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 161, s. 75-81 Tidskriftsartikel (refereegranskat)abstract During infrared processing, transmitted energy is attenuated exponentially with penetration distance, and its intensity is gradually lost while passing through absorbing or scattering media. Penetration depth is a complex function of chemical composition of a food product, its physico-chemical state and physical properties and wavelength spectrum of energy source. Knowing penetration depth leads to better designing commercial sterilization processes for food products like spices. Therefore, the objective of this study was to determine penetration depth of various spices (paprika powder, black pepper and oregano) as a function of water activity under infrared processing conditions. For this purpose, spice samples were prepared at various water activity (aw) levels, and heat flux measurements were carried out to determine the penetration depth. Penetration depth was determined to increase with increasing aw for black pepper seeds and paprika powder while there was no significant change for oregano leaves as a function of aw. Knowing penetration depth is important to design an effective infra-red processing system and an important issue for surface pasteurization processes since infrared radiation effects on microbial inactivation decrease with sample thickness
24.	Fritzson, Anna, 1977, et al. (författare) Efficient energy use in a slaughter and meat processing plant-opportunities for process integration 2006 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 76:4, s. 594-604 Tidskriftsartikel (refereegranskat)abstract In this paper, process integration methods are used to investigate the potential to decrease the energy usage in the slaughtering and meat processing industry. Above ambient temperatures, heating of water with different target temperatures is a large heat demand in a plant, while at subambient temperatures the refrigeration plant needs almost all of the shaftwork used at the site. Interaction between, on one hand, energy demands above ambient temperature and, on the other, cooling needs below ambient temperature can take place with freezing compressors or heat pumps. By using process integration methods above and below ambient temperatures, potentials for saving both shaftwork and external heat demand in food plants can be identified. A case study at a modern plant illustrates that even though many energy-saving measures have been taken there is still a technical potential for saving 30% of the external heat demand and more than 10% of the shaftwork used in the plant. The economic potential for the savings is dependent on the conditions at the plant.
25.	Fritzson, Anna, 1977, et al. (författare) Energy efficiency in the slaughter and meat processing industry-opportunities for improvements in future energy markets 2006 Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774 .- 1873-5770. ; 77:4, s. 792-802 Tidskriftsartikel (refereegranskat)abstract In the study presented in this paper different energy efficiency measures that can be carried out in a slaughter and meat processing (SMP) plant were evaluated both in terms of economy and CO2 emission reduction for four different future energy market developments. It was found that it is economically interesting to invest in an increased heat exchanger network or heat pumps in the fictitious non-integrated plants studied and that between 5% and 35% of the total CO2 emissions can be saved. The most cost effective way of reducing CO2 emissions was found to be switching fuel from heavy fuel oil to natural gas or wood chips. For the studied plants that are already heat integrated it was shown that investing in a new heat pump can be economically interesting and can reduce CO2 emissions. The profitability of investing in a combined heat and power (CHP) unit for the SMP plants was also investigated and found to be smaller than extended heat recovery or new heat pumps in the studied plants. However, the payback period for CHP units installed at an ecocyclic industrial park, consisting of an SMP plant and for example a Swedish dairy, was found to be short enough to be interesting. © 2005 Elsevier Ltd. All rights reserved.

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