The implementation of innovative volumetric food preservation technologies has the potential to reduce the overprocessing of products, by intensifying the preservation effects of treatments and reducing their exposure to them. However, empirical data are insufficient for engineers and food technologists to optimize and develop safe processing protocols. It is therefore essential to develop digital models that can provide a comprehensive representation of the system, as well as a foundation for the computer-assisted optimization of novel technologies. However, a gap in the literature hinders the acquisition of the insights necessary to accomplish this task. This review paper provides an overview of conventional and innovative preservation technologies, outlining their fundamental principles and operational mechanisms. It then presents a comprehensive examination of the numerical methodologies employed for the digital simulation of these technologies, delineating their distinctive requirements. Furthermore, the review assesses potential strategies for ensuring the reliability of data validation and techniques for reducing the complexity of numerical modelling with artificial intelligence (AI). This literature review identified the requisite knowledge for the implementation of numerical simulations and important details that need to be considered to avoid the divergence of the calculations and save costly computational hours. Furthermore, the review proposed a time–temperature integrator-based validation for the obtained data and evaluated the benefits of supporting numerical simulations with AI.

Achieving uniform heating in whole vegetables during ohmic processing is challenging due to their heterogeneous structure and uneven electrical conductivity. This study aimed to use pulsed electric fields (PEF) prior to ohmic heating (OH) to equalise the electrical conductivity and thus improve the cooking performance of red beetroot. PEF treatments were carried out at electric field strength of E = 1.0 and 2.0 kV/cm, and specific energy input varied between 0.1 and 16.1 kJ/kg, varying the number of pulses. Two PEF pre-treatments were selected to assess the impact on cooking performance (1.0 kJ/kg and 4.0 kJ/kg). The cooking performance and quality of the cooked products were evaluated using temperature kinetics, thermal camera images of temperature distribution, analysis of mechanical properties and changes in optical properties (CIE lab). The results revealed that untreated beetroot exhibited an uneven temperature distribution and notable hardness variations across different beetroot areas. Both PEF pre-treated samples showed a homogeneous heat distribution, drastically reducing the hardness differences within the vegetable tissue. PEF-treated samples had hardness values comparable to those of commercially sold cooked beetroot after 14 min of cooking, whereas untreated samples did not reach the same values even after 21 min of cooking. Consequently, the combined use of PEF and ohmic heating has remarkable potential as an industrial application for cooking large, complex vegetables by equalising temperature distribution and reducing cooking time.

Hierarchically porous structures combine microporosity, mesoporosity, and microporosity to enhance pore accessibility and transport, which are crucial to develop high performance materials for biofabrication, food, and pharmaceutical applications. This work aimed to develop a 4D-printed smart hierarchical macroporous structure through 3D printing of Pickering-type high internal phase emulsions (Pickering-HIPEs). The key was the utilization of surface-active (hydroxybutylated) starch nanomaterials, including starch nanocrystals (SNCs) (from waxy maize starch through acid hydrolysis) or starch nanoparticles (SNPs) (obtained through an ultrasound treatment). An innovative procedure to fabricate the functionalized starch nanomaterials was accomplished by grafting 1,2-butene oxide using a cold plasma technique to enhance their surface hydrophobicity, improving their aggregation, and thus attaining a colloidally stabilized Pickering-HIPEs with a low concentration of each surface-active starch nanomaterial. A flocculation of droplets in Pickering-HIPEs was developed after the addition of modified SNCs or SNPs, leading to the formation of a gel-like structure. The 3D printing of these Pickering-HIPEs developed a highly interconnected large pore structure, possessing a self-assembly property with thermoresponsive behavior. As a potential drug delivery system, this thermoresponsive macroporous 3D structure offered a lower critical solution temperature (LCST)-type phase transition at body temperature, which can be used in the field of smart releasing of bioactive compounds.

The characterization of continuous thermal processing (CTP) is a crucial aspect in the design and selection of technologies for the production of safe products with optimal quality retention after the thermal stress. Conventional methods for CTP characterization are constrained in their capacity to comprehensively capture the complex dynamics of fluid flow through pipelines and the different heating principles that contribute to local temperature variations. These methods rely on isolated local temperature measurements, which fail to account for the intricate interactions between temperature, heat transfer phenomena and fluid dynamics. In view of the aforementioned limitations, this study presents the implementation of a computational fluid dynamic digital model as a toolbox for the characterization and comparison of a conventional heating (CH) ultra-high temperature (UHT) sterilization process and ohmic heating (OH) UHT sterilization. This serves as a tool for an extensive and accurate comparison of the two processes. The model enabled the estimation of each technology's thermal load through the F0 value, thereby providing a more comprehensive assessment than local temperature measurements alone. Furthermore, this approach accounted for the flow behavior throughout the sterilization process. This strategy demonstrated that 2.5 % of the food product is exposed to an up to 75.4 times the average thermal load, whereas for OH treatments only 0.4 % of the product was exposed up to 5.1 times the average thermal load. This is due to the volumetric heating feature of OH, which leads to a 54.7 % reduction in the cooking grade of the product. Furthermore, the computer-aided comparison revealed no statistically significant difference (p-value of 0.6) between the two technologies in their capacity to inactivate Geobacillus stearothermophilus spores in terms of thermal load. This study highlights the importance of computer-aided engineering methodologies for the technological assessment of food sterilization processes prior to industrial transfer.

PEF technology is a non-thermal food process gaining popularity for treating fruits and vegetables. However, there has been little investigation into the impact of PEF on the biomolecular components of plant tissues. This study assesses the influence of PEF at low (1.5 kJ/kg) and medium (151 kJ/kg) intensities on the physicochemical parameters of pectin fractions isolated from green and red tomatoes. Monopolar exponential decay pulses of 1.0 and 10.0 kV/cm were delivered to alcohol-insoluble residue (AIR) recovered from mature green and ripe red tomatoes. Topography and recognition imaging were performed using atomic force microscopy (AFM) on three pectin fractions: water-soluble pectin (WSP), chelator-soluble pectin (CSP), and diluted alkali-soluble pectin (DASP). Image analysis has been used to characterize the geometrical properties of pectin. PEF treatments generated considerable structural alterations in all pectin fractions. The effect varied depending on the stage of tomato ripening and the energy input applied. The average length of WSP fibres in red tomatoes decreased dramatically (up to 50

Ohmic cooking is considered a fast and homogeneous process. However, achieving heating uniformity depends on several process parameters and intrinsic product characteristics. Furthermore, reference indicators for evaluating the ohmic process and generating reliable comparisons with conventional cooking are still lacking. The objective of this study was to investigate the reliability of the use of power input and cooking value as process indicators. The results showed that the specific ohmic power did affect only the heating rate but not the heating uniformity and the tissue softening rate. Therefore, the power input as process acceleration tool is not sufficient as stand-alone process indicator because other critical parameters (i.e., electrical conductivity) need to be taken into account to display the complex product-process-interactions. The cooking value was proven to be not valid as indicator for ohmic heating, as it does not take into account additional effects not attributable to only thermal exposure.

Summary Understanding the behaviour of legumes during soaking results of importance since this might affect subsequent processing steps and thus final product quality. The aim of this study was to determine the effect of different ultrasound‐assisted soaking conditions (45.8–108.7 W cm −2 for 10–30 min) on the hydration, physicochemical and nutritional properties of kabuli chickpeas. During sonication, the temperature of the soaking media was either controlled at 20 °C (treatment referred to as US) or allowed to rise (treatment referred to as US + T). Selected temperature treatments without sonication (treatment referred to as T) were also included to identify thermal effects. Results showed that higher sonication intensities enhanced water imbibition up to a moisture content of 74.5% (w/w), being more pronounced in treatments where a temperature rise was allowed. Hydration kinetics were well described by the Peleg model ( R 2 = 0.961–0.998). Samples treated with temperature (US + T; T) showed high solid (0.8–5.1%), di‐ (13.2–59.7%) and α‐galactosyl‐sucrose oligosaccharide (5.4–58.7%) losses. In contrast, high US treatments enhanced oligosaccharides to up to 26.2% as well as pasting properties, while decreasing leaching losses (0.93–3.33%). Nutritional properties of sonicated chickpeas were only slightly affected after cooking following no clear trend. Overall, sonication was an effective pre‐treatment to reduce hydration time of up to 90% in chickpeas, especially when combined with temperature, and could be applied to drastically reduce the processing time of chickpea and chickpea flour in the food industry.

Continuous thermal processing (CTP) is a common method for sterilizing food. However, it can result in an uneven temperature distribution, which can lead to a varying degree of processing intensity. Ohmic heating (OH) can be advantageous in this regard, as it enables volumetric heating for more homogenous treatments. However, evaluating the processing intensity distribution inside the equipment for OH is challenging due to the complex interaction between electrical, mechanical and thermal phenomena. Furthermore, the comparison of OH and conventional heating treatments often lack a profound basis of comparable treatment intensity considerations. To gain a deeper mechanistic understanding of the technology, a numerical computational fluid dynamics model for the OH sterilization of a clear carrot juice from the heating region to the cooling process was developed. The model was validated with thermal and electrical measurements and showed an error rate below 2.5% in its prediction capacities. Moreover, the model was implanted for the validation of the products sterilization and compared to a conventional validation approach, reviling a 33.3% underestimation of the thermal load by conventional manners, which can lead to faulty sterilization of the food product. Additionally, the model was expanded to also be able to predict the microbial inactivation ratio of the system with an average error of 1.10 +/- 0.74%. In addition, results indicate that the numerical calculation of the F0 values and their validation with the microbial inactivation ratio have a notable potential for localization and evaluation of hotspots in OH simulations. Therefore, it can be seen as a promising step for establishing a foundation for computer-assisted optimization of CTP and targeted processing.

Abstract There are several classifications of foods that also include the level of their processing, with NOVA classification appearing to be the most adopted. However scientific consensus is still missing on how to define, characterize and classify food processing. The classifications are typically based on the health impacts of foods and do not fully include the engineering perspective of processing, i.e., the application of physical, chemical, or biotechnological unit operations during food manufacturing, and the composition of a food product. This review offers an engineering perspective and definition of food processing, based on the change of mass and energy, allowing distinguishment of the impacts caused by food processing during the biomass transformation to food products. The improved understanding of the causes of undesired changes in food properties could be used for nutritional public policy recommendations and would contribute to combating some of the chronic diseases related to food consumption patterns. Proposed is the definition of “Food processing” as a sum of all intentional additions or removals of either edible matter or energy (except for any transport or for removal of inedible parts of food) between the harvest of ingredients and consumption of the product. Graphical Abstract

This study investigates the application of Pulsed Electric Field (PEF) technology to improve the freeze-drying process, the final product quality and the stability of kiwi fruits, red bell peppers, and red beetroots. Freezedrying is a fundamental drying technology that aims to maintain the natural attributes of food, but it often leads to challenges such as prolonged drying times and quality degradation. To further understand the implications of applying PEF before freeze-drying, the storage stability of the freeze-dried samples was investigated under both illuminated and dark conditions. PEF treatment was carried out at constant electric field strength of E = 1.0 kV/cm, and specific energy input was varied between 0.2 and 20.8 kJ/kg. This study revealed that PEF treatment significantly decreased the freeze-drying time (2-fold) exclusively for bell peppers. PEF treatment substantially improved volume retention and rehydration capacity for both kiwi fruits and bell peppers, indicating enhanced structural integrity. However, applying PEF had an overall adverse impact on the colour stability of the freeze-dried samples (Delta E > 3). The quality decline was mitigated storing the samples in dark conditions. The results of this study suggest that applying PEF before freeze-drying can represent a promising strategy to enhance the quality of freeze-dried products with improved drying kinetics, volume retention, and rehydration capacity. Careful consideration of storage conditions is essential to prevent the deterioration of product quality over time.

IntroductionImpact of processing on product characteristics, sustainability, traceability, authenticity, and public health along the food chain becomes more and more important not only to the producer but also to the customer and the trust of a consumer toward a brand. In recent years, the number of juices and smoothies containing so called super foods or fruits, which have been “gently pasteurized,” has increased significantly. However, the term “gentle pasteurization” related to the application of emerging preservation technologies such as pulsed electric fields (PEF), high pressure processing (HPP) or ohmic heating (OH) is not clearly defined.MethodsTherefore, the presented study investigated the influence of PEF, HPP, OH, and thermal treatment on quality characteristics and microbial safety of sea buckthorn syrup. Syrups from two different varieties were investigated under the following conditions HPP (600 MPa 4–8 min), OH (83°C and 90°C), PEF (29.5 kV/cm, 6 μs, 100 Hz), and thermal (88°C, hot filling). Analyses to test the influence on quality parameters like ascorbic acid (AA), flavonoids, carotenoids, tocopherols, antioxidant activity; metabolomical/chemical profiling (fingerprinting) via U-HPLC-HRMS/MS (here especially flavonoids and fatty acids); sensory evaluation, as well as microbial stability including storage, were conducted.Results and discussionIndependent from the treatment, the samples were stable over 8 weeks of storage at 4°C. The influence on the nutrient content [Ascorbic acid (AA), total antioxidant activity (TAA), total phenolic compounds (TPC), tocopherols (Vit E)] was similar for all tested technologies. Employing statistical evaluation Principal Component Analysis (PCA) a clear clustering based on the processing technologies was observed. Flavonoids as well as fatty acids were significantly impacted by the type of used preservation technology. This was obvious during the storage time of PEF and HPP syrups, where enzyme activity was still active. The color as well as taste of the syrups were found to be more fresh-like for the HPP treated samples.

The addition of fat to gluten-free (GF) bread can influence several quality attributes, such as texture and starch retrogradation. Therefore, the aim of this study was to investigate the influence of different fats on GF bread properties using two different baking methods (conventional and ohmic heating), in order to understand how these affect the physical bread quality, the formation of amylose-lipid complexes and its effect on crumb firming behavior. Fats (coconut, rapeseed, butter, and palm) with different physico-chemical properties, and physical state (solid, liquid) were tested in standard GF bread formulations. Results showed that fat significantly improved crumb pore uniformity. Crumb texture and pasting properties were mostly influenced by the type of fat, storage time and baking method. Staling was delayed in all breads added with fat due to the formation of amylose-lipid complexes, which were highest with palm fat and were usually higher when baked by ohmic heating.

Cherry kernels occur in significant amounts as waste material during the processing of fruits. However, their subsequent use is limited due to the presence of cyanogenic glycosides, which are potentially dangerous to human health. In this study, the application of pulsed electric fields (PEF) was investigated as pre-treatment to improve the debittering process and to facilitate the degradation of cyanide precursors, naturally present in cherry kernels. Diverse PEF treatments were carried out at constant electric field strength of E = 2.2 kV/cm and specific energy input was varied between 10 and 50 kJ/kg, varying the number of pulses. Two different debit-tering procedures were performed with a common incubation time 0-20 h at 40 degrees C: a) incubation of whole kernels in deionized water; b) incubation of whole kernels without water stored in air at 80% relative humidity. HPLC analysis was used to examine the kinetics of the amygdalin and HCN contents. In both debittering methods, the PEF-treated samples with the highest intensity (2.2 kV/cm, 50 kJ/kg) showed higher and faster detoxification efficiency for the investigated compounds as compared to the untreated sample. In particular, the PEF treated samples incubated with water showed a reduction in the amygdalin and HCN contents of up to 86% (up to 72% of the raw material content.). Moreover, the PEF pre-treatment led to comparable efficiency in amygdalin reduction in both debittering processes: 86% reduction for the incubation with water and 81% for the incubation without water. Consequently, the combined application of PEF and the debittering process including incubation without water has remarkable potential as an industrial application due to its inherent reduced water con-sumption, and therefore, diminished wastewater management issues. A further advantage of this process is the minimizing of sugar loss typically occurring during the debittering through soaking.

This opinion of the Senate Commission on Food Safety (SKLM) of the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) presents arguments for an updated risk assessment of diet-related exposure to acrylamide (AA), based on a critical review of scientific evidence relevant to low dose exposure. The SKLM arrives at the conclusion that as long as an appropriate exposure limit for AA is not exceeded, genotoxic effects resulting in carcinogenicity are unlikely to occur. Based on the totality of the evidence, the SKLM considers it scientifically justified to derive a tolerable daily intake (TDI) as a health-based guidance value.

The three-dimensional (3D) printing and its extension four-dimensional (4D) printing technique show great promise for advanced additive manufacturing of functional and architected materials with engineered micro- and nanoscale features. The actual usage of additive manufacturing to produce 3D/4D structures is primarily dependent on the improvement of printable polymeric inks. Thermoresponsive polymers (TRPs) show broad application prospects in additive manufacturing since they enable changing the physicochemical properties of the system at a specific temperature. Continuing to progress in the understanding of TRP phenomena enable the design of new feedstocks and their compatibility with fabrication processes. Therefore, increasing the overlap between the fields of fundamental TRPs and application-based research efforts can be important to emerging the technology. In this review, we provide an overview of the functional design of the TRPs, the different classes of TRPs, and their application in 3D printing, ranging from biosensors via advanced self-assembly to a variety of biofabrication, biomedical, biotechnology, and food applications. Basic knowledge of imperative processes like gelation mechanisms of TRPs, bio-based adsorption on the surfaces and adhesion, and fabrication strategies using 3D printing is also provided. For diverse TRPs synthesis and the basic physical and chemical features are described and the mechanism of their TRPs behavior is highlighted. Fabrication methods of TRP surfaces have also been discussed describing several methods in detail.

Peeling is a standard food processing operation that removes the outer layer of fruits and vegetables. It can improve the appearance and texture of many fruits and vegetables and is often necessary for further food preparation. Developing new and innovative peeling methods to minimise losses and enhance product quality is an area of active research in the food industry. The objective of this study was to evaluate how PEF affects the peeling ability of tomatoes and kiwi fruits, as well as the chemical and physical characteristics of the resulting peeled products. In detail, monopolar exponential decay pulses were applied, with an electric field strength of 1.0 kV/cm and a resulting total energy input in the range of 0.6 and 5.0 kJ/kg for tomatoes and 1.2 and 12.6 kJ/kg for kiwi fruits. Two methods were used to compare the effectiveness of PEF treatments with traditional peeling methods: hot-water blanching (98°C for 60 s) and lye peeling (98°C for 45 s, in 2% NaOH solution). The peeling efficiency was evaluated through manual and mechanical methods as well as measuring weight loss. The quality of the final peeled product was assessed by mechanical properties of the pericarp, colour (L*, a*, b* scale), ascorbic acid content, chlorophyll a and b, carotenoids, total polyphenols content and antioxidant activity. The PEF treatment applied to whole red tomatoes (1.0 kV/cm, 5.0 kJ/kg) and whole kiwi fruits (1.0 kV/cm, 12.6 kJ/kg) resulted in a significant decrease (p ≤ 0.05) of up to 43% and 83% in the force required for mechanical peeling, respectively. The PEF treatment showed comparable or superior peeling ability and significantly reduced product losses compared to hot-water blanching and lye peeling methods. However, the softening and the weight losses tend to increase by increasing the pulses for both investigated matrices. Moreover, by applying PEF instead of blanching or lye peeling, the chemical quality and the colour were better preserved (ΔE < 2). This study proved that PEF could be a promising non-thermal technology to better peel tomatoes and kiwi fruits without affecting their final quality. Consequently, applying PEF as a treatment to facilitate peeling has remarkable potential as an industrial application to reduce energy consumption and issues related to wastewater management typically occurring during the peeling with lye agents.

The potential of three different portable near infrared (NIR) spectrometers (TellSpec, SCiO, MicroNIR) to monitor freshness of organic carp and lake trout fillets was assessed. The intercomparison was supported by data obtained with standard methods (for biogenic amine content, microbiological parameters, total volatile basic nitrogen content, fatty acid profiles, drip loss, color and texture change) including non-targeted metabolomics by dynamic headspace - gas chromatography - time-of-flight mass spectrometry (DHS-GC-TOFMS). Fillets were measured after 1, 3, 6 and 9 days of storage at +4 degrees C. Discriminant and class modelling approaches (orthogonal partial least square discriminant analysis (OPLS-DA) and data-driven soft independent modelling of class analogy (DDSIMCA)) were applied in order to evaluate the performance of the NIR handhelds to distinguish fresh from spoiled fish. NIR data were correlated with data from standard methods in order to identify a set of characteristic wavelengths describing the spoilage process. Correlated wavelengths were evaluated regarding the improvement of the chemometric models. Handheld NIR spectrometers were able to discriminate carp fillets according to freshness with high sensitivity (88-100% for OPLS-DA, 100% for DD-SIMCA) and specificity (88-100% for OPLS-DA, 60-100% for DD-SIMCA). However, for trout fillets, both classification methods led to lower sensitivity and specificity compared to carp. Reduction of wavelengths to only those correlating with standard methods including DHS-GC-TOFMS data, improved the models' performance for trout samples measured with TellSpec and MicroNIR but did not improve the performance of carp models generated using MicroNIR and SCiO data. The results showed that the studied NIR handheld devices yielded different classification results depending on the investigated fish species. It can be concluded that NIR handhelds are a useful tool for on-site fish freshness assessment, however, primarily as a screening tool. For confirmation of results obtained in the field, lab-based analysis for freshness assessment by common spoilage indicators is required.

Summary Batter stabilisation presents a great challenge for gluten‐free (GF) bread, as CO 2 is released during bread‐making process, resulting in small, dense and crumbly breads. Apart from starch, protein plays a crucial role in gas cell stabilisation. This study aims to assess the effect of non‐gluten protein from different sources (plant and animal) on GF batter's rheological behaviour (pasting properties, rheology and foam stability) and on bread properties after baking with conventional and ohmic heating method. Hence, this study evaluated the functional properties (protein solubility, hydrophobicity, sulfhydryl groups, foaming and emulsification properties) of selected non‐gluten protein relevant for foam stabilisation. Furthermore, a correlation matrix was established by involving the functional properties of the proteins and their interaction with starch on batter rheology and bread quality. Among proteins, egg albumin and potato proteins were reported to perform superior functionality in GF bread; in particular, potato protein generated breads with the highest volume for both baking methods, which was potential to replace egg albumin. According to the correlation matrix, protein solubility was required in foaming and emulsification behaviour to improve GF bread properties.

Airborne microbial re-contaminations are among the most frequent causes of food spoilage, contributing to food waste and economic losses. Cleanrooms can help to avoid bioaerosol re-contaminations, but are not suitable for open food processing environments. The present study assessed airborne microbial levels and their contamination routes within bakery production. Current airborne mold and total viable counts (TVCs) were evaluated over 8 months, indicating mold and TVCs ranging from 20 to 960 CFU/m3 and from 20 to 1600 CFU/m3, respectively. The relative contamination level of each source point towards the cooling zone was virtually reproduced. The overall aim of this study was to develop a tailored cost-effective and easy-to-apply partial protection strategy, based on filter fan units (FFUs). The FFU concept with an air velocity of 0.3 m/s resulted in a significant reduction of the relative contamination (99.94%). Hence, this study suggests an alternative FFU-based control strategy for airborne contaminations within open food processing areas.

In this study, the effect of matrix compounds from natural curcuminoid resources on the stability of curcuminoids and emulsions thereof was evaluated. Curcuminoid emulsions were prepared curcuminoid rich sources (curcuminoid extract, an aqueous turmeric concentrate and turmeric powder) with medium-chain triglyceride oil as lipid phase, lecithin, and pectin as emulsifiers. The curcuminoid emulsions were exposed to light in the visible wavelength range (300 nm–800 nm) at the specific energy input of 0.47 kW/m 2 for 7 days and to the temperature of 4 °C, 25 °C, 40 °C for 49 days. The total curcuminoid retention (TC), droplet size (DS) change, instability index (InI), and yellowness reduction (YR) was observed during the storage time. The half-life of curcuminoids in emulsions was increased to 21 h, while the half-life of free curcuminoids was 1.3 h in the light exposure test. The co-compounds from the curcuminoid sources contributed to the emulsion stability by increasing the viscosity. In the thermal exposure test, the matrix compound system retained more than 93% curcuminoids after 49 days of storage at 40 °C, whereas the phase separation increased significantly. However, the TC reduction was independent of the InI change and droplet agglomeration. The YR depended on the TC and the amount of co-components in the emulsion.