Influence of the processing on composition, protein structure and techno-functional properties of mealworm protein concentrates produced by isoelectric precipitation and ultrafiltration/diafiltration.

Edible insects represent a great alternative protein source but food neophobia remains the main barrier to consumption. However, the incorporation of insects as protein-rich ingredients, such as protein concentrates, could increase acceptance. In this study, two methods, isoelectric precipitation and ultrafiltration-diafiltration, were applied to produce mealworm protein concentrates, which were compared in terms of composition, protein structure and techno-functional properties. The results showed that the protein content of the isoelectric precipitation concentrate was higher than ultrafiltration-diafiltration (80 versus 72%) but ash (1.91 versus 3.82%) and soluble sugar (1.43 versus 8.22%) contents were lower. Moreover, the protein structure was affected by the processing method, where the ultrafiltration-diafiltration concentrate exhibited a higher surface hydrophobicity (493.5 versus 106.78 a.u) and a lower denaturation temperature (161.32 versus 181.44 °C). Finally, the ultrafiltration-diafiltration concentrate exhibited higher solubility (87 versus 41%) and emulsifying properties at pH 7 compared to the concentrate obtained by isoelectric precipitation.

Effect of Moderate Electric Fields on the Physical and Chemical Characteristics of Cheese Emulsions.

Cheese powder is a multifunctional ingredient that is produced by spray drying a hot cheese emulsion called cheese feed. Feed stability is achieved by manipulating calcium equilibrium using emulsifying salts. However, the increased demand for 'green' products created a need for alternative production methods. Therefore, this study investigated the impact of ohmic heating (OH) on Cheddar cheese, mineral balance, and the resulting cheese feed characteristics compared with a conventional method. A full factorial design was implemented to determine the optimal OH parameters for calcium solubilization. Electric field exposure and temperature had a positive correlation with mineral solubilization, where temperature had the greatest impact. Structural differences in pre-treated cheeses (TC) were analyzed using thermorheological and microscopic techniques. Obtained feeds were analyzed for particle size, stability, and viscosity. OH-treatment caused a weaker cheese structure, indicating the potential removal of calcium phosphate complexes. Lower component retention of OH_TC was attributed to the electroporation effect of OH treatment. Microscopic images revealed structural changes, with OH_TC displaying a more porous structure. Depending on the pre-treatment method, component recovery, viscosity, particle size distribution, and colloidal stability of the obtained feeds showed differences. Our findings show the potential of OH in mineral solubilization; however, further improvements are needed for industrial application.

An Integrated Model of Heat Transfer in Meat Products during Multistage Operations.

This work focuses on the modelling of the heat transfer in the key processes during the manufacturing of salted-smoked loin pork, a traditional Danish product called "Hamburgerryg". Drying, smoking, steam-cooking, water-cooling, and air-cooling processes are important process steps in the production of "Hamburgerryg". A mathematical model that describes the heat transfer during these processes was developed. A current model formulation, multiple unit operations, and the transfer between these unit operations were considered and described by an equation that combines boundary conditions. The model governing and boundary equations were solved using the finite element method (COMSOL Multi-physics® version 5.6). The product temperature profile during the processes was predicted as a function of position and time in the loin. The model was validated using measured temperature profiles from industrial production, and a good agreement between the measured and simulated temperature profiles was obtained. Additionally, the effects of the position (in the heating, cooking, and cooling chamber) on the temperature profile were also investigated. The obtained model can be used as a simulation tool to predict the temperature profile (particularly cold and hot spots) for entire processes and this can aid in the digitization of food processes by providing a more accurate and efficient means of temperature control.

Positive Influences of Ohmicsonication on Phytochemical Profile and Storage Stability of Not-from-Concentrate Mango Juice.

Processing technique and storage conditions are the main factors that affect the phytochemical profile of Not-from-Concentrate (NFC) juice, which could decrease the nutritional and bioactive properties of the corresponding juice. The aim of this study was to evaluate the quality changes that occurred in NFC mango juice after Ohmicsonication (OS) and during storage in comparison to other processing methods such as sonication (S), thermosonication (TS), ohmic heating (OH), and conventional heating (CH). Quality attributes such as polyphenoloxidase (PPO) and pectinmethylesterase (PME) activities, ascorbic acid and hydroxymethyl furfural (HMF) contents, total phenolics, total flavonoids, total carotenoids, electric conductivity, color values and microbial load (total plate count, mold, yeast, and psychrophilic bacteria) were examined. OS and OH treatments demonstrated the highest inactivation of PPO (100%), while CH and TS displaying inhibitions 89% and 90%, respectively and only S treatment exhibited insufficient inactivation of both PPO and microbial load. However, the inhibition of PME followed the order OS (96.5%) > OH (94.9%) > TS (92.5%) > CH (88.5%). The best treatment, with the highest retention of phytochemical contents (ascorbic acid, total carotenoids, antioxidant activity, total flavonoids, and total phenolic content) for NFC mango juice and during storage was obtained with OS treated samples compared to other treatments (in the order from the lowest to highest percentage, OS < OH < TS < CH). Consequently, the results indicated that OS could be applied as a new mild thermal treatment in the production of mango juice with improved quality properties of stored NFC mango juice.

Physical and Oxidative Stability of Low-Fat Fish Oil-in-Water Emulsions Stabilized with Black Soldier Fly (Hermetia illucens) Larvae Protein Concentrate.

The physical and oxidative stability of fish oil-in-water (O/W) emulsions were investigated using black soldier fly larvae (BSFL) (Hermetia illucens) protein concentrate as an emulsifier. To improve the protein extraction and the techno-functionality, defatted BSFL powder was treated with ohmic heating (BSFL-OH) and a combination of ohmic heating and ultrasound (BSFL-UOH). Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were performed in order to characterize the secondary structure and thermal stability of all protein concentrate samples. The interfacial properties were evaluated by the pendant drop technique. The lowest interfacial tension (12.95 mN/m) after 30 min was observed for BSFL-OH. Dynamic light scattering, ζ-potential and turbiscan stability index (TSI) were used to evaluate the physical stability of emulsions. BSFL-OH showed the smallest droplet size (0.68 µm) and the best emulsion stability (TSI = 8.89). The formation of primary and secondary volatile oxidation products and consumption of tocopherols were evaluated for all emulsions, revealing that OH and ultrasound treatment did not improve oxidative stability compared to the emulsion with untreated BSFL. The results revealed the promising application of BSFL proteins as emulsifiers and the ability of ohmic heating to improve the emulsifying properties of BSFL proteins.

Modelling Processes and Products in the Cereal Chain.

In recent years, modelling techniques have become more frequently adopted in the field of food processing, especially for cereal-based products, which are among the most consumed foods in the world. Predictive models and simulations make it possible to explore new approaches and optimize proceedings, potentially helping companies reduce costs and limit carbon emissions. Nevertheless, as the different phases of the food processing chain are highly specialized, advances in modelling are often unknown outside of a single domain, and models rarely take into account more than one step. This paper introduces the first high-level overview of modelling techniques employed in different parts of the cereal supply chain, from farming to storage, from drying to milling, from processing to consumption. This review, issued from a networking project including researchers from over 30 different countries, aims at presenting the current state of the art in each domain, showing common trends and synergies, to finally suggest promising future venues for research.

Impact of ohmicsonication treatment on pectinmethylesterase in not-from-concentrate orange juice.

The present study investigates the application of ohmicsonication (OS) as a new hurdle technology for pasteurization of Not-from-concentrate orange juice (NFCOJ). OS process parameters to inactivate pectinmethylesterase (PME) activity in NFCOJ were optimized using response surface methodology. The influence of Sonication (S), Thermosonication (TS), Ohmic heating (OH) and OS on inactivation of PME were compared to conventional heat (CH) treatment. Their effects on physical, chemical and microbiological contents were included. In comparison to fresh orange juice, the inactivation of PME was 96%, 95%, 89%, 90% and 29% for OS, OH, TS, CH and S treatments, respectively. Highest cloud value was obtained for OS (1.240 A) treatment. OS treatment gave a lower vitamin C loss compared to TS, OH and CH treatments. A significant increase in the total phenolic content were obtained in the following order OS > TS > OH > CH. OS treated juice also contained the lowest value of hydroxymethyl furfural (0.90 mg/L) compared to OH (0.95 mg/L), TS (1.37 mg/L) and CH (2.72 mg/L) treated samples. Overall, the results indicated that OS can be integrated as a substitute to pasteurization of NFCOJ.

Optimization of ohmic heating parameters for polyphenoloxidase inactivation in not-from-concentrate elstar apple juice using RSM.

In this study, optimization of ohmic heating (OH) process parameters (temperature and voltage gradient) to inactivate polyphenoloxidase (PPO) of not-from-concentrate (NFC) apple juice was conducted. Response surface methodology was used for optimization of OH parameters, where the voltage gradient and temperature on the PPO activity in the NFC apple juice was evaluated. Then the optimized condition was used to produce the NFC apple juice and the quality parameters were evaluated and compared to NFC apple juice prepared by conventional heating (CH). The studied parameters were: PPO activity, total phenolic, total carotenoids, ascorbic acid, cloud value, color as well as physical properties (i.e., TSS, acidity, electric conductivity and viscosity). The reduction of PPO activities was 97 and 91% for OH (at 40 V/cm and 80 °C) and CH (at 90 °C and 60 s), respectively. The reduction of the ascorbic acid was 66.8% for OH significantly lower than the 80% for CH treated samples. The total extracted phenolic content was increased by 5.4 and 2.5% with OH and CH treatments, respectively. The decrease in the concentration of total carotenoids for OH (13.17%) was significantly lower than for CH (34.23%). The color values (L*, a*, b* and ΔE) were only significantly increased in the OH treatment. OH is a potential mild thermal treatment in the production of apple juice with improved functional properties instead of conventional methods.

3D modelling of coupled mass and heat transfer of a convection-oven roasting process.

A 3D mathematical model of coupled heat and mass transfer describing oven roasting of meat has been developed from first principles. The proposed mechanism for the mass transfer of water is modified and based on a critical literature review of the effect of heat on meat. The model equations are based on a conservation of mass and energy, coupled through Darcy's equations of porous media - the water flow is mainly pressure-driven. The developed model together with theoretical and experimental assessments were used to explain the heat and water transport and the effect of the change in microstructure (permeability, water binding capacity and elastic modulus) that occur during the meat roasting process. The developed coupled partial differential equations were solved by using COMSOL Multiphysics®3.5 and state variables are predicted as functions of both position and time. The proposed mechanism was partially validated by experiments in a convection oven where temperatures were measured online.