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Abstract Food materials with high moisture content were prone to occur drying shrinkage-deformation during dying process. In-depth understanding of drying shrinkage-deformation mechanism for food materials was crucial for optimizing drying parameters as well as for obtaining better quality dried foods. Therefore, the main aim of the present work was to investigate the drying shrinkage-deformation mechanism of apple slices during process of heat and mass transfer. Hot air drying experiment of freshed apple slices was conducted and the shrinkage-deformation values of apple slices were obtained by image analysis. Simultaneously, Heat-mass transfer coupled with stress-strain mathematical model were constructed and solved by COMSOL Multiphysics software. Results showed that the mathematical models of heat-mass transfer and stress-strain can be used to simulate the hot-air drying process of apple slices effectively, and the maximum relative errors of simulated value and experimental value were less than 10%. Temperature distribution and moisture distribution of apple slices during hot-air drying process were uniform. The maximum value of thermal stress and moisture stress were occurred at the middle period of the whole drying process; and the moisture stress during the whole drying process of apple slices were higher than thermal stress, which indicated that moisture stress was the main factor causing the drying shrinkage deformation of apple slices. Highlights • The heat-mass transfer and stress-strain mechanism are analyzed for creating the mathematical model. • The drying shrinkage-deformation of apple slices are obtained experimentally by image processing technology. • The heat-mass transfer and stress-strain mathematical model are numerically solved by COMSOL Multiphysics software. • Experimental and predicted values are in close agreement with each other. • Moisture stress is the main factor causing the drying shrinkage-deformation of apple slices. [ABSTRACT FROM AUTHOR]

Drying shrinkage occurs accompanying with heat-moisture transfer during drying process of high-moisture porous media and forming mechanism of drying shrinkage is complicated and influenced by micro-pore structure characteristics of porous media. In order to explore the forming mechanism of shrinkage caused by drying, the pore-scale modeling of heat-moisture and stress-strain distributions for high-moisture porous media was directly established considering the effect of micro-pore structure characteristics of porous media in drying process and analyzed using self-developed pore network simulation algorithm. Simulation results indicated that the drying curves (moisture vs drying time, average temperature vs drying time, and shrinkage vs drying time) were in a good agreement with hot-air drying experimental measurement using apple slices as the typical representation of high-moisture porous media. The phenomenon of dry spots, wet spots, irregular drying front, and irregular asymmetric shrinkage were reflected through pore network simulation. Capillary stress was a key factor affecting drying shrinkage and capillary stress was negative related to the porosity of materials and positive related to the coordination number of materials. Capillary stress produced by materials with uniform diameter distribution was larger, followed by the distribution of normal distribution materials and experimental materials. The findings in current elucidate the mechanism of drying shrinkage and provide insights into drying optimization of high-moisture porous media. [ABSTRACT FROM AUTHOR]

• A host–guest self-assembly nanoprobe MTB was constructed for NO 2 – and FA detection. • MTB can report FA, NO 2 –, and FA/NO 2 – with different optical signals. • MTB was successfully adopted to detect FA and NO 2 – in real foods samples. Nitrite (NO 2 –) and formaldehyde (FA) are practice common food hazards, seriously threatening human health. Herein, for the first time a de novo nanoprobe, named MTB, with a single response group exhibiting different optical signals for NO 2 –/FA was reported, which had the following characteristics: i) An adamantane-labeled small molecule NI-adH grafted with polycyclodextrin (Poly-β-CD) to form MTB with excellent water-solubility and biocompatibility. ii) O -phenylenediamine (OPD) with photoinduced electron transfer (PET) played both a fluorescence quencher and as NO 2 –/FA trappers. Interestingly, fixed on pH6.0, OPD rapidly reacted with NO 2 – forming triazoles, inhibiting the PET effect and releasing bright fluorescence at 530 nm. While adding FA, OPD ultrafast formed Schiff-base, and MTB absorption red-shifted from 452 nm to 545 nm. Moreover, MTB exhibited excellent selectivity, high sensitivity (21.8 nM/17.1 nM), and rapid response towards (60 s/65 s) NO 2 –/FA. Impressively, MTB has been successfully adopted to detect NO 2 –/FA in real foods with satisfactory results. [ABSTRACT FROM AUTHOR]

A three-dimensional model of the steam ejector heat pump for the dryer section of the paper machine was developed by applying the Computational Fluid Dynamics (CFD) technique, which provided the pressure and velocity distributions of fluid flow in heat pump. The results indicated that the fluid velocity field in heat pump has an incomplete axially symmetrical distribution. The entrainment ratio of the heat pump initially increases rapidly with the increase of the ejected steam inlet pressure and then decreases after the inlet pressure exceeds one certain value. There exists a critical value for the mixed fluid pressure under the given operating conditions. The optimal ratio of the diameter of constant area mixing section to the steam nozzle throat diameter is about 3.4 and the optimal ratio of length to diameter of constant area mixing section L/D m is 6. An optimal divergence angle of diffuser was observed under different diffuser length. There is an optimized steam nozzle position under the given operating condition where the maximum of entrainment ratio was observed. The CFD technique is found to be an efficient alternative to predict the ejector performance and the conclusions of the research can provide a beneficial reference for structural optimization design of ejector. [ABSTRACT FROM AUTHOR]

• Presents an approach to user knowledge acquisition with dynamic user requirements. • Using nature language processing technology to transform text form solutions into data. • Recommendation system is used to help users to improve their solutions. • Extraction of user knowledge and decision of product model based on the rough set theory. As the world increasingly moves towards a knowledge-based economy, user requirements become an important factor for enterprises to drive product collaborative design evolution. To map user requirements to the product model, user requirements are generally extracted into knowledge that can be used for design decisions. However, because users are interest-driven participants and not professional design engineers, the effect of user knowledge acquisition is not ideal. There are significant challenges for rapid knowledge acquisition with dynamic user requirements. This paper presents an approach to user knowledge acquisition in the product design process, which obtains the tangible requirements of users under the premise that users are adequate for participation. In this approach, the typical information flow is divided into four stages: submission, interaction, knowledge discovery, and model evolution. In the submission stage, natural language processing technology is used to transform text form solutions into data, so that computer technology can be applied to manage large-scale user requirements. In the interaction stage, users are helped to improve their solutions by the iterative recommendation process. In the knowledge discovery stage, after less concerned partial solutions are removed and vacant items are predicted to be supplemented, the final collection of user design information is obtained. Finally, based on rough set theory, design knowledge can be extracted to support the decision of the product model. The washing machine design project is used as a case study to explain the implementation of the proposed approach. [ABSTRACT FROM AUTHOR]

[Display omitted] • The MH+EOD effectively addresses the non-uniformity inherent in microwave drying processes. • MH+EOD pretreatment enhanced the exchange of ethanol and water, and increased the puffing power in the CO 2 -EPD process. • The effect of different pretreatment methods (no treatment, hot air pretreatment, MH, EOD, MH+EOD) on the quality of the potato CO2-EPD was compared and analyzed. • The effects of microwave power, microwave time, ethanol concentration and ethanol soaking time on potato puffing and drying quality were analyzed. To enhance the drying quality of potato slices, this investigation employed a microwave heating (MH) combined with ethanol osmotic dehydration (EOD) pretreatment strategy to improve the quality of explosion puffing drying (EPD). This paper systematically investigated the effects of different pretreatment methods (no treatment, HAD, MH, EOD, MH+EOD) on the quality and physicochemical properties of potato slices subjected to CO 2 -EPD. The results showed that after MH and EOD pretreatments, the internal pores of the potato slices exhibited a uniform porous structure. The MH+EOD+CO 2 -EPD treatment demonstrated superior expansion, crispness, hardness, and color, with higher retention rates of vitamin C and protein. The measurements were an expansion ratio of 2.15, hardness of 1290.01 g, crispness of 745.94 g, ΔE of 6.54, protein content of 1.99 g/100 g, and VC content of 17.33 mg/100 g. Additionally, the study explored the effects of microwave power, microwave drying time, ethanol concentration, and ethanol soaking time on the expansion ratio, hardness, crispness, protein content, VC content, and color. MH+EOD+CO 2 -EPD is an environmentally sustainable and efficient solution with potential for widespread industrial application to enhance processing quality and economic benefits. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two fluorescent probes (CM-PhSH , CM-Ratio-PhSH) were constructed for PhSH detection. • CM-Ratio-PhSH becomes ratiometric probe by introducing a nitro group on CM-PhSH. • These two probes were successfully used for PhSH detection and imaging in the environment and food. Thiophenol (PhSH), a highly reactive aromatic thiol, plays an essential role as a common industrial raw material in food, pesticides, pharmaceuticals, and cosmetics. In this work, we designed and constructed two fluorescent probes CM-PhSH and CM-Ratio-PhSH by a rational strategy. Specifically, coumarin fluorophores with excellent optical properties were modified, and olefinic unsaturated bonds served as reaction sites for the detection of PhSH. Based on this, the introduction of the nitro group at specific positions of the CM-PhSH changed the fluorescence emission of the CM-Ratio-PhSH , eventually obtaining a novel ratiometric fluorescent probe CM-Ratio-PhSH for PhSH detection. Surprisingly, these two probes exhibited advantages such as high specificity and low limit of detection (LOD) for CM-PhSH 32.3 nM and CM-Ratio-PhSH 40.2 nM, respectively. Furthermore, subsequent experiments demonstrated CM-PhSH and CM-Ratio-PhSH could be successfully used for highly selective and rapid detection of PhSH in aqueous solutions, live cells, and complex food samples. [ABSTRACT FROM AUTHOR]

• Construction of a new turn-on NIR fluorescent sensor NIR-Se for selective detection of Sec. • NIR-Se responses to Sec rapidly with high selectivity and sensitivity over biothiols during 60 s. • NIR-Se has a good imaging resolution in selenium-enriched foods and biosystems. As a naturally occurring amino acid, selenocysteine (Sec) plays a key role in a variety of cellular functions and Se-enriched foods. In this work, a robust water soluble fluorescence turn-on near-infrared (NIR) sensor NIR-Sec was constructed for Sec detection over biothiols in Se-enriched foods. Specifically, NIR-Sec contains a readily prepared water soluble NIR dicyanoisophorone fluorophore and a well-known response-site 2,4-dinitrobenzenesulfonyl moiety with strong intramolecular charge transfer (ICT) effect to quench the fluorescence intensity of NIR fluorophore. Upon addition of Sec, the NIR dicyanoisophorone fluorophore was released and a bright red emission at 663 nm was observed. Moreover, NIR-Sec toward Sec exhibited rapid response time (∼1 min), a large stoke shift (183 nm), and high selectivity and sensitivity (LOD: 52 nM). Impressively, NIR-Sec was successfully employed to detect and image Sec in Se-enriched foods and shrimp, indicating NIR-Sec could provide a robust tool for investigating the role of Sec in complex real-food samples. [ABSTRACT FROM AUTHOR]