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Abstract Photocatalysis‐based advanced oxidation technologies have been developed as an attractive strategy for degrading pollutants. However, the question of how to increase removal specificity without sacrificing the degradation effect remains a difficult one. In this work, a photocatalytic system for the simultaneous targeted elimination of nine heterocyclic amines (HCAs) is established using a green‐prepared photocatalyst (CN@Mn–FeOOH@MIP) that activates sodium persulfate (PS) under visible light. Mn–FeOOH clusters are in situ covered on laminar g‐C3N4 (CN) carrier to form a heterojunction, along with a molecularly imprinted layer self‐polymerized from dopamine, which is grown on the outer layer, resulting in both the desired photochemical activity and specific sites for recognition. The conditions of composite and photocatalysis are explored and optimized for efficient and selective degradation. Notably, CN@Mn–FeOOH@MIP is synthesized free of any organic reagents, and the biosafety is confirmed by cellular and in vivo toxicity evaluation. The developed CN@Mn–FeOOH@MIP/PS system with visible‐light‐driven is applied to the removal of HCAs in coffee samples with the recoveries over 70% and the reuse rates greater than 85%. It coupled the advantages of specific enrichment and rapid degradation, which furnishes a novel approach for the control of trace thermal processing pollutants.

Milk is a common ingredient in fried foods. Allergen cross-contact can occur through the reuse of frying oil. To enable assessment of the allergy risk of reused oil, methods for quantification of milk protein in oil are needed. This study evaluated four commercial ELISA test kits in comparison with the 660 nm total protein assay for the detection of milk protein in oil after frying. Corn oil spiked with nonfat or whole milk powder were fried at 150 °C or 180 °C for 3 min and were analyzed by ELISA kits either directly or after preextraction with phosphate-buffered saline containing 0.05% Tween (PBST). All four ELISA kits performed well in quantifying milk protein in unheated oil, achieving normalized recoveries of 72.1–115.9% compared with that determined in reference solutions (PBST spiked with nonfat or whole milk powder, 100%). Frying lowered the amount of protein detected, but the extent of reduction differed between test kits. In nonfat milk powder-spiked oil fried at 150 °C, normalized recoveries determined by Veratox Total Milk and BioKits BLG Assay (49.9% and 43.6%, respectively) were higher than that determined by the 660 nm assay (25.4%). Normalized recoveries determined by ELISA Systems Casein and Beta-Lactoglobulin (BLG) kits were substantially lower (9.7% and 2.4%, respectively). In samples fried under typical frying temperature (180 °C), very little protein (0.1–7.4%) was detected. Inclusion of PBST preextraction improved the detection of the two test kits targeting BLG but lowered the level of protein detected by Veratox and ELISA Systems Casein in fried samples. Overall, the ELISA kits evaluated could effectively quantify milk protein in unheated oil without the need to remove the oil phase prior to analysis. Heat treatment was the key factor negatively affecting protein quantitation. Such impact needs to be considered when ELISA test results are used for assessing the allergy risk of reused frying oil.

Oil oxidation products can react with food substrates to produce harmful substances, and oil saturation is closely related to oil oxidation in the process of frying. Therefore, the influence of the composition of fatty acids in oil on the formation of harmful substances in fried pork balls was explored. The five frying oils with the lowest unsaturated fatty acid (UFA) content, ranked in ascending order, were palm oil, peanut oil, soybean oil, corn oil, and colza oil (64.94%, 79.94%, 82.65%, 83.07%, and 92.26%, respectively). The overall levels of four harmful substances (acrylamide, polycyclic aromatic hydrocarbons, heterocyclic amines, and trans fatty acids) found in the oil used to fry pork balls followed a descending order: canola oil, corn oil, peanut oil, soybean oil, and palm oil (33.66 μg/kg, 27.17 μg/kg, 23.45 μg/kg, 18.67 μg/kg, and 13.19 μg/kg, respectively). This order was generally consistent with the trend in the content of UFAs. Therefore, the formation of harmful substances is closely related to the saturation of oil. Compared with other frying oils, soybean oil as a household oil produces relatively low amounts of harmful substances and has less negative impact on the quality (oil content, moisture content, and higher protein digestibility) of fried products.

In the process of studying the spatiotemporal cause mechanism of urban heat island (UHI) effects, the classification method used will directly affect the robustness of urban surface heat classification. Applying five commonly used standard classification methods, we divided Beijing's urban surface temperatures in the summer of 2020 into five levels. We then compared the reliability of the five classification methods in resolving 12-period data and the seasonal average temperature in UHI patches, based on two indicators: UHI area and UHI intensity. The actual land-use composition of the UHI patches obtained with traditional methods was applied to confirm our results. The mean-standard deviation method and natural breaks (Jenks) method were more robust with regard to UHI classification and 12-period data reliability. For the UHI area index, the mean-standard deviation method produced the smallest total area of UHI patches for summer days and nights. For the UHI intensity index, the quantile method, mean-standard deviation method, and natural breaks (Jenks) method were associated with smaller errors. Considering the composition of land-use types in UHI patches, the mean-standard deviation method, and natural breaks (Jenks) method were more rigorous. Thus, our research results provide guidance for method selection when classifying UHI.

Recently, we found that sucrose from beet sources exhibited only one large endothermic DSC peak, whereas sucrose from most cane sources exhibited two peaks. Thus, our objective was to unravel the cause of this wide variation in thermal behavior by investigating both commercial and recrystallized sucrose samples, using a variety of analytical techniques, including DSC, HPLC, SXRD, and Micro-CT. With the aid of recrystallization method enhancements and compositional changes, sucrose crystals were intentionally altered to produce a variety of thermal behaviors, including DSC curves exhibiting one or two endothermic peaks or a single peak with either a low (144 °C) or a high (190 °C) Tmonset value. SXRD results for all sucrose crystals studied were consistent with the known structure of sucrose. Thus, polymorphism is not the cause of thermal behavior variation, but rather, the variation is attributed to the influence of occlusion composition and chemistry on thermal decomposition. Micro-CT supported this assertion by revealing the development of large cavities within the sucrose crystal during heat treatment when occlusion composition and chemistry was conducive to thermal decomposition (e.g., low ash content and pH), but showed impeded cavity formation when occlusions contained inhibitory attributes (e.g., high ash content, sulfite, or water removal via grinding). [ABSTRACT FROM AUTHOR]