No abstract

In this study, the quick HPLC-MS/MS method for the simultaneous separation of 2-acetyl-4(5)-tetrahydrox-ybuthylimidazole (THI) and 4-(5)-methylimidazole (4-MI) in alkaline medium was used for caramel color and processed foods in Korea. After a simple sample pretreatment, 51 4-MI-labeled samples were positive for 4-MI and 2 also contained THI. The concentration of 4-MI was 260.5 ~ 24,499.3 μg/kg in caramel color, less than LOD ~ 1,712.5 μg/kg in sauce, 1,242.3, 5,972.2 μg/kg in balsamic vinegar, 2,118.3 ~ 5,802.4 μg/kg in complex seasoning, 82.7 ~ 5,110.6 μg/kg in curry, and 29.9 ~ 464.4 μg/kg in soft drinks. The recovery rate of 4-MI was 97.1 ~ 111.0% in sauce and 81.9 ~ 110.0% in powder and that of THI was 83.6 ~ 106.4% in sauce and 61.2 ~ 99.4% in powder. Our results concluded a safe amount of 4-MI and THI compared to the limit of Korea additive code but the processed foods do not have a limit of caramel color and 4-MI in Korea. Therefore, research and monitoring of 4-MI and THI is needed for processed foods in Korea.

We determined the sugar content of 75 samples, including eight black sugar beverages (BSBs) and seven Dalgona lattes (DLs) from Seoul, Korea, using high-performance liquid chromatography-evaporative light scattering detector. The mean sugar content per 100 g was 12.7 g and 12.3 g for BSB and DL, respectively. According to the World Health Organization, the mean sugar content per serving in BSB and DL were 34.8 g and 32.5 g, respectively, equivalent to 65∼ 70% of the recommended daily intake for added sugars. The highest sugar was sucrose (56.5% in BSB and 64.4% in DL). The sugar content could be adjusted in 27 out of 40 stores for BSB and 25 out of 35 stores for DL. The relative standard deviation of the content (g/100 g) per store by the manufacturer ranged between 5.7∼21.6% for BSB and 2.3∼29.5% for DL. This suggests that a uniform recipe is required for manufacturing beverages.

Camera calibration is an indispensable process for improving measurement accuracy in industry fields such as machine vision. However, existing calibration cannot be applied to the calibration of mid-wave and long-wave infrared cameras. Recently, with the growing use of infrared thermal cameras that can measure defects from thermal properties, development of an applicable calibration target has become necessary. Thus, based on heat conduction analysis using finite element analysis, we developed a calibration target that can be used with both existing visible cameras and infrared thermal cameras, by implementing optimal design conditions, with consideration of factors such as thermal conductivity and emissivity, colors and materials. We performed comparative experiments on calibration target images from infrared thermal cameras and visible cameras. The results demonstrated the effectiveness of the proposed calibration target.

No abstract