Determination of 4-Methylimidazole and 2-Acetyl-4(5)- tetrahydroxybutylimidazole in Caramel Color and Processed Foods by LC-MS/MS
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.
Quality Characteristics of Tteokgalbi with Black Rice Bran and Organic Acid to Substitute Synthetic Caramel Colorant
This study aimed to evaluate the quality characteristics of Tteokgalbi with 1% (w/w) black rice bran only (T1), or with black rice bran and one of the following four types of organic acid: ascorbic acid (T2), citric acid (T3), tartaric acid (T4), or maleic acid (T5) as a substitute for caramel colorant. Tteokgalbi with only black rice bran showed the highest (p<0.05) values of moisture content and water holding capacity (WHC), while there were no significant differences in protein content, fat content, ash content, and thiobarbituric acid reactive substance (TBARS) values in treatments and controls (p>0.05). All the treated samples with any one of the four organic acids showed lower pH than controls (p<0.05). The lightness and redness of Tteokgalbi treated with any one of the four organic acids and black rice bran were higher than those of T1. The volatile basic nitrogen (VBN) values of T4 and T5 were higher than those of the other treatments (p<0.05). With regards to sensory characteristics, T1 and T2 showed overall acceptability similar to that of the controls (p>0.05). The results reported in this study show that Tteokgalbi with black rice bran and any one of the four organic acids listed above not only improved quality characteristics in cooking loss, WHC, lipid oxidation but also could successfully replace the synthetic caramel colorant. Overall, the most satisfactory results were obtained by adding black rice bran and ascorbic acid.
The Distribution of Cigarette Smoke Components between Mainstream and Sidestream Smoke: II. Bases
Abstract Yields in sidestream smoke (SS) and mainstream smoke (MS) and sidestream smoke to mainstream smoke distribution ratios (SS/MS) of 34 bases were examined from four types of cigarettes made from bright, Burley, Turkish and domestic (c.v. Matsukawa) tobacco. Irrespective of tobacco variety, major bases in sidestream smoke were ammonia, nicotine, 3-vinylpyridine, pyridine and 3-hydroxypyridine, and those in mainstream smoke were nicotine, 3-hydroxypyridine, ammonia, 3-picoline and pyridine. SS/ MS ratios of the bases were generally larger than 1.0 and the largest SS/MS ratio was that of ammonia, followed by those of 3-vinylpyridine, 3-cyanopyridine, nicotyrine and pyridine in that order. The preponderance of bases in sidestream smoke over mainstream smoke might be one of the major causes for the differences in aroma and irritation between sidestream smoke and mainstream smoke.