Photobleaching Rules of Fluorescent Brightener 28

• 1、School of Food Science and Technology, Jiangnan University, JiangSu Wuxi 214122
• 2、School of Food Science and Technology, Jiangnan University, Wuxi, 214122

Abstract：The Fluorescent Brightener 28 (F-28) is used as a standard fluorescent whitening agent to conform the migration of fluorescent brightener from the contact materials to food in the European Union Standards EN 648-2006"Paper and board intended to come into contact with foodstuffs determination of the fastness of fluorescent whitened paper and board". However, to date the effect of fluorescent photobleaching of F-28 has not been studied. The filter paper and glass fiber paper stained by F-28 were evaluated as fluorescent whitened comparison papers and the excitation wavelength was set at 365 nm. The results showed that the attenuation rate with excitation time of 60 s of Evaluation Grade 4 (3 mg/L), Evaluation Grade 3(8 mg/L), Evaluation Grade 2 (31 mg/L), Evaluation Grade 1 (125 mg/L) on filter paper and glass fiber paper were 0.16%, 0.29%, 0.92%, 0.44%, 2.59%, 1.99%, 0.49% and 3.14%, respectively. Moreover, the attenuation rate increased to 4.67%, 4.22%, 5.51%, 2.75%, 35.37%, 39.78%, 28.09% and 39.38% when 1800 s irradiated. Therefore, specify procedures should be considered in the testing of the fastness of fluorescent whitened paper to come into contact with foodstuffs. And the fluorescence of filter paper is more stable than glass fiber paper as fluorescent whitened comparison papers.

Keywords： Fluorescent brightener Food contacting materials Photobleaching