Protective effect of aminoreductone on photo-degradation of riboflavin

The effects of aminoreductone (AR) on photo-degradation of riboflavin were studied for a riboflavin solution (1.5 mg L−1) and UHT-treated milk during exposure to irradiation at 7000 lux light intensity for 2.5 h. In riboflavin solution, AR protected riboflavin against degradation under exposure to light, and this ability depended on concentration of AR. In addition, the protective ability of AR was higher than that of ascorbic acid, which has the ability to reduce photo-degradation of riboflavin. The study in milk clarified that heat-treatment of milk enhanced the protective ability against photo-degradation of riboflavin because of generation of AR during the Maillard reaction. In parallel with the decrease of AR concentration in UHT-treated milk by the addition of Cu2+, the protective ability correspondingly decreased. Thus, it may be concluded that AR was a principal compound which was responsible for the photo-stability of riboflavin in UHT-treated milk.