2020 年 31 巻 2 号 p. 93-101
To evaluate the remain of riboflavin in various foods by light illumination, plant and animal products and processed food samples were exposed to the fluorescent light of 4000 lx for 6hr at 4℃.
Japanese horseradish (raw) showed a 63.7% residual ratio of the riboflavin content which was the lowest ratio of the plant samples. In addition, three nut samples, dried almond (Prunus dulcis), fried almond and fried cashew nut (Anacardium occidentale), and two mushroom samples, Enoki mushroom (Flanmulina velutipes) and Bunashimeji mushroom (Hypsizygus tessellatus), were observed to have under 80% residual ratio. In contrast, the riboflavin contents in immature soybean and leafy vegetables, such as Moroheiya (raw) (Corchorus olitorius) and Ashitaba (Angelica keiskei), were not reduced.
On the other hand, small amounts of riboflavin in all the animal products and processed food samples were remained, especially yogurt and pudding were observed to have 14.4% and 44.7% residual ratio, respectively.
We speculated that the difference in the riboflavin residual ratio between the plant and animal products reflected the presence of effective vitamins that inhibit the riboflavin degradation in each food. Based on this study, it was clear that the residual ratio of riboflavin in foods by fluorescent light was different in each food. This suggested that light-sensitive foods should be protected against light not only in the distribution system but also on the grocery shelf in stores.