Riboflavin is a natural part of vitamin B2 and is present in some
the product. Riboflavin tetrabutylate, a fat-soluble derivative of
riboflavin, is used as a food additive to enrich the vitamin B2 level
in many foods. Riboflavin is an essential nutrient in the human
body because it is an active part of the coenzymes of flavin mononucleotide
(FMN) and flavin adenine dinucleotide (FAD). However,
the main barriers that prevent commercial application of riboflavin
in the food industry are its high light sensitivity and limited
information about its effect on edible fats. In general, riboflavin
is also considered to have a pro-oxidation effect on certain foods.
Riboflavin has a complex photochemistry when affected by light.
This is due to its ability to easily degrade and be oxidised by
accepting and donating hydrogen or an electron (Choe, Huang, &
Min, 2005). In an aqueous system, riboflavin produces singlet oxygen
from ordinary triplet oxygen when exposed to light. This takes
place via the excited triplet riboflavin and triplet oxygen annihilation
mechanism. Consequently, lipid oxidation photosensitised
by riboflavin has been implicated as the causative factor in the
off-flavour of many foods (Choe et al., 2005; Lee, Jung, & Kim,
1998). However, Ohama and Yagi (1969) reported that riboflavin
in linoleic acid suppresses hydroperoxide formation under light.
Also, Toyosaki, Yamamoto, and Mineshita (1987) showed that
riboflavin tetrabutylate has an antioxidant effect on emulsions in
the dark. To effectively evaluate the role of riboflavin in emulsion
systems, the degradation of riboflavin and the stability of food
lipids during storage should be further investigated.