Scientific Opinion on Flavouring Group Evaluation 17, Revision 3 (FGE.17Rev3): Pyrazine derivatives from chemical group 24

Safety and efficacy of pyrazine derivatives including saturated ones belonging to chemical group 24 when used as flavourings for all animal species

Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of 22 compounds belonging to chemical group 24 (pyrazine derivatives). They are currently authorised as flavours in food. The FEEDAP Panel concludes that: 2,3-diethylpyrazine [14.005], 2-ethyl-3-methylpyrazine [14.006], 5,6,7,8-tetrahydroquinoxaline [14.015], 2,3,5,6-tetramethylpyrazine [14.018], 2,3,5-trimethylpyrazine [14.019], 2,5-dimethylpyrazine [14.020], 2,6-dimethylpyrazine [14.021], 2-ethylpyrazine [14.022], 2-ethyl-3,5-dimethylpyrazine [14.024], 2,5 or 6-methoxy-3-methylpyrazine [14.025], 2-methylpyrazine [14.027], acetylpyrazine [14.032], 6,7-dihydro-5-methyl-5H-cyclopenta(b)pyrazine [14.037], 2-isobutyl-3-methoxypyrazine [14.043], 2-acetyl-3-ethylpyrazine [14.049], 2,3-dimethylpyrazine [14.050], 2,3-diethyl-5-methylpyrazine [14.056], 2-(sec-butyl)-3-methoxypyrazine [14.062], 3,(5- or 6-)-dimethyl-2-ethylpyrazine [14.100], 2-ethyl-3-methoxypyrazine [14.112] and 2-methoxy-3-methylpyrazine [14.126] are safe at the proposed maximum dose level (0.5 mg/kg complete feed) as feed for cattle, salmonids and non-food-producing animals, and at the proposed normal use level of 0.1 mg/kg complete feed for pigs and poultry; 5-methylquinoxaline [14.028] are safe only at concentrations below the proposed use levels (0.08 mg/kg complete feed for cattle, salmonids and non-food-producing animals, and 0.05 mg/kg complete feed for pigs and poultry). No safety concern would arise for the consumer from the use of these compounds up to the highest proposed level in feeds. Hazards for skin and eye contact, and respiratory exposure are recognised for the majority of the compounds under application. Most are classified as irritating to the respiratory system. The proposed maximum use levels in feed are unlikely to have detrimental effects on the terrestrial and fresh water compartments. Because all the compounds under assessment are used in food as flavourings and their function in feed is essentially the same as that in food, no further demonstration of efficacy is necessary.

The scent of wolves: pyrazine analogs induce avoidance and vigilance behaviors in prey

The common gray wolf (Canis lupus) is an apex predator located at the top of the food chain in the Northern Hemisphere. It preys on rodents, rabbits, ungulates, and many other kinds of mammal. However, the behavioral evidence for, and the chemical basis of, the fear-inducing impact of wolf urine on prey are unclear. Recently, the pyrazine analogs 2, 6-dimethylpyrazine, 2, 3, 5-trimethylpyrazine and 3-ethyl-2, 5-dimethyl pyrazine were identified as kairomones in the urine of wolves. When mice were confronted with a mixture of purified pyrazine analogs, vigilance behaviors, including freezing and excitation of neurons at the accessory olfactory bulb, were markedly increased. Additionally, the odor of the pyrazine cocktail effectively suppressed the approach of deer to a feeding area, and for those close to the feeding area elicited fear-related behaviors such as the "tail-flag," "flight," and "jump" actions. In this review, we discuss the transfer of chemical information from wolf to prey through the novel kairomones identified in wolf urine and also compare the characteristics of wolf kairomones with other predator-produced kairomones that affect rodents.