Effect of Partial Replacement of Monosodium Glutamate with 5´Inosine Monophosphate on Some Organs, Hormonal Balance and Activity of Rats

The effects of oral intake of the most well known flavour enhancer monosodium glutamate (MSG) and/or inosine monophosphate (5´-IMP) on neuronal brain damages, pancreas injury, hypoactivity and imbalance release of noradrenaline (NA) and insulin (Ins) were studied in both adult and infant rats. Different neuronal damages were observed in different brain areas included cerebrum, hypothalamus and hippocampus when MSG was administrated alone at level of 60 mg/kg body weight/day. Synchronous with these damages, hypoactivity in the movement behavior of both adult and infant rats was noticed. Also, imbalance of hormone secretion was demonstrated by recording raised level of NA and reduction in Ins release in blood serum, resulting in raise of blood glucose concentration. Pancreatic damages such as hypertrophy of Langerhan’s islets, hemorrhage, and leucocytic cells infiltration were also observed. Partial replacement of MSG with 5´-IMP (1:1 w/w) led to significant (P<0.05) reduction in these undesirable changes. The infant rats are more susceptible to the MSG toxic effects than the adult rats. Therefore, the present study is concerned that the use of MSG as a flavour enhancer in the human diet prepared for the adults should be minimized and totally avoided from the infant foods. Although use of 5´-IMP led to minimize MSG-induced hazards, it is not recommended for the free use in infant foods in the early stages of live. Further investigations on safety of the mixture of MSG and 5´-IMP are also required. Sensory evaluation of MSG: 5´-IMP mixture added to beef burger was also achieved. The taste of beef burger contained this mixture was significantly (P <0.05) enhanced comparing with that contained MSG alone.