Volatile compounds produced from monosodium glutamate in common food cooking

A mixture of soybean oil and/or water, sugar and/or monosodium glutamate (M SG) was water-boiled or oil-heated at 100, 120, 140, 160, or 170 degrees C, respectively, and volatile compounds produced were isolated by solid-phase microextraction and then identified by GC and GC/MS. Oxidative thermal deg radation products of fatty acids (OTDPFA) were the major volatile compounds detected for all water-boiled samples. When MSG and sugar were heated toge ther, 2,5-dimethyl pyrazine and methyl pyrazine were also detected at or af ter 160 min heating. Water added in soybean oil increased OTDPFA production . In oil-heated samples of soybean oil alone, soybean oil with MSG, and soy bean oil with sugar, OTDPFA were also the major compounds found. The sample s containing MSG also produced 2-pyrrolidone, and the samples containing su gar also produced furfural and 5-hydroxy methyl furfural. The samples conta ining soybean oil, sugar, and MSG produced 23 pyr azines, OTDPFA, and gamma -butyrolactone as the major volatile compounds. The contents of OTDPFA were lower in MSG plus sugar and MSG-added samples, and it is postulated that a ntioxidant activities were produced in cooking.