title: [Identification of alkylbenzenes being formed in the model reaction of ribose with lysine].
abstract: BACKGROUND
  While studying volatile compounds in model experiments which simulated the broiling of meat (the reactions of ribose with lysine), there were alkylbenzenes identified. They belong to food contaminants and they could be originated from the detergents and petroleum as well as geochemical samples, but they were also obtained in Maillard reactions.
  
  
  OBJECTIVE
  The aim of the studies was the attempt of the alkylbenzenes identification being formed in the model reaction of ribose with lysine.
  
  
  METHODS
  Aqueous solutions of ribose and lysine (at concentration of 0.1 mol/dm3 each) were mixed in equal volumes 10 cm3 + 10 cm3. The pH of the mixtures were adjusted to 5.6 using citrate-phosphorous buffer. In that way conditions simulating pH of meat were obtained. The mixtures were heated inside the gastronomic roaster during 0, 5, 10, 15, 30, 45 and 60 minutes respectively, at the temperature 185 +/- 5 degrees C. After reactions, in the mixtures, the profiles of volatile compounds, including alkylbenzenes, were analyzed by GC-MS method. The compounds were being identified by: comparing each mass spectrum (MS) with spectra from the known libraries of MS; calculating the linear retention indexes (LRI); seeking similar LRI values of analogue compounds in literature. Amounts of volatiles were calculated in relation to amount of internal standard (IS) [-], dividing the area of the compound by area of IS.
  
  
  RESULTS
  The kinds and amounts of alkylbenzenes depended on the duration of the reaction time. Maximally 16 various alkylbenzenes were developed. More of these compounds could be identified with the probability of 85-90%, using only MS, because of the lack information in literature. Moreover, the multi-dimensional GCxGC-MS or other chromatographic methods in order to make these compounds being better explored seems to be advisable.
  
  
  CONCLUSIONS
  The identification of the compounds being formed during broiling of meat is very important, because of the fact that many of arising substances are considered to be unhealthy and undesirable food contaminants. Thus these compounds should be routinely investigated in food products.
authors: Katedra Zywności Funkcjonalnej i Towaroznawstwa, Wydział Nauk o Zywieniu Człowieka i Konsumpcji, Szkoła Główna Gospodarstwa Wiejskiego, Warszawa. elzbieta_biller@sggw.pl
authors: Elzbieta
authors: E
authors: Biller
mesh_terms: D001554:Benzene / Q000032:analysis* / Q000138:chemical synthesis / Q000737:chemistry; D003296:Cooking / Q000379:methods*; D005504:Food Analysis; D005506:Food Contamination / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008239:Lysine / Q000737:chemistry*; D015416:Maillard Reaction; D013058:Mass Spectrometry; D008460:Meat / Q000032:analysis*; D008958:Models, Molecular; D012266:Ribose / Q000737:chemistry*
chemical_list: D012266:Ribose; D001554:Benzene; D008239:Lysine