Volatile compounds and antioxidant activity from cysteine/ribose and beef fat model system

This study was designed to examine the volatile compounds, antioxidant activity and safety evaluation of the reaction products between beef fat and triglycerides with cysteine and ribose model systems. Sixty nine and sixty three volatile compounds were isolated and identified in beef fat/cysteine/ ribose and beef triglyceride/cysteine/ribose model systems, respectively with the predominance of esters and sulfur-containing compounds. Sensory evaluation was also performed for the model systems according to ISA and the results revealed that the presence of volatiles having roasted meat-like aroma might be due to certain components such as pyrazine and thiazobes derivatives as the main compounds. The radical scavenging activity of the model systems was quantified spectrophotometrically, using DPPH radical and ?-carotene bleaching assays. Biological evaluation was also carried out to determine the safety of meaty flavor produced by studying the Maillard reaction products [MRPs] supplementation on body weight, relative organs weight, liver and kidney functions, as well as level of total antioxidant capacity as antioxidant biomarkers

Studies on the antioxidant activity of the volatile and non volatile compounds isolated from Eucalyptus globules leaves

The Eucalyptus globules leaves were subjected to hydrodistillation for 8 hoursusing a Clevenger type apparatus; the yield of the obtained essential oil wasabout 0.6%. The residue of the leaves was subjected to sequential extractionwith n-hexane, dichloromethane and ethanol. Each extract was reduced byevaporation to a standard volume then stored in a dark container at 5 deguntil work up. The antioxidant activity of each extract and of the essentialoil was determined using the reducing power test and the thiobarbituric acidmethod. The ethanol extract had the highest reducing power compared with theother extracts, and with butylated hydroxy toluene [BHT] and butylated hydroxyanisole [BHA]. Each extract was fractionated using column chromatography. Evaluation of the most active fraction was carried out, in addition tocharacterization of the major fractions