Aroma compounds sulphur volatiles

Certain vegetables are also examples of foods with volatile components which stimulate both aroma and pungency. These are all sulphur compounds, present as precursors in the whole vegetable and are converted into the active constituents only by action of enzymes released when the structure is destroyed by cooking or grinding. 

The analysis of natural compounds in foods is also assisted by the use of the purge and trap technique in methods for distinguishing strawberry varieties [100] the aroma of unprocessed foods including gherkin [101], durian [102], garlic [103] and meat [104-107] cheese [108,109] and other dairy products [110] tobacco, tea and coffee [111,112] and peanuts [112]. Food additives including sulphur dioxide [113,114] and food contaminants such as VOCs [115-126], have been recovered by PT, particularly from table-ready foods. Animal [127,128] and plant tissues [129,130] have also been subjected to PT for separation of volatile compounds. 

Aroma. Aroma Is considered to be much more complex than taste and has many dimensions (92). While the number of compounds conferring aroma In fruits and vegetables Is large, they can generally be classified as hydroxy compounds, aldehydes, ketones, acids, esters, sulphur-containing compounds, O2 heterocyclics and pyrazlnes ( 2) Several hydrolases and proteases Involved In the synthesis of fatty acid and amino acid precursors to volatiles are synthesized or activated during the respiratory climacteric (98-1001. 

Volatile sulphur compounds are natural compounds in foods and could be formed during heat processing and storage (Maga et al., 1973). Formation of these compounds has been reported in blanched peas (Jakobsen et al., 1998). Sulphur compounds contribute to the overall flavour and aroma of foods (Jakobsen et al, 1998). For example, dimethyl disulfide, one of the major sulphur containing compounds identified, has a diffuse, intense onion odour. Dimethyl sulfide, on the other hand, has an intense, cabbage odour (Burdock, 2002). 

Allium species, such as onions, garhc and leeks are a rich source of sulphur-containing compounds, many of which are volatile and give rise to the characteristic flavour and aroma of these species. The volatile compounds are formed by the hydrolysis of non-volatile alkyl-... 

F. Pelusio, T. Nilsson, L. Montanarella, R. Tilio, B. Larsen, S. Facchetti and J. O. Madsen, Headspace solid-phase mieroextraction analysis of volatile organic sulphur compounds in black and white truffle aroma, J. Agric. Food Chem. 43, 2138-2143 (1995). 

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