Cooked vegetable flavours

Maillard reactions are responsible in part for the odours and flavours of freshly baked bread, roasted coffee, cocoa, beer, cooked meats and cooked vegetables. Hodge and co-workers have classified these flavours into four groups (Fig. 6) by correlating their aromas. 

The roundish flower head, the curd, of the cauliflower plant (Brasska oleracea var. botrytis) is the edible portion of this vegetable. It can be eaten raw in salads or as a pickled condiment in vinegar. More often it is boiled and eaten with the main meal or is converted into sauces and soups. Over 80 volatile compounds have been identified in raw and cooked cauliflower. Among the compounds potentially active in cooked cauliflower, certain sulfides such as methanethiol, dimethyl sulfide and dimethyl trisulflde have often been incriminated in objectionable sulfurous aromas and overcooked off-flavours [169, 177, 178, 181-183]. Additional aldehydes have been found to be the most abundant cauliflower volatiles, with nonanal as a major component [175,177]. A recent study showed that volatiles such as 2-propenyl isothiocyanate, dimethyl trisulflde, di-... 

Oxazoles have been found in relatively few cooked foods, although over 30 have been reported in coffee and cocoa, and 9 in cooked meat. Oxazolines have been found in cooked meat and roast peanuts, but not to any extent in other foods. 2,4,5-Trimethyl-3-oxazoline has been regularly detected in cooked meat [26], and when it was first identified in boiled beef [27] it was thought that the compound possessed the characteristic meat aroma however, on synthesis it was shown to have a woody, musty, green flavour with a threshold value of 1 mg/kg [28]. Other 3-oxazolines have nutty, sweet or vegetable-like aromas and the oxazoles also appear to be green and vegetable-like [28]. The contribution of these compounds to the overall aroma of heated foods is probably not as important as the closely related thiazoles and thiazolines. 

Cardamom is often employed for Oriental rice-and-meat dishes. To prepare these, meats (more rarely vegetables) are braised in a thick, aromatic sauce, then uncooked rice is added and cooked slowly so that it absorbs the sauce and all its flavours. 

Asparagus develops the characteristic taste upon cooking a vegetable-green topnote with a strong sulphurous-sweet characteristic overall flavour. 

Tomatoes are eaten raw, cooked and mainly in the form of canned puree and ketchup. The taste of ripe, flavourful tomatoes (there exist many cultivars without the typical taste and flavour) is well balanced between sweet, sour and salty with an acid green, vegetable like, slight floral aroma. 

Milkfat is an ingredient of major importance in ice-cream in order to balance the mix properly. The main sources are fresh cream, butter and butterfat. In regions where the use of milkfat is not feasible, coconut or other vegetable fats with similar melting points have been substituted. In many cases a butter or cream flavour is added to these products to compensate for the absence of milkfat. The use of condensed milk can result in a cooked note. The milkfat has no influence on the freezing point. A high content limits the consumption, a low content reduces the rate of whipping. 

---