Sour flavour compounds

Key flavour compounds Peach P. persica) Nectarine P. persica var. nucipersica) Apricot P. armeniaca) Plum P. domestica) Sweet cherry P. avium) Sour cherry (P cerasus)... 

The typical flavour of sour cherries is produced during processing into wine, liqueur, juice, jam or fruit sauce. Benzaldehyde has been determined to be the most important aroma compound in sour cherries [82], but benzyl alcohol, eu-genol and vanillin are also important flavour compounds (Table 7.2, Fig. 7.5) [83]. Growing and storage conditions affect the concentration of benzaldehyde, benzyl alcohol, eugenol and vanillin [83, 84], and cold and rainy weather produces sour cherries with a less delicate sour cherry aroma [83]. 

Non-volatile flavour compounds in the sense of this chapter are defined as molecules which cause one of the sensory impressions sweet, bitter, salty, sour or umami (Fig. 23.2). 

An essential requirement of ice cream products is that they taste appealing. The flavours used in ice cream manufacture are usually supplied as solutions of aroma and taste compounds. Some flavour molecules are fat soluble, whereas others are water soluble. This affects the perception of flavour in ice cream water-soluble flavours are present in the matrix and are released rapidly on consumption, whereas fat-soluble flavours are released more slowly. Flavours may be natural, i.e. extracted from sources such as plants, or synthetic. The latter can be nature identical (artificially produced but identical to the naturally occurring form) or artificial (artificially produced and not occurring in nature). They are used to impart flavour to products, to enhance inherent flavours and to ensure uniformity of flavour between batches. Fruit acids, such as citric or malic acid are added to fruit flavoured water ice products to give them extra bite , by making them sour. The three most important ice cream flavours are vanilla, chocolate and strawberry. 

During fermentation of sour dough, different amounts of lactic acid, acetic acid, flavour precursors and volatile compounds are produced... 

Hansen and Lund, 1987). In rye bread, compounds such as alcohols, esters and carbonyls have been identified (Hansen et al., 1989). Choice of fermentation temperature, dough yield, flour quality and starter culture all influence the sensory properties of the final bread. Free amino acids formed during fermentation increase Maillard reaction products, thus intensifying the taste. Sensory analysis has shown that sour dough rye breadcrumbs had the most intense and bread-like flavour compared with chemically acidified doughs (Hansen et al., 1989). 

Hansen, A. and Lund, B. (1987) Volatile compounds in rye sour dough. In Flavour Science and Technology, (eds. Martens, M., Dalen, G.A. and Russwurm Jr., H.). John Wiley and Sons, Chichester. 

It is mainly the lower carboxylic acids and some aromatic carboxylic acids that are active as odour- or taste-active compounds. Taste-active substances are predominantly polyhydric carboxylic acids and some aliphatic carboxylic acids such as acetic and lactic acids, which are major carriers of the sour taste in food raw materials and foods. Short chain fatty acids also have some importance as flavour-active substances (C and Cg) and medium chain fatty acids (Cg-Ci2). A number of carboxylic acids can become precursors of important flavour-active derivatives, such as, for example, esters and lactones. 

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