Flavours strawberry

Sugars, acids and aroma compounds contribute to the characteristic strawberry flavour [85]. Over 360 different volatile compounds have been identified in strawberry fruit [35]. Strawberry aroma is composed predominately of esters (25-90% of the total volatile mass in ripe strawberry fruit) with alcohols, ketones, lactones and aldehydes being present in smaller quantities [85]. Esters provide a fruity and floral characteristic to the aroma [35,86], but aldehydes and furanones also contribute to the strawberry aroma [85, 87]. Terpenoids and sulfur compounds may also have a significant impact on the characteristic strawberry fruit aroma although they normally only make up a small portion of the strawberry volatile compounds [88, 89]. Sulfur compounds, e.g. methanethiol. 

With these building blocks it is possible to reassemble various types of strawberry flavours with fruity, spicy or ripe flavour character without dealing with the complexity of more than 300 single raw materials. This approach speeds up the combinatorial elements of the flavour work and provides an excellent learning platform for young fiavourists. 

The following example shows a strawberry flavour, analysed by the GC/MSD coupling technique using the TIC-method (Fig. 6.5). The identification of peak No. 5 (ethyl isovalerate), peak No. 14 (alpha-ionone) and peak No. 21 (ethyl 3-phenyl-glycidate) by the mass-spectrum shows the usefulness of this modem analysis technique. 

N. Fischer and F.J. Hammerschmidt. A contribution to the analysis of fresh strawberry flavour. Chem. Mikrobiol. Technol. Lebensm., 14, 141-148 (1992). 

Strawberry is the third most popular ice cream flavour in the UK. Fresh or fresh-frozen strawberries may be used, although the fruit alone does not generally give a sufficiently intense flavour. Strawberry flavours are available as extracts from the prepared fruit, as artificial compounds or as artificially fortified extracts. To obtain a good strawberry flavour it is necessary to have the correct sugar/acid balance. This can be achieved by adding fruit acids, e.g. malic acid or citric acid. 

Zabetakis, I., Holden, M. A. (1997). Strawberry flavour analysis and biosynthesis. Journal of the Science of Food Agriculture, 74, 421-434. 

Boland, A.B., Delahunty, CM., van Ruth, S.M. (2006) Influence of the texture of gelatin gels and pectin gels on strawberry flavour release and perception. Food Chemistry, 96, 452-460. 

Raab, T, Lbpez-Raez, J.A., Klein, D., Caballero, J.L., Monyano, E Schwab, W., and Munoz-Bianco, J. (2006) FaQR, required for the biosynthesis of the strawberry flavour compound 4-hydroxy-2,5-dimethyl-3(2H)-furanone, encodes an enone oxidoreductase. Plant Cell, 18, 1023-1037. 

Chee CP, Gallaher JJ, Djotdjevic D, et al. 2005. Chemical and sensory aneilysis of strawberry flavoured yogurt supplemented with tm eilgae oR emulsion. J Dairy Res 72(3) 311-316. 

PTR-MS nose-space evaluation of custards was further studied by Aprea et al. [71], who also specifically investigated the effects of texture and oral proeessing on the release of strawberry flavour in custards. The in-nose concentrations of strawberry flavour compounds during the consumption of the custard were significantly affected by the oral processing protocol involved (free chewing or imposed). This demonstrated how in vivo measurements can provide information about individual consumers. 

Aprea, E., Biasioli, F, Gasperi, F et al. (2006) In vivo monitoring of strawberry flavour release from model custards effect of texture and oral processing. Flavour Fragrance J. 21, 53. 

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