Flavour format

G. P. Rizzi, Heat-Induced Flavour Formation from Peptides. In Thermal Generation of Aromas T. H. Parliament, R. J. McGorrin,... 

Mottram DS, Nobrega ICC (1998) In Contis ET, Ho C-T, Mussinan CJ, Parliment TH, Sha-hidi F, Spanier AM (eds) Food Flavours Formation, Origin, Analysis and Packaging Influences. Developments in Food Science 40. Elsevier, Amsterdam, p 483... 

Formation of new flavouring substances and, as a direct result, off-flavour formation... 

Hendrickx, H., Demoor, H. and Dovogelaere, R. 1963. The mechanism of light-flavour formation in milk. II. The significance of riboflavin in the development of light-flavour. Comite voor Wetenschappelijk en Technisch Zuivelouderzock Centrum GENT 29, 119-140. (Dutch). 

Canning of liver sausage encounters a problem from the formation of burnt off-odours,271 the intensity of which was found to be linearly related to the loss of free Gly, Glu, and Thr in model experiments. Addition prior to canning of reduced glutathione left flavour and colour unaffected, but the addition of /V-acctylcystcinc inhibited burnt flavour formation, optimally at 0.15%.272 However, an acid taste developed, but was prevented by the further addition of 0.25% diphosphate. 

For other product classes, it is characteristic that the flavour only forms or is changed significantly during production. Thermal, enzymatic and microbiological processes can be responsible for these changes. Examples are the ripening of salami and sour dough fermentation. In both cases, undesired bacteria can cause off-flavour formation. 

As result of a multitude of scientific investigations there is a very good theoretical understanding of the basic mechanisms of flavour formation in biochemical reactions. The application, however, of such processes is still more art and craftsmanship than exact natural science. On the other hand, the industrial evaluation of such manufacturing processes has led into better defined process conditions. There is significant progress, especially in the reproducibility and constancy of quality of the obtained products. 

Continuous storage at freezing temperatures is necessary to prevent bacterial destruction and off-flavour formation, processes which easily develop in this highly diluted and acidic medium. 

Besides the improvement of fermentation performance and simplification of the process, the improvement of product quality is a target for yeast strain development. Genetic modification of yeast strains and the expression of heterologous genes (e.g. acetolactate-decarboxylase) have increased the possibilities of modifying desired or undesired flavour formation. 

Polyphenol oxidase Mushroom, grape, pear, kiwi, sago, tea, potato, strawberry, olive, beet, cocoa Enzymatic browning (pig-ments),ripening of fruits, flavour formation, colour e.g. strawberries) formation... 

Peroxidase Horse radish, apple, bean, grape, barley, potato, cucumber, pea, peanut, tomato Ripening of foods, several functions in plants, colour formation (off-) flavour formation. 

Milk lipases may give undesirable rancidity when fresh milk is used for cheese making. The heat sensitivity of these lipases restricts them playing a major role in ripening of cheese made from pasteurized milk. Lipases play a very important role in flavour formation especially in mould cheeses such as Roquefort and Gorgonzola. 

Schieberle, P. (1995) Quantitation of important roast-smeUing odorants in popcorn by stable isotope dilution assays and model studies on flavour formation during popping. J. Agric. Food Chem. 42, 2442-2448... 

Yvon, M., and Rijnen, L. 2001. Cheese flavour formation by amino acid catabolism. Int. Dairy J. 11 185-201. 

Mottram, D.S. 1999. Flavour formation in meat and meat products. Food Chem., 62,415 24. 

Jousse, F. et al. SimpMed kinetic scheme of flavour formation by the Maillard reaction, J. Food ScL, 67, 2534, 2002. 

Willaert R. and Nedovic V. Primary beer fermentation by immobilised yeast-A review on flavour formation and control strategies. Journal of Chemical Technology and Biotechnology 81 (8) (2006) 1353-1367. 

Ardo, Y. (2006) Flavour formation by amino acid catabolism. Biotechnol Adv., 24, 238-242. 

Branyik, T., Vicente, A. A., Dostalek, R, Teixeira, J. A. (2008). A review of flavour formation in continuous beer fermentations. Journal of the Institute of Brewing, 114, 3-13. 

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