BioMatNet Item: AIR3-CT94-2193 - Hydrolytic Flavour Release from Glycosidically Bound Precursors in Fruits and Some Other Plant-Derived Foods

AIR3-CT94-2193
Hydrolytic Flavour Release from Glycosidically Bound Precursors in Fruits and Some Other Plant-Derived Foods

Contacts
Further Information

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AIR Cluster V - Speciality Chemicals : Biological Conversion : Flavours/Fragrances

	Contract No	AIR3-CT94-2193
	Total Cost	1 046 310
	EC Contribution	934 155
	Start Date	01/01/1994
	Duration	36 months

SUMMARY

The perceived flavour of many foods and beverages of plant origin, including wine and other fermented drinks, reflects the release of volatile aroma compounds. Many of these are secondary metabolites based on aromatic compounds which are complexed in the plant tissue, with sugar molecules in the form of glycones. These are often soluble in water and will be extracted on pressing juice, for example. However, for the same reason they are not volatile and hence their presence may not be perceived by the consumer. If the sugar molecule is separated the resulting compound (termed an aglycone) becomes volatile and contributes to the appreciation of flavour. In theory, the flavour can be enhanced if the sugar is removed using enzymes. In many cases, this could be achieved by one class of enzymes known as glucosidases. To do this requires suitable food grade enzymes, as well as an understanding of the chemistry of the precursors involved. The purpose of this activity is to develop analytical tools to look at typical precursors and to develop enzymes of the types which could be applied for this purpose.

OBJECTIVE

In a number of fruits and other plant tissues many secondary metabolites, including important aroma chemicals, are glycosylated and accumulate as non-volatile glycosides. These abundant glycosidically bound compounds can be hydrolyzed during processing to generate volatile aroma compounds. They are therefore precursors of recoverable flavour. For this reason, the following studies are envisaged to recognize the unexploited, high potential of glycosidically bound flavour compounds in fruits and other plant-derived foods fundamental to develop strategies for its industrial application, i.e. :

(a) Structural elucidation of glycosidically bound precursors and aglycones including enantiodifferentiations;
(b) Enzymatic precursor hydrolysis studies of flavour production and enhancement ;
(c) Selection, purification, characterisation, and production of exogenous enzymes liberating flavour compounds

With a as central analytical pool, parts a-c are strictly cross-linked enabling effective developments of selective enzymatic applications for flavour production and enhancement, i.e. leading to quality improvement of plant-derived foods.

Contacts

Coordinator

Prof Dr Peter SCHREIER / Universitaet Wuerzburg Food Chemistry - Am Hubland / GERMANY

EC Scientific Officer

Ciarán MANGAN / European Commission - DG Research Quality of Life Programme - Unit B1.2 / BELGIUM

Participant