The BACIS Archives

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• New Test should Elucidate the Effectiveness of Antioxidants

Investigators of the Institute of Biomembranes (Utrecht University, The Netherlands) and of the Unilever Research Laboratory (Vlaardingen, The Netherlands) have developed a method to test the activity of antioxidants in living cells.
The test concerns a method to analyse the protecting activity of various combinations of antioxidants.
More background information about this new test will be published in the Dutch Chemisch Magazine of May 1998.

Perhaps more details can be found at the web sites of Unilever and the Institute of Biomembranes.

• Chemical Identities of Compounds with a Fruity Odour

INTRODUCTION

In the forthcoming issues the chemical identities of compounds with certain sensory properties, such as the olfactive or organoleptic qualities, will be discussed.
In this issue the chemical compounds with a fruity odour character will be treated.

DISCUSSION

Branched chain aliphatic esters and ketones with up to 12 carbon atoms are well-known for their fruity odour characters.

A nice example is the organoleptic quality of banana, for which isoamyl acetate is rather characteristic.

For the odour of the Bartlett pear is ethyl (E,Z)-decadienoate a characteristic compound.

The various sensory qualities of different types of apples are:

- the alcohol apple with cis-3-hexenol,

- the aldehyde apple with optical active 2-methylbutanal, and

- the esters of dicarboxylic acids, such as diethyl malate and others.

para-Hydroxybenzylacetone (4-(4-hydroxyphenyl)-2-butanone) is an organoleptic character-impact compound for the aroma quality of raspberry. The commercial chemical compound is also called frambinone or raspberry ketone.

The organoleptic quality of strawberry is found in the chemical compounds 2,5-dimethyl-3,4-furanolone and in the lower esters of 4-methylpent-3-enoic acid.

Allyl esters and especially allyl 3-cyclohexylpropanoate represent the odour quality of pineapple.

In the flavour of cherries benzaldehyde has been found as a character-impact compound.

In black currant 1-methoxy-3-methylbutane-3-thiol is detected in low concentration as a organoleptically characteristic compound.

gamma-Lactones with 6 to 10 carbon atoms represent the aroma of peach, apricot and nectarines.

The flavour of coconut is found in the aromatic compound gamma-undecalactone.

Damasc(en)ones in part per million (ppm) concentrations can strongly influence the organoleptic qualities of several fruit flavours, for instance those of berries and apples.