Premium
Changes in onion ( Allium cepa L.) flavour components resulting from some post‐harvest processes
Author(s) -
Freeman George G.,
Whenham Robert J.
Publication year - 1974
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740250509
Subject(s) - flavour , allium , chemistry , food science , pickling , dehydration , aroma , horticulture , biology , biochemistry
The effect of the following processes on the flavour of the product as compared with that of fresh onion has been investigated: pickling, canning, boiling and frying under domestic conditions, dehydration in hot air and by freeze‐drying and freezing. Flavour assessments were based on determination of pyruvate, thiolsulphinate and volatile components in headspace, gas‐liquid chromatograms as well as sensory testing in certain cases. All the methods of flavour assessment led to the conclusion that these processes were accompanied by large flavour losses. Quantitative estimates of the losses, varied with the analytical method in question, but were in general of the order of 90 to 95%. Freeze‐drying gave a product which retained more of the characteristic flavour components of fresh onion, as judged by sensory tests, than the other processes and in this case the taste threshold test indicated a flavour loss of 95%, pyruvate (P E ) a loss of 25%, thiolsulphinate 26% loss and gas‐liquid chromatography a loss of total peak area of 57%. Evidence that onions are consumed mainly for their flavour rather than as a source of nutrients in the classical nutritional sense is discussed and other factors which influence the flavour strength of the vegetable are reviewed.