X-Message-Number: 27474
From: "Basie" <>
Subject: Formaldehyde forms in frozen tissue
Date: Thu, 12 Jan 2006 19:52:06 -0500

Abstract  Proteins of fish muscle undergo chemical and physical changes 
during frozen storage which may result in, under certain conditions (i. e. 
long periods of storage, poor freezing practices, temperature fluctuations, 
etc), loss of quality, reflected mainly by an unacceptable texture as well 
as an undesirable flavour, odour and colour.
In frozen gadoid fish species, most of these changes are caused by the 
production of formaldehyde in the muscle. Formaldehyde is produced, along 
with dimethylamine, by the enzymatic reduction of trimethylamine oxide 
(TMAO). Many aspects of formaldehyde production by TMAO demethylase 
(TMAOase) have been studied throughout the last decade. In addition, 
different approaches have been used to investigate the effect of 
formaldehyde production on protein denaturation and the associated muscle 
textural changes.
Some insight into the reaction between protein and formaldehyde has 
clarified the possible mechanism of formaldehyde-mediated denaturation. 
However, evidence of covalent bonding between proteins and formaldehyde, to 
form crosslinks, has not explained fully the changes observed in fish 
proteins during frozen storage. The study of cold-induced denaturation of 
proteins might give new clues for further investigation of the problem.
The implications of formaldehyde in toxicological and nutritional issues is 
also reviewed, as general concern about the safety of food products is a 
growing field in food science.
Finally, different approaches have been proposed to avoid the detrimental 
action of formaldehyde during frozen storage of gadoid fish; they are some 
of the practical applications of the knowledge acquired after years of study 
of different workers in the field.

European Food Research and Technology (Historical Archive)
Publisher: Springer-Verlag GmbH
ISSN: 1438-2377 (Paper) 1438-2385 (Online)
DOI: 10.1007/BF01192902
Issue:  Volume 200, Number 1

Date:  January 1995
Pages: 14 - 23 

Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=27474