ISSN:
1365-2095
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
The effect of heat treatment during fish meal processing on amino acid racemization was studied. The hydrolysis-induced racemization rate (R) and the d-isomer content in the sample before hydrolysis (I) were differentiated by means of deuterium labelling and gas chromatography-mass spectrometry (GC-MS) analysis in selected ion monitoring mode. A preliminary experiment on laboratory-made herring meals cooked at 125°C for different time intervals showed aspartic acid (Asp) as the only amino acid with significant racemization before hydrolysis. Aspartic acid racemization rate appeared to be a nearly linear function of the duration of thermal treatment (R2= 0.93; P 〈 0.01). Analyses were carried out on several samples of commercial fish meals from different origin. Low-temperature-dried fish meals had a d-Asp content, expressed as I= 100 [d-isomer concentration before hydrolysis / (d- +l-isomer concentration before hydrolysis)], at less than 1%, while the d-isomer content of high-temperature dried fish meals exceeded 2%. Differences between the two commercial categories were statistically significant (P 〈 0.001). Further studies are required in order to evaluate the effects of d-Asp in protein of fish feeds and the role of the raw material and processing parameters in inducing amino acid racemization in protein of fish meals.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2095.1996.tb00014.x
