ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
A method was proposed to prepare a peptide-type low-phenylalanine, high-tyrosine food for curing phenylketonuria. A fish protein concentrate (FPC) and a soybean protein isolate (SPI) were used as starting materials. Each was limitedly hydrolyzed with a very small amount of pepsin The peptic hydrolysate was further hydrolyzed with Pronase under an unconventional pH-condition to liberate aromatic amino acids. These were removed by Sephadex G-15 with the aid of its adsorp tion activity. To the resulting aromatic amino acid-free fraction were added ethyl esters of L-tyrosine and L-tryptophan and the mixture was incubated with papain under such conditions as its reverse process called “plastein synthesis reaction” proceeded efficiently. The reaction product was treated by ultrafiltration to obtain a plastein as a fraction having the lowest molecular weight of 500. The yields were 69.3% from FPC and 60.9% from SPI. Phenylalanine, tyrosine and tryptophan contents were 0.05%, 7.82% and 2.98% in the FPC plastein and 0.23%, 7.69% and 2.80% in the SPI plastein. Each plastem did not contain any free amino acids and was almost completely flat in taste and odor.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1976.tb14382.x
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