ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Isolation and characterization of 7 sorts of diffusable bitter peptides in peptic hydrolyzate of soybean protein were presented. One liter of dilute HCI solution containing 25 g of soybean cold-insoluble protein and 250 mg of pepsin was incubated at 37°C for 24 hr. The resulting peptic hydrolyzate was dialyzed against water and the diffusable fraction was, after being concentrated at 40°C, investigated by gel permeation chromatography using Sephadex G-10, ionexchange chromatography of Dowex 50 (w)-X2 (pyridinium) and thin-layer chromatography with silica gel G. Bitterness of the diffusable fraction was attributable to free amino acids having bitter flavor, such as isoleucine, leucine, phenylalanine and valine; also to peptides such as H. Gly-Leu. OH, H. Leu-Phe. OH, H. Ser-Lys-Gly-Leu . OH, H-Leu-Lys . OH, H. Phe-(lle, Leu2)- Gin-Gly-Val . OH, H. Arg-Leu-Leu . OH and H. Arg-Leu . OH. It was characteristic that almost all diffusable bitter peptides investigated here had leucine at the termini. Through carboxypeptidase A treatment on these peptides, the bitterness decreased considerably. Furthermore, applying carboxypeptidase A or Nagane, a bacterial neutral proteinase, to the diffusable fraction of the peptic hydrolyzate was also effective in removing the bitterness somewhat.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1970.tb12141.x
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